{"rowid": 336, "title": "Practical Microformats with hCard", "contents": "You\u2019ve probably heard about microformats over the last few months. You may have even read the easily digestible introduction at Digital Web Magazine, but perhaps you\u2019ve not found time to actually implement much yet. That\u2019s understandable, as it can sometimes be difficult to see exactly what you\u2019re adding by applying a microformat to a page. Sure, you\u2019re semantically enhancing the information you\u2019re marking up, and the Semantic Web is a great idea and all, but what benefit is it right now, today? \n\nWell, the answer to that question is simple: you\u2019re adding lots of information that can be and is being used on the web here and now. The big ongoing battle amongst the big web companies if one of territory over information. Everyone\u2019s grasping for as much data as possible. Some of that information many of us are cautious to give away, but a lot of is happy to be freely available. Of the data you\u2019re giving away, it makes sense to give it as much meaning as possible, thus enabling anyone from your friends and family to the giant search company down the road to make the most of it.\n\nOk, enough of the waffle, let\u2019s get working.\n\nIntroducing hCard\n\nYou may have come across hCard. It\u2019s a microformat for describing contact information (or really address book information) from within your HTML. It\u2019s based on the vCard format, which is the format the contacts/address book program on your computer uses. All the usual fields are available \u2013 name, address, town, website, email, you name it.\n\nIf you\u2019re running Firefox and Greasemonkey (or if you can, just to try this out), install this user script. What it does is look for instances of the hCard microformat in a page, and then add in a link to pass any hCards it finds to a web service which will convert it to a vCard. Take a look at the About the author box at the bottom of this article. It\u2019s a hCard, so you should be able to click the icon the user script inserts and add me to your Outlook contacts or OS X Address Book with just a click.\n\nSo microformats are useful after all. Free microformats all round!\n\nImplementing hCard\n\nThis is the really easy bit. All the hCard microformat is, is a bunch of predefined class names that you apply to the markup you\u2019ve probably already got around your contact information. Let\u2019s take the example of the About the author box from this article. Here\u2019s how the markup looks without hCard:\n\n<div class=\"bio\">\n     <h3>About the author</h3>\n     <p>Drew McLellan is a web developer, author and no-good swindler from \n     just outside London, England. At the \n     <a href=\"http://www.webstandards.org/\">Web Standards Project</a> he works \n     on press, strategy and tools. Drew keeps a \n     <a href=\"http://www.allinthehead.com/\">personal weblog</a> covering web \n     development issues and themes.</p>\n</div>\n\nThis is a really simple example because there\u2019s only two key bits of address book information here:- my name and my website address. Let\u2019s push it a little and say that the Web Standards Project is the organisation I work for \u2013 that gives us Name, Company and URL.\n\nTo kick off an hCard, you need a containing object with a class of vcard. The div I already have with a class of bio is perfect for this \u2013 all it needs to do is contain the rest of the contact information.\n\nThe next thing to identify is my name. hCard uses a class of fn (meaning Full Name) to identify a name. As is this case there\u2019s no element surrounding my name, we can just use a span. These changes give us:\n\n<div class=\"bio vcard\">\n     <h3>About the author</h3>\n     <p><span class=\"fn\">Drew McLellan</span> is a web developer...\n\nThe two remaining items are my URL and the organisation I belong to. The class names designated for those are url and org respectively. As both of those items are links in this case, I can apply the classes to those links. So here\u2019s the finished hCard.\n\n<div class=\"bio vcard\">\n     <h3>About the author</h3>\n     <p><span class=\"fn\">Drew McLellan</span> is a web developer, author and \n     no-good swindler from just outside London, England. \n     At the <a class=\"org\" href=\"http://www.webstandards.org/\">Web Standards Project</a> \n     he works on press, strategy and tools. Drew keeps a \n     <a class=\"url\" href=\"http://www.allinthehead.com/\">personal weblog</a> covering web \n     development issues and themes.</p>\n</div>\n\nOK, that was easy. By just applying a few easy class names to the HTML I was already publishing, I\u2019ve implemented an hCard that right now anyone with Greasemonkey can click to add to their address book, that Google and Yahoo! and whoever else can index and work out important things like which websites are associated with my name if they so choose (and boy, will they so choose), and in the future who knows what. In terms of effort, practically nil.\n\nWhere next?\n\nSo that was a trivial example, but to be honest it doesn\u2019t really get much more complex even with the most pernickety permutations. Because hCard is based on vCard (a mature and well thought-out standard), it\u2019s all tried and tested. Here\u2019s some good next steps.\n\n\n\tPlay with the hCard Creator\n\tTake a deep breath and read the spec\n\tStart implementing hCard as you go on your own projects \u2013 it takes very little time\n\n\nhCard is just one of an ever-increasing number of microformats. If this tickled your fancy, I suggest subscribing to the microformats site in your RSS reader to keep in touch with new developments.\n\nWhat\u2019s the take-away?\n\nThe take-away is this. They may sound like just more Web 2-point-HoHoHo hype, but microformats are a well thought-out, and easy to implement way of adding greater depth to the information you publish online. They have some nice benefits right away \u2013 certainly at geek-level \u2013 but in the longer term they become much more significant. We\u2019ve been at this long enough to know that the web has a long, long memory and that what you publish today will likely be around for years. But putting the extra depth of meaning into your documents now you can help guard that they\u2019ll continue to be useful in the future, and not just a bunch of flat ASCII.", "year": "2005", "author": "Drew McLellan", "author_slug": "drewmclellan", "published": "2005-12-06T00:00:00+00:00", "url": "https://24ways.org/2005/practical-microformats-with-hcard/", "topic": "code"}
{"rowid": 335, "title": "Naughty or Nice? CSS Background Images", "contents": "Web Standards based development involves many things \u2013 using semantically sound HTML to provide structure to our documents or web applications, using CSS for presentation and layout, using JavaScript responsibly, and of course, ensuring that all that we do is accessible and interoperable to as many people and user agents as we can.\n\nThis we understand to be good. \n\nAnd it is good. \n\nExcept when we don\u2019t clearly think through the full implications of using those techniques.\n\nWhich often happens when time is short and we need to get things done.\n\nHere are some naughty examples of CSS background images with their nicer, more accessible counterparts.\n\nTransaction related messages\n\nI\u2019m as guilty of this as others (or, perhaps, I\u2019m the only one that has done this, in which case this can serve as my holiday season confessional)  We use lovely little icons to show status messages for a transaction to indicate if the action was successful, or was there a warning or error? For example:\n\n\u201cYour postal/zip code was not in the correct format.\u201d\n\nNotice that we place a nice little icon there, and use background colours and borders to convey a specific message: there was a problem that needs to be fixed. Notice that all of this visual information is now contained in the CSS rules for that div:\n\n<div class=\"error\">\n     <p>Your postal/zip code was not in the correct format.</p>\n </div>\n\n div.error {\n     background: #ffcccc url(../images/error_small.png) no-repeat 5px 4px;\n     color: #900;\n     border-top: 1px solid #c00;\n     border-bottom: 1px solid #c00;\n     padding: 0.25em 0.5em 0.25em 2.5em;\n     font-weight: bold;\n }\n\nUsing this approach also makes it very easy to create a div.success and div.warning CSS rules meaning we have less to change in our HTML.\n\nNice, right?\n\nNo. Naughty. \n\nVisual design communicates\n\nThe CSS is being used to convey very specific information. The choice of icon, the choice of background colour and borders tell us visually that there is something wrong. \n\nWith the icon as a background image \u2013 there is no way to specify any alt text for the icon, and significant meaning is lost. A screen reader user, for example, misses the fact that it is an \u201cerror.\u201d \n\nThe solution? Ask yourself: what is the bare minimum needed to indicate there was an error? Currently in the absence of CSS there will be no icon \u2013 which (I\u2019m hoping you agree) is critical to communicating there was an error.\n\nThe icon should be considered content and not simply presentational.\n\nThe borders and background colour are certainly much less critical \u2013 they belong in the CSS.\n\nLets change the code to place the image directly in the HTML and using appropriate alt text to better communicate the meaning of the icon to all users:\n\n<div class=\"bettererror\">\n     <img src=\"images/error_small.png\" alt=\"Error\" />\n     <p>Your postal/zip code was not in the correct format.</p>\n </div>\n\n div.bettererror {\n     background-color: #ffcccc;\n     color: #900;\n     border-top: 1px solid #c00;\n     border-bottom: 1px solid #c00;\n     padding: 0.25em 0.5em 0.25em 2.5em;\n     font-weight: bold;\n     position: relative;\n     min-height: 1.25em;\n }\n\n div.bettererror img {\n     display: block;\n     position: absolute;\n     left: 0.25em;\n     top: 0.25em;\n     padding: 0;\n     margin: 0;\n }\n\n div.bettererror p {\n     position: absolute;\n     left: 2.5em;\n     padding: 0;\n     margin: 0;\n }\n\nCompare these two examples of transactional messages\n\nStatus of a Record\n\nThis example is pretty straightforward. Consider the following: a real estate listing on a web site. There are three \u201cstates\u201d for a listing: new, normal, and sold. Here\u2019s how they look:\n\nExample of a New Listing\n\nExample of A Sold Listing\n\nIf we (forgive the pun) blindly apply the \u201cuse a CSS background image\u201d technique we clearly run into problems with the new and sold images \u2013 they actually contain content with no way to specify an alternative when placed in the CSS.\n\nIn this case of the \u201cnew\u201d image, we can use the same strategy as we used in the first example (the transaction result). The \u201cnew\u201d image should be considered content and is placed in the HTML as part of the <h2>...</h2> that identifies the listing.\n\nHowever when considering the \u201csold\u201d listing, there are less changes to be made to keep the same look by leaving the \u201cSOLD\u201d image as a background image and providing the equivalent information elsewhere in the listing \u2013 namely, right in the heading.\n\nFor those that can\u2019t see the background image, the status is communicated clearly and right away. A screen reader user that is navigating by heading or viewing a listing will know right away that a particular property is sold.\n\nOf note here is that in both cases (new and sold) placing the status near the beginning of the record helps with a zoom layout as well.\n\nBetter Example of A Sold Listing\n\nSummary\n\nRemember: in the holiday season, its what you give that counts!! Using CSS background images is easy and saves time for you but think of the children. And everyone else for that matter\u2026 \n\nCSS background images should only be used for presentational images, not for those that contain content (unless that content is already represented and readily available elsewhere).", "year": "2005", "author": "Derek Featherstone", "author_slug": "derekfeatherstone", "published": "2005-12-20T00:00:00+00:00", "url": "https://24ways.org/2005/naughty-or-nice-css-background-images/", "topic": "code"}
{"rowid": 334, "title": "Transitional vs. Strict Markup", "contents": "When promoting web standards, standardistas often talk about XHTML as being more strict than HTML. In a sense it is, since it requires that all elements are properly closed and that attribute values are quoted. But there are two flavours of XHTML 1.0 (three if you count the Frameset DOCTYPE, which is outside the scope of this article), defined by the Transitional and Strict DOCTYPEs. And HTML 4.01 also comes in those flavours.\n\nThe names reveal what they are about: Transitional DOCTYPEs are meant for those making the transition from older markup to modern ways. Strict DOCTYPEs are actually the default \u2013 the way HTML 4.01 and XHTML 1.0 were constructed to be used.\n\nA Transitional DOCTYPE may be used when you have a lot of legacy markup that cannot easily be converted to comply with a Strict DOCTYPE. But Strict is what you should be aiming for. It encourages, and in some cases enforces, the separation of structure and presentation, moving the presentational aspects from markup to CSS. From the HTML 4 Document Type Definition:\n\n\n\tThis is HTML 4.01 Strict DTD, which excludes the presentation attributes and elements that W3C expects to phase out as support for style sheets matures. Authors should use the Strict DTD when possible, but may use the Transitional DTD when support for presentation attribute and elements is required.\n\n\nAn additional benefit of using a Strict DOCTYPE is that doing so will ensure that browsers use their strictest, most standards compliant rendering modes.\n\nTommy Olsson provides a good summary of the benefits of using Strict over Transitional in Ten questions for Tommy Olsson at Web Standards Group:\n\n\n\tIn my opinion, using a Strict DTD, either HTML 4.01 Strict or XHTML 1.0 Strict, is far more important for the quality of the future web than whether or not there is an X in front of the name. The Strict DTD promotes a separation of structure and presentation, which makes a site so much easier to maintain.\n\n\nFor those looking to start using web standards and valid, semantic markup, it is important to understand the difference between Transitional and Strict DOCTYPEs. For complete listings of the differences between Transitional and Strict DOCTYPEs, see XHTML: Differences between Strict & Transitional, Comparison of Strict and Transitional XHTML, and XHTML1.0 Element Attributes by DTD.\n\nSome of the differences are more likely than others to cause problems for developers moving from a Transitional DOCTYPE to a Strict one, and I\u2019d like to mention a few of those.\n\nElements that are not allowed in Strict DOCTYPEs\n\n\n\tcenter\n\tfont\n\tiframe\n\tstrike\n\tu\n\n\nAttributes not allowed in Strict DOCTYPEs\n\n\n\talign (allowed on elements related to tables: col, colgroup, tbody, td, tfoot, th, thead, and tr)\n\tlanguage\n\tbackground\n\tbgcolor\n\tborder (allowed on table)\n\theight (allowed on img and object)\n\thspace\n\tname (allowed in HTML 4.01 Strict, not allowed on form and img in XHTML 1.0 Strict)\n\tnoshade\n\tnowrap\n\ttarget\n\ttext, link, vlink, and alink\n\tvspace\n\twidth (allowed on img, object, table, col, and colgroup)\n\n\nContent model differences\n\nAn element type\u2019s content model describes what may be contained by an instance of the element type. The most important difference in content models between Transitional and Strict is that blockquote, body, and form elements may only contain block level elements. A few examples:\n\n\n\ttext and images are not allowed immediately inside the body element, and need to be contained in a block level element like p or div\n\tinput elements must not be direct descendants of a form element\n\ttext in blockquote elements must be wrapped in a block level element like p or div\n\n\nGo Strict and move all presentation to CSS\n\nSomething that can be helpful when doing the transition from Transitional to Strict DOCTYPEs is to focus on what each element of the page you are working on is instead of how you want it to look.\n\nWorry about looks later and get the structure and semantics right first.", "year": "2005", "author": "Roger Johansson", "author_slug": "rogerjohansson", "published": "2005-12-13T00:00:00+00:00", "url": "https://24ways.org/2005/transitional-vs-strict-markup/", "topic": "code"}
{"rowid": 333, "title": "The Attribute Selector for Fun and (no ad) Profit", "contents": "If I had a favourite CSS selector, it would undoubtedly be the attribute selector (Ed: You really need to get out more). For those of you not familiar with the attribute selector, it allows you to style an element based on the existence, value or partial value of a specific attribute.\n\nAt it\u2019s very basic level you could use this selector to style an element with particular attribute, such as a title attribute.\n\n<abbr title=\"Cascading Style Sheets\">CSS</abbr>\n\nIn this example I\u2019m going to make all <abbr> elements with a title attribute grey. I am also going to give them a dotted bottom border that changes to a solid border on hover. Finally, for that extra bit of feedback, I will change the cursor to a question mark on hover as well. \n\nabbr[title] {\n     color: #666;\n     border-bottom: 1px dotted #666;\n }\n\n abbr[title]:hover {\n     border-bottom-style: solid;\n     cursor: help;\n }\n\nThis provides a nice way to show your site users that <abbr> elements with title tags are special, as they contain extra, hidden information.\n\nMost modern browsers such as Firefox, Safari and Opera support the attribute selector. Unfortunately Internet Explorer 6 and below does not support the attribute selector, but that shouldn\u2019t stop you from adding nice usability embellishments to more modern browsers.\n\nInternet Explorer 7 looks set to implement this CSS2.1 selector, so expect to see it become more common over the next few years.\n\nStyling an element based on the existence of an attribute is all well and good, but it is still pretty limited. Where attribute selectors come into their own is their ability to target the value of an attribute. You can use this for a variety of interesting effects such as styling VoteLinks.\n\nVoteWhats?\n\nIf you haven\u2019t heard of VoteLinks, it is a microformat that allows people to show their approval or disapproval of a links destination by adding a pre-defined keyword to the rev attribute.\n\nFor instance, if you had a particularly bad meal at a restaurant, you could signify your dissaproval by adding a rev attribute with a value of vote-against.\n\n<a href=\"http://www.mommacherri.co.uk/\" rev=\"vote-against\">Momma Cherri's</a>\n\nYou could then highlight these links by adding an image to the right of these links.\n\na[rev=\"vote-against\"]{\n     padding-right: 20px;\n     background: url(images/vote-against.png) no-repeat right top;\n}\n\nThis is a useful technique, but it will only highlight VoteLinks on sites you control. This is where user stylesheets come into effect. If you create a user stylesheet containing this rule, every site you visit that uses VoteLinks will receive your new style.\n\nCool huh?\n\nHowever my absolute favourite use for attribute selectors is as a lightweight form of ad blocking. Most online adverts conform to industry-defined sizes. So if you wanted to block all banner-ad sized images, you could simply add this line of code to your user stylesheet.\n\nimg[width=\"468\"][height=\"60\"],\nimg[width=\"468px\"][height=\"60px\"]  {\n     display: none !important;\n}\n\nTo hide any banner-ad sized element, such as flash movies, applets or iFrames, simply apply the above rule to every element using the universal selector.\n\n*[width=\"468\"][height=\"60\"], *[width=\"468px\"][height=\"60px\"]  {\n     display: none !important;\n}\n\nJust bare in mind when using this technique that you may accidentally hide something that isn\u2019t actually an advert; it just happens to be the same size.\n\nThe Interactive Advertising Bureau lists a number of common ad sizes. Using these dimensions, you can create stylesheet that blocks all the popular ad formats. Apply this as a user stylesheet and you never need to suffer another advert again.\n\nHere\u2019s wishing you a Merry, ad-free Christmas.", "year": "2005", "author": "Andy Budd", "author_slug": "andybudd", "published": "2005-12-11T00:00:00+00:00", "url": "https://24ways.org/2005/the-attribute-selector-for-fun-and-no-ad-profit/", "topic": "code"}
{"rowid": 332, "title": "CSS Layout Starting Points", "contents": "I build a lot of CSS layouts, some incredibly simple, others that cause sleepless nights and remind me of the torturous puzzle books that were given to me at Christmas by aunties concerned for my education. However, most of the time these layouts fit quite comfortably into one of a very few standard formats. For example:\n\n\n\tLiquid, multiple column with no footer\n\tLiquid, multiple column with footer\n\tFixed width, centred\n\n\nRather than starting out with blank CSS and (X)HTML documents every time you need to build a layout, you can fairly quickly create a bunch of layout starting points, that will give you a solid basis for creating the rest of the design and mean that you don\u2019t have to remember how a three column layout with a footer is best achieved every time you come across one! \n\nThese starting points can be really basic, in fact that\u2019s exactly what you want as the final design, the fonts, the colours and so on will be different every time. It\u2019s just the main sections we want to be able to quickly get into place. For example, here is a basic starting point CSS and XHTML document for a fixed width, centred layout with a footer.\n\n <!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Strict//EN\"\n     \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd\">\n<html xmlns=\"http://www.w3.org/1999/xhtml\">\n<head>\n     <title>Fixed Width and Centred starting point document</title>\n     <link rel=\"stylesheet\" type=\"text/css\" href=\"fixed-width-centred.css\" />\n     <meta http-equiv=\"Content-Type\" content=\"text/html; charset=utf-8\" />\n</head>\n<body>\n<div id=\"wrapper\">\n     <div id=\"side\">\n          <div class=\"inner\">\n               <p>Sidebar content here</p>\n          </div>\n     </div>\n     <div id=\"content\">\n          <div class=\"inner\">\n               <p>Your main content goes here.</p>\n          </div>\n     </div>\n     <div id=\"footer\">\n          <div class=\"inner\">\n               <p>Ho Ho Ho!</p>\n          </div>\n     </div>\n</div>\n</body>\n</html>\n\n body {\n     text-align: center;\n     min-width: 740px;\n     padding: 0;\n     margin: 0;\n }\n\n #wrapper {\n     text-align: left;\n     width: 740px;\n     margin-left: auto;\n     margin-right: auto;\n     padding: 0;\n }\n\n #content {\n     margin: 0 200px 0 0;\n }\n\n #content .inner {\n     padding-top: 1px;\n     margin: 0 10px 10px 10px;\n }\n\n #side {\n     float: right;\n     width: 180px;\n     margin: 0;\n }\n\n #side .inner {\n     padding-top: 1px;\n     margin: 0 10px 10px 10px;\n }\n\n #footer {\n     margin-top: 10px;\n     clear: both;\n }\n\n #footer .inner {\n     margin: 10px;\n }\n\n9 times out of 10, after figuring out exactly what main elements I have in a layout, I can quickly grab the \u2018one I prepared earlier\u2019, mark-up the relevant sections within the ready-made divs, and from that point on, I only need to worry about the contents of those different areas. The actual layout is tried and tested, one that I know works well in different browsers and that is unlikely to throw me any nasty surprises later on. In addition, considering how the layout is going to work first prevents the problem of developing a layout, then realising you need to put a footer on it, and needing to redevelop the layout as the method you have chosen won\u2019t work well with a footer.\n\nWhile enjoying your mince pies and mulled wine during the \u2018quiet time\u2019 between Christmas and New Year, why not create some starting point layouts of your own? The css-discuss Wiki, CSS layouts section is a great place to find examples that you can try out and find your favourite method of creating the various layout types.", "year": "2005", "author": "Rachel Andrew", "author_slug": "rachelandrew", "published": "2005-12-04T00:00:00+00:00", "url": "https://24ways.org/2005/css-layout-starting-points/", "topic": "code"}
{"rowid": 331, "title": "Splintered Striper", "contents": "Back in March 2004, David F. Miller demonstrated a little bit of DOM scripting magic in his A List Apart article Zebra Tables.\n\nHis script programmatically adds two alternating CSS background colours to table rows, making them more readable and visually pleasing, while saving the document author the tedious task of manually assigning the styling to large static data tables.\n\nAlthough David\u2019s original script performs its duty well, it is nonetheless very specific and limited in its application. It only:\n\n\n\tworks on a single table, identified by its id, with at least a single tbody section\n\tassigns a background colour\n\tallows two colours for odd and even rows\n\tacts on data cells, rather than rows, and then only if they have no class or background colour already defined\n\n\nTaking it further\n\nIn a recent project I found myself needing to apply a striped effect to a medium sized unordered list. Instead of simply modifying the Zebra Tables code for this particular case, I decided to completely recode the script to make it more generic.\n\nBeing more general purpose, the function in my splintered striper experiment is necessarily more complex. Where the original script only expected a single parameter (the id of the target table), the new function is called as follows:\n\nstriper('[parent element tag]','[parent element class or null]','[child element tag]','[comma separated list of classes]')\n\nThis new, fairly self-explanatory function:\n\n\n\ttargets any type of parent element (and, if specified, only those with a certain class)\n\tassigns two or more classes (rather than just two background colours) to the child elements inside the parent\n\tpreserves any existing classes already assigned to the child elements\n\n\nSee it in action\n\nView the demonstration page for three usage examples. For simplicity\u2019s sake, we\u2019re making the calls to the striper function from the body\u2019s onload attribute. In a real deployment situation, we would look at attaching a behaviour to the onload programmatically \u2014 just remember that, as we need to pass variables to the striper function, this would involve creating a wrapper function which would then be attached\u2026something like:\n\nfunction stripe() {\n    striper('tbody','splintered','tr','odd,even');\n}\n\nwindow.onload=stripe;\n\nA final thought\n\nJust because the function is called striper does not mean that it\u2019s limited to purely applying a striped look; as it\u2019s more of a general purpose \u201calternating class assignment\u201d script, you can achieve a whole variety of effects with it.", "year": "2005", "author": "Patrick Lauke", "author_slug": "patricklauke", "published": "2005-12-15T00:00:00+00:00", "url": "https://24ways.org/2005/splintered-striper/", "topic": "code"}
{"rowid": 327, "title": "Improving Form Accessibility with DOM Scripting", "contents": "The form label element is an incredibly useful little element \u2013 it lets you link the form field unquestionably with the descriptive label text that sits alongside or above it. This is a very useful feature for people using screen readers, but there are some problems with this element.\n\nWhat happens if you have one piece of data that, for various reasons (validation, the way your data is collected/stored etc), needs to be collected using several form elements?\n\nThe classic example is date of birth \u2013 ideally, you\u2019ll ask for the date of birth once but you may have three inputs, one each for day, month and year, that you also need to provide hints about the format required. The problem is that to be truly accessible you need to label each field. So you end up needing something to say \u201cthis is a date of birth\u201d, \u201cthis is the day field\u201d, \u201cthis is the month field\u201d and \u201cthis is the day field\u201d. Seems like overkill, doesn\u2019t it? And it can uglify a form no end.\n\nThere are various ways that you can approach it (and I think I\u2019ve seen them all). Some people omit the label and rely on the title attribute to help the user through; others put text in a label but make the text 1 pixel high and merging in to the background so that screen readers can still get that information. The most common method, though, is simply to set the label to not display at all using the CSS display:none property/value pairing (a technique which, for the time being, seems to work on most screen readers). But perhaps we can do more with this?\n\nThe technique I am suggesting as another alternative is as follows (here comes the pseudo-code):\n\n\n\tStart with a totally valid and accessible form\n\tEnsure that each form input has a label that is linked to its related form control\n\tApply a class to any label that you don\u2019t want to be visible (for example superfluous)\n\n\nThen, through the magic of unobtrusive JavaScript/the DOM, manipulate the page as follows once the page has loaded:\n\n\n\tFind all the label elements that are marked as superfluous and hide them\n\tFind out what input element each of these label elements is related to\n\tThen apply a hint about formatting required for input (gleaned from the original, now-hidden label text) \u2013 add it to the form input as default text\n\tFinally, add in a behaviour that clears or selects the default text (as you choose)\n\n\nSo, here\u2019s the theory put into practice \u2013 a date of birth, grouped using a fieldset, and with the behaviours added in using DOM, and here\u2019s the JavaScript that does the heavy lifting. \n\nBut why not just use display:none? As demonstrated at Juicy Studio, display:none seems to work quite well for hiding label elements. So why use a sledge hammer to crack a nut? In all honesty, this is something of an experiment, but consider the following:\n\n\n\tUsing the DOM, you can add extra levels of help, potentially across a whole form \u2013 or even range of forms \u2013 without necessarily increasing your markup (it goes beyond simply hiding labels)\n\tScreen readers today may  identify a label that is set not to display, but they may not in the future \u2013 this might provide a way around\n\tBy expanding this technique above, it might be possible to visually change the parent container that groups these items \u2013 in this case, a fieldset and legend, which are notoriously difficult to style consistently across different browsers \u2013 while still retaining the underlying semantic/logical structure\n\n\nWell, it\u2019s an idea to think about at least. How is it for you? How else might you use DOM scripting to improve the accessiblity or usability of your forms?", "year": "2005", "author": "Ian Lloyd", "author_slug": "ianlloyd", "published": "2005-12-03T00:00:00+00:00", "url": "https://24ways.org/2005/improving-form-accessibility-with-dom-scripting/", "topic": "code"}
{"rowid": 326, "title": "Don't be eval()", "contents": "JavaScript is an interpreted language, and like so many of its peers it includes the all powerful eval() function. eval() takes a string and executes it as if it were regular JavaScript code. It\u2019s incredibly powerful and incredibly easy to abuse in ways that make your code slower and harder to maintain. As a general rule, if you\u2019re using eval() there\u2019s probably something wrong with your design.\n\nCommon mistakes\n\nHere\u2019s the classic misuse of eval(). You have a JavaScript object, foo, and you want to access a property on it \u2013 but you don\u2019t know the name of the property until runtime. Here\u2019s how NOT to do it:\n\nvar property = 'bar';\nvar value = eval('foo.' + property);\n\nYes it will work, but every time that piece of code runs JavaScript will have to kick back in to interpreter mode, slowing down your app. It\u2019s also dirt ugly.\n\nHere\u2019s the right way of doing the above:\n\nvar property = 'bar';\nvar value = foo[property];\n\nIn JavaScript, square brackets act as an alternative to lookups using a dot. The only difference is that square bracket syntax expects a string.\n\nSecurity issues\n\nIn any programming language you should be extremely cautious of executing code from an untrusted source. The same is true for JavaScript \u2013 you should be extremely cautious of running eval() against any code that may have been tampered with \u2013 for example, strings taken from the page query string. Executing untrusted code can leave you vulnerable to cross-site scripting attacks.\n\nWhat\u2019s it good for?\n\nSome programmers say that eval() is B.A.D. \u2013 Broken As Designed \u2013 and should be removed from the language. However, there are some places in which it can dramatically simplify your code. A great example is for use with XMLHttpRequest, a component of the set of tools more popularly known as Ajax. XMLHttpRequest lets you make a call back to the server from JavaScript without refreshing the whole page. A simple way of using this is to have the server return JavaScript code which is then passed to eval(). Here is a simple function for doing exactly that \u2013 it takes the URL to some JavaScript code (or a server-side script that produces JavaScript) and loads and executes that code using XMLHttpRequest and eval().\n\nfunction evalRequest(url) {\n     var xmlhttp = new XMLHttpRequest();\n     xmlhttp.onreadystatechange = function() {\n          if (xmlhttp.readyState==4 && xmlhttp.status==200) {\n               eval(xmlhttp.responseText);\n          }\n     }\n     xmlhttp.open(\"GET\", url, true);\n     xmlhttp.send(null);\n }\n\nIf you want this to work with Internet Explorer you\u2019ll need to include this compatibility patch.", "year": "2005", "author": "Simon Willison", "author_slug": "simonwillison", "published": "2005-12-07T00:00:00+00:00", "url": "https://24ways.org/2005/dont-be-eval/", "topic": "code"}
{"rowid": 323, "title": "Introducing UDASSS!", "contents": "Okay. What\u2019s that mean?\n\nUnobtrusive Degradable Ajax Style Sheet Switcher!\n\nBoy are you in for treat today \u2018cause we\u2019re gonna have a whole lotta Ajaxifida Unobtrucitosity CSS swappin\u2019 Fun!\n\nOkay are you really kidding? Nope. I\u2019ve even impressed myself on this one. Unfortunately, I don\u2019t have much time to tell you the ins and outs of what I actually did to get this to work. We\u2019re talking JavaScript, CSS, PHP\u2026Ajax. But don\u2019t worry about that. I\u2019ve always believed that a good A.P.I. is an invisible A.P.I\u2026 and this I felt I achieved. The only thing you need to know is how it works and what to do.\n\nA Quick Introduction Anyway\u2026\n\nFirst of all, the idea is very simple. I wanted something just like what Paul Sowden put together in \nAlternative Style: Working With Alternate Style Sheets from Alistapart Magazine EXCEPT a few minor (not-so-minor actually) differences which I\u2019ve listed briefly below:\n\n\n\n\tAllow users to switch styles without JavaScript enabled (degradable)\n\tPreventing the F.O.U.C. before the window \u2018load\u2019 when getting preferred styles\n\tKeep the JavaScript entirely off our markup (no onclick\u2019s or onload\u2019s)\n\tMake it very very easy to implement (ok, Paul did that too)\n\n\nWhat I did to achieve this was used server-side cookies instead of JavaScript cookies. Hence, PHP. However this isn\u2019t a \u201cPHP style switcher\u201d \u2013 which is where Ajax comes in. For the extreme technical folks, no, there is no xml involved here, or even a callback response. I only say Ajax because everyone knows what \u2018it\u2019 means. With that said, it\u2019s the Ajax that sets the cookies \u2018on the fly\u2019. Got it? Awesome!\n\nWhat you need\n\nLuckily, I\u2019ve done the work for you. It\u2019s all packaged up in a nice zip file (at the end\u2026keep reading for now) \u2013 so from here on out, \njust follow these instructions\n\nAs I\u2019ve mentioned, one of the things we\u2019ll be working with is PHP. So, first things first, open up a file called index and save it with a \u2018.php\u2019 extension.\n\nNext, place the following text at the top of your document (even above your DOCTYPE)\n\n<?php\n require_once('utils/style-switcher.php');\n // style sheet path[, media, title, bool(set as alternate)]\n $styleSheet = new AlternateStyles();\n $styleSheet->add('css/global.css','screen,projection'); // [Global Styles]\n $styleSheet->add('css/preferred.css','screen,projection','Wog Standard'); // [Preferred Styles]\n $styleSheet->add('css/alternate.css','screen,projection','Tiny Fonts',true); // [Alternate Styles]\n $styleSheet->add('css/alternate2.css','screen,projection','Big O Fonts',true); // // [Alternate Styles]\n $styleSheet->getPreferredStyles();\n ?>\n\nThe way this works is REALLY EASY. Pay attention closely.\n\nNotice in the first line we\u2019ve included our style-switcher.php file.\n\nNext we instantiate a PHP class called AlternateStyles() which will allow us to configure our style sheets. \nSo for kicks, let\u2019s just call our object $styleSheet\n\nAs part of the AlternateStyles object, there lies a public method called add. So naturally with our $styleSheet object, we can call it to (da \u2013 da-da-da!) Add Style Sheets!\n\nHow the add() method works\n\nThe add method takes in a possible four arguments, only one is required. However, you\u2019ll want to add some\u2026 since the whole point is working with alternate style sheets.\n\n$path can simply be a uri, absolute, or relative path to your style sheet. $media adds a media attribute to your style sheets. $title gives a name to your style sheets (via title attribute).$alternate (which shows boolean) simply tells us that these are the alternate style sheets.\n\nadd() Tips\n\nFor all global style sheets (meaning the ones that will always be seen and will not be swapped out), simply use the add method as shown next to // [Global Styles].\n\nTo add preferred styles, do the same, but add a \u2018title\u2019.\n\nTo add the alternate styles, do the same as what we\u2019ve done to add preferred styles, but add the extra boolean and set it to true.\n\nNote following when adding style sheets\n\n\n\tMultiple global style sheets are allowed\n\tYou can only have one preferred style sheet (That\u2019s a browser rule)\n\tFeel free to add as many alternate style sheets as you like\n\n\nMoving on\n\nSimply add the following snippet to the <head> of your web document:\n\n<script type=\"text/javascript\" src=\"js/prototype.js\"></script>\n <script type=\"text/javascript\" src=\"js/common.js\"></script>\n <script type=\"text/javascript\" src=\"js/alternateStyles.js\"></script>\n <?php\n $styleSheet->drop();\n ?>\n\nNothing much to explain here. Just use your copy & paste powers.\n\nHow to Switch Styles\n\nWhether you knew it or not, this baby already has the built in \u2018ubobtrusive\u2019 functionality that lets you switch styles by the drop of any link with a class name of \u2018altCss\u2018. Just drop them where ever you like in your document as follows:\n\n<a class=\"altCss\" href=\"index.php?css=Bog_Standard\">Bog Standard</a>\n <a class=\"altCss\" href=\"index.php?css=Really_Small_Fonts\">Small Fonts</a>\n <a class=\"altCss\" href=\"index.php?css=Large_Fonts\">Large Fonts</a>\n\nTake special note where the file is linking to. Yep. Just linking right back to the page we\u2019re on. The only extra parameters we pass in is a variable called \u2018css\u2019 \u2013 and within that we append the names of our style sheets.\n\nAlso take very special note on the names of the style sheets have an under_score to take place of any spaces we might have.\n\nGo ahead\u2026 play around and change the style sheet on the example page. Try disabling JavaScript and refreshing your browser. Still works!\n\nCool eh?\n\nWell, I put this together in one night so it\u2019s still a work in progress and very beta. If you\u2019d like to hear more about it and its future development, be sure stop on by my site where I\u2019ll definitely be maintaining it.\n\nDownload the beta anyway\n\nWell this wouldn\u2019t be fun if there was nothing to download. So we\u2019re hooking you up so you don\u2019t go home (or logoff) unhappy\n\n Download U.D.A.S.S.S | V0.8\n\nMerry Christmas!\n\nThanks for listening and I hope U.D.A.S.S.S. has been well worth your time and will bring many years of Ajaxy Style Switchin\u2019 Fun!\n\nMany Blessings, Merry Christmas and have a great new year!", "year": "2005", "author": "Dustin Diaz", "author_slug": "dustindiaz", "published": "2005-12-18T00:00:00+00:00", "url": "https://24ways.org/2005/introducing-udasss/", "topic": "code"}
{"rowid": 322, "title": "Introduction to Scriptaculous Effects", "contents": "Gather around kids, because this year, much like in that James Bond movie with Denise Richards, Christmas is coming early\u2026 in the shape of scrumptuous smooth javascript driven effects at your every whim.\n\nNow what I\u2019m going to do, is take things down a notch. Which is to say, you don\u2019t need to know much beyond how to open a text file and edit it to follow this article. Personally, I for instance can\u2019t code to save my life.\n\nWell, strictly speaking, that\u2019s not entirely true. If my life was on the line, and the code needed was really simple and I wasn\u2019t under any time constraints, then yeah maybe I could hack my way out of it\n\nBut my point is this: I\u2019m not a programmer in the traditional sense of the word. In fact, what I do best, is scrounge code off of other people, take it apart and then put it back together with duct tape, chewing gum and dumb blind luck.\n\nNo, don\u2019t run! That happens to be a good thing in this case. You see, we\u2019re going to be implementing some really snazzy effects (which are considerably more relevant than most people are willing to admit) on your site, and we\u2019re going to do it with the aid of Thomas Fuchs\u2019 amazing Script.aculo.us library. And it will be like stealing candy from a child.\n\nWhat Are We Doing?\n\nI\u2019m going to show you the very basics of implementing the Script.aculo.us javascript library\u2019s Combination Effects. These allow you to fade elements on your site in or out, slide them up and down and so on.\n\nWhy Use Effects at All?\n\nBefore get started though, let me just take a moment to explain how I came to see smooth transitions as something more than smoke and mirror-like effects included for with little more motive than to dazzle and make parents go \u2018uuh, snazzy\u2019.\n\nEarlier this year, I had the good fortune of meeting the kind, gentle and quite knowledgable Matt Webb at a conference here in Copenhagen where we were both speaking (though I will be the first to admit my little talk on Open Source Design was vastly inferior to Matt\u2019s talk). Matt held a talk called Fixing Broken Windows (based on the Broken Windows theory), which really made an impression on me, and which I have since then referred back to several times.\n\nYou can listen to it yourself, as it\u2019s available from Archive.org. Though since Matt\u2019s session uses many visual examples, you\u2019ll have to rely on your imagination for some of the examples he runs through during it. Also, I think it looses audio for a few seconds every once in a while.\n\nAnyway, one of the things Matt talked a lot about, was how our eyes are wired to react to movement. The world doesn\u2019t flickr. It doesn\u2019t disappear or suddenly change and force us to look for the change. Things move smoothly in the real world. They do not pop up.\n\nHow it Works\n\nOnce the necessary files have been included, you trigger an effect by pointing it at the ID of an element. Simple as that.\n\nImplementing the Effects\n\nSo now you know why I believe these effects have a place in your site, and that\u2019s half the battle. Because you see, actually getting these effects up and running, is deceptively simple.\n\nFirst, go and download the latest version of the library (as of this writing, it\u2019s version 1.5 rc5). Unzip itand open it up.\n\nNow we\u2019re going to bypass the instructions in the readme file. Script.aculo.us can do a bunch of quite advanced things, but all we really want from it is its effects. And by sidestepping the rest of the features, we can shave off roughly 80KB of unnecessary javascript, which is well worth it if you ask me.\n\nAs with Drew\u2019s article on Easy Ajax with Prototype, script.aculo.us also uses the Prototype framework by  Sam Stephenson. But contrary to Drew\u2019s article, you don\u2019t have to download Prototype, as a version comes bundled with script.aculo.us (though feel free to upgrade to the latest version if you so please).\n\nSo in the unzipped folder, containing the script.aculo.us files and folder, go into \u2018lib\u2019 and grab the \u2018prototype.js\u2019 file. Move it to whereever you want to store the javascript files. Then fetch the \u2018effects.js\u2019 file from the \u2018src\u2019 folder and put it in the same place.\n\nTo make things even easier for you to get this up and running, I have prepared a small javascript snippet which does some checking to see what you\u2019re trying to do. The script.aculo.us effects are all either \u2018turn this off\u2019 or \u2018turn this on\u2019. What this snippet does, is check to see what state the target currently has (is it on or off?) and then use the necessary effect.\n\nYou can either skip to the end and download the example code, or copy and paste this code into a file manually (I\u2019ll refer to that file as combo.js):\n\nEffect.OpenUp = function(element) {\n     element = $(element);\n     new Effect.BlindDown(element, arguments[1] || {});\n }\n\n Effect.CloseDown = function(element) {\n     element = $(element);\n     new Effect.BlindUp(element, arguments[1] || {});\n }\n\n Effect.Combo = function(element) {\n     element = $(element);\n     if(element.style.display == 'none') { \n          new Effect.OpenUp(element, arguments[1] || {}); \n     }else { \n          new Effect.CloseDown(element, arguments[1] || {}); \n     }\n }\n\nCurrently, this code uses the BlindUp and BlindDown code, which I personally like, but there\u2019s nothing wrong with you changing the effect-type into one of the other effects available.\n\nNow, include the three files in the header of your code, like so:\n\n<script src=\"prototype.js\" type=\"text/javascript\"></script>\n<script src=\"effects.js\" type=\"text/javascript\"></script>\n<script src=\"combo.js\" type=\"text/javascript\"></script>\n\nNow insert the element you want to use the effect on, like so:\n\n<div id=\"content\" style=\"display: none;\">Lorem ipsum dolor sit amet.</div>\n\nThe above element will start out invisible, and when triggered will be revealed. If you want it to start visible, simply remove the style parameter.\n\nAnd now for the trigger \n\n<a href=\"javascript:Effect.Combo('content');\">Click Here</a>\n\nAnd that, is pretty much it. Clicking the link should unfold the DIV targeted by the effect, in this case \u2018content\u2019.\n\nEffect Options\n\nNow, it gets a bit long-haired though. The documentation for script.aculo.us is next to non-existing, and because of that you\u2019ll have to do some digging yourself to appreciate the full potentialof these effects.\n\nFirst of all, what kind of effects are available? Well you can go to the demo page and check them out, or you can open the \u2018effects.js\u2019 file and have a look around, something I recommend doing regardlessly, to gain an overview of what exactly you\u2019re dealing with.\n\nIf you dissect it for long enough, you can even distill some of the options available for the various effects. In the case of the BlindUp and BlindDown effect, which we\u2019re using in our example (as triggered from combo.js), one of the things that would be interesting to play with would be the duration of the effect. If it\u2019s too long, it will feel slow and unresponsive. Too fast and it will be imperceptible.\n\nYou set the options like so:\n\n<a href=\"javascript:Effect.Combo('content', {duration: .2});\">Click Here</a>\n\nThe change from the previous link being the inclusion of , {duration: .2}. In this case, I have lowered the duration to 0.2 second, to really make it feel snappy.\n\nYou can also go all-out and turn on all the bells and whistles of the Blind effect like so (slowed down to a duration of three seconds so you can see what\u2019s going on):\n\n<a href=\"javascript:Effect.Combo('content', {duration: 3, scaleX: true, scaleContent: true});\">Click Here</a>\n\nConclusion\n\nAnd that\u2019s pretty much it. The rest is a matter of getting to know the rest of the effects and their options as well as finding out just when and where to use them. Remember the ancient Chinese saying: Less is more.\n\nDownload Example\n\nI have prepared a very basic example, which you can download and use as a reference point.", "year": "2005", "author": "Michael Heilemann", "author_slug": "michaelheilemann", "published": "2005-12-12T00:00:00+00:00", "url": "https://24ways.org/2005/introduction-to-scriptaculous-effects/", "topic": "code"}
{"rowid": 321, "title": "Tables with Style", "contents": "It might not seem like it but styling tabular data can be a lot of fun. From a semantic point of view, there are plenty of elements to tie some style into. You have cells, rows, row groups and, of course, the table element itself. Adding CSS to a paragraph just isn\u2019t as exciting.\n\nWhere do I start?\n\nFirst, if you have some tabular data (you know, like a spreadsheet with rows and columns) that you\u2019d like to spiffy up, pop it into a table \u2014 it\u2019s rightful place!\n\nTo add more semantics to your table \u2014 and coincidentally to add more hooks for CSS \u2014 break up your table into row groups. There are three types of row groups: the header (thead), the body (tbody) and the footer (tfoot). You can only have one header and one footer but you can have as many table bodies as is appropriate.\n\nSample table example\n\nInspiration\n\nTable Striping\n\nTo improve scanning information within a table, a common technique is to style alternating rows. Also known as zebra tables. Whether you apply it using a class on every other row or turn to JavaScript to accomplish the task, a handy-dandy trick is to use a semi-transparent PNG as your background image. This is especially useful over patterned backgrounds. \n\ntbody tr.odd td {\n     background:transparent url(background.png) repeat top left;\n }\n\n * html tbody tr.odd td {\n     background:#C00;\n     filter: progid:DXImageTransform.Microsoft.AlphaImageLoader(\n          src='background.png', sizingMethod='scale');\n }\n\nWe turn off the default background and apply our PNG hack to have this work in Internet Explorer. \n\nStyling Columns\n\nDid you know you could style a column? That\u2019s right. You can add special column (col) or column group (colgroup) elements. With that you can add border or background styles to the column.\n\n<table>\n     <col id=\"ingredients\">\n     <col id=\"serve12\">\n     <col id=\"serve24\">\n ...\n\nCheck out the example.\n\nFun with Backgrounds\n\nPop in a tiled background to give your table some character! Internet Explorer\u2019s PNG hack unfortunately only works well when applied to a cell.\n\nTo figure out which background will appear over another, just remember the hierarchy:\n\n (bottom) Table \u2192 Column \u2192 Row Group \u2192 Row \u2192 Cell (top)\n\nThe Future is Bright\n\nOnce browser-makers start implementing CSS3, we\u2019ll have more power at our disposal. Just with :first-child and :last-child, you can pull off a scalable version of our previous table with rounded corners and all \u2014 unfortunately, only Firefox manages to pull this one off successfully. And the selector the masses are clamouring for, nth-child, will make zebra tables easy as eggnog.", "year": "2005", "author": "Jonathan Snook", "author_slug": "jonathansnook", "published": "2005-12-19T00:00:00+00:00", "url": "https://24ways.org/2005/tables-with-style/", "topic": "code"}
{"rowid": 320, "title": "DOM Scripting Your Way to Better Blockquotes", "contents": "Block quotes are great. I don\u2019t mean they\u2019re great for indenting content \u2013 that would be an abuse of the browser\u2019s default styling. I mean they\u2019re great for semantically marking up a chunk of text that is being quoted verbatim. They\u2019re especially useful in blog posts. \n\n<blockquote>\n     <p>Progressive Enhancement, as a label for a strategy for Web design, \n     was coined by Steven Champeon in a series of articles and presentations \n     for Webmonkey and the SxSW Interactive conference.</p>\n </blockquote>\n\nNotice that you can\u2019t just put the quoted text directly between the <blockquote> tags. In order for your markup to be valid, block quotes may only contain block-level elements such as paragraphs.\n\nThere is an optional cite attribute that you can place in the opening <blockquote> tag. This should contain a URL containing the original text you are quoting:\n\n<blockquote cite=\"http://en.wikipedia.org/wiki/Progressive_Enhancement\">\n     <p>Progressive Enhancement, as a label for a strategy for Web design, \n     was coined by Steven Champeon in a series of articles and presentations \n     for Webmonkey and the SxSW Interactive conference.</p>\n </blockquote>\n\nGreat! Except\u2026 the default behavior in most browsers is to completely ignore the cite attribute. Even though it contains important and useful information, the URL in the cite attribute is hidden.\n\nYou could simply duplicate the information with a hyperlink at the end of the quoted text:\n\n<blockquote cite=\"http://en.wikipedia.org/wiki/Progressive_Enhancement\">\n     <p>Progressive Enhancement, as a label for a strategy for Web design, \n     was coined by Steven Champeon in a series of articles and presentations \n     for Webmonkey and the SxSW Interactive conference.</p>\n     <p class=\"attribution\">\n          <a href=\"http://en.wikipedia.org/wiki/Progressive_Enhancement\">source</a>\n     </p>\n </blockquote>\n\nBut somehow it feels wrong to have to write out the same URL twice every time you want to quote something. It could also get very tedious if you have a lot of quotes.\n\nWell, \u201ctedious\u201d is no problem to a programming language, so why not use a sprinkling of DOM Scripting? Here\u2019s a plan for generating an attribution link for every block quote with a cite attribute:\n\n\n\tWrite a function called prepareBlockquotes.\n\tBegin by making sure the browser understands the methods you will be using.\n\tGet all the blockquote elements in the document.\n\tStart looping through each one.\n\tGet the value of the cite attribute.\n\tIf the value is empty, continue on to the next iteration of the loop.\n\tCreate a paragraph.\n\tCreate a link.\n\tGive the paragraph a class of \u201cattribution\u201d.\n\tGive the link an href attribute with the value from the cite attribute.\n\tPlace the text \u201csource\u201d inside the link.\n\tPlace the link inside the paragraph.\n\tPlace the paragraph inside the block quote.\n\tClose the for loop.\n\tClose the function.\n\n\nHere\u2019s how that translates to JavaScript:\n\nfunction prepareBlockquotes() {\n     if (!document.getElementsByTagName || !document.createElement || !document.appendChild) return;\n     var quotes = document.getElementsByTagName(\"blockquote\");\n     for (var i=0; i<quotes.length; i++) {\n          var source = quotes[i].getAttribute(\"cite\");\n          if (!source) continue;\n          var para = document.createElement(\"p\");\n          var link = document.createElement(\"a\");\n          para.className = \"attribution\";\n          link.setAttribute(\"href\",source);\n          link.appendChild(document.createTextNode(\"source\"));\n          para.appendChild(link);\n          quotes[i].appendChild(para);\n     }\n }\n\n\nNow all you need to do is trigger that function when the document has loaded:\n\nwindow.onload = prepareBlockquotes;\n\nBetter yet, use Simon Willison\u2019s handy addLoadEvent function to queue this function up with any others you might want to execute when the page loads.\n\nThat\u2019s it. All you need to do is save this function in a JavaScript file and reference that file from the head of your document using <script> tags.\n\nYou can style the attribution link using CSS. It might look good aligned to the right with a smaller font size.\n\nIf you\u2019re looking for something to do to keep you busy this Christmas, I\u2019m sure that this function could be greatly improved. Here are a few ideas to get you started:\n\n\n\tShould the text inside the generated link be the URL itself?\n\tIf the block quote has a title attribute, how would you take its value and use it as the text inside the generated link?\n\tShould the attribution paragraph be placed outside the block quote? If so, how would you that (remember, there is an insertBefore method but no insertAfter)?\n\tCan you think of other instances of useful information that\u2019s locked away inside attributes? Access keys? Abbreviations?", "year": "2005", "author": "Jeremy Keith", "author_slug": "jeremykeith", "published": "2005-12-05T00:00:00+00:00", "url": "https://24ways.org/2005/dom-scripting-your-way-to-better-blockquotes/", "topic": "code"}
{"rowid": 319, "title": "Avoiding CSS Hacks for Internet Explorer", "contents": "Back in October, IEBlog issued a call to action, asking developers to clean up their CSS hacks for IE7 testing. Needless to say, a lot of hubbub ensued\u2026 both on IEBlog and elsewhere. My contribution to all of the noise was to suggest that developers review their code and use good CSS hacks. But what makes a good hack?\n\nTantek \u00c7elik, the Godfather of CSS hacks, gave us the answer by explaining how CSS hacks should be designed. In short, they should (1) be valid, (2) target only old/frozen/abandoned user-agents/browsers, and (3) be ugly. Tantek also went on to explain that using a feature of CSS is not a hack.\n\nNow, I\u2019m not a frequent user of CSS hacks, but Tantek\u2019s post made sense to me. In particular, I felt it gave developers direction on how we should be coding to accommodate that sometimes troublesome browser, Internet Explorer. But what I\u2019ve found, through my work with other developers, is that there is still much confusion over the use of CSS hacks and IE. Using examples from the code I\u2019ve seen recently, allow me to demonstrate how to clean up some IE-specific CSS hacks.\n\nThe two hacks that I\u2019ve found most often in the code I\u2019ve seen and worked with are the star html bug and the underscore hack. We know these are both IE-specific by checking Kevin Smith\u2019s CSS Filters chart. Let\u2019s look at each of these hacks and see how we can replace them with the same CSS feature-based solution.\n\nThe star html bug\n\nThis hack violates Tantek\u2019s second rule as it targets current (and future) UAs. I\u2019ve seen this both as a stand alone rule, as well as an override to some other rule in a style sheet. Here are some code samples:\n\n* html div#header {margin-top:-3px;}\n.promo h3 {min-height:21px;}\n* html .promo h3 {height:21px;}\n\nThe underscore hack\n\nThis hack violates Tantek\u2019s first two rules: it\u2019s invalid (according to the W3C CSS Validator) and it targets current UAs. Here\u2019s an example:\n\nol {padding:0; _padding-left:5px;}\n\nUsing child selectors\n\nWe can use the child selector to replace both the star html bug and underscore hack. Here\u2019s how:\n\n Write rules with selectors that would be successfully applied to all browsers. This may mean starting with no declarations in your rule!\n\ndiv#header {}\n.promo h3 {}\nol {padding:0;}\n\n \nTo these rules, add the IE-specific declarations.\n\ndiv#header {margin-top:-3px;}\n.promo h3 {height:21px;}\nol {padding:0 0 0 5px;}\n\n \nAfter each rule, add a second rule. The selector of the second rule must use a child selector. In this new rule, correct any IE-specific declarations previously made.\n\ndiv#header {margin-top:-3px;}\nbody > div#header {margin-top:0;}\n\n.promo h3 {height:21px;}\n.promo > h3 {height:auto; min-height:21px;}\n\nol {padding:0 0 0 5px;}\nhtml > body ol {padding:0;}\n\n \n\nVoil\u00e0 \u2013 no more hacks! There are a few caveats to this that I won\u2019t go into\u2026 but assuming you\u2019re operating in strict mode and barring any really complicated stuff you\u2019re doing in your code, your CSS will still render perfectly across browsers. And while this may make your CSS slightly heftier in size, it should future-proof it for IE7 (or so I hope). Happy holidays!", "year": "2005", "author": "Kimberly Blessing", "author_slug": "kimberlyblessing", "published": "2005-12-17T00:00:00+00:00", "url": "https://24ways.org/2005/avoiding-css-hacks-for-internet-explorer/", "topic": "code"}
{"rowid": 318, "title": "Auto-Selecting Navigation", "contents": "In the article Centered Tabs with CSS Ethan laid out a tabbed navigation system which can be centred on the page. A frequent requirement for any tab-based navigation is to be able to visually represent the currently selected tab in some way.\n\nIf you\u2019re using a server-side language such as PHP, it\u2019s quite easy to write something like class=\"selected\" into your markup, but it can be even simpler than that.\n\nLet\u2019s take the navigation div from Ethan\u2019s article as an example.\n\n<div id=\"navigation\">\n     <ul>\n          <li><a href=\"#\"><span>Home</span></a></li>\n          <li><a href=\"#\"><span>About</span></a></li>\n          <li><a href=\"#\"><span>Our Work</span></a></li>\n          <li><a href=\"#\"><span>Products</span></a></li>\n          <li class=\"last\"><a href=\"#\"><span>Contact Us</span></a></li>\n     </ul>\n </div>\n\nAs you can see we have a standard unordered list which is then styled with CSS to look like tabs. By giving each tab a class which describes it\u2019s logical section of the site, if we were to then apply a class to the body tag of each page showing the same, we could write a clever CSS selector to highlight the correct tab on any given page. \n\nSound complicated? Well, it\u2019s not a trivial concept, but actually applying it is dead simple.\n\nModifying the markup\n\nFirst thing is to place a class name on each li in the list:\n\n<div id=\"navigation\">\n     <ul>\n          <li class=\"home\"><a href=\"#\"><span>Home</span></a></li>\n          <li class=\"about\"><a href=\"#\"><span>About</span></a></li>\n          <li class=\"work\"><a href=\"#\"><span>Our Work</span></a></li>\n          <li class=\"products\"><a href=\"#\"><span>Products</span></a></li>\n          <li class=\"last contact\"><a href=\"#\"><span>Contact Us</span></a></li>\n     </ul>\n </div>\n\nThen, on each page of your site, apply the a matching class to the body tag to indicate which section of the site that page is in. For example, on your About page:\n\n<body class=\"about\">...</body>\n\nWriting the CSS selector\n\nYou can now write a single CSS rule to match the selected tab on any given page. The logic is that you want to match the \u2018about\u2019 tab on the \u2018about\u2019 page and the \u2018products\u2019 tab on the \u2018products\u2019 page, so the selector looks like this:\n\nbody.home #navigation li.home,\n body.about #navigation li.about,\n body.work #navigation li.work,\n body.products #navigation li.products,\n body.contact #navigation li.contact{\n      ... whatever styles you need to show the tab selected ...\n } \n\nSo all you need to do when you create a new page in your site is to apply a class to the body tag to say which section it\u2019s in. The CSS will do the rest for you \u2013 without any server-side help.", "year": "2005", "author": "Drew McLellan", "author_slug": "drewmclellan", "published": "2005-12-10T00:00:00+00:00", "url": "https://24ways.org/2005/auto-selecting-navigation/", "topic": "code"}
{"rowid": 316, "title": "Have Your DOM and Script It Too", "contents": "When working with the XMLHttpRequest object it appears you can only go one of three ways: \n\n\n\tYou can stay true to the colorful moniker du jour and stick strictly to the responseXML property\n\tYou can play with proprietary \u2013 yet widely supported \u2013 fire and inject the value of responseText property into the innerHTML of an element of your choosing\n\tOr you can be eval() and parse JSON or arbitrary JavaScript delivered via responseText\n\n\nBut did you know that there\u2019s a fourth option giving you the best of the latter two worlds? Mint uses this unmentioned approach to grab fresh HTML and run arbitrary JavaScript simultaneously. Without relying on eval(). \u201cBut wait-\u201d, you might say, \u201cwhen would I need to do this?\u201d Besides the example below this technique is handy for things like tab groups that need initialization onload but miss the main onload event handler by a mile thanks to asynchronous scripting.\n\nConsider the problem\n\nOriginally Mint used option 2 to refresh or load new tabs into individual Pepper panes without requiring a full roundtrip to the server. This was all well and good until I introduced the new Client Mode which when enabled allows anyone to view a Mint installation without being logged in. If voyeurs are afoot as Client Mode is disabled, the next time they refresh a pane the entire login page is inserted into the current document. That\u2019s not very helpful so I needed a way to redirect the current document to the login page.\n\n\n\nEnter the solution\n\nWouldn\u2019t it be cool if browsers interpreted the contents of script tags crammed into innerHTML? Sure, but unfortunately, that just wasn\u2019t meant to be. However like the body element, image elements have an onload event handler. When the image has fully loaded the handler runs the code applied to it. See where I\u2019m going with this?\n\nBy tacking a tiny image (think single pixel, transparent spacer gif \u2013 shudder) onto the end of the HTML returned by our Ajax call, we can smuggle our arbitrary JavaScript into the existing document. The image is added to the DOM, and our stowaway can go to town.\n\n<p>This is the results of our Ajax call.</p>\n <img src=\"../images/loaded.gif\" alt=\"\" onload=\"alert('Now that I have your attention...');\" />\n\nPlease be neat\n\nSo we\u2019ve just jammed some meaningless cruft into our DOM. If our script does anything with images this addition could have some unexpected side effects. (Remember The Fly?) So in order to save that poor, unsuspecting element whose innerHTML we just swapped out from sharing Jeff Goldblum\u2019s terrible fate we should tidy up after ourselves. And by using the removeChild method we do just that.\n\n<p>This is the results of our Ajax call.</p>\n <img src=\"../images/loaded.gif\" alt=\"\" \n     onload=\"alert('Now that I have your attention...');this.parentNode.removeChild(this);\" />", "year": "2005", "author": "Shaun Inman", "author_slug": "shauninman", "published": "2005-12-24T00:00:00+00:00", "url": "https://24ways.org/2005/have-your-dom-and-script-it-too/", "topic": "code"}
{"rowid": 315, "title": "Edit-in-Place with Ajax", "contents": "Back on day one we looked at using the Prototype library to take all the hard work out of making a simple Ajax call. While that was fun and all, it didn\u2019t go that far towards implementing something really practical. We dipped our toes in, but haven\u2019t learned to swim yet.\n\nSo here is swimming lesson number one. Anyone who\u2019s used Flickr to publish their photos will be familiar with the edit-in-place system used for quickly amending titles and descriptions on photographs. Hovering over an item turns its background yellow to indicate it is editable. A simple click loads the text into an edit box, right there on the page.\n\n\n\nPrototype includes all sorts of useful methods to help reproduce something like this for our own projects. As well as the simple Ajax GETs we learned how to do last time, we can also do POSTs (which we\u2019ll need here) and a whole bunch of manipulations to the user interface \u2013 all through simple library calls. Here\u2019s what we\u2019re building, so let\u2019s do it.\n\nGetting Started\n\nThere are two major components to this process; the user interface manipulation and the Ajax call itself. Our set-up is much the same as last time (you may wish to read the first article if you\u2019ve not already done so). We have a basic HTML page which links in the prototype.js file and our own editinplace.js. Here\u2019s what Santa dropped down my chimney: \n\n<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Strict//EN\"\n     \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd\">\n <html xmlns=\"http://www.w3.org/1999/xhtml\" xml:lang=\"en\" lang=\"en\">\n <head>\n     <meta http-equiv=\"Content-Type\" content=\"text/html; charset=utf-8\"/>\n    <title>Edit-in-Place with Ajax</title>\n     <link href=\"editinplace.css\" rel=\"Stylesheet\" type=\"text/css\" />\n     <script src=\"prototype.js\" type=\"text/javascript\"></script>\n     <script src=\"editinplace.js\" type=\"text/javascript\"></script>    \n</head> \n<body>\n     <h1>Edit-in-place</h1>\n     <p id=\"desc\">Dashing through the snow on a one horse open sleigh.</p>\n </body>\n </html>\n\nSo that\u2019s our page. The editable item is going to be the <p> called desc. The process goes something like this:\n\n\n\tHighlight the area onMouseOver\n\tClear the highlight onMouseOut\n\tIf the user clicks, hide the area and replace with a <textarea> and buttons\n\tRemove all of the above if the user cancels the operation\n\tWhen the Save button is clicked, make an Ajax POST and show that something\u2019s happening\n\tWhen the Ajax call comes back, update the page with the new content\n\n\nEvents and Highlighting\n\nThe first step is to offer feedback to the user that the item is editable. This is done by shading the background colour when the user mouses over. Of course, the CSS :hover pseudo class is a straightforward way to do this, but for three reasons, I\u2019m using JavaScript to switch class names.\n\n\n\t:hover isn\u2019t supported on many elements in Internet Explorer for Windows\n\tI want to keep control over when the highlight switches off after an update, regardless of mouse position\n\tIf JavaScript isn\u2019t available we don\u2019t want to end up with the CSS suggesting it might be\n\n\nWith this in mind, here\u2019s how editinplace.js starts:\n\nEvent.observe(window, 'load', init, false);\n\n function init(){\n     makeEditable('desc');\n }\n\n function makeEditable(id){\n     Event.observe(id, 'click', function(){edit($(id))}, false);\n     Event.observe(id, 'mouseover', function(){showAsEditable($(id))}, false);\n     Event.observe(id, 'mouseout', function(){showAsEditable($(id), true)}, false);\n }\n\n function showAsEditable(obj, clear){\n     if (!clear){\n          Element.addClassName(obj, 'editable');\n     }else{\n          Element.removeClassName(obj, 'editable');\n     }\n }\n\nThe first line attaches an onLoad event to the window, so that the function init() gets called once the page has loaded. In turn, init() sets up all the items on the page that we want to make editable. In this example I\u2019ve just got one, but you can add as many as you like.\n\nThe function madeEditable() attaches the mouseover, mouseout and click events to the item we\u2019re making editable. All showAsEditable does is add and remove the class name editable from the object. This uses the particularly cunning methods Element.addClassName() and Element.removeClassName() which enable you to cleanly add and remove effects without affecting any styling the object may otherwise have.\n\nOh, remember to add a rule for .editable to your style sheet:\n\n.editable{\n     color: #000;\n     background-color: #ffffd3;\n }\n\nThe Switch\n\nAs you can see above, when the user clicks on an editable item, a call is made to the function edit(). This is where we switch out the static item for a nice editable textarea. Here\u2019s how that function looks.\n\nfunction edit(obj){\n     Element.hide(obj);\n\n     var textarea ='<div id=\"' + obj.id + '_editor\">\n          <textarea id=\"' + obj.id + '_edit\" name=\"' + obj.id + '\" rows=\"4\" cols=\"60\">'\n          + obj.innerHTML + '</textarea>';\n\n     var button = '<input id=\"' + obj.id + '_save\" type=\"button\" value=\"SAVE\" /> OR \n          <input id=\"' + obj.id + '_cancel\" type=\"button\" value=\"CANCEL\" /></div>';\n\n     new Insertion.After(obj, textarea+button);\n\n     Event.observe(obj.id+'_save', 'click', function(){saveChanges(obj)}, false);\n     Event.observe(obj.id+'_cancel', 'click', function(){cleanUp(obj)}, false);\n\n }\n\nThe first thing to do is to hide the object. Prototype comes to the rescue with Element.hide() (and of course, Element.show() too). Following that, we build up the textarea and buttons as a string, and then use Insertion.After() to place our new editor underneath the (now hidden) editable object.\n\nThe last thing to do before we leave the user to edit is it attach listeners to the Save and Cancel buttons to call either the saveChanges() function, or to cleanUp() after a cancel.\n\nIn the event of a cancel, we can clean up behind ourselves like so:\n\nfunction cleanUp(obj, keepEditable){\n     Element.remove(obj.id+'_editor');\n     Element.show(obj);\n     if (!keepEditable) showAsEditable(obj, true);\n }\n\nSaving the Changes\n\nThis is where all the Ajax fun occurs. Whilst the previous article introduced Ajax.Updater() for simple Ajax calls, in this case we need a little bit more control over what happens once the response is received. For this purpose, Ajax.Request() is perfect. We can use the onSuccess and onFailure parameters to register functions to handle the response.\n\nfunction saveChanges(obj){\n     var new_content = escape($F(obj.id+'_edit'));\n\n     obj.innerHTML = \"Saving...\";\n     cleanUp(obj, true);\n\n     var success = function(t){editComplete(t, obj);}\n     var failure = function(t){editFailed(t, obj);}\n\n     var url = 'edit.php';\n     var pars = 'id=' + obj.id + '&content=' + new_content;\n     var myAjax = new Ajax.Request(url, {method:'post',\n          postBody:pars, onSuccess:success, onFailure:failure});\n }\n\n function editComplete(t, obj){\n     obj.innerHTML = t.responseText;\n     showAsEditable(obj, true);\n }\n\n function editFailed(t, obj){\n     obj.innerHTML = 'Sorry, the update failed.';\n     cleanUp(obj);\n }\n\nAs you can see, we first grab in the contents of the textarea into the variable new_content. We then remove the editor, set the content of the original object to \u201cSaving\u2026\u201d to show that an update is occurring, and make the Ajax POST.\n\nIf the Ajax fails, editFailed() sets the contents of the object to \u201cSorry, the update failed.\u201d Admittedly, that\u2019s not a very helpful way to handle the error but I have to limit the scope of this article somewhere. It might be a good idea to stow away the original contents of the object (obj.preUpdate = obj.innerHTML) for later retrieval before setting the content to \u201cSaving\u2026\u201d. No one likes a failure \u2013 especially a messy one.\n\nIf the Ajax call is successful, the server-side script returns the edited content, which we then place back inside the object from editComplete, and tidy up.\n\nMeanwhile, back at the server\n\nThe missing piece of the puzzle is the server-side script for committing the changes to your database. Obviously, any solution I provide here is not going to fit your particular application. For the purposes of getting a functional demo going, here\u2019s what I have in PHP.\n\n<?php\n     $id = $_POST['id'];\n     $content = $_POST['content'];\n     echo htmlspecialchars($content);\n ?>\n\nNot exactly rocket science is it? I\u2019m just catching the content item from the POST and echoing it back. For your application to be useful, however, you\u2019ll need to know exactly which record you should be updating. I\u2019m passing in the ID of my <div>, which is not a fat lot of use. You can modify saveChanges() to post back whatever information your app needs to know in order to process the update.\n\nYou should also check the user\u2019s credentials to make sure they have permission to edit whatever it is they\u2019re editing. Basically the same rules apply as with any script in your application.\n\nLimitations\n\nThere are a few bits and bobs that in an ideal world I would tidy up. The first is the error handling, as I\u2019ve already mentioned. The second is that from an idealistic standpoint, I\u2019d rather not be using innerHTML. However, the reality is that it\u2019s presently the most efficient way of making large changes to the document. If you\u2019re serving as XML, remember that you\u2019ll need to replace these with proper DOM nodes.\n\nIt\u2019s also important to note that it\u2019s quite difficult to make something like this universally accessible. Whenever you start updating large chunks of a document based on user interaction, a lot of non-traditional devices don\u2019t cope well. The benefit of this technique, though, is that if JavaScript is unavailable none of the functionality gets implemented at all \u2013 it fails silently. It is for this reason that this shouldn\u2019t be used as a complete replacement for a traditional, universally accessible edit form. It\u2019s a great time-saver for those with the ability to use it, but it\u2019s no replacement.\n\nSee it in action\n\nI\u2019ve put together an example page using the inert PHP script above. That is to say, your edits aren\u2019t committed to a database, so the example is reset when the page is reloaded.", "year": "2005", "author": "Drew McLellan", "author_slug": "drewmclellan", "published": "2005-12-23T00:00:00+00:00", "url": "https://24ways.org/2005/edit-in-place-with-ajax/", "topic": "code"}
{"rowid": 314, "title": "Easy Ajax with Prototype", "contents": "There\u2019s little more impressive on the web today than a appropriate touch of Ajax. Used well, Ajax brings a web interface much closer to the experience of a desktop app, and can turn a bear of an task into a pleasurable activity.\n\nBut it\u2019s really hard, right? It involves all the nasty JavaScript that no one ever does often enough to get really good at, and the browser support is patchy, and urgh it\u2019s just so much damn effort. Well, the good news is that \u2013 ta-da \u2013 it doesn\u2019t have to be a headache. But man does it still look impressive. Here\u2019s how to amaze your friends.\n\nIntroducing prototype.js\n\nPrototype is a JavaScript framework by Sam Stephenson designed to help make developing dynamic web apps a whole lot easier. In basic terms, it\u2019s a JavaScript file which you link into your page that then enables you to do cool stuff.\n\nThere\u2019s loads of capability built in, a portion of which covers our beloved Ajax. The whole thing is freely distributable under an MIT-style license, so it\u2019s good to go. What a nice man that Mr Stephenson is \u2013 friends, let us raise a hearty cup of mulled wine to his good name. Cheers! sluurrrrp.\n\nFirst step is to download the latest Prototype and put it somewhere safe. I suggest underneath the Christmas tree.\n\nCutting to the chase\n\nBefore I go on and set up an example of how to use this, let\u2019s just get to the crux. Here\u2019s how Prototype enables you to make a simple Ajax call and dump the results back to the page:\n\nvar url = 'myscript.php';\nvar pars = 'foo=bar';\nvar target = 'output-div';\t\nvar myAjax = new Ajax.Updater(target, url, {method: 'get', parameters: pars});\n\nThis snippet of JavaScript does a GET to myscript.php, with the parameter foo=bar, and when a result is returned, it places it inside the element with the ID output-div on your page.\n\nKnocking up a basic example\n\nSo to get this show on the road, there are three files we need to set up in our site alongside prototype.js. Obviously we need a basic HTML page with prototype.js linked in. This is the page the user interacts with. Secondly, we need our own JavaScript file for the glue between the interface and the stuff Prototype is doing. Lastly, we need the page (a PHP script in my case) that the Ajax is going to make its call too.\n\nSo, to that basic HTML page for the user to interact with. Here\u2019s one I found whilst out carol singing:\n\n<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Strict//EN\"\n    \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd\">\n<html xmlns=\"http://www.w3.org/1999/xhtml\" xml:lang=\"en\" lang=\"en\">\n<head>\n    <meta http-equiv=\"Content-Type\" content=\"text/html; charset=utf-8\"/>\n    <title>Easy Ajax</title>\n    <script type=\"text/javascript\" src=\"prototype.js\"></script>\n    <script type=\"text/javascript\" src=\"ajax.js\"></script>\n</head> \n<body>\n    <form method=\"get\" action=\"greeting.php\" id=\"greeting-form\">\n        <div>\n            <label for=\"greeting-name\">Enter your name:</label>\n            <input id=\"greeting-name\" type=\"text\" />\n            <input id=\"greeting-submit\" type=\"submit\" value=\"Greet me!\" />\n        </div>\n        <div id=\"greeting\"></div>\n    </form>\n</body>\n</html>\n\nAs you can see, I\u2019ve linked in prototype.js, and also a file called ajax.js, which is where we\u2019ll be putting our glue. (Careful where you leave your glue, kids.)\n\nOur basic example is just going to take a name and then echo it back in the form of a seasonal greeting. There\u2019s a form with an input field for a name, and crucially a DIV (greeting) for the result of our call. You\u2019ll also notice that the form has a submit button \u2013 this is so that it can function as a regular form when no JavaScript is available. It\u2019s important not to get carried away and forget the basics of accessibility.\n\nMeanwhile, back at the server\n\nSo we need a script at the server which is going to take input from the Ajax call and return some output. This is normally where you\u2019d hook into a database and do whatever transaction you need to before returning a result. To keep this as simple as possible, all this example here will do is take the name the user has given and add it to a greeting message. Not exactly Web 2-point-HoHoHo, but there you have it.\n\nHere\u2019s a quick PHP script \u2013 greeting.php \u2013 that Santa brought me early.\n\n<?php\n     $the_name = htmlspecialchars($_GET['greeting-name']);\n     echo \"<p>Season's Greetings, $the_name!</p>\";\n?>\n\nYou\u2019ll perhaps want to do something a little more complex within your own projects. Just sayin\u2019.\n\nGluing it all together\n\nInside our ajax.js file, we need to hook this all together. We\u2019re going to take advantage of some of the handy listener routines and such that Prototype also makes available. The first task is to attach a listener to set the scene once the window has loaded. He\u2019s how we attach an onload event to the window object and get it to call a function named init():\n\nEvent.observe(window, 'load', init, false);\n\nNow we create our init() function to do our evil bidding. Its first job of the day is to hide the submit button for those with JavaScript enabled. After that, it attaches a listener to watch for the user typing in the name field.\n\nfunction init(){\n     $('greeting-submit').style.display = 'none';\n     Event.observe('greeting-name', 'keyup', greet, false);\n}\n\nAs you can see, this is going to make a call to a function called greet() onkeyup in the greeting-name field. That function looks like this:\n\nfunction greet(){\n     var url = 'greeting.php';\n     var pars = 'greeting-name='+escape($F('greeting-name'));\n     var target = 'greeting';\n     var myAjax = new Ajax.Updater(target, url, {method: 'get', parameters: pars});\n}\n\nThe key points to note here are that any user input needs to be escaped before putting into the parameters so that it\u2019s URL-ready. The target is the ID of the element on the page (a DIV in our case) which will be the recipient of the output from the Ajax call.\n\nThat\u2019s it\n\nNo, seriously. That\u2019s everything. Try the example. Amaze your friends with your 1337 Ajax sk1llz.", "year": "2005", "author": "Drew McLellan", "author_slug": "drewmclellan", "published": "2005-12-01T00:00:00+00:00", "url": "https://24ways.org/2005/easy-ajax-with-prototype/", "topic": "code"}
{"rowid": 313, "title": "Centered Tabs with CSS", "contents": "Doug Bowman\u2019s Sliding Doors is pretty much the de facto way to build tabbed navigation with CSS, and rightfully so \u2013 it is, as they say, rockin\u2019 like Dokken. But since it relies heavily on floats for the positioning of its tabs, we\u2019re constrained to either left- or right-hand navigation. But what if we need a bit more flexibility? What if we need to place our navigation in the center?\n\nStyling the li as a floated block does give us a great deal of control over margin, padding, and other presentational styles. However, we should learn to love the inline box \u2013 with it, we can create a flexible, centered alternative to floated navigation lists.\n\nHumble Beginnings\n\nDo an extra shot of \u2018nog, because you know what\u2019s coming next. That\u2019s right, a simple unordered list:\n\n<div id=\"navigation\">\n     <ul>\n          <li><a href=\"#\"><span>Home</span></a></li>\n          <li><a href=\"#\"><span>About</span></a></li>\n          <li><a href=\"#\"><span>Our Work</span></a></li>\n          <li><a href=\"#\"><span>Products</span></a></li>\n          <li class=\"last\"><a href=\"#\"><span>Contact Us</span></a></li>\n     </ul>\n</div>\n\nIf we were wedded to using floats to style our list, we could easily fix the width of our ul, and trick it out with some margin: 0 auto; love to center it accordingly. But this wouldn\u2019t net us much flexibility: if we ever changed the number of navigation items, or if the user increased her browser\u2019s font size, our design could easily break.\n\nInstead of worrying about floats, let\u2019s take the most basic approach possible: let\u2019s turn our list items into inline elements, and simply use text-align to center them within the ul:\n\n#navigation ul, #navigation ul li {\n     list-style: none;\n     margin: 0;\n     padding: 0;\n}\n\n#navigation ul {\n     text-align: center;\n}\n\n#navigation ul li {\n     display: inline;\n     margin-right: .75em;\n}\n\n#navigation ul li.last {\n     margin-right: 0;\n}\n\nOur first step is sexy, no? Well, okay, not really \u2013 but it gives us a good starting point. We\u2019ve tamed our list by removing its default styles, set the list items to display: inline, and centered the lot. Adding a background color to the links shows us exactly how the different elements are positioned.\n\nNow the fun stuff.\n\nInline Elements, Padding, and You\n\nSo how do we give our links some dimensions? Well, as the CSS specification tells us, the height property isn\u2019t an option for inline elements such as our anchors. However, what if we add some padding to them?\n\n#navigation li a {\n     padding: 5px 1em;\n}\n\nI just love leading questions. Things are looking good, but something\u2019s amiss: as you can see, the padded anchors seem to be escaping their containing list.\n\nThankfully, it\u2019s easy to get things back in line. Our anchors have 5 pixels of padding on their top and bottom edges, right? Well, by applying the same vertical padding to the list, our list will finally \u201ccontain\u201d its child elements once again.\n\n\u2019Tis the Season for Tabbing\n\nNow, we\u2019re finally able to follow the \u201cSliding Doors\u201d model, and tack on some graphics:\n\n#navigation ul li a {\n     background: url(\"tab-right.gif\") no-repeat 100% 0;\n     color: #06C;\n     padding: 5px 0;\n     text-decoration: none;\n}\n\n#navigation ul li a span {\n     background: url(\"tab-left.gif\") no-repeat;\n     padding: 5px 1em;\n}\n\n#navigation ul li a:hover span {\n     color: #69C;\n     text-decoration: underline;\n}\n\nFinally, our navigation\u2019s looking appropriately sexy. By placing an equal amount of padding on the top and bottom of the ul, our tabs are properly \u201ccontained\u201d, and we can subsequently style the links within them.\n\n\n\nBut what if we want them to bleed over the bottom-most border? Easy: we can simply decrease the bottom padding on the list by one pixel, like so.\n\nA Special Note for Special Browsers\n\nThe Mac IE5 users in the audience are likely hopping up and down by now: as they\u2019ve discovered, our centered navigation behaves rather annoyingly in their browser. As Philippe Wittenbergh has reported, Mac IE5 is known to create \u201cphantom links\u201d in a block-level element when text-align is set to any value but the default value of left. Thankfully, Philippe has documented a workaround that gets that [censored] venerable browser to behave. Simply place the following code into your CSS, and the links will be restored to their appropriate width:\n\n/**//*/\n#navigation ul li a {\n     display: inline-block;\n     white-space: nowrap;\n     width: 1px;\n}\n/**/\n\nIE for Windows, however, displays an extra kind of crazy. The padding I\u2019ve placed on my anchors is offsetting the spans that contain the left curve of my tabs; thankfully, these shenanigans are easily straightened out:\n\n/**/\n* html #navigation ul li a {\n     padding: 0;\n}\n/**/\n\nAnd with that, we\u2019re finally finished.\n\nAll set.\n\nAnd that\u2019s it. With your centered navigation in hand, you can finally enjoy those holiday toddies and uncomfortable conversations with your skeevy Uncle Eustace.", "year": "2005", "author": "Ethan Marcotte", "author_slug": "ethanmarcotte", "published": "2005-12-08T00:00:00+00:00", "url": "https://24ways.org/2005/centered-tabs-with-css/", "topic": "code"}
{"rowid": 310, "title": "Fairytale of new Promise", "contents": "There are only four good Christmas songs.\nI know, yeah, JavaScript or whatever. We\u2019ll get to that in a minute, I promise.\nFirst\u2014and I cannot stress this enough\u2014 there are four good Christmas songs. You\u2019re free to disagree with me here, of course, but please try to understand that you will be wrong.\nThey don\u2019t all have the most safe-for-work titles; I can\u2019t list all of them here, but if you choose to let your fingers do the walkin\u2019 to your nearest search engine, I will say that one was released by the band FEAR way back in 1982 and one was on Run the Jewels\u2019 self-titled debut album. The lyrics are a hell of a lot worse than the titles, so maybe wait until you get home from work before you queue them up. Wear headphones, if you\u2019ve got thin walls.\nFor my money, though, the two I can reference by name are the top of that small heap: Tom Waits\u2019 Christmas Card from a Hooker in Minneapolis, and The Pogues\u2019 Fairytale of New York. The former once held the honor of being the only good Christmas song\u2014about which which I was also unequivocally correct, right up until I changed my mind. It\u2019s not the song up for discussion today, but feel free to familiarize yourself just the same\u2014I\u2019ll wait.\nFairytale of New York\u2014the top of the list\u2014starts out by hinting at some pretty standard holiday fare; dreams and cheer and whatnot. Typical seasonal stuff, so long as you ignore that the story seems to be recounted as a drunken flashback in a jail cell. You can probably make a few guesses at the underlying spirit of the song based on that framing: following a lucky break, our bright-eyed protagonists move to New York in search of fame and fortune, only to quickly descend into bad decisions, name-calling, and vaguely festive chaos.\nThis song speaks to me on a couple of levels, not the least of which is as a retelling of my day-to-day interactions with JavaScript. Each day\u2019s melody might vary a little bit, granted, but the lyrics almost always follow a pretty clear arc toward \u201cPARENTAL ADVISORY: EXPLICIT CONTENT.\u201d You might have heard a similar tune yourself; it goes a little somethin\u2019 like setTimeout(function() { console.log( \"this should be happening last\" ); }, 1000); . Callbacks are calling callbacks calling callbacks and something is happening somewhere, as the JavaScript interpreter plods through our code start-to-finish, line-by-line, step-by-step. If we need to take actions based on the results of something that could take its sweet time resolving, well, we\u2019d better fiddle with the order of things to make sure those actions don\u2019t happen too soon.\n\u201cBut I can see a better time,\u201d as the song says, \u201cwhen all our dreams come true.\u201d So, with that Pogues brand of holiday spirit squarely in mind\u2014by which I mean that your humble narrator is almost certainly drunk, and may be incarcerated at the time of publication\u2014gather \u2019round for a story of hope, of hardships, of semi-asynchronous JavaScript programming, and ultimately: of Promise unfulfilled.\nThe Main Thread\nJavaScript is single-minded, in a manner of speaking. Anything we tell the JavaScript runtime to do goes into a single-file queue; you\u2019ll see it referred to as the \u201cmain thread,\u201d or \u201cUI thread.\u201d That thread can be shared by a number of critical browser processes, like rendering and re-rendering parts of the page, and user interactions ranging from the simple\u2014say, highlighting text\u2014to the more complex\u2014interacting with form elements.\nIf that sounds a little scary to you, well, that\u2019s because it is. The more complex our scripts, the more we\u2019re cramming into that single-file main thread, to be processed along with\u2014say\u2014some of our CSS animations. Too much JavaScript clogging up the main thread means a lot of user-facing performance jankiness. Getting away from that single thread is a big part of all the excitement around Web Workers, which allow us to offload entire scripts into their own dedicated background threads\u2014though not without limitations of their own. Outside of Web Workers, that everything-thread is the only game in town: scripts executed one thing at a time, functions calling functions calling functions, taking numbers and crowding up the same deli counter as a user\u2019s interactions\u2014which, in this already strained metaphor, would be ham, I guess?\nAsynchronous JavaScript\nNow, those queued actions may include asynchronous things. For example: AJAX callbacks, setTimeout/setInterval, and addEventListener won\u2019t block the main thread while we\u2019re waiting for a request to come back, a timer to tick away, or an event to trigger. Once those things do kick in, though, the actions they\u2019re meant to perform will get shuffled right back into that single-thread queue.\nThere are a couple of places you might have written asynchronously-fired JavaScript, even if you\u2019re not super familiar with the overarching concept: XMLHttpRequest\u2014\u201cAJAX,\u201d if ya nasty\u2014or just kicking off a function once a user triggers a click or mouseenter event. Event-driven development is writ a little larger, with the overall flow of the script dictated by events, both internal and external. Writing event-driven JavaScript applications is a step in the right direction for sure\u2014it won\u2019t cure what ails the main thread, but it does work with the medium in a reasonable way. Event-driven development allows us to manage our use of the main thread in a way that makes sense. If any of this rings a bell for you, the motivation for Promises should feel familiar.\nFor example, a custom init event might kick things off, and fire a create event that applies our classes and restructures our markup which, on completion, fires a bindEvents event to handle all the event listeners for user interaction. There might not sound like much difference between that and one big function that kicks off, manipulates the DOM, and binds our events line-by-line\u2014but in a script of sufficient size and complexity we\u2019re not only provided with a decoupled flow through the script, but obvious touchpoints for future updates and a predictable structure for ongoing maintenance. \nThis pattern falls apart a little where we were still creating, binding, and listening for events in the same top-to-bottom, one-item-at-a-time way\u2014we had to set a listener on a given object before the event fires, or nothing would happen:\n// Create the event:\nvar event = document.createEvent( \"Event\" );\n\n// Name the event:\nevent.initEvent( \"doTheStuff\", true, true );\n\n// Listen for the custom `doTheStuff` event on `window`:\nwindow.addEventListener( \"doTheStuff\", initializeEverything );\n\n// Fire the custom event\nwindow.dispatchEvent( event );\nThis example is a little contrived, and this stuff is a lot more manageable for sure with the addition of a framework, but that\u2019s the basic gist: create and name the event, add a listener for the event, and\u2014after setting our listener\u2014dispatch the event.\nEvents and callbacks aren\u2019t the only game in town for weaving our way in and out of the main thread, though\u2014at least, not anymore. \nPromises\nA Promise is, at the risk of sounding sentimental, pure potential\u2014an empty container into which a value eventually results. A Promise can exist in several states: \u201cpending,\u201d while the computation they contain is being performed or \u201cresolved\u201d once that computation is complete. Once resolved, a Promise is \u201cfulfilled\u201d if it gave us back something we expect, or \u201crejected\u201d if it didn\u2019t.\nThe Promise constructor accepts a callback with two arguments: resolve and reject. We perform an action\u2014asynchronous or otherwise\u2014within that callback. If everything in there has gone according to plan, we call resolve. If something has gone awry, we call reject\u2014with an error, conventionally. To illustrate, let\u2019s tack something together with a pretty decent chance of doing what we don\u2019t want: a promise meant only to give us the number 1, but has a chance of giving us back a 2. No reasonable person would ever do this, of course, but I wouldn\u2019t necessarily put it past me.\nvar promisedOne = new Promise( function( resolve, reject ) {\n  var coinToss = Math.floor( Math.random() * 2 ) + 1;\n\n  if( coinToss === 1 ) {\n    resolve( coinToss );\n  } else {\n    reject( new Error( \"That ain\u2019t a one.\" ) );\n  }\n});\nThere\u2019s nothing too surprising in there, after you boil it all down. It\u2019s a little return-y, with the exception that we\u2019re flagging results as \u201cas expected\u201d or \u201csomething went wrong.\u201d\nTapping into that Promise uses another new keyword: then\u2014and as someone who attempts to make sense of JavaScript by breaking it down to plain ol\u2019 human-language, I\u2019m a big fan of this syntax. then is tacked onto our Promise identifier, and does just what it says on the tin: once the Promise is resolved, then do one of two things, both supplied as callbacks: the first in the case of a fulfilled promise, and the second in the case of a rejected one. Those two callbacks will have, as arguments, the results we specified with resolve orreject, respectively. It sounds like a lot in prose, but in code it\u2019s a pretty simple pattern:\npromisedOne.then( function( result ) {\n  console.log( result );\n}, function( error ) {\n  console.error( error );\n});\nIf you\u2019ve spent any time working with AJAX\u2014jQuery-wise, in particular\u2014you\u2019ve seen something like this pattern before: a success callback and an error callback. The state of a promise, once fulfilled or rejected, cannot be changed\u2014any reference we make to promisedOne will have a single, fixed result.\nIt may not look like too much the way I\u2019m using it here, but it\u2019s powerful stuff\u2014a pattern for asynchronously resolving anything. I\u2019ve recently used Promises alongside a script that emulates Font Load Events, to apply webfonts asynchronously and avoid a potential performance hit. Font Face Observer allows us to, as the name implies, determine when the files referenced by our @font-face rules have finished loading. \nvar fontObserver = new FontFaceObserver( \"Fancy Font\" );\n\nfontObserver.check().then(function() {\n  document.documentElement.className += \" fonts-loaded\";\n}, function( error ) {\n  console.error( error );\n});\nfontObserver.check() gives us back a Promise, allowing us to chain on a then containing our callbacks for success and failure. We use the fulfilled callback to bolt a class onto the page once the font file has been fully transferred. We don\u2019t bother including an argument in the first function, since we don\u2019t care about the result itself so much as we care that the promise resolved without error\u2014we\u2019re not doing anything with the resolved value, just adding a class to the page. We do include the error argument, since we\u2019ll want to know what happened should something go wrong.\nNow, this isn\u2019t the tidiest syntax around\u2014at least to my eyes\u2014with those two functions just kinda floating in a then. Luckily there\u2019s an similar alternative syntax; one that I find a bit easier to parse at-a-glance:\nfontObserver.check()\n  .then(function() {\n    document.documentElement.className += \" fonts-loaded\";\n  })\n  .catch(function( error ) {\n    console.log( error );\n  });\nThe first callback inside then provides us with our success state, while the catch provides us with a single, explicit \u201csomething went wrong\u201d callback. The two syntaxes aren\u2019t completely identical in all situations, but for a simple case like this, I find it a little neater.\nThe Common Thread\nI guess I still owe you an explanation, huh. Not about the JavaScript-whatever; I think I\u2019ve explained that plenty. No, I mean Fairytale of New York, and why it\u2019s perched up there at the top of the four (4) song heap.\nFairytale is a sad song, ostensibly. If you follow the main thread\u2014start to finish, line-by-line, step by step\u2014 Fairytale is a sad song. And I can see you out there, visions of Die Hard dancing in your heads: \u201cbut is it a Christmas song?\u201d\nWell, for my money, nothing says \u201cholidays\u201d quite like unreliable narration.\nShane MacGowan, the song\u2019s author, has placed the first verse about \u201cChristmas Eve in the drunk tank\u201d as happening right after the \u201clucky one, came in eighteen-to-one\u201d\u2014not at the chronological end of the story. That means the song might not be mostly drunken flashback, but all of it a single, overarching flashback including a Christmas Eve in protective custody. It could be that the man and woman are, together, recounting times long past\u2014good times and bad times\u2014maybe not even in chronological order. Hell, the \u201cNYPD Choir\u201d mentioned in the chorus? There\u2019s no such thing.\nWe\u2019re not big Christmas folks, my family and I. But just the same, every year, the handful of us get together, and every year\u2014like clockwork\u2014there\u2019s a lull in conversation, there\u2019s a sharp exhale, and Ma says \u201cwe all made it.\u201d Not to a house, not to a dinner, but through another year, to another Christmas. At this point, without fail, someone starts telling a story\u2014and one begets another, and so on. Sometimes the stories are happy, sometimes they\u2019re sad, more often than not they\u2019re both. Some are about things we were lucky to walk away from, some are about a time when another one of us didn\u2019t.\nStart-to-finish, line-by-line, step-by-step, the main thread through the year doesn\u2019t change, and maybe there isn\u2019t a whole lot we can do to change it. But by carefully weaving our way in and out of that thread\u2014stories all out of sync and resolving one way or the other, with the results determined by questionably reliable narrators\u2014we can change the way we interact with it and, little by little, we can start making sense of it.", "year": "2016", "author": "Mat Marquis", "author_slug": "matmarquis", "published": "2016-12-19T00:00:00+00:00", "url": "https://24ways.org/2016/fairytale-of-new-promise/", "topic": "code"}
{"rowid": 309, "title": "HTTP/2 Server Push and Service Workers: The Perfect Partnership", "contents": "Being a web developer today is exciting! The web has come a long way since its early days and there are so many great technologies that enable us to build faster, better experiences for our users. One of these technologies is HTTP/2 which has a killer feature known as HTTP/2 Server Push.\nDuring this year\u2019s Chrome Developer Summit, I watched a really informative talk by Sam Saccone, a Software Engineer on the Google Chrome team. He gave a talk entitled Planning for Performance, and one of the topics that he covered immediately piqued my interest; the idea that HTTP/2 Server Push and Service Workers were the perfect web performance combination.\n\nIf you\u2019ve never heard of HTTP/2 Server Push before, fear not - it\u2019s not as scary as it sounds. HTTP/2 Server Push simply allows the server to send data to the browser without having to wait for the browser to explicitly request it first. In this article, I am going to run through the basics of HTTP/2 Server Push and show you how, when combined with Service Workers, you can deliver the ultimate in web performance to your users.\nWhat is HTTP/2 Server Push?\nWhen a user navigates to a URL, a browser will make an HTTP request for the underlying web page. The browser will then scan the contents of the HTML document for any assets that it may need to retrieve such as CSS, JavaScript or images. Once it finds any assets that it needs, it will then make multiple HTTP requests for each resource that it needs and begin downloading one by one. While this approach works well, the problem is that each HTTP request means more round trips to the server before any data arrives at the browser. These extra round trips take time and can make your web pages load slower. \nBefore we go any further, let\u2019s see what this might look like when your browser makes a request for a web page. If you were to view this in the developer tools of your browser, it might look a little something like this:\n\nAs you can see from the image above, once the HTML file has been downloaded and parsed, the browser then makes HTTP requests for any assets that it needs. \nThis is where HTTP/2 Server Push comes in. The idea behind HTTP/2 Server Push is that when the browser requests a web page from the server, the server already knows about all the assets that are needed for the web page and \u201cpushes\u201d it to browser. This happens when the first HTTP request for the web page takes place and it eliminates an extra round trip, making your site faster. \nUsing the same example above, let\u2019s \u201cpush\u201d the JavaScript and CSS files instead of waiting for the browser to request them. The image below gives you an idea of what this might look like.\n\nWhoa, that looks different - let\u2019s break it down a little. Firstly, you can see that the JavaScript and CSS files appear earlier in the waterfall chart. You might also notice that the loading times for the files are extremely quick. The browser doesn\u2019t need to make an extra HTTP request to the server, instead it receives the critical files it needs all at once. Much better! \nThere are a number of different approaches when it comes to implementing HTTP/2 Server Push. Adoption is growing and many commercial CDNs such as Akamai and Cloudflare already offer support for Server Push. You can even roll your own implementation depending on your environment. I\u2019ve also previously blogged about building a basic HTTP/2 Server Push example using Node.js. In this post, I\u2019m not going to dive into how to implement HTTP/2 Server Push as that is an entire post in itself! However, I do recommend reading this article to find out more about the inner workings.\nHTTP/2 Server Push is awesome, but it isn\u2019t a magic bullet. It is fantastic for improving the load time of a web page when it first loads for a user, but it isn\u2019t that great when they request the same web page again. The reason for this is that HTTP/2 Server Push is not cache \u201caware\u201d. This means that the server isn\u2019t aware about the state of your client. If you\u2019ve visited a web page before, the server isn\u2019t aware of this and will push the resource again anyway, regardless of whether or not you need it. HTTP/2 Server Push effectively tells the browser that it knows better and that the browser should receive the resources whether it needs them or not. In theory browsers can cancel HTTP/2 Server Push requests if they\u2019re already got something in cache but unfortunately no browsers currently support it. The other issue is that the server will have already started to send some of the resource to the browser by the time the cancellation occurs.\nHTTP/2 Server Push & Service Workers\nSo where do Service Workers fit in? Believe it or not, when combined together HTTP/2 Server Push and Service Workers can be the perfect web performance partnership. If you\u2019ve not heard of Service Workers before, they are worker scripts that run in the background of your website. Simply put, they act as middleman between the client and the browser and enable you to intercept any network requests that come and go from the browser. They are packed with useful features such as caching, push notifications, and background sync. Best of all, they are written in JavaScript, making it easy for web developers to understand.\nUsing Service Workers, you can easily cache assets on a user\u2019s device. This means when a browser makes an HTTP request for an asset, the Service Worker is able to intercept the request and first check if the asset already exists in cache on the users device. If it does, then it can simply return and serve them directly from the device instead of ever hitting the server.\nLet\u2019s stop for a second and analyse what that means. Using HTTP/2 Server Push, you are able to push critical assets to the browser before the browser requests them. Then, using Service Workers you are able to cache these resources so that the browser never needs to make a request to the server again. That means a super fast first load and an even faster second load!\nLet\u2019s put this into action. The following HTML code is a basic web page that retrieves a few images and two JavaScript files.\n<!DOCTYPE html>\n<html>\n<head>\n  <meta charset=\"UTF-8\">\n  <title>HTTP2 Push Demo</title>\n</head>\n<body>\n  <h1>HTTP2 Push</h1>\n  <img src=\"./images/beer-1.png\" width=\"200\" height=\"200\" />\n  <img src=\"./images/beer-2.png\" width=\"200\" height=\"200\" />\n  <br>\n  <br>\n  <img src=\"./images/beer-3.png\" width=\"200\" height=\"200\" />\n  <img src=\"./images/beer-4.png\" width=\"200\" height=\"200\" />\n  <!-- Scripts -->\n  <script async src=\"./js/promise.min.js\"></script>\n  <script async src=\"./js/fetch.js\"></script>\n  <script>\n  // Register the service worker\n  if ('serviceWorker' in navigator) {\n    navigator.serviceWorker.register('./service-worker.js').then(function(registration) {\n      // Registration was successful\n      console.log('ServiceWorker registration successful with scope: ', registration.scope);\n    }).catch(function(err) {\n      // registration failed :(\n      console.log('ServiceWorker registration failed: ', err);\n    });\n  }\n  </script>\n</body>\n</html>\nIn the HTML code above, I am registering a Service Worker file named service-worker.js. In order to start caching assets, I am going to use the Service Worker toolbox . It is a lightweight helper library to help you get started creating your own Service Workers. Using this library, we can actually cache the base web page with the path /push.\nThe Service Worker Toolbox comes with a built-in routing system which is based on the same routing as Express. With just a few lines of code, you can start building powerful caching patterns.\nI\u2019ve add the following code to the service-worker.js file.\n(global => {\n  'use strict';\n\n  // Load the sw-toolbox library.\n  importScripts('/js/sw-toolbox/sw-toolbox.js');\n\n  // The route for any requests\n  toolbox.router.get('/push', global.toolbox.fastest);\n\n  toolbox.router.get('/images/(.*)', global.toolbox.fastest);\n\n  toolbox.router.get('/js/(.*)', global.toolbox.fastest);\n\n  // Ensure that our service worker takes control of the page as soon as possible.\n  global.addEventListener('install', event => event.waitUntil(global.skipWaiting()));\n  global.addEventListener('activate', event => event.waitUntil(global.clients.claim()));\n})(self);\nLet\u2019s break this code down further. Around line 4, I am importing the Service Worker toolbox. Next, I am specifying a route that will listen to any requests that match the URL /push. Because I am also interested in caching the images and JavaScript for that page, I\u2019ve told the toolbox to listen to these routes too.\nThe best thing about the code above is that if any of the assets exist in cache, we will instantly return the cached version instead of waiting for it to download. If the asset doesn\u2019t exist in cache, the code above will add it into cache so that we can retrieve it when it\u2019s needed again.\nYou may also notice the code global.toolbox.fastest - this is important because gives you the compromise of fulfilling from the cache immediately, while firing off an additional HTTP request updating the cache for the next visit.\nBut what does this mean when combined with HTTP/2 Server Push? Well, it means that on the first load of the web page, you are able to \u201cpush\u201d everything to the user at once before the browser has even requested it. The Service Worker activates and starts caching the assets on the users device. The next time a user visits the page, the Service Worker will intercept the request and serve the asset directly from cache. Amazing! \nUsing this technique, the waterfall chart for a repeat visit should look like the image below.\n\nIf you look closely at the image above, you\u2019ll notice that the web page returns almost instantly without ever making an HTTP request over the network. Using the Service Worker library, we cached the base page for the route /push, which allowed us to retrieve this directly from cache.\nWhether used on their own or combined together, the best thing about these two features is that they are the perfect progressive enhancement. If your user\u2019s browser doesn\u2019t support them, they will simply fall back to HTTP/1.1 without Service Workers. Your users may not experience as fast a load time as they would with these two techniques, but it would be no different from their normal experience. HTTP/2 Server Push and Service Workers are really the perfect partners when it comes to web performance.\nSummary\nWhen used correctly, HTTP/2 Server Push and Service Workers can have a positive impact on your site\u2019s load times. Together they mean super fast first load times and even faster repeat views to a web page. Whilst this technique is really effective, it\u2019s worth noting that HTTP/2 push is not a magic bullet. Think about the situations where it might make sense to use it and don\u2019t just simply \u201cpush\u201d everything; it could actually lead to having slower page load times. If you\u2019d like to learn more about the rules of thumb for HTTP/2 Server Push, I recommend reading this article for more information. \nAll of the code in this example is available on my Github repo - if you have any questions, please submit an issue and I\u2019ll get back to you as soon as possible. \nIf you\u2019d like to learn more about this technique and others relating to HTTP/2, I highly recommend watching Sam Saccone\u2019s talk at this years Chrome Developer Summit. \nI\u2019d also like to say a massive thank you to Robin Osborne, Andy Davies and Jeffrey Posnick for helping me review this article before putting it live!", "year": "2016", "author": "Dean Hume", "author_slug": "deanhume", "published": "2016-12-15T00:00:00+00:00", "url": "https://24ways.org/2016/http2-server-push-and-service-workers/", "topic": "code"}
{"rowid": 308, "title": "How to Make a Chrome Extension to Delight (or Troll) Your Friends", "contents": "If you\u2019re like me, you grew up drawing mustaches on celebrities. Every photograph was subject to your doodling wrath, and your brilliance was taken to a whole new level with computer programs like Microsoft Paint. The advent of digital cameras meant that no one was safe from your handiwork, especially not your friends. And when you finally got your hands on Photoshop, you spent hours maniacally giggling at your artistic genius. \nBut today is different. You\u2019re a serious adult with important things to do and a reputation to uphold. You keep up with modern web techniques and trends, and have little time for fun other than a random Giphy on Slack\u2026 right? \nNope. \nIf there\u2019s one thing 2016 has taught me, it\u2019s that we\u2014the self-serious, world-changing tech movers and shakers of the universe\u2014haven\u2019t changed one bit from our younger, more delightable selves.\nHow do I know? This year I created a Chrome extension called Tabby Cat and watched hundreds of thousands of people ditch productivity for randomly generated cats. Tabby Cat replaces your new tab page with an SVG cat featuring a silly name like \u201cStinky Dinosaur\u201d or \u201cTiny Potato\u201d. Over time, the cats collect goodies that vary in absurdity from fishbones to lawn flamingos to Raybans. Kids and adults alike use this extension, and analytics show the majority of use happens Monday through Friday from 9-5. The popularity of Tabby Cat has convinced me there\u2019s still plenty of room in our big, grown-up hearts for fun.\n\n\nToday, we\u2019re going to combine the formula behind Tabby Cat with your intrinsic desire to delight (or troll) your friends, and create a web app that generates your friends with random objects and environments of your choosing. You can publish it as a Chrome extension to replace your new tab, or simply host it as a website and point to it with the New Tab Redirect extension. \nHere\u2019s a sneak peek at my final result featuring my partner, my cat, and I in cheerfully weird accessories. Your result will look however you want it to.\n\nAlong the way, we\u2019ll cover how to build a Chrome extension that replaces the new tab page, and explore ways to program randomness into your work to create something truly delightful. \nWhat you\u2019ll need\n\nAdobe Illustrator (or a similar illustration program to export PNG)\nSome images of your friends\nA text editor\n\nNote: This can be as simple or as complex as you want it to be. Most of the application is pre-built so you can focus on kicking back and getting in touch with your creative side. If you want to dive in deeper, you\u2019ll find ways to do it.\nGetting started\n\nDownload a local copy of the boilerplate for today\u2019s tutorial here, and open it in a text editor. Inside, you\u2019ll find a simple web app that you can run in Chrome. \nOpen index.html in Chrome. You should see a grey page that says \u201cNoname\u201d.\nOpen template.pdf in Adobe Illustrator or a similar program that can export PNG. The file contains an artboard measuring 800px x 800px, with a dotted blue outline of a face. This is your template.\n\nNote: We\u2019re using Google Chrome to build and preview this application because the end-result is a Chrome extension. This means that the application isn\u2019t totally cross-browser compatible, but that\u2019s okay.\nStep 1: Gather your friends\nThe first thing to do is choose who your muses are. Since the holidays are upon us, I\u2019d suggest finding inspiration in your family.\nCreate your artwork\nFor each person, find an image where their face is pointed as forward as possible. Place the image onto the Artwork layer of the Illustrator file, and line up their face with the template. Then, rename the artboard something descriptive like face_bob. Here\u2019s my crew:\nAs you can see, my use of the word \u201cfamily\u201d extends to cats. There\u2019s no judgement here.\nNotice that some of my photos don\u2019t completely fill the artboard\u2013that\u2019s fine. The images will be clipped into ovals when they\u2019re rendered in the application.\nNow, export your images by following these steps:\n\nTurn the Template layer off and export the images as PNGs. \nIn the Export dialog, tick the \u201cUse Artboards\u201d checkbox and enter the range with your faces. \nExport at 72ppi to keep things running fast. \nSave your images into the images/ folder in your project.\n\nAdd your images to config.js\nOpen scripts/config.js. This is where you configure your extension. \nAdd key value pairs to the faces object. The key should be the person\u2019s name, and the value should be the filepath to the image.\nfaces: {\n    leslie: 'images/face_leslie.png',\n    kyle: 'images/face_kyle.png',\n    beep: 'images/face_beep.png'\n}\nThe application will choose one of these options at random each time you open a new tab. This pattern is used for everything in the config file. You give the application groups of choices, and it chooses one at random each time it loads. The only thing that\u2019s special about the faces object is that person\u2019s name will also be displayed when their face is chosen.\nNow, when you refresh the project in Chrome, you should see one of your friends along with their name, like this:\n\nCongrats, you\u2019re off and running!\nStep 2: Add adjectives\nNow that you\u2019ve loaded your friends into the application, it\u2019s time to call them names. This step definitely yields the most laughs for the least amount of effort.\nAdd a list of adjectives into the prefixes array in config.js. To get the words flowing, I took inspiration from ways I might describe some of my relatives during a holiday gathering\u2026\nprefixes: [\n    'Loving',\n    'Drunk',\n    'Chatty',\n    'Merry',\n    'Creepy',\n    'Introspective',\n    'Cheerful',\n    'Awkward',\n    'Unrelatable',\n    'Hungry',\n    ...\n]\nWhen you refresh Chrome, you should see one of these words prefixed before your friend\u2019s name. Voila!\n\nStep 3: Choose your color palette\nReal talk: I\u2019m bad at choosing color palettes, so I have a trick up my sleeve that I want to share with you. If you\u2019ve been blessed with the gift of color aptitude, skip ahead.\nHow to choose colors\nTo create a color palette, I start by going to a Coolors.co, and I hit the spacebar until I find a palette that I like. We need a wide gamut of hues for our palette, so lock down colors you like and keep hitting the spacebar until you find a nice, full range. You can use as many or as few colors as you like.\nCopy these colors into your swatches in Adobe Illustrator. They\u2019ll be the base for any illustrations you create later.\nNow you need a set of background colors. Here\u2019s my trick to making these consistent with your illustration palette without completely blending in. Use the \u201cAdjust Palette\u201d tool in Coolors to dial up the brightness a few notches, and the saturation down just a tad to remove any neon effect. These will be your background colors.\n\nAdd your background colors to config.js\nCopy your hex codes into the bgColors array in config.js.\nbgColors: [\n    '#FFDD77',\n    '#FF8E72',\n    '#ED5E84',\n    '#4CE0B3',\n    '#9893DA',\n    ...\n]\nNow when you go back to Chrome and refresh the page, you\u2019ll see your new palette!\n\nStep 4: Accessorize\nThis is the fun part. We\u2019re going to illustrate objects, accessories, lizards\u2014whatever you want\u2014and layer them on top of your friends.\nYour objects will be categorized into groups, and one option from each group will be randomly chosen each time you load the page. Think of a group like \u201chats\u201d or \u201cglasses\u201d. This will allow combinations of accessories to show at once, without showing two of the same type on the same person.\nCreate a group of accessories\nTo get started, open up Illustrator and create a new artboard out of the template. Think of a group of objects that you can riff on. I found hats to be a good place to start. If you don\u2019t feel like illustrating, you can use cut-out images instead.\n\nNext, follow the same steps as you did when you exported the faces. Here they are again:\n\nTurn the Template layer off and export the images as PNGs. \nIn the Export dialog, tick the \u201cUse Artboards\u201d checkbox and enter the range with your hats. \nExport at 72ppi to keep things running fast. \nSave your images into the images/ folder in your project.\n\nAdd your accessories to config.js\nIn config.js, add a new key to the customProps object that describes the group of accessories that you just created. Its value should be an array of the filepaths to your images. This is my hats array:\ncustomProps: {\n    hats: [     \n        'images/hat_crown.png',\n        'images/hat_santa.png',\n        'images/hat_tophat.png',\n        'images/hat_antlers.png'\n    ]\n}\nRefresh Chrome and behold, accessories!\n\nCreate as many more accessories as you want\nRepeat the steps above to create as many groups of accessories as you want. I went on to make glasses and hairstyles, so my final illustrator file looks like this:\n\nThe last step is adding your new groups to the config object. List your groups in the order that you want them to be stacked in the DOM. My final output will be hair, then hats, then glasses:\ncustomProps: {\n    hair: [     \n        'images/hair_bowl.png',\n        'images/hair_bob.png'\n    ],  \n    hats: [     \n        'images/hat_crown.png',\n        'images/hat_santa.png',\n        'images/hat_tophat.png',\n        'images/hat_antlers.png'\n    ],\n    glasses: [\n        'images/glasses_aviators.png',\n        'images/glasses_monacle.png'\n    ]\n}\nAnd, there you have it! Randomly generated friends with random accessories. \n\nFeel free to go much crazier than I did. I considered adding a whole group of animals in celebration of the new season of Planet Earth, or even adding Sir David Attenborough himself, or doing a bit of role reversal and featuring the animals with little safari hats! But I digress\u2026\nStep 5: Publish it\nIt\u2019s time to put this in your new tabs! You have two options:\n\nPublish it as a Chrome extension in the Chrome Web Store.\nHost it as a website and point to it with the New Tab Redirect extension.\n\nToday, we\u2019re going to cover Option #1 because I want to show you how to make the simplest Chrome extension possible. However, I recommend Option #2 if you want to keep your project private. Every Chrome extension that you publish is made publicly available, so unless your friends want their faces published to an extension that anyone can use, I\u2019d suggest sticking to Option #2.\nHow to make a simple Chrome extension to replace the new tab page\nAll you need to do to make your project into a Chrome extension is add a manifest.json file to the root of your project with the following contents. There are plenty of other properties that you can add to your manifest file, but these are the only ones that are required for a new tab replacement:\n{\n    \"manifest_version\": 2,\n    \"name\": \"Your extension name\",\n    \"version\": \"1.0\",\n    \"chrome_url_overrides\" : {\n        \"newtab\": \"index.html\"\n    }\n}\nTo test your extension, you\u2019ll need to run it in Developer Mode. Here\u2019s how to do that:\n\nGo to the Extensions page in Chrome by navigating to chrome://extensions/.\nTick the checkbox in the upper-right corner labelled \u201cDeveloper Mode\u201d.\nClick \u201cLoad unpacked extension\u2026\u201d and select this project.\nIf everything is running smoothly, you should see your project when you open a new tab. If there are any errors, they should appear in a yellow box on the Extensions page.\n\nVoila! Like I said, this is a very light example of a Chrome extension, but Google has tons of great documentation on how to take things further. Check it out and see what inspires you.\nShare the love\nNow that you know how to make a new tab extension, go forth and create! But wield your power responsibly. New tabs are opened so often that they\u2019ve become a part of everyday life\u2013just consider how many tabs you opened today. Some people prefer to-do lists in their tabs, and others prefer cats. \nAt the end of the day, let\u2019s make something that makes us happy. Cheers!", "year": "2016", "author": "Leslie Zacharkow", "author_slug": "lesliezacharkow", "published": "2016-12-08T00:00:00+00:00", "url": "https://24ways.org/2016/how-to-make-a-chrome-extension/", "topic": "code"}
{"rowid": 307, "title": "Get the Balance Right: Responsive Display Text", "contents": "Last year in 24 ways I urged you to Get Expressive with Your Typography. I made the case for grabbing your readers\u2019 attention by setting text at display sizes, that is to say big. You should consider very large text in the same way you might a hero image: a picture that creates an atmosphere and anchors your layout.\nWhen setting text to be read, it is best practice to choose body and subheading sizes from a pre-defined scale appropriate to the viewport dimensions. We set those sizes using rems, locking the text sizes together so they all scale according to the page default and your reader\u2019s preferences.  You can take the same approach with display text by choosing larger sizes from the same scale.\nHowever, display text, as defined by its purpose and relative size, is text to be seen first, and read second. In other words a picture of text. When it comes to pictures, you are likely to scale all scene-setting imagery - cover photos, hero images, and so on - relative to the viewport. Take the same approach with display text: lock the size and shape of the text to the screen or browser window.\nIntroducing viewport units\nWith CSS3 came a new set of units which are locked to the viewport. You can use these viewport units wherever you might otherwise use any other unit of length such as pixels, ems or percentage. There are four viewport units, and in each case a value of 1 is equal to 1% of either the viewport width or height as reported in reference1 pixels:\n\nvw - viewport width,\nvh - viewport height,\nvmin - viewport height or width, whichever is smaller\nvmax - viewport height or width, whichever is larger\n\nIn one fell swoop you can set the size of a display heading to be proportional to the screen or browser width, rather than choosing from a scale in a series of media queries. The following makes the heading font size 13% of the viewport width:\nh1 {\n    font-size: 13 vw;\n}\nSo for a selection of widths, the rendered font size would be:\nRendered font size (px)\nViewport width\n13\u202fvw\n320\n42\n768\n100\n1024\n133\n1280\n166\n1920\n250\n\nA problem with using vw in this manner is the difference in text block proportions between portrait and landscape devices. Because the font size is based on the viewport width, the text on a landscape display is far bigger than when rendered on the same device held in a portrait orientation. \nLandscape text is much bigger than portrait text when using vw units.\nThe proportions of the display text relative to the screen are so dissimilar that each orientation has its own different character, losing the inconsistency and considered design you would want when designing to make an impression.\nHowever if the text was the same size in both orientations, the visual effect would be much more consistent. This where vmin comes into its own. Set the font size using vmin and the size is now set as a proportion of the smallest side of the viewport, giving you a far more consistent rendering.\nh1 {\n    font-size: 13vmin;\n}\nLandscape text is consistent with portrait text when using vmin units.\nComparing vw and vmin renderings for various common screen dimensions, you can see how using vmin keeps the text size down to a usable magnitude:\nRendered font size (px)\nViewport\n13\u202fvw\n13\u202fvmin\n320 \u00d7 480\n42\n42\n414 \u00d7 736\n54\n54\n768 \u00d7 1024\n100\n100\n1024 \u00d7 768\n133\n100\n1280 \u00d7 720\n166\n94\n1366 \u00d7 768\n178\n100\n1440 \u00d7 900\n187\n117\n1680 \u00d7 1050\n218\n137\n1920 \u00d7 1080\n250\n140\n2560 \u00d7 1440\n333\n187\n\nHybrid font sizing\nUsing vertical media queries to set text in direct proportion to screen dimensions works well when sizing display text. In can be less desirable when sizing supporting text such as sub-headings, which you may not want to scale upwards at the same rate as the display text. For example, we can size a subheading using vmin so that it starts at 16 px on smaller screens and scales up in the same way as the main heading:\nh1 {\n    font-size: 13vmin;\n}\nh2 {\n    font-size: 5vmin;\n}\nUsing vmin alone for supporting text can scale it too quickly\nThe balance of display text to supporting text on the phone works well, but the subheading text on the tablet, even though it has been increased in line with the main heading, is starting to feel disproportionately large and a little clumsy. This problem becomes magnified on even bigger screens.\nA solution to this is use a hybrid method of sizing text2. We can use the CSS calc() function to calculate a font size simultaneously based on both rems and viewport units. For example:\nh2 {\n    font-size: calc(0.5rem + 2.5vmin);\n}\nFor a 320 px wide screen, the font size will be 16 px, calculated as follows:\n(0.5 \u00d7 16) + (320 \u00d7 0.025) = 8 + 8 = 16px\nFor a 768 px wide screen, the font size will be 27 px:\n(0.5 \u00d7 16) + (768 \u00d7 0.025) = 8 + 19 = 27px\nThis results in a more balanced subheading that doesn\u2019t take emphasis away from the main heading:\n\nTo give you an idea of the effect of using a hybrid approach, here\u2019s a side-by-side comparison of hybrid and viewport text sizing:\ntable.ex--scale{width:100%;overflow: hidden;} table.ex--scale td{vertical-align:baseline;text-align:center;padding:0} tr.ex--scale-key{color:#666} tr.ex--scale-key td{font-size:.875rem;padding:0 0.125em} .ex--scale-2 tr.ex--scale-size{color:#ccc} tr.ex--scale-size td{font-size:1em;line-height:.34em;padding-bottom:.5rem} td.ex--scale-step{color:#000} td.ex--scale-hilite{color:red} .ex--scale-3 tr.ex--scale-size td{line-height:.9em}\n\ntop: calc() hybrid method; bottom: vmin only\n16\n20\n27\n32\n35\n40\n44\n16\n24\n38\n48\n54\n64\n72\n320\n480\n768\n960\n1080\n1280\n1440\n\nOver this festive period, try experiment with the proportion of rem and vmin in your hybrid calculation to see what feels best for your particular setting.\n\n\n\n\nA reference pixel is based on the logical resolution of a device which takes into account double density screens such as Retina displays.\u00a0\u21a9\ufe0e\n\n\nFor even more sophisticated uses of hybrid text sizing see the work of Mike Riethmuller.\u00a0\u21a9\ufe0e", "year": "2016", "author": "Richard Rutter", "author_slug": "richardrutter", "published": "2016-12-09T00:00:00+00:00", "url": "https://24ways.org/2016/responsive-display-text/", "topic": "code"}
{"rowid": 306, "title": "What next for CSS Grid Layout?", "contents": "In 2012 I wrote an article for 24 ways detailing a new CSS Specification that had caught my eye, at the time with an implementation only in Internet Explorer. What I didn\u2019t realise at the time was that CSS Grid Layout was to become a theme on which I would base the next four years of research, experimentation, writing and speaking. \nAs I write this article in December 2016, we are looking forward to CSS Grid Layout being shipped in Chrome and Firefox. What will ship early next year in those browsers is expanded and improved from the early implementation I explored in 2012. Over the last four years the spec has been developed as part of the CSS Working Group process, and has had input from browser engineers, specification writers and web developers. Use cases have been discussed, and features added.\nThe CSS Grid Layout specification is now a Candidate Recommendation. This status means the spec is to all intents and purposes, finished. The discussions now happening are on fine implementation details, and not new feature ideas. It makes sense to draw a line under a specification in order that browser vendors can ship complete, interoperable implementations. That approach is good for all of us, it makes development far easier if we know that a browser supports all of the features of a specification, rather than working out which bits are supported. However it doesn\u2019t mean that works stops here, and that new use cases and features can\u2019t be proposed for future levels of Grid Layout. Therefore, in this article I\u2019m going to take a look at some of the things I think grid layout could do in the future. I would love for these thoughts to prompt you to think about how Grid - or any CSS specification - could better suit the use cases you have.\nSubgrid - the missing feature of Level 1\nThe implementation of CSS Grid Layout in Chrome, Firefox and Webkit is comparable and very feature complete. There is however one standout feature that has not been implemented in any browser as yet - subgrid. Once you set the value of the display property to grid, any direct children of that element become grid items. This is similar to the way that flexbox behaves, set display: flex and all direct children become flex items. The behaviour does not apply to children of those items. You can nest grids, just as you can nest flex containers, but the child grids have no relationship to the parent.\n\nNesting Grids by Rachel Andrew (@rachelandrew) on CodePen.\nThe subgrid behaviour would enable the grid defined on the parent to be used by the children. I feel this would be most useful when working with a multiple column flexible grid - for example a typical 12 column grid. I could define a grid on a wrapper, then position UI elements on that grid - from the major structural elements of my page down through the child elements to a form where I wanted the field to line up with items above.\nThe specification contained an initial description of subgrid, with a value of subgrid for grid-template-columns and grid-template-rows, you can read about this in the August 2015 Working Draft. This version of the specification would have meant you could declare a subgrid in one dimension only, and create a different set of tracks in the other.\nIn an attempt to get some implementation of subgrid, a revised specification was proposed earlier this year. This gives a single subgrid value of the display property. As we now cannot specify a subgrid on rows OR columns this limits us to have a subgrid that works in two dimensions. At this point neither version has been implemented by anyone, and subgrids are marked as \u201cat risk\u201d in the Level 1 Candidate Recommendation. With regard to \u2018at-risk\u2019 this is explained as follows:\n\n\u201c\u2018At-risk\u2019 is a W3C Process term-of-art, and does not necessarily imply that the feature is in danger of being dropped or delayed. It means that the WG believes the feature may have difficulty being interoperably implemented in a timely manner, and marking it as such allows the WG to drop the feature if necessary when transitioning to the Proposed Rec stage, without having to publish a new Candidate Rec without the feature first.\u201d \n\nIf we lose subgrid from Level 1, as it looks likely that we will, this does give us a chance to further discuss and iterate on that feature. My current thoughts are that I\u2019m not completely happy about subgrids being tied to both dimensions and feel that a return to the earlier version, or something like it, would be preferable. \nFurther reading about subgrid\n\nMy post from 2015 detailing why I feel subgrid is important\nMy post based on the revised specification\nEric Meyer\u2019s thoughts on subgrid\nWrite-up of a discussion from Igalia who work on the Blink and Webkit browser implementations\n\nStyling cells, tracks and areas\nHaving defined a grid with CSS Grid Layout you can place child elements into that grid, however what you can\u2019t do is style the grid tracks or cells. Grid doesn\u2019t even go as far as multiple column layout, which has the column-rule properties.\nIn order to set a background colour on a grid cell at the moment you would have to add an empty HTML element or insert some generated content as in the below example. I\u2019m using a 1 pixel grid gap to fake lines between grid cells, and empty div elements, and some generated content to colour those cells.\n\nFaked backgrounds and borders by Rachel Andrew (@rachelandrew) on CodePen.\nI think it would be a nice addition to Grid Layout to be able to directly add backgrounds and borders to cells, tracks and areas. There is an Issue raised in the CSS WG Drafts repository for Decorative Grid Cell pseudo-elements, if you want to add thoughts to that.\nMore control over auto placement\nIf you haven\u2019t explicitly placed the direct children of your grid element they will be laid out according to the grid auto placement rules. You can see in this example how we have created a grid and the items are placing themselves into cells on that grid.\n\nItems auto-place on a defined grid by Rachel Andrew (@rachelandrew) on CodePen.\nThe auto-placement algorithm is very cool. We can position some items, leaving others to auto-place; we can set items to span more than one track; we can use the grid-auto-flow property with a value of dense to backfill gaps in our grid.\n\nWebsafe colors meet CSS Grid (auto-placement demo) by Rachel Andrew (@rachelandrew) on CodePen.\nI think however this could be taken further. In this issue posted to my CSS Grid AMA on GitHub, the question is raised as to whether it would be possible to ask grid to place items on the next available line of a certain name. This would allow you to skip tracks in the grid when using auto-placement, an issue that has also been raised by Emil Bj\u00f6rklund in this post to the www-style list prior to spec discussion moving to Github. I think there are probably similar issues, if you can think of one add a comment here.\nCreating non-rectangular grid areas\nA grid area is a collection of grid cells, defined by setting the start and end lines for columns and rows or by creating the area in the value of the grid-template-areas property as shown below. Those areas however must be rectangular - you can\u2019t create an L-shaped or otherwise non-regular shape.\n\nGrid Areas by Rachel Andrew (@rachelandrew) on CodePen.\n\nPerhaps in the future we could define an L-shape or other non-rectangular area into which content could flow, as in the below currently invalid code where a quote is embedded into an L-shaped content area.\n.wrapper {\n  display: grid;\n  grid-template-areas:\n      \"sidebar header  header\"\n      \"sidebar content quote\"\n      \"sidebar content content\";\n}\nFlowing content through grid cells or areas\nSome uses cases I have seen perhaps are not best solved by grid layout at all, but would involve grid working alongside other CSS specifications. As I detail in this post, there are a class of problems that I believe could be solved with the CSS Regions specification, or a revised version of that spec.\nBeing able to create a grid layout, then flow content through the areas could be very useful. Jen Simmons presented to the CSS Working Group at the Lisbon meeting a suggestion as to how this might work.\nIn a post from earlier this year I looked at a collection of ideas from specifications that include Grid, Regions and Exclusions. These working notes from my own explorations might prompt ideas of your own.\nSolving the keyboard/layout disconnect\nOne issue that grid, and flexbox to a lesser extent, raises is that it is very easy to end up with a layout that is disconnected from the underlying markup. This raises problems for people navigating using the keyboard as when tabbing around the document you find yourself jumping to unexpected places. The problem is explained by L\u00e9onie Watson with reference to flexbox in Flexbox and the keyboard navigation disconnect.\nThe grid layout specification currently warns against creating such a disconnect, however I think it will take careful work by web developers in order to prevent this. It\u2019s also not always as straightforward as it seems. In some cases you want the logical order to follow the source, and others it would make more sense to follow the visual. People are thinking about this issue, as you can read in this mailing list discussion.\nBringing your ideas to the future of Grid Layout\nWhen I\u2019m not getting excited about new CSS features, my day job involves working on a software product - the CMS that is serving this very website, Perch. When we launched Perch there were many use cases that we had never thought of, despite having a good idea of what might be needed in a CMS and thinking through lots of use cases. The additional use cases brought to our attention by our customers and potential customers informed the development of the product from launch. The same will be true for Grid Layout.\nAs a \u201cproduct\u201d grid has been well thought through by many people. Yet however hard we try there will be use cases we just didn\u2019t think of. You may well have one in mind right now. That\u2019s ok, because as with any CSS specification, once Level One of grid  is complete, work can begin on Level Two. The feature set of Level Two will be informed by the use cases that emerge as people get to grips with what we have now.\nThis is where you get to contribute to the future of layout on the web. When you hit up against the things you cannot do, don\u2019t just mutter about how the CSS Working Group don\u2019t listen to regular developers and code around the problem. Instead, take a few minutes and write up your use case. Post it to your blog, to Medium, create a CodePen and go to the CSS Working Group GitHub specs repository and post an issue there. Write some pseudo-code, draw a picture, just make sure that the use case is described in enough detail that someone can see what problem you want grid to solve. It may be that - as with any software development - your use case can\u2019t be solved in exactly the way you suggest. However once we have a use case, collected with other use cases, methods of addressing that class of problems can be investigated. \nI opened this article by explaining I\u2019d written about grid layout four years ago, and how we\u2019re only now at a point where we will have Grid Layout available in the majority of browsers. Specification development, and implementation into browsers takes time. This is actually a good thing, as it\u2019s impossible to take back CSS once it is out there and being used by production websites. We want CSS in the wild to be well thought through and that takes time. So don\u2019t feel that because you don\u2019t see your use case added to a spec immediately it has been ignored. Do your future self a favour and write down your frustrations or thoughts, and we can all make sure that the web platform serves the use cases we\u2019re dealing with now and in the future.", "year": "2016", "author": "Rachel Andrew", "author_slug": "rachelandrew", "published": "2016-12-12T00:00:00+00:00", "url": "https://24ways.org/2016/what-next-for-css-grid-layout/", "topic": "code"}
{"rowid": 305, "title": "CSS Writing Modes", "contents": "Since you may not have a lot of time, I\u2019m going to start at the end, with the dessert.\nYou can use a little-known, yet important and powerful CSS property to make text run vertically. Like this.\n\nOr instead of running text vertically, you can layout a set of icons or interface buttons in this way. Or, of course, with anything on your page.  \nThe CSS I\u2019ve applied makes the browser rethink the orientation of the world, and flow the layout of this element at a 90\u00b0 angle to \u201cnormal\u201d. Check out the live demo, highlight the headline, and see how the cursor is now sideways.\nSee the Pen Writing Mode Demo \u2014 Headline by Jen Simmons (@jensimmons) on CodePen.\n\nThe code for accomplishing this is pretty simple. \nh1 { \n  writing-mode: vertical-rl;\n}\nThat\u2019s all it takes to switch the writing mode from the web\u2019s default horizontal top-to-bottom mode to a vertical right-to-left mode. If you apply such code to the html element, the entire page is switched, affecting the scroll direction, too. \nIn my example above, I\u2019m telling the browser that only the h1 will be in this vertical-rl mode, while the rest of my page stays in the default of horizontal-tb.\nSo now the dessert course is over. Let me serve up this whole meal, and explain the the CSS Writing Mode Specification.\nWhy learn about writing modes?\nThere are three reasons I\u2019m teaching writing modes to everyone\u2014including western audiences\u2014and explaining the whole system, instead of quickly showing you a simple trick.\n\n\nWe live in a big, diverse world, and learning about other languages is fascinating. Many of you lay out pages in languages like Chinese, Japanese and Korean. Or you might be inspired to in the future.\n\n\nUsing writing-mode to turn bits sideways is cool. This CSS can be used in all kinds of creative ways, even if you are working only in English.\n\nMost importantly, I\u2019ve found understanding Writing Modes incredibly helpful when understanding Flexbox and CSS Grid. Before I learned Writing Mode, I felt like there was still a big hole in my knowledge, something I just didn\u2019t get about why Grid and Flexbox work the way they do. Once I wrapped my head around Writing Modes, Grid and Flexbox got a lot easier. Suddenly the Alignment properties, align-* and justify-*, made sense.\n\nWhether you know about it or not, the writing mode is the first building block of every layout we create. You can do what we\u2019ve been doing for 25 years \u2013 and leave your page set to the default left-to-right direction, horizontal top-to-bottom writing mode. Or you can enter a world of new possibilities where content flows in other directions.\nCSS properties\nI\u2019m going to focus on the CSS writing-mode property in this article. It has five possible options:\n  writing-mode: horizontal-tb;\n  writing-mode: vertical-rl;\n  writing-mode: vertical-lr;\n  writing-mode: sideways-rl;\n  writing-mode: sideways-lr;\nThe CSS Writing Modes Specification is designed to support a wide range of written languages in all our human and linguistic complexity. Which\u2014spoiler alert\u2014is pretty insanely complex. The global evolution of written languages has been anything but simple. \nSo I\u2019ve got to start with explaining some basic concepts of web page layout and writing systems. Then I can show you what these CSS properties do. \nInline Direction, Block Direction, and Character Direction\nIn the world of the web, there\u2019s a concept of \u2018block\u2019 and \u2018inline\u2019 layout. If you\u2019ve ever written display: block or display: inline, you\u2019ve leaned on these concepts.  \nIn the default writing mode, blocks stack vertically starting at the top of the page and working their way down. Think of how a bunch of block-levels elements stack\u2014like a bunch of a paragraphs\u2014that\u2019s the block direction. \n\nInline is how each line of text flows. The default on the web is from left to right, in horizontal lines. Imagine this text that you are reading right now, being typed out one character at a time on a typewriter. That\u2019s the inline direction. \n\nThe character direction is which way the characters point. If you type a capital \u201cA\u201d for instance, on which side is the top of the letter? Different languages can point in different directions. Most languages have their characters pointing towards the top of the page, but not all.\n\nPut all three together, and you start to see how they work as a system. \nThe default settings for the web work like this.\nNow that we know what block, inline, and character directions mean, let\u2019s see how they are used in different writing systems from around the world.\nThe four writing systems of CSS Writing Modes\nThe CSS Writing Modes Specification handles all the use cases for four major writing systems; Latin, Arabic, Han and Mongolian. \nLatin-based systems\nOne writing system dominates the world more than any other, reportedly covering about 70% of the world\u2019s population. \n\nThe text is horizontal, running from left to right, or LTR. The block direction runs from top to bottom. \nIt\u2019s called the Latin-based system because it includes all languages that use the Latin alphabet, including English, Spanish, German, French, and many others. But there are many non-Latin-alphabet languages that also use this system, including Greek, Cyrillic (Russian, Ukrainian, Bulgarian, Serbian, etc.), and Brahmic scripts (Devanagari, Thai, Tibetan), and many more.\nYou don\u2019t need to do anything in your CSS to trigger this mode. This is the default. \nBest practices, however, dictate that you declare in your opening <html> element which language and which direction (LTR or RTL) you are using. This website, for instance, uses <html lang='en-gb' dir='ltr'> to let the browser know this content is published in Great Britian\u2019s version of English, in a left to right direction. \nArabic-based systems\nArabic, Hebrew and a few other languages run the inline direction from right to left. This is commonly known as RTL.  \nNote that the inline direction still runs horizontally. The block direction runs from top to bottom. And the characters are upright.\n\nIt\u2019s not just the flow of text that runs from right to left, but everything about the layout of the website. The upper right-hand corner is the starting position. Important things are on the right. The eyes travel from right to left. So, typically RTL websites use layouts that are just like LTR websites, only flipped.\nOn websites that support both LTR and RTL, like the United Nations\u2019 site at un.org, the two layouts are mirror images of each other.\nFor many web developers, our experiences with internationalization have focused solely on supporting Arabic and Hebrew script. \nCSS layout hacks for internationalization & RTL\nTo prepare an LTR project to support RTL, developers have had to create all sorts of hacks. For example, the Drupal community started a convention of marking every margin-left and -right, every padding-left and -right, every float: left and float: right with the comment /* LTR */. Then later developers could search for each instance of that exact comment, and create stylesheets to override each left with right, and vice versa. It\u2019s a tedious and error prone way to work. CSS itself needed a better way to let web developers write their layout code once, and easily switch language directions with a single command.\nOur new CSS layout system does exactly that. Flexbox, Grid and Alignment use start and end instead of left and right. This lets us define everything in relationship to the writing system, and switch directions easily. By writing justify-content: flex-start, justify-items: end, and eventually margin-inline-start: 1rem we have code that doesn\u2019t need to be changed. \nThis is a much better way to work. I know it can be confusing to think through start and end as replacements for left and right. But it\u2019s better for any multiligual project, and it\u2019s better for the web as a whole.\nSadly, I\u2019ve seen CSS preprocessor tools that claim to \u201cfix\u201d the new CSS layout system by getting rid of start and end and bringing back left and right. They want you to use their tool, write justify-content: left, and feel self-righteous. It seems some folks think the new way of working is broken and should be discarded. It was created, however, to fulfill real needs. And to reflect a global internet. As Bruce Lawson says, WWW stands for the World Wide Web, not the Wealthy Western Web. Please don\u2019t try to convince the industry that there\u2019s something wrong with no longer being biased towards western culture. Instead, spread the word about why this new system is here.  \nSpend a bit of time drilling the concept of inline and block into your head, and getting used to start and end. It will be second nature soon enough. \nI\u2019ve also seen CSS preprocessors that let us use this new way of thinking today, even as all the parts aren\u2019t fully supported by browsers yet. Some tools let you write text-align: start instead of text-align: left, and let the preprocessor handle things for you. That is terrific, in my opinion. A great use of the power of a preprocessor to help us switch over now. \nBut let\u2019s get back to RTL. \nHow to declare your direction\nYou don\u2019t want to use CSS to tell the browser to switch from an LTR language to RTL. You want to do this in your HTML. That way the browser has the information it needs to display the document even if the CSS doesn\u2019t load.\nThis is accomplished mainly on the html element. You should also declare your main language. As I mentioned above, the 24 ways website is using <html lang='en-gb' dir='ltr'> to declare the LTR direction and the use of British English. The UN Arabic website uses <html lang='ar' dir='rtl'>to declare the site as an Arabic site, using a RTL layout. \nThings get more complicated when you\u2019ve got a page with a mix of languages. But I\u2019m not going to get into all of that, since this article is focused on CSS and layouts, not explaining everything about internationalization. \nLet me just leave direction here by noting that much of the heavy work of laying out the characters which make up each word is handled by Unicode. If you are interested in learning more about LTR, RTL and bidirectional text, watch this video: Introduction to Bidirectional Text, a presentation by Elika Etemad. \nMeanwhile, let\u2019s get back to CSS.\nThe writing mode CSS for Latin-based and Arabic-based systems\nFor both of these systems\u2014Latin-based and Arabic-based, whether LTR or RTL\u2014the same CSS property applies for specifying the writing mode: writing-mode: horizontal-tb. That\u2019s because in both systems, the inline text flow is horizontal, while the block direction is top-to-bottom. This is expressed as horizontal-tb.\nhorizontal-tb is the default writing mode for the web, so you don\u2019t need to specify it unless you are overriding something else higher up in the cascade. You can just imagine that every site you\u2019ve ever built came with:\nhtml {\n  writing-mode: horizontal-tb;\n}\nNow let\u2019s turn our attention to the vertical writing systems. \nHan-based systems\nThis is where things start to get interesting. \nHan-based writing systems include CJK languages, Chinese, Japanese, Korean and others. There are two options for laying out a page, and sometimes both are used at the same time.\nMuch of CJK text is laid out like Latin-based languages, with a horizontal top-to-bottom block direction, and a left-to-right inline direction. This is the more modern way to doing things, started in the 20th century in many places, and further pushed into domination by the computer and later the web. \nThe CSS to do this bit of the layouts is the same as above:\nsection {\n  writing-mode: horizontal-tb;\n}\nOr, you know, do nothing, and get that result as a default. \nAlternatively Han-based languages can be laid out in a vertical writing mode, where the inline direction runs vertically, and the block direction goes from right to left. \nSee both options in this diagram:\n\nNote that the horizontal text flows from left to right, while the vertical text flows from right to left. Wild, eh? \nThis Japanese issue of Vogue magazine is using a mix of writing modes. The cover opens on the left spine, opposite of what an English magazine does.  \n\nThis page mixes English and Japanese, and typesets the Japanese text in both horizontal and vertical modes. Under the title \u201cRichard Stark\u201d in red, you can see a passage that\u2019s horizontal-tb and LTR, while the longer passage of text at the bottom of the page is typeset vertical-rl. The red enlarged cap marks the beginning of that passage. The long headline above the vertical text is typeset LTR, horizontal-tb.\n\nThe details of how to set the default of the whole page will depend on your use case. But each element, each headline, each section, each article can be marked to flow the opposite of the default however you\u2019d like.\nFor example, perhaps you leave the default as horizontal-tb, and specify your vertical elements like this:\ndiv.articletext {\n  writing-mode: vertical-rl;\n}\nOr alternatively you could change the default for the page to a vertical orientation, and then set specific elements to horizontal-tb, like this:\nhtml { \n  writing-mode: vertical-rl;\n}\nh2, .photocaptions, section {\n  writing-mode: horizontal-tb;\n}\nIf your page has a sideways scroll, then the writing mode will determine whether the page loads with upper left corner as the starting point, and scroll to the right (horizontal-tb as we are used to), or if the page loads with the upper right corner as the starting point, scrolling to the left to display overflow. Here\u2019s an example of that change in scrolling direction, in a CSS Writing Mode demo by Chen Hui Jing. Check out her demo \u2014 you can switch from horizontal to vertical writing modes with a checkbox and see the difference. \n\nMongolian-based systems\nNow, hopefully so far all of this kind of makes sense. It might be a bit more complicated than expected, but it\u2019s not so hard. Well, enter the Mongolian-based systems.\nMongolian is also a vertical script language. Text runs vertically down the page. Just like Han-based systems. There are two major differences. First, the block direction runs the other way. In Mongolian, block-level elements stack from left to right. \nHere\u2019s a drawing of how Wikipedia would look in Mongolian if it were laid out correctly.\nPerhaps the Mongolian version of Wikipedia will be redone with this layout.\nNow you might think, that doesn\u2019t look so weird. Tilt your head to the left, and it\u2019s very familiar. The block direction starts on the left side of the screen and goes to the right. The inline direction starts on the top of the page and moves to the bottom (similar to RTL text, just turned 90\u00b0 counter-clockwise). But here comes the other huge difference. The character direction is \u201cupside down\u201d. The top of the Mongolian characters are not pointing to the left, towards the start edge of the block direction. They point to the right. Like this:\n\nNow you might be tempted to ignore all this. Perhaps you don\u2019t expect to be typesetting Mongolian content anytime soon. But here\u2019s why this is important for everyone \u2014 the way Mongolian works defines the results writing-mode: vertical-lr. And it means we cannot use vertical-lr for typesetting content in other languages in the way we might otherwise expect. \nIf we took what we know about vertical-rl and guessed how vertical-lr works, we might imagine this:\n\nBut that\u2019s wrong. Here\u2019s how they actually compare:\n\nSee the unexpected situation? In both writing-mode: vertical-rl and writing-mode: vertical-lr latin text is rotated clockwise. Neither writing mode let\u2019s us rotate text counter-clockwise. \nIf you are typesetting Mongolian content, apply this CSS in the same way you would apply writing-mode to Han-based writing systems. To the whole page on the html element, or to specific pages of the page like this:\nsection {\n  writing-mode: vertical-lr;\n}\nNow, if you are using writing-mode for a graphic design effect on a language that is otherwise typesets horizontally, I don\u2019t think writing-mode: vertical-lr is useful. If the text wraps onto two lines, it stacks in a very unexpected way. So I\u2019ve sort of obliterated it from my toolkit. I find myself using writing-mode: vertical-rl a lot. And never using -lr. Hm.\nWriting modes for graphic design\nSo how do we use writing-mode to turn English headlines sideways? We could rely on transform: rotate()\nHere are two examples, one for each direction. (By the way, each of these demos use CSS Grid for their overall layout, so be sure to test them in a browser that supports CSS Grid, like Firefox Nightly.)\n\nIn this demo 4A, the text is rotated clockwise using this code: \nh1 {\n  writing-mode: vertical-rl;\n}\n\nIn this demo 4B, the text is rotated counter-clockwise using this code: \nh1 {\n  writing-mode: vertical-rl;\n  transform: rotate(180deg);\n  text-align: right;\n}\nI use vertical-rl to rotate the text so that it takes up the proper amount of space in the overall flow of the layout. Then I rotate it 180\u00b0 to spin it around to the other direction. And then I use text-align: right to get it to rise up to the top of it\u2019s container. This feels like a hack, but it\u2019s a hack that works.\nNow what I would like to do instead is use another CSS value that was designed for this use case \u2014 one of the two other options for writing mode.\nIf I could, I would lay out example 4A with:\nh1 {\n  writing-mode: sideways-rl;\n}\nAnd layout example 4B with: \nh1 {\n  writing-mode: sideways-lr;\n}\nThe problem is that these two values are only supported in Firefox. None of the other browsers recognize sideways-*. Which means we can\u2019t really use it yet. \nIn general, the writing-mode property is very well supported across browsers. So I\u2019ll use writing-mode: vertical-rl for now, with the transform: rotate(180deg); hack to fake the other direction. \nThere\u2019s much more to what we can do with the CSS designed to support multiple languages, but I\u2019m going to stop with this intermediate introduction. \nIf you do want a bit more of a taste, look at this example that adds text-orientation: upright; to the mix \u2014 turning the individual letters of the latin font to be upright instead of sideways.\n\nIt\u2019s this demo 4C, with this CSS applied: \nh1 {\n  writing-mode: vertical-rl;\n  text-orientation: upright;\n  text-transform: uppercase;\n  letter-spacing: -25px;\n}\nYou can check out all my Writing Modes demos at labs.jensimmons.com/#writing-modes. \n\nI\u2019ll leave you with this last demo. One that applies a vertical writing mode to the sub headlines of a long article. I like how small details like this can really bring a fresh feeling to the content. \nSee the Pen Writing Mode Demo \u2014 Article Subheadlines by Jen Simmons (@jensimmons) on CodePen.", "year": "2016", "author": "Jen Simmons", "author_slug": "jensimmons", "published": "2016-12-23T00:00:00+00:00", "url": "https://24ways.org/2016/css-writing-modes/", "topic": "code"}
{"rowid": 303, "title": "We Need to Talk About Technical Debt", "contents": "In my work with clients, a lot of time is spent assessing old, legacy, sprawling systems and identifying good code, bad code, and technical debt.\nOne thing that constantly strikes me is the frequency with which bad code and technical debt are conflated, so let me start by saying this:\nNot all technical debt is bad code, and not all bad code is technical debt.\nSometimes your bad code is just that: bad code. Calling it technical debt often feels like a more forgiving and friendly way of referring to what may have just been a poor implementation or a substandard piece of work.\nIt is an oft-misunderstood phrase, and when mistaken for meaning \u2018anything legacy or old hacky or nasty or bad\u2019, technical debt is swept under the carpet along with all of the other parts of the codebase we\u2019d rather not talk about, and therein lies the problem.\nWe need to talk about technical debt.\nWhat We Talk About When We Talk About Technical Debt\nThe thing that separates technical debt from the rest of the hacky code in our project is the fact that technical debt, by definition, is something that we knowingly and strategically entered into. Debt doesn\u2019t happen by accident: debt happens when we choose to gain something otherwise-unattainable immediately in return for paying it back (with interest) later on.\nAn Example\nYou\u2019re a front-end developer working on a SaaS product, and your sales team is courting a large customer \u2013 a customer so large that you can\u2019t really afford to lose them. The customer tells you that as long as you can allow them to theme your SaaS application according to their branding, they are willing to sign on the dotted line\u2026 the problem being that your CSS architecture was never designed to incorporate theming at all, and there isn\u2019t currently a nice, clean way to incorporate a theme into the codebase.\nYou and the business make the decision that you will hack a theme into the product in two days. It\u2019s going to be messy, it\u2019s going to be ugly, but you can\u2019t afford to lose a huge customer just because your CSS isn\u2019t quite right, right now. This is technical debt.\nYou deliver the theme, the customer signs up, and everyone is happy. Except you (and the business, because you are one and the same) have a decision to make:\n\nDo we go back and build theming into the CSS architecture as a first-class citizen, porting the hacked theme back into a codified and formal framework?\nDo we carry on as we are? Things are working okay, and the customer paid up, so is there any reason to invest time and effort into things after we (and the customer) got what we wanted?\n\nOption 1 is choosing to pay off your debts; Option 2 is ignoring your repayments.\nWith Option 1, you\u2019re acknowledging that you did what you could given the constraints, but, free of constraints, you\u2019d have done something different. Now, you are choosing to implement that something different.\nWith Option 2, however, you are avoiding your responsibility to repay your debt, and you are letting interest accrue. The problem here is that\u2026\n\nyour SaaS product now offers theming to one of your customers;\nanother potential customer might also demand the ability to theme their instance of your product;\nyou can\u2019t refuse them that request, nor can you quickly fulfil it;\nyou hack in another theme, thus adding to the balance of your existing debt;\nand so on (plus interest) for every subsequent theme you need to implement.\n\nHere you have increased entropy whilst making little to no attempt to address what you already knew to be problems.\nYour second, third, fourth, fifth request for theming will be hacked on top of your hack, further accumulating debt whilst offering nothing by way of a repayment. After a long enough period, the code involved will get so unwieldy, so hard to work with, that you are forced to tear it all down and start again, and the most painful part of this is that you\u2019re actually paying off even more than your debt repayments would have been in the first place. Two days of hacking plus, say, five days of subsequent refactoring, would still have been substantially less than the weeks you will now have to spend rewriting your CSS to fix and incorporate the themes properly. You\u2019ve made a loss; your strategic debt ultimately became a loss-making exercise.\nThe important thing to note here is that you didn\u2019t necessarily write bad code. You knew there were two options: the quick way and the correct way. The decision to take the quick route was a definite choice, because you knew there was a better way. Implementing the better way is your repayment.\nGood Debt and Bad Debt\nTechnical debt is acceptable as long as you have intentions to settle; it can be a valuable solution to a business problem, provided the right approach is taken afterwards. That doesn\u2019t, however, mean that all debt is born equal. Just as in real life, there is good debt and there is bad debt.\nGood debt might be\u2026\n\na mortgage;\na student loan, or;\na business loan.\n\nThese are types of debt that will secure you the means of repaying them. These are well considered debts whose very reason for being will allow you to make the money to pay them off\u2014they have real, tangible benefit.\nA business loan to secure some equipment and premises will allow you to start an enterprise whose revenue will allow you to pay that debt back; a student loan will allow you to secure the kind of job that has the ability to pay a student loan back.\nThese kinds of debt involve a considered and well-balanced decision to acquire something in the short term in the knowledge that you will have the means, in the long term, to pay it back.\nConversely, bad debt might be\u2026\n\nborrowing $1,000 from a loan shark so you can go to Vegas, or;\ntaking out a payday loan in order to buy a new television.\n\nBoth of these kinds of debt will leave you paying for things that didn\u2019t provide you a way of earning your own capital. That is to say, the loans taken did not secure anything that would help pay off said loans. These are bad debts that will usually provide a net loss. You really are only gaining the short term in exchange for a long term financial responsibility: i.e., was it worth it?\nA good litmus test for debt is to compare the gains of its immediate benefit with the cost of its long term commitment.\nThe earlier example of theming a site is a good debt, provided we are keeping up our repayments (all debt is bad debt if you don\u2019t). A calculated decision to do something \u2018wrong\u2019 in the short term with the promise of better payoffs later on.\nBad Technical Debt\nThe majority of my work is with front-end development teams\u2014CSS is what I do. To that end, the most succinct example of technical debt for that audience is simply:\n!important\nAll front-end developers know the horrors and dangers associated with using !important, yet we continue to use it. Why?\nIt\u2019s not necessarily because we\u2019re bad developers, but because we see a shortcut. !important is usually implemented as a quick way out of a sticky specificity situation. We could spend the rest of the day refactoring our CSS to fix the issue at its source, or we can spend mere seconds typing the word !important and patch over the symptoms.\nThis is us making an explicit decision to do something less than ideal now in exchange for immediate benefit. After all, refactoring our CSS will take a lot more time, and will still only leave us with the same outcome that the vastly quicker !important solution will, so it seems to make better business sense.\nHowever, this is a bad debt. !important takes seconds to implement but weeks to refactor. The cost of refactoring this back out later will be an order of magnitude higher than it would be to have done things properly the first time. The first !important usually sets a precedent, and subsequent developers are likely to have to use it themselves in order to get around the one that you left.\nSo many CSS projects deteriorate because of this one simple word, and rewrites become more and more imminent. That makes it possibly the most costly 10 bytes a CSS developer could ever write.\nBad Code\nNow we\u2019ve got a good idea of what constitutes technical debt, let\u2019s take a look at what constitutes bad code. Something I hear time and time again in my client work goes a little like this:\n\nWe\u2019ve amassed a lot of technical debt and we\u2019d like to get a strategy in place\nto begin dealing with it.\n\nWhilst I genuinely admire their willingness to identify and desire to fix problems in their code, sometimes they\u2019re not looking at technical debt at\nall\u2014sometimes they\u2019re just looking at bad code, plain and simple.\nWhere technical debt is knowing that there\u2019s a better way, but the quicker way makes more sense right now, bad code is not caring if there\u2019s a better way at all.\nAgain, looking at a CSS-specific world, a lot of bad code is contributed by non-front-end developers with little training, appreciation, or even respect for the front-end landscape. Writing code with reckless abandon should not be described as technical debt, because to do so would imply that\u2026\n\nthe developers knew they were implementing a sub-par solution, but\u2026\nthe developers also knew that a better solution was out there, which\u2026\nimplies that it can be tidied up relatively simply.\n\nDevelopers writing bad code is a larger and more cultural problem that requires a lot more effort to fix. Hopefully\u2014and usually\u2014bad code is in the minority, but it helps to be objective in identifying and solving it. Bad code usually doesn\u2019t happen for a good enough reason, and is therefore much harder to justify.\nTechnical debt often represents ability in judgement, whereas bad code often represents a gap in skills.\nTakeaway\nTake time to familiarise yourself with the true concepts underlying technical debt and why it exists. Understand that technical debt can be good or bad. Admit that sometimes code is just of poor quality.\nUnderstanding these points will allow you to make better calls around what you might need to refactor and when, and what skills gaps you might have in your team.\n\nSometimes it\u2019s okay to cut corners if there is a tangible gain to be had in the immediate term.\nTechnical debt is okay provided it is a sensible debt and you have intentions to pay it off.\nTechnical debt is not necessarily synonymous with bad code, and bad code isn\u2019t necessarily technical debt. Technical debt is code that was implemented given limited knowledge or resource, with the understanding that you would need to repay something in future.\nTechnical debt is not inherently bad\u2014failure to make repayments is. Periodically, it is justifiable\u2014encouraged, even\u2014to enter a debt in order to fulfil a more pressing matter. However, it is imperative that we begin making repayments as soon as we are capable, be that based on newly available time or knowledge.\nBad code is worse than technical debt as it represents a lack of knowledge or quality control within a team. It needs a much more fundamental fix.", "year": "2016", "author": "Harry Roberts", "author_slug": "harryroberts", "published": "2016-12-05T00:00:00+00:00", "url": "https://24ways.org/2016/we-need-to-talk-about-technical-debt/", "topic": "code"}
{"rowid": 300, "title": "Taking Device Orientation for a Spin", "contents": "When The Police sang \u201cDon\u2019t Stand So Close To Me\u201d they weren\u2019t talking about using a smartphone to view a panoramic image on Facebook, but they could have been. For years, technology has driven relentlessly towards devices we can carry around in our pockets, and now that we\u2019re there, we\u2019re expected to take the thing out of our pocket and wave it around in front of our faces like a psychotic donkey in search of its own dangly carrot.\nBut if you can\u2019t beat them, join them.\nA brave new world\nA couple of years back all sorts of specs for new HTML5 APIs sprang up much to our collective glee. Emboldened, we ran a few tests and found they basically didn\u2019t work in anything and went off disheartened into the corner for a bit of a sob.\nTurns out, while we were all busy boohooing, those browser boffins have actually being doing some work, and lo and behold, some of these APIs are even half usable. Mostly literally half usable\u2014we\u2019re still talking about browsers, after all.\nNow, of course they\u2019re all a bit JavaScripty and are going to involve complex methods and maths and science and probably about a thousand dependancies from Github that will fall out of fashion while we\u2019re still trying to locate the documentation, right? Well, no! \nSo what if we actually wanted to use one of these APIs, say to impress our friends with our ability to make them wave their phones in front of their faces (because no one enjoys looking hapless more than the easily-technologically-impressed), how could we do something like that? Let\u2019s find out.\nThe Device Orientation API\nThe phone-wavy API is more formally known as the DeviceOrientation Event Specification. It does a bunch of stuff that basically doesn\u2019t work, but also gives us three values that represent orientation of a device (a phone, a tablet, probably not a desktop computer) around its x, y and z axes. You might think of it as pitch, roll and yaw if you like to spend your weekends wearing goggles and a leather hat.\nThe main way we access these values is through an event listener, which can inform our code every time the value changes. Which is constantly, because you try and hold a phone still and then try and hold the Earth still too.\nThe API calls those pitch, roll and yaw values alpha, beta and gamma. Chocks away:\nwindow.addEventListener('deviceorientation', function(e) {\n    console.log(e.alpha);\n    console.log(e.beta);\n    console.log(e.gamma);\n});\nIf you look at this test page on your phone, you should be able to see the numbers change as you twirl the thing around your body like the dance partner you never had. Wrist strap recommended.\nOne important note\nLike may of these newfangled APIs, Device Orientation is only available over HTTPS. We\u2019re not allowed to have too much fun without protection, so make sure that you\u2019re working on a secure line. I\u2019ve found a quick and easy way to share my local dev environment over TLS with my devices is to use an ngrok tunnel.\nngrok http -host-header=rewrite mylocaldevsite.dev:80\nngrok will then set up a tunnel to your dev site with both HTTP and HTTPS URL options. You, of course, want the HTTPS option.\nRight, where were we?\nMake something to look at\nIt\u2019s all well and good having a bunch of numbers, but they\u2019re no use unless we do something with them. Something creative. Something to inspire the generations. Or we could just build that Facebook panoramic image viewer thing (because most of us are familiar with it and we\u2019re not trying to be too clever here). Yeah, let\u2019s just build one of those.\nOur basic framework is going to be similar to that used for an image carousel. We have a container, constrained in size, and CSS overflow property set to hidden. Into this we place our wide content and use positioning to move the content back and  forth behind the \u2018window\u2019 so that the part we want to show is visible.\nHere it is mocked up with a slider to set the position. When you release the slider, the position updates. (This actually tests best on desktop with your window slightly narrowed.)\nThe details of the slider aren\u2019t important (we\u2019re about to replace it with phone-wavy goodness) but the crucial part is that moving the slider results in a function call to position the image. This takes a percentage value (0-100) with 0 being far left and 100 being far right (or \u2018alt-nazi\u2019 or whatever).\nvar position_image = function(percent) {\n    var pos = (img_W / 100)*percent;\n    img.style.transform = 'translate(-'+pos+'px)'; \n};\nAll this does is figure out what that percentage means in terms of the image width, and set the transform: translate(\u2026); CSS property to move the image. (We use translate because it might be a bit faster to animate than left/right positioning.)\nOk. We can now read the orientation values from our device, and we can programatically position the image. What we need to do is figure out how to convert those raw orientation values into a nice tidy percentage to pass to our function and we\u2019re done. (We\u2019re so not done.)\nThe maths bit\nIf we go back to our raw values test page and make-believe that we have a fascinating panoramic image of some far-off beach or historic monument to look at, you\u2019ll note that the main value that is changing as we swing back and forth is the \u2018alpha\u2019 value. That\u2019s the one we want to track.\nAs our goal here is hey, these APIs are interesting and fun and not let\u2019s build the world\u2019s best panoramic image viewer, we\u2019ll start by making a few assumptions and simplifications:\n\nWhen the image loads, we\u2019ll centre the image and take the current nose-forward orientation reading as the middle.\nMoving left, we\u2019ll track to the left of the image (lower percentage).\nMoving right, we\u2019ll track to the right (higher percentage).\nIf the user spins round, does cartwheels or loads the page then hops on a plane and switches earthly hemispheres, they\u2019re on their own.\n\nNose-forward\nWhen the page loads, the initial value of alpha gives us our nose-forward position. In Safari on iOS, this is normalised to always be 0, whereas most everywhere else it tends to be bound to pointy-uppy north. That doesn\u2019t really matter to us, as we don\u2019t know which direction the user might be facing in anyway \u2014 we just need to record that initial state and then use it to compare any new readings.\nvar initial_position = null;\n\nwindow.addEventListener('deviceorientation', function(e) {\n    if (initial_position === null) {\n        initial_position = Math.floor(e.alpha);\n    };\n\n    var current_position = initial_position - Math.floor(e.alpha);\n});\n(I\u2019m rounding down the values with Math.floor() to make debugging easier - we\u2019ll take out the rounding later.)\nWe get our initial position if it\u2019s not yet been set, and then calculate the current position as a difference between the new value and the stored one.\nThese values are weird\nOne thing you need to know about these values, is that they range from 0 to 360 but then you also get weird left-of-zero values like -2 and whatever. And they wrap past 360 back to zero as you\u2019d expect if you do a forward roll.\nWhat I\u2019m interested in is working out my rotation. If 0 is my nose-forward position, I want a positive value as I turn right, and a negative value as I turn left. That puts the awkward 360-tipping point right behind the user where they can\u2019t see it.\nvar rotation  = current_position;\nif (current_position > 180) rotation = current_position-360;\nWhich way up?\nSince we\u2019re talking about orientation, we need to remember that the values are going to be different if the device is held in portrait on landscape mode. See for yourself - wiggle it like a steering wheel and you get different values. That\u2019s easy to account for when you know which way up the device is, but in true browser style, the API for that bit isn\u2019t well supported. The best I can come up with is:\nvar screen_portrait = false;\nif (window.innerWidth < window.innerHeight) {\n    screen_portrait = true;\n}\nIt works. Then we can use screen_portrait to branch our code:\nif (screen_portrait) {\n        if (current_position > 180) rotation = current_position-360;\n} else {\n        if (current_position < -180) rotation = 360+current_position;\n}\nHere\u2019s the code in action so you can see the values for yourself. If you change screen orientation you\u2019ll need to refresh the page (it\u2019s a demo!).\nLimiting rotation\nNow, while the youth of today are rarely seen without a phone in their hands, it would still be unreasonable to ask them to spin through 360\u00b0 to view a photo. Instead, we need to limit the range of movement to something like 60\u00b0-from-nose in either direction and normalise our values to pan the entire image across that 120\u00b0 range. -60 would be full-left (0%) and 60 would be full-right (100%).\nIf we set max_rotation = 60, that code ends up looking like this:\nif (rotation > max_rotation) rotation = max_rotation;\nif (rotation < (0-max_rotation)) rotation = 0-max_rotation;\n\nvar percent = Math.floor(((rotation + max_rotation)/(max_rotation*2))*100);\nWe should now be able to get a rotation from -60\u00b0 to +60\u00b0 expressed as a percentage. Try it for yourself.\nThe big reveal\nAll that\u2019s left to do is pass that percentage to our image positioning function and would you believe it, it might actually work.\nposition_image(percent);\nYou can see the final result and take it for a spin. Literally.\nSo what have we made here? Have we built some highly technical panoramic image viewer to aid surgeons during life-saving operations using only JavaScript and some slightly questionable mathematics? No, my friends, we have not. Far from it. \nWhat we have made is progress. We\u2019ve taken a relatively newly available hardware API and a bit of simple JavaScript and paired it with existing CSS knowledge and made something that we didn\u2019t have this morning. Something we probably didn\u2019t even want this morning. Something that if you take a couple of steps back and squint a bit might be a prototype for something vaguely interesting. But more importantly, we\u2019ve learned that our browsers are just a little bit more capable than we thought.\nThe web platform is maturing rapidly. There are new, relatively unexplored APIs for doing all sorts of crazy thing that are often dismissed as the preserve of native apps. Like some sort of app marmalade. Poppycock. \nThe web is an amazing, exciting place to create things. All it takes is some base knowledge of the fundamentals, a creative mind and a willingness to learn. We have those! So let\u2019s create things.", "year": "2016", "author": "Drew McLellan", "author_slug": "drewmclellan", "published": "2016-12-24T00:00:00+00:00", "url": "https://24ways.org/2016/taking-device-orientation-for-a-spin/", "topic": "code"}
{"rowid": 298, "title": "First Steps in VR", "contents": "The web is all around us. As web folk, it is our responsibility to consider the impact our work can have. Part of this includes thinking about the future; the web changes lives and if we are building the web then we are the ones making decisions that affect people in every corner of the world. I find myself often torn between wanting to make the right decisions, and just wanting to have fun. To fiddle and play. We all know how important it is to sometimes just try ideas, whether they will amount to much or not. \nI think of these two mindsets as production and prototyping, though of course there are lots of overlap and phases in between. I mention this because virtual reality is currently seen as a toy for rich people, and in some ways at the moment it is. But with WebVR we are able to create interesting experiences with a relatively low entry point. I want us to have open minds, play around with things, and then see how we can use the tools we have at our disposal to make things that will help people.\nEvery year we see articles saying it will be the \u201cyear of virtual reality\u201d, that was especially prevalent this year. 2016 has been a year of progress, VR isn\u2019t quite mainstream but with efforts like Playstation VR and Google Cardboard, we are definitely seeing much more of it. This year also saw the consumer editions of the Oculus Rift and HTC Vive. So it does seem to be a good time for an overview of how to get involved with creating virtual reality on the web.\nWebVR is an API for connecting to devices and retrieving continuous data such as the position and orientation. Unlike the Web Audio API and some other APIs, WebVR does not feel like a framework. You use it however you want, taking the data and using it as you wish. To make it easier, there are plenty of resources such as Three.js, A-Frame and ReactVR that help to make the heavy lifting a bit easier.\nGetting Started with A-Frame\nI like taking the opportunity to learn new things whenever I can. So while planning this article I thought that instead of trying to teach WebGL or even Three.js in a way that is approachable for all, I would create my first project using A-Frame and write about that. This is not a tutorial as such, I just want to show how to go about getting involved with VR. The beauty of A-Frame is that it is very similar to web components, you can just write HTML to build worlds that will automatically work on all the different types of devices. It uses WebGL and WebVR but in such a way that it quite drastically reduces the learning curve. That\u2019s not to say you can\u2019t build complex things, you have complete access to write JavaScript and shaders.\nI\u2019m lazy. Whenever I learn a new language or framework I have found that the best way, personally, for me to learn is to have a project and to copy the starting code from someone else. A project lets you have a good idea of what you want to produce and it means you can ignore a lot of the irrelevant documentation, focussing purely on what you need. That reduces the stress of figuring things out. Copying code also makes it easier, because you know your boilerplate code is working. There\u2019s nothing worse than getting stuck before anything actually works the first time. So I tinker. I take code and I modify it, I play around. It\u2019s fun.\nFor this project I wanted to keep things as simple as possible, so I can easily explain it without the classic \u201cdraw a circle then draw an owl\u201d. I wrote a list of requirements, with some stretch goals that you can give a try yourself if you fancy:\n\nMust work on Google Cardboard at a minimum, because of price\nTherefore, it must not rely on having a controller\nAuto-moving around a maze would be a good example\nMove in direction you look\nStretch goal: Scoring, time until you hit a wall or get stuck in maze\nStretch goal: Levels, so the map doesn\u2019t need to be random\nStretch goal: Snow!\n\nI decided to  base this project on an example, Platforms, by Don McCurdy who wrote the really useful aframe-extras. Platforms has random 3D blocks that you can jump onto, going up into the sky. So I took his code and reduced it so that the blocks are randomly spread on the ground. \n<!DOCTYPE html>\n<html>\n<head>\n    <meta charset=\"utf-8\">\n    <meta name=\"viewport\" content=\"width=device-width\">\n    <title>24 ways</title>\n    <script src=\"https://aframe.io/releases/0.3.2/aframe.js\"></script>\n    <script src=\"//cdn.rawgit.com/donmccurdy/aframe-extras/v2.6.1/dist/aframe-extras.min.js\"></script>\n</head>\n<body>\n<a-scene>\n    <a-entity id=\"player\"\n              camera\n              universal-controls\n              kinematic-body\n              position=\"0 1.8 0\">\n    </a-entity>\n\n    <a-entity id=\"walls\"></a-entity>\n\n    <a-grid id=\"ground\" static-body></a-grid>\n\n    <a-sky id=\"sky\" color=\"#AADDF0\"></a-sky>\n\n    <!-- Lighting -->\n    <a-light type=\"ambient\" color=\"#ccc\"></a-light>\n</a-scene>\n<script>\n    document.querySelector('a-scene').addEventListener('render-target-loaded', function () {\n        var MAP_SIZE = 10,\n                PLATFORM_SIZE = 5,\n                NUM_PLATFORMS = 50;\n        var platformsEl = document.querySelector('#walls');\n        var v, box;\n        for (var i = 0;  i < NUM_PLATFORMS; i++) {\n            // y: 0 is ground\n            v = {\n                x: (Math.floor(Math.random() * MAP_SIZE) - PLATFORM_SIZE) * PLATFORM_SIZE,\n                y: PLATFORM_SIZE / 2,\n                z: (Math.floor(Math.random() * MAP_SIZE) - PLATFORM_SIZE) * PLATFORM_SIZE\n            };\n            box = document.createElement('a-box');\n            platformsEl.appendChild(box);\n            box.setAttribute('color', '#39BB82');\n            box.setAttribute('width', PLATFORM_SIZE);\n            box.setAttribute('height', PLATFORM_SIZE);\n            box.setAttribute('depth', PLATFORM_SIZE);\n            box.setAttribute('position', v.x + ' ' + v.y + ' ' + v.z);\n            box.setAttribute('static-body', '');\n        }\n        console.info('Platforms loaded.');\n    });\n</script>\n</body>\n</html>\nAs you can see, this is very readable. Especially if you ignore the JavaScript that is used to create the maze. A-Frame (with A-Frame Extras) gives you a lot of power with relatively little to learn. We start with an <a-scene> which is the container for everything that is going to show up on the screen. There are a few <a-entity> which can be compared to <div> as they are essentially non-semantic containers, able to be used for any purpose. The attributes are used to define functionality, for example the camera attribute sets the entity to function as a camera and kinematic-body makes it collide instead of go through objects. Attributes are also used to set position and sizes, often using JavaScript to dynamically define them.\nStyling\nNow we\u2019ve got the HTML written, we need to style it. To do this we add A-Frame compatible attributes such as color and material. I recommend playing around, you can get some quite impressive effects fairly easily. Originally I wanted a light snowy maze but it ended up being dark and foggy, as I really liked the feeling it gave.\nNote, you will probably need a server running for images to work. You can do this by running python -m \"SimpleHTTPServer\" in the folder where the code is, then go to localhost:8000 in browser.\nTextures\nUnless you are going for a cartoony style, you probably want to find some textures. I found some on textures.com, one image worked well for the walls and the other for the floor.\n<a-assets>\n    <img id=\"texture-floor\" src=\"floor.jpg\">\n    <img id=\"texture-wall\" src=\"wall.jpg\">\n</a-assets>\nThe <a-assets> is used to define (as well as preload and cache) all assets, including images, audio and video. As you can see, images in the Asset Management System just use normal img tags. The ids are important here as we can use them later for using the textures. \nTo apply a texture to an object, you create a material. For a simple material where it just shows the image, you set the src to the id selector of the image.\nReplace: \n<a-grid id=\"ground\" static-body></a-grid>\nWith:\n<a-grid id=\"ground\" static-body material=\"src: #texture-floor\"></a-grid>\nThis will automatically make the image repeat over the entire floor, in my case filling it with bricks. The walls are pretty much identical, with the slight exception that it is set in JavaScript as they are dynamically defined.\nbox.setAttribute('material', 'src: #texture-wall');\nThat\u2019s it for the textures, for now at least. These will not look completely realistic, as the light will bump off the rectangular wall rather than texture itself. This can be improved by using maps, textures that are used to modify the shape and physical properties of the object. \nLighting\nThe next part of styling is lighting. By using fog and different types of lighting, we are able to add atmospheric details to the game to make it feel that bit more realistic and polished.\nThere are lots of types of light in A-Frame (most coming from Three.js). You can add a light either by using the <a-light> entity or by attaching a light attribute to any other entity. If there are no lights defined then A-Frame adds some by default so that the scene is always lit.\nTo start with I wanted to light up the scene with a general light, type=\"ambient\", so that the whole game felt slightly dark. I chose to set the light to a reddish colour #92455E. After playing around with intensity I chose 0.4, it added enough light to get the feeling I wanted without it being overly red. I also added a blue skybox (<a-sky>), as it looked a bit odd with a white sky.\n<a-light type=\"ambient\" color=\"#92455E\" intensity=\"0.4\"></a-light>\n<a-sky id=\"sky\" color=\"#0000ff\"></a-sky>\nI felt that the maze looked good with a red tinge but it was a bit flat, everything was the same colour and it was a bit dark. So I added a light within the #player entity, this could have been as an attribute but I set it as a child a-light instead. By using type=\"point\" with a high intensity and low distance, it showed close walls as being lighter. It also added a sort-of object to the player, it isn\u2019t a walking human or anything but by moving light where the player is it feels a bit more physical.\n<a-light color=\"#fff\" distance=\"5\" intensity=\"0.7\" type=\"point\"></a-light>\n\nBy this point it was starting to look decent, so I wanted to add the fog to really give some personality and depth to the maze. To do this I added the fog attribute to the <a-scene> with type=exponential so it looks thicker the further away it is and a mid intensity, so you feel a bit lost but can still see.\n\nI was very happy with this result. It took a lot of playing around with colours and values, which is fun in itself. I highly recommend you take the code (or write your own) and play around with the numbers.\nMovement\nOne of the reasons I decided to use aframe-extras is that it has a few different camera controls built in. As you saw earlier, I am using the universal-controls which gives WASD (keyboard) controls by default. I wanted to make it automatically move in the direction that you\u2019re looking, but I wasn\u2019t quite sure how without rewriting the controls. So I asked Don McCurdy for advice and he very nicely gave me a small snippet of code to get it working.\nAFRAME.registerComponent('automove-controls', {\n    init: function () {\n        this.speed = 0.1;\n        this.isMoving = true;\n        this.velocityDelta = new THREE.Vector3();\n    },\n    isVelocityActive: function () {\n        return this.isMoving;\n    },\n    getVelocityDelta: function () {\n        this.velocityDelta.z = this.isMoving ? -speed : 0;\n        return this.velocityDelta.clone();\n    }\n});\nReplace:\nuniversal-controls\nWith:\nuniversal-controls=\"movementControls: automove, gamepad, keyboard\"\nThis works by creating a component automove-controls that adds auto-move to the player without overriding movement completely. It doesn\u2019t even touch direction, it just checks if isMoving is true then moves the player by the set speed. Components can be creating for adding all kinds of functionality with relative ease. It makes it very powerful for people of all difficulty levels.\nBuilding a map\nCurrently the maze is created randomly, which is great but means there will often be walls that overlap or the player gets trapped with nowhere to go. So to solve this, I decided to use a map editor (Tiled) so that we can create the mazes ourselves. This is a great start towards one of the stretch goals, levels.\nI made the maze in Tiled by finding a random tileset online (we don\u2019t need to actually show the images), I used one tile for the wall and another for the player. Then I exported as a JavaScript file and modified it in my text editor to get rid of everything I didn\u2019t need. I made it so 0 is the path, 1 is the wall and 2 is the player. I then added the script to the HTML, as a separate file so it\u2019s easy to update in the future. \nvar map =\n{\n \"data\":[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 0, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],\n \"height\":10,\n \"width\":10\n}\n\nAs you can see, this gives a simple 10x10 maze with some dead ends. The player starts in the bottom right corner (my choice, could be anywhere). I rewrote the random platforms code (from Don\u2019s example) to instead loop over the map data and place walls where it is 1 and position the player where data is 2. I set the position so that the origin of the map would be 0,1.5,0. The y axis is in this case the height (ground being 0), but if a wall is positioned at 0 by its centre then some of it is underground. So the y needed to be the height divided by 2.\ndocument.querySelector('a-scene').addEventListener('render-target-loaded', function () {\n    var WALL_SIZE = 5,\n        WALL_HEIGHT = 3;\n    var el = document.querySelector('#walls');\n    var wall;\n\n    for (var x = 0; x < map.height; x++)  {\n        for (var y = 0; y < map.width; y++) {\n\n            var i = y*map.width + x;\n            var position = (x-map.width/2)*WALL_SIZE + ' ' + 1.5 + ' ' + (y-map.height/2)*WALL_SIZE;\n            if (map.data[i] === 1) {\n                // Create wall\n                wall = document.createElement('a-box');\n                el.appendChild(wall);\n                wall.setAttribute('color', '#fff');\n                wall.setAttribute('material', 'src: #texture-wall;');\n                wall.setAttribute('width', WALL_SIZE);\n                wall.setAttribute('height', WALL_HEIGHT);\n                wall.setAttribute('depth', WALL_SIZE);\n                wall.setAttribute('position', position);\n                wall.setAttribute('static-body', ');\n            }\n\n            if (map.data[i] === 2)  {\n                // Set player position\n                document.querySelector('#player').setAttribute('position', position);\n            }\n\n        }\n    }\n    console.info('Walls added.');\n});\n\nWith this added, it makes it nice and easy to change around the map as well as to add new features. Perhaps you want monsters or objects. Just set the number in the map data and add an if statement to the loop. In the future you could add layers, so multiple things can be in the same position. Or perhaps even make the maze go up the y axis too, with ramps or staircases. There\u2019s a lot you can do with relative ease. As you can see, A-Frame really does reduce the learning curve of 3D and VR on the web.\nIt\u2019s Not All Fun And Games\nA lot of examples of virtual reality are games, including this one. So it is understandable to think that VR is for gaming, but actually that\u2019s just a tiny subset. There are all sorts of applications for VR, including story telling, data visualisation and even meditation.\nThere have been a number of cases where it has been shown virtual reality can help as a tool for therapies:\n\nOxford study finds virtual reality can help treat severe paranoia\nVirtual Reality Therapy for Phobias at the Duke Faculty Practice\nBravemind: Virtual Reality Exposure Therapy at the University of Southern California\n\nThese are just a few examples of where virtual reality is being used around the world to help people feel better and get through some very tough times. There have also been examples of it being used for simulating war zones or medical situations, both as a teaching and journalism tool.\nWrapping Up\nTen years ago, on this very site, Cameron Moll wrote an article explaining the mobile web. He explained how mobile phones with data plans were becoming increasingly common, that WAP 2.0 included the XHTML Mobile Profile meaning it would be familiar with web folk. \u201cThe mobile web is rapidly becoming an XHTML environment, and thus you and I can apply our existing \u201cdesktop web\u201d skills to understand how to develop content for it.\u201d\nWe can look at that and laugh a little, we have come a very long way in the last decade. Even people in developing countries with very little money have mobile phones with access to a web that is far more capable than the \u201cdesktop web\u201d Cameron was referring to.\nSo while I am not saying virtual reality is going to change the world or replace our phones, who knows! We can use our skills as web folk to dabble, we don\u2019t need to learn any new languages. If on the 2026 edition of 24 ways, somebody references this article and looks at how far we have come\u2026 well, let\u2019s hope we have used our skills well and made the world just that little bit better. And if VR is a fad? Well it\u2019s fun\u2026 have a go anyway.", "year": "2016", "author": "Shane Hudson", "author_slug": "shanehudson", "published": "2016-12-11T00:00:00+00:00", "url": "https://24ways.org/2016/first-steps-in-vr/", "topic": "code"}
{"rowid": 296, "title": "Animation in Design Systems", "contents": "Our modern front-end workflow has matured over time to include design systems and component libraries that help us stay organized, improve workflows, and simplify maintenance. These systems, when executed well, ensure proper documentation of the code available and enable our systems to scale with reduced communication conflicts. \nBut while most of these systems take a critical stance on fonts, colors, and general building blocks, their treatment of animation remains disorganized and ad-hoc. Let\u2019s leverage existing structures and workflows to reduce friction when it comes to animation and create cohesive and performant user experiences. \nUnderstand the importance of animation\nPart of the reason we treat animation like a second-class citizen is that we don\u2019t really consider its power. When users are scanning a website (or any environment or photo), they are attempting to build a spatial map of their surroundings. During this process, nothing quite commands attention like something in motion. \nWe are biologically trained to notice motion: evolutionarily speaking, our survival depends on it. For this reason, animation when done well can guide your users. It can aid and reinforce these maps, and give us a sense that we understand the UX more deeply. We retrieve information and put it back where it came from instead of something popping in and out of place. \n\n\u201cWhere did that menu go? Oh it\u2019s in there.\u201d \n\nFor a deeper dive into how animation can connect disparate states, I wrote about the Importance of Context-Shifting in UX Patterns for CSS-Tricks.\nAn animation flow on mobile.\nAnimation also aids in perceived performance. Viget conducted a study where they measured user engagement with a standard loading GIF versus a custom animation. Customers were willing to wait almost twice as long for the custom loader, even though it wasn\u2019t anything very fancy or crazy. Just by showing their users that they cared about them, they stuck around, and the bounce rates dropped.\n\n14 second generic loading screen.22 second custom loading screen.\nThis also works for form submission. Giving your personal information over to an online process like a static form can be a bit harrowing. It becomes more harrowing without animation used as a signal that something is happening, and that some process is completing. That same animation can also entertain users and make them feel as though the wait isn\u2019t as long. \nEli Fitch gave a talk at CSS Dev Conf called: \u201cPerceived Performance: The Only Kind That Really Matters\u201d, which is one of my favorite talk titles of all time. In it, he discussed how we tend to measure things like timelines and network requests because they are more quantifiable\u2013and therefore easier to measure\u2013but that measuring how a user feels when visiting the site is more important and worth the time and attention. \nIn his talk, he states \u201cHumans over-estimate passive waits by 36%, per Richard Larson of MIT\u201d. This means that if you\u2019re not using animation to speed up how fast the wait time of a form submission loads, users are perceiving it to be much slower than the dev tools timeline is recording.\nReign it in\nUnlike fonts, colors, and so on, we tend to add animation in as a last step, which leads to disorganized implementations that lack overall cohesion. If you asked a designer or developer if they would create a mockup or build a UI without knowing the fonts they were working with, they would dislike the idea. Not knowing the building blocks they\u2019re working with means that the design can fall apart or the development can break with something so fundamental left out at the start. Good animation works the same way.\nThe first step in reigning in your use of animation is to perform an animation audit. Look at all the places you are using animation on your site, or the places you aren\u2019t using animation but probably should. (Hint: perceived performance of a loader on a form submission can dramatically change your bounce rates.) \nNot sure how to perform a good audit? Val Head has a great chapter on it in her book, Designing Interface Animations, which has of buckets of research and great ideas.\nEven some beautiful component libraries that have animation in the docs make this mistake. You don\u2019t need every kind of animation, just like you don\u2019t need every kind of font. This bloats our code. Ask yourself questions like: do you really need a flip 180 degree animation? I can\u2019t even conceive of a place on a typical UI where that would be useful, yet most component libraries that I\u2019ve seen have a mixin that does just this.\nWhich leads to\u2026\nHave an opinion\nMany people are confused about Material Design. They think that Material Design is Motion Design, mostly because they\u2019ve never seen anyone take a stance on animation before and document these opinions well. But every time you use Material Design as your motion design language, people look at your site and think GOOGLE. Now that\u2019s good branding.\nBy using Google\u2019s motion design language and not your own, you\u2019re losing out on a chance to be memorable on your own website.\nWhat does having an opinion on motion look like in practice? It could mean you\u2019ve decided that you never flip things. It could mean that your eases are always going to glide. In that instance, you would put your efforts towards finding an ease that looks \u201cgliding\u201d and pulling out any transform: scaleX(-1) animation you find on your site. Across teams, everyone knows not to spend time mocking up flipping animation (even if they\u2019re working on an entirely different codebase), and to instead work on something that feels like it glides. You save time and don\u2019t have to communicate again and again to make things feel cohesive.\nCreate good developer resources\nSometimes people don\u2019t incorporate animation into a design system because they aren\u2019t sure how, beyond the base hover states. All animation properties can be broken into interchangeable pieces. This allows developers and designers alike to mix and match and iterate quickly, while still staying in the correct language. Here are some recommendations (with code and a demo to follow):\nCreate timing units, similar to h1, h2, h3. In a system I worked on recently, I called these t1, t2, t3. T1 would be reserved for longer pieces, down to t5 which is a bit like h5 in that it\u2019s the default (usually around .25 seconds or thereabouts).\nKeep animation easings for entrance, exit, entrance emphasis and exit emphasis that people can commonly refer to. This, and the animation-fill-mode, are likely to be the only two properties that can be reused for the entrance and exit of the animation.\nUse the animation-name property to define the keyframes for the animation itself. I would recommend starting with 5 or 6 before making a slew of them, and see if you need more. Writing 30 different animations might seem like a nice resource, but just like your color palette having too many can unnecessarily bulk up your codebase, and keep it from feeling cohesive. Think critically about what you need here. \nSee the Pen Modularized Animation for Component Libraries by Sarah Drasner (@sdras) on CodePen.\n\nThe example above is pared-down, but you can see how in a robust system, having pieces that are interchangeable cached across the whole system would save time for iterations and prototyping, not to mention make it easy to make adjustments for different feeling movement on the same animation easily.\nOne low hanging fruit might be a loader that leads to a success dialog. On a big site, you might have that pattern many times, so writing up a component that does only that helps you move faster while also allowing you to really zoom in and focus on that pattern. You avoid throwing something together at the last minute, or using a GIF, which are really heavy and mushy on retina. You can make singular pieces that look really refined and are reusable. \nReact and Vue Implementations are great for reusable components, as you can create a building block with a common animation pattern, and once created, it can be a resource for all. Remember to take advantage of things like props to allow for timing and easing adjustments like we have in the previous example!\nResponsive\nAt the very least we should ensure that interaction also works well on mobile, but if we\u2019d like to create interactions that take advantage of all of the gestures mobile has to offer, we can use libraries like zingtouch or hammer to work with swipe or multiple finger detection. With a bit of work, these can all be created through native detection as well.\nResponsive web pages can specify initial-scale=1.0 in the meta tag so that the device is not waiting the required 300ms on the secondary tap before calling action. Interaction for touch events must either start from a larger touch-target (40px \u00d7 40px or greater) or use @media(pointer:coarse) as support allows.\nBuy-in\nSometimes people don\u2019t create animation resources simply because it gets deprioritized. But design systems were also something we once had to fight for, too. This year at CSS Dev Conf, Rachel Nabors demonstrated how to plot out animation wants vs. needs on a graph (reproduced with her permission) to help prioritize them:\n\n\nThis helps people you\u2019re working with figure out the relative necessity and workload of the addition of these animations and think more critically about it. You\u2019re also more likely to get something through if you\u2019re proving that what you\u2019re making is needed and can be reused. \nGood compromises can be made this way: \u201cwe\u2019re not going to go all out and create an animated \u2018About Us\u2019 page like you wanted, but I suppose we can let our users know their contact email went through with a small progress and success notification.\u201d \nSuccessfully pushing smaller projects through helps build trust with your team, and lets them see what this type of collaboration can look like. This builds up the type of relationship necessary to push through projects that are more involved. It can\u2019t be overstressed that good communication is key.\nGet started!\nWith these tools and good communication, we can make our codebases more efficient, performant, and feel better for our users. We can enhance the user experience on our sites, and create great resources for our teams to allow them to move more quickly while innovating beautifully.", "year": "2016", "author": "Sarah Drasner", "author_slug": "sarahdrasner", "published": "2016-12-16T00:00:00+00:00", "url": "https://24ways.org/2016/animation-in-design-systems/", "topic": "code"}
{"rowid": 295, "title": "Internet of Stranger Things", "contents": "This year I\u2019ve been running a workshop about using JavaScript and Node.js to work with all different kinds of electronics on the Raspberry Pi. So especially for 24 ways I\u2019m going to show you how I made a very special Raspberry Pi based internet connected project! And nothing says Christmas quite like a set of fairy lights connected to another dimension1.\nWhat you\u2019ll see\nYou can rig up the fairy lights in your home, with the scrawly letters written under each one. The people from the other side (i.e. the internet) will be able to write messages to you from their browser in real time. In fact why not try it now; check this web page. When you click the lights in your browser, my lights (and yours) will turn on and off in real life! (There may be a queue if there are lots of people accessing it, hit the \u201cSend a message\u201d button and wait your turn.)\n\n\n\n\nIt\u2019s all done with JavaScript, using Node.js running on both the Raspberry Pi and on the server. I\u2019m using WebSockets to communicate in real time between the browser, server and Raspberry Pi.\nWhat you\u2019ll need\n\nRaspberry Pi any of the following models: Zero (will need straight male header pins soldered2 and Micro USB OTG adaptor), A+, B+, 2, or 3\nMicro SD card at least 4Gb Class 10 speed3\nMicro USB power supply at least 2A\nUSB Wifi dongle (unless you have a Pi 3 - that has wifi built in). \nAddressable fairy lights\nLogic level shifter (with pins soldered unless you want to do it!)\nBreadboard\nJumper wires (3x male to male and 4x female to male)\n\nOptional but recommended\n\nBase board to hold the Pi and Breadboard (often comes with a breadboard!)\n\nFind links for where to buy all of these items that goes along with this tutorial. The total price should be around $1004.\nSetting up the Raspberry Pi\nYou\u2019ll need to install the SD card for the Raspberry Pi. You\u2019ll find a link to download a disk image on the support document, ready-made with the Raspbian version of Linux, along with Node.js and all the files you need. Download it and write it to the SD card using the fantastic free software Etcher5. \nNext up you have to configure the wifi details on the SD card. If you plug the card into your computer you should see a drive called BOOT. There\u2019s a text file on there called wpa_supplicant.conf. Open it up in your favourite text editor and replace mywifi and mypassword with your wifi details6.\nnetwork={\n   ssid=\"mywifi\"\n   psk=\"mypassword\"\n}\nSave the file, eject the card from your computer and plug it into the Raspberry Pi. \nIf you have a base board or holder for the Raspberry Pi, attach it now. Then connect the wifi USB dongle7 and power supply, but don\u2019t plug it in yet!\nWiring!\nTime to wire everything up! \nFirst of all, push the Logic Level Converter into the middle of the breadboard:\n\nLogic Level Converter\nThe logic level converter may be labelled differently from the one in the diagram but the pins are usually exactly the same internally. I would just make sure the pins marked HV (High Voltage) are on the bottom and LV (Low Voltage) are on the top. \n\nRaspberry Pi pins only output 3.3v but the lights need 5v. That\u2019s why we need the logic level converter in there to boost up the signal.\nConnect the first two wires between the Raspberry Pi pins and the breadboard:\n\nNote that the pins on the Raspberry Pi are male, so you need a female to male jumper wire to connect between them and the breadboard. The colours don\u2019t have to match but it\u2019s easier to follow (and check) if you use the same ones as in the diagram. \n\nThen the next two:\n\nThis is what you should have so far:\n\nLights\nNow to connect the lights! My ones have a connector with three holes in it that I can push jumper wires into, and hopefully yours will too! So I used the male-to-male jumper wires to connect them to the breadboard.\n\n\n\nMake sure that you connect the right end of the lights, mine has a male connector at the wrong end so it\u2019s impossible to do this, but double check.  \nAlso make sure that the holes in the light connector are the same as mine. To do this, follow the wires from the connector to the first light and look at the circuit board inside. You should just about be able to make out the connections labelled + (sometimes 5V, V+ or VCC), GND (or \u2018-\u2019 or G) and DI (sometimes DIN for data in).\n\nYou can just about make out the +, DI and GND on this picture. Note that on the other side of the board there is a DO for data out - that\u2019s what takes the data along to the chip in the next light. Make sure that you\u2019re plugging into the data-in and not the data-out! \nThat\u2019s it! Everything\u2019s plugged in and ready to go! But before you plug power into your Pi, double check all your wires and make sure they\u2019re exactly right! You could damage your Raspberry Pi if it is not wired correctly. So triple check!\n\nThe Moment of Truth!\nPlug in the Raspberry Pi and wait around a minute or two for it to boot up. If all is well, the lights should strobe rainbow colours for one second - that\u2019s your confirmation that it\u2019s connected to my WebSocket server and ready to receive messages from the upside-down! \n\nHowever, if the first light in the string is pulsing red, it means that you\u2019re not connected to the internet. So check the Troubleshooting section of the support document. If it\u2019s pulsing green then you\u2019re connected to the internet but can\u2019t connect to my server. It must have gone down. Sorry! The code will keep trying so leave it running and maybe it\u2019ll come back up.  \nRig up the lights!\nFix the lights up on the wall however you want, pins, nails, tape. I\u2019ve used cable clips. Just be careful! I\u2019m using a 50 light string so I\u2019ve programmed it to use the lights at the end for the letters. That way I have just under half the string to extend down to the floor where I can keep the Raspberry Pi. \nCheck the photo here to see how the lights line up, note that there are spare unused lights in-between each row:\n\nNow visit lights.seb.ly and you\u2019ll see this : \n\nIf you\u2019re the only one online you\u2019ll have direct connection to the lights and any letter you click on will light up both in the browser and in real life. If there are other people there, you\u2019ll need to click the button to join the queue and wait your turn. \nHow it works - the geeky details!\nElectronics:\nThe pins on the Raspberry Pi are known as GPIO pins, general-purpose input/output. You can connect a wide variety of electronic components to them, LED lights, buttons, switches, and sensors. You can turn the power to the pins on and off using Node.js (or Python, if you prefer). \nAddressable LEDs or \u201cNeopixels\u201d\nWe\u2019re only using one GPIO pin on the Raspberry Pi (the other connections are 5V, 3.3V and ground) and that single pin is controlling all of the lights in the string. The code turns the pin on and off really fast in strictly timed morse-code-like dots and dashes to transmit binary data. The chips attached to each LED decode the binary and adjust the output to the LED accordingly. That chip then sends the data on to the next light in the string. \nThe chips on each light are the WS2811, part of the WS281x family that come in a multitude of different form factors and are often packaged with tiny LEDs in a single component. They are commonly referred to as Neopixels8 and I used them on my Laser Light Synths project.\nNeopixels with the chip and the LED all in one - it\u2019s the white square shaped component and the darker square inside is the chip. These are only 5mm wide!\nA Laser Light Synth! Covered with around 800 super bright neopixels!\nLogic Level Converter\nThe logic level converter is a really cheap and easy way to change the level from 3.3v to 5v and back again. You must be careful that you do not connect 5v into a GPIO pin or you will most likely damage the Raspberry Pi processor chip. \nPower\nNeopixels can often draw a lot of current so you need to be careful how you power them. I\u2019ve measured the current draw from the string to be less than 800mA so you should be fine wired directly to the 5V output. But if you use more lights or have them all on really bright at once, you\u2019ll need to use a separate 5V power supply. If you want to learn more, check out Adafruit\u2019s Neopixel Uberguide. \nNode.js\nThere are two Node.js apps running here, one on the Raspberry Pi and one on my server. You can see the code on my GitHub at github.com/sebleedelisle/stranger-lights for the Raspberry Pi and github.com/sebleedelisle/stranger-lights-server for the server.  And they\u2019re hosted on npm as stranger-lights and stranger-lights-server.  \nThe server side code sets up a standard web server to deliver the HTML for the web interface. It also sets up a WebSocket server that allows for real-time communication between the browser and the server. This server code also manages the queue and who is in control of the lights at any given time.\nWebSockets\nI\u2019m using the excellent Socket.io library to manage the WebSocket connection. Both the browser and the Raspberry Pi Node.js app connects to my WebSocket server. \nWhen you click on a letter in the browser, a message is sent to the server, which forwards it to the connected Raspberry Pi clients and also all the web browsers9. \nThe Raspberry Pi code\nThe Node.js app runs automatically on startup, and I made this happen by adding this to the /etc/rc.local file: \nnode /home/pi/strangerthings/client.js > /dev/null &\nAnything in the rc.local file gets executed when the Pi boots up and this line of code runs the Node.js app and routes its output to nowhere (ie /dev/null). The & means that it runs it in the background and doesn\u2019t hold up the boot process. \nWorking with the Raspberry Pi headless\nYou might know that when a computer has no screen or keyboard, you would refer to it as \u201crunning headless\u201d. So just like most web servers, you need to configure it over the network with ssh10. If you\u2019re on a mac you can find your Pi on the network through the name raspberrypi.local11, otherwise you\u2019ll need to find its IP address. There\u2019s more on the guide to Remote Access instructions on the Raspberry Pi website. And if you\u2019re very new to the terminal, I highly recommend this great online Linux command line tutorial.\nImprovements\nThis is quite an early experiment and I\u2019m sure I\u2019ll discover lots of optimisations over the next few weeks, especially if the server gets a proper hammering today! But there are a few things you can do. Obviously I\u2019ve just rigged up my lights with Post-it notes. It\u2019d be a lot nicer to get a paint brush and try to recreate the Winona-in-a-manic-state text style. \nWhere next?\nFinding quality resources about Node.js for electronics on the Pi can be somewhat hit and miss, but this is getting better all the time. Alternatively I am thinking about running some online courses, please let me know if that\u2019s something you\u2019d be interested in, or sign up to my mailing list at st4i.com. \nThere are many many more resources for the Raspberry Pi with Python (gpiozero is a good place to start), so if that language works for you, you\u2019ll be spoilt for choice! \nAlso take a look at Arduino - it\u2019s an incredibly popular platform for electronics and the internet is literally bursting with resources. \nI hope you enjoyed this little foray into the world of JavaScript electronics on the Raspberry Pi! If you get this working at home please let me know! Tweet me at @seb_ly. \n\n\n\n\nNot a particularly original idea, but I don\u2019t think I\u2019ve seen anyone do it quite like this before, ie using WebSockets, and Node.js on a Raspberry Pi. Other examples: Internet of Stranger Things, Strangerlights.com, and loads of examples on Instructables\u00a0\u21a9\ufe0e\n\n\nVideo guide to soldering pins on to a Pi Zero and further soldering advice from Adafruit\u00a0\u21a9\ufe0e\n\n\nSlower cards will work but performance may suffer\u00a0\u21a9\ufe0e\n\n\nOr \u00a35,000 in UK money. Sorry, Brexit joke :)\u00a0\u21a9\ufe0e\n\n\nYou will need a card reader on your computer - most micro SD cards come with an adaptor that fits standard SD slots. \u00a0\u21a9\ufe0e\n\n\nSSID and password should be all that you need but you can see all the config options on this wpa supplicant guide\u00a0\u21a9\ufe0e\n\n\nRaspberry Pi Zero will require the OTG to USB adaptor to attach the wifi dongle\u00a0\u21a9\ufe0e\n\n\nThanks to Adafruit who invented the term neopixels so we don\u2019t have to refer to them as WS281x any more!\u00a0\u21a9\ufe0e\n\n\nSo you can see other people sending messages in the browser\u00a0\u21a9\ufe0e\n\n\nssh is short for Secure Shell and is a way to connect to a remote computer and type in it just like you would in the terminal.\u00a0\u21a9\ufe0e\n\n\nYou can change this default hostname using raspi-config\u00a0\u21a9\ufe0e", "year": "2016", "author": "Seb Lee-Delisle", "author_slug": "sebleedelisle", "published": "2016-12-01T00:00:00+00:00", "url": "https://24ways.org/2016/internet-of-stranger-things/", "topic": "code"}
{"rowid": 294, "title": "New Tricks for an Old Dog", "contents": "Much of my year has been spent helping new team members find their way around the expansive and complex codebase that is the TweetDeck front-end, trying to build a happy and productive group of people around a substantial codebase with many layers of legacy.\nI\u2019ve loved doing this. Everything from writing new documentation, drawing diagrams, and holding technical architecture sessions teaches you something you didn\u2019t know or exposes an area of uncertainty that you can go work on.\nIn this article, I hope to share some experiences and techniques that will prove useful in your own situation and that you can impress your friends in some new and exciting ways!\nHow do you do, fellow kids?\nTo start with I\u2019d like to introduce you to our JavaScript framework, Flight. Right now it\u2019s used by twitter.com and TweetDeck although, as a company, Twitter is largely moving to React.\nOver time, as we used Flight for more complex interfaces, we found it wasn\u2019t scaling with us.\nComposing components into trees was fiddly and often only applied for a specific parent-child pairing. It seems like an obvious feature with hindsight, but it didn\u2019t come built-in to Flight, and it made reusing components a real challenge.\nThere was no standard way to manage the state of a component; they all did it slightly differently, and the technique often varied by who was writing the code. This cost us in maintainability as you just couldn\u2019t predict how a component would be built until you opened it.\nMaking matters worse, Flight relied on events to move data around the application. Unfortunately, events aren\u2019t good for giving structure to complex logic. They jump around in a way that\u2019s hard to understand and debug, and force you to search your code for a specific string \u2014 the event name\u201a to figure out what\u2019s going on.\nTo find fixes for these problems, we looked around at other frameworks. We like React for it\u2019s simple, predictable state management and reactive re-render flow, and Elm for bringing strict functional programming to everyone.\nBut when you have lots of existing code, rewriting or switching framework is a painful and expensive option. You have to understand how it will interact with your existing code, how you\u2019ll test it alongside existing code, and how it will affect the size and performance of the application. This all takes time and effort!\nInstead of planning a rewrite, we looked for the ideas hidden within other frameworks that we could reapply in our own situation or bring to the tools we already were using.\nBoiled down, what we liked seemed quite simple:\n\nComponent nesting & composition\nEasy, predictable state management\nNormal functions for data manipulation\n\nMaking these ideas applicable to Flight took some time, but we\u2019re in a much better place now. Through persistent trial-and-error, we have well documented, testable and standard techniques for creating complex component hierarchies, updating and reacting to state changes, and passing data around the app.\nWhile the specifics of our situation and Flight aren\u2019t really important, this experience taught me something: \n\nDistill good tech into great ideas. You can apply great ideas anywhere.\n\nYou don\u2019t have to use cool kids\u2019 latest framework, hottest build tool or fashionable language to benefit from them. If you can identify a nugget of gold at the heart of it all, why not use it to improve what you have already?\nTimes, they are a changin\u2019\nApart from stealing ideas from the new and shiny, how can we keep make the most of improved tooling and techniques? Times change and so should the way we write code.\nGoing back in time a bit, TweetDeck used some slightly outmoded tools for building and bundling. Without a transpiler like Babel we were missing out new language features, and without a more advanced build tools like Webpack, every module\u2019s source was encased in AMD boilerplate.\nIn fact, we found ourselves with a mix of both AMD syntaxes:\ndefine([\"lodash\"], function (_) {\n  // . . .\n});\n\ndefine(function (require) {\n  var _ = require(\"lodash\");\n  // . . .\n});\nThis just wouldn\u2019t do. And besides, what we really wanted was CommonJS, or even ES2015 module syntax:\nimport _ from \"lodash\";\nThese days we\u2019re using Babel, Webpack, ES2015 modules and many new language features that make development just\u2026 better. But how did we get there?\nTo explain, I want to introduce you to codemods and jscodeshift.\nA codemod is a large-scale refactor of a whole codebase, often mechanical or repetitive. Think of renaming a module or changing an API like URL(\"...\") to new URL(\"...\").\njscodeshift is a toolkit for running automated codemods, where you express a code transformation using code. The automated codemod operates on each file\u2019s syntax tree \u2013 a data-structure representation of the code \u2014 finding and modifying in place as it goes.\nHere\u2019s an example that renames all instances of the variable foo to bar:\nmodule.exports = function (fileInfo, api) {\n  return api\n    .jscodeshift(fileInfo.source)\n    .findVariableDeclarators('foo')\n    .renameTo('bar')\n    .toSource();\n};\nIt\u2019s a seriously powerful tool, and we\u2019ve used it to write a series of codemods that:\n\nrename modules,\nunify our use of AMD to a single syntax,\ntransition from one testing framework to another, and\nswitch from AMD to CommonJS.\n\nThese changes can be pretty huge and far-reaching. Here\u2019s an example commit from when we switched to CommonJS:\ncommit 8f75de8fd4c702115c7bf58febba1afa96ae52fc\nDate:   Tue Jul 12 2016\n\n   Run AMD -> CommonJS codemod\n\n 418 files changed, 47550 insertions(+), 48468 deletions(-)\n\nYep, that\u2019s just under 50k lines changed, tested, merged and deployed without any trouble. AMD be gone!\n\nFrom this step-by-step approach,  using codemods to incrementally tweak and improve, we extracted a little codemod recipe for making significant, multi-stage changes:\n\nFind all the existing patterns\nChoose the two most similar\nUnify with a codemod\nRepeat.\n\nFor example:\n\nFor module loading, we had 2 competing AMD patterns plus some use of CommonJS\nThe two AMD syntaxes were the most similar\nWe used a codemod to move to unify the AMD patterns\nLater we returned to AMD to convert it to CommonJS\n\nIt\u2019s worked for us, and if you\u2019d like to know more about codemods then check out Evolving Complex Systems Incrementally by Facebook engineer, Christoph Pojer.\nWelcome aboard!\nAs TweetDeck has gotten older and larger, the amount of things a new engineer has to learn about has exploded. The myriad of microservices that manage our data and their layers of authentication, security and business logic around them make for an overwhelming amount of information to hand to a newbie.\nInspired by Amy\u2019s amazing Guide to the Care and Feeding of Junior Devs, we realised it was important to take time to design our onboarding that each of our new hires go through to make the most of their first few weeks.\nJoining a new company, team, or both, is stressful and uncomfortable. Everything you can do to help a new hire will be valuable to them. So please, take time to design your onboarding!\nAnd as you build up an onboarding process, you\u2019ll create things that are useful for more than just new hires; it\u2019ll force you to write documentation, for example, in a way that\u2019s understandable for people who are unfamiliar with your team, product and codebase. This can lead to more outside contributions: potential contributors feel more comfortable getting set up on your product without asking for help.\nThis is something that\u2019s taken for granted in open source, but somehow I think we forget about it in big companies.\nAfter all, better documentation is just a good thing. You will forget things from time to time, and you\u2019d be surprised how often the \u201cbeginner\u201d docs help!\nFor TweetDeck, we put together system and architecture diagrams, and one-pager explanations of important concepts:\n\nWhat are our dependencies?\nWhere are the potential points of failure?\nWhere does authentication live? Storage? Caching?\nWho owns \u201cX\u201d?\n\n\nOf course, learning continues long after onboarding. The landscape is constantly shifting; old services are deprecated, new APIs appear and what once true can suddenly be very wrong. Keeping up with this is a serious challenge, and more than any one person can track.\nTo address this, we\u2019ve thought hard about our knowledge sharing practices across the whole team. For example, we completely changed the way we do code review.\nIn my opinion, code review is the single most effective practice you can introduce to share knowledge around, and build the quality and consistency of your team\u2019s work. But, if you\u2019re not doing it, here\u2019s my suggestion for getting started:\n\nEvery pull request gets a +1 from someone else.\n\nThat\u2019s all \u2014 it\u2019s very light-weight and easy. Just ask someone to have a quick look over your code before it goes into master.\nAt Twitter, every commit gets a code review. We do a lot of reviewing, so small efficiency and effectiveness improvements make a big difference. Over time we learned some things:\n\nDon\u2019t review for more than hour 1\nKeep reviews smaller than ~400 lines 2\nCode review your own code first 2\n\nAfter an hour, and above roughly 400 lines, your ability to detect issues in a code review starts to decrease. So review little and often. The gaps around lunch, standup and before you head home are ideal. And remember, if someone\u2019s put code up for a review, that review is blocking them doing other work. It\u2019s your job to unblock them.\nOn TweetDeck, we actually try to keep reviews under 250 lines. It doesn\u2019t sound like much, but this constraint applies pressure to make smaller, incremental changes. This makes breakages easier to detect and roll back, and leads to a very natural feature development process that encourages learning and iteration.\nBut the most important thing I\u2019ve learned personally is that reviewing my own code is the best way to spot issues. I try to approach my own reviews the way I approach my team\u2019s: with fresh, critical eyes, after a break, using a dedicated code review tool.\nIt\u2019s amazing what you can spot when you put a new in a new interface around code you\u2019ve been staring at for hours!\nAnd yes, this list features science. The data backs up these conclusions, and if you\u2019d like to learn more about scientific approaches to software engineering then I recommend you buy Making Software: What Really Works, and Why We Believe It. It\u2019s ace.\nFor more dedicated information sharing, we\u2019ve introduced regular seminars for everyone who works on a specific area or technology. It works like this: a team-member shares or teaches something to everyone else, and next time it\u2019s someone else\u2019s turn. Giving everyone a chance to speak, and encouraging a wide range of topics, is starting to produce great results.\nIf you\u2019d like to run a seminar, one thing you could try to get started: run a point at the thing you least understand in our architecture session \u2014 thanks to James for this idea. And guess what\u2026 your onboarding architecture diagrams will help (and benefit from) this!\nMore, please!\nThere\u2019s a few ideas here to get you started, but there are even more in a talk I gave this year called Frontend Archaeology, including a look at optimising for confidence with front-end operations.\nAnd finally, thanks to Amy for proof reading this and to Passy for feedback on the original talk.\n\n\n\n\nDunsmore et al. 2000. Object-Oriented Inspection in the Face of Delocalisation. Beverly, MA: SmartBear Software.\u00a0\u21a9\n\n\nCohen, Jason. 2006. Best Kept Secrets of Peer Code Review. Proceedings of the 22nd ICSE 2000: 467-476.\u00a0\u21a9 \u21a9", "year": "2016", "author": "Tom Ashworth", "author_slug": "tomashworth", "published": "2016-12-18T00:00:00+00:00", "url": "https://24ways.org/2016/new-tricks-for-an-old-dog/", "topic": "code"}
{"rowid": 293, "title": "A Favor for Your Future Self", "contents": "We tend to think about the future when we build things. What might we want to be able to add later? How can we refactor this down the road? Will this be easy to maintain in six months, a year, two years? As best we can, we try to think about the what-ifs, and build our websites, systems, and applications with this lens. \nWe comment our code to explain what we knew at the time and how that impacted how we built something. We add to-dos to the things we want to change. These are all great things! Whether or not we come back to those to-dos, refactor that one thing, or add new features, we put in a bit of effort up front just in case to give us a bit of safety later.\nI want to talk about a situation that Past Alicia and Team couldn\u2019t even foresee or plan for. Recently, the startup I was a part of had to remove large sections of our website. Not just content, but entire pages and functionality. It wasn\u2019t a very pleasant experience, not only for the reason why we had to remove so much of what we had built, but also because it\u2019s the ultimate \u201cI really hope this doesn\u2019t break something else\u201d situation. It was a stressful and tedious effort of triple checking that the things we were removing weren\u2019t dependencies elsewhere. To be honest, we wouldn\u2019t have been able to do this with any amount of success or confidence without our test suite.\nWriting tests for code is one of those things that developers really, really don\u2019t want to do. It\u2019s one of the easiest things to cut in the development process, and there\u2019s often a struggle to have developers start writing tests in the first place. One of the best lessons the web has taught us is that we can\u2019t, in good faith, trust the happy path. We must make sure ourselves, and our users, aren\u2019t in a tough spot later on because we only thought of the best case scenarios.\nJavaScript\nRegardless of your opinion on whether or not everything needs to be built primarily with JavaScript, if you\u2019re choosing to build a JavaScript heavy app, you absolutely should be writing some combination of unit and integration tests.\nUnit tests are for testing extremely isolated and small pieces of code, which we refer to as the units themselves. Great for reused functions and small, scoped areas, this is the closest you examine your code with the testing microscope. For example, if we were to build a calculator, the most minute piece we could test could be the basic operations.\n/*\n * This example uses a test framework called Jasmine\n */\n\ndescribe(\"Calculator Operations\", function () {\n\n    it(\"Should add two numbers\", function () {\n\n    // Say we have a calculator\n        Calculator.init();\n\n    // We can run the function that does our addition calculation...\n        var result = Calculator.addNumbers(7,3);\n\n    // ...and ensure we're getting the right output\n        expect(result).toBe(10);\n\n    });\n});\nEven though these teeny bits work in isolation, we should ensure that connecting the large pieces work, as well. This is where integration tests excel. These tests ensure that two or more different areas of code, that may not directly know about each other, still behave in expected ways. Let\u2019s build upon our calculator - we may want the operations to be saved in memory after a calculation runs. This isn\u2019t as suited for a unit test because there are a few other moving pieces involved in the process (the calculations, checking if the result was an error, etc.).\n    it(\u201cShould remember the last calculation\u201d, function () {\n\n    // Run an operation\n        Calculator.addNumbers(7,10);\n\n    // Expect something else to have happened as a result\n        expect(Calculator.updateCurrentValue).toHaveBeenCalled();\n        expect(Calculator.currentValue).toBe(17);\n    });\nUnit and integration tests provide assurance that your hand-rolled JavaScript should, for the most part, never fail in a grand fashion. Although it still might happen, you could be able to catch problems way sooner than without a test suite, and hopefully never push those failures to your production environment.\nInterfaces\nRegardless of how you\u2019re building something, it most definitely has some kind of interface. Whether you\u2019re using a very barebones structure, or you\u2019re leveraging a whole design system, these things can be tested as well.\nAcceptance testing helps us ensure that users can get from point A to point B within our web things, which can provide assurance that major features are always functioning properly. By simulating user input and data entry, we can go through whole user workflows to test for both success and failure scenarios. These are not necessarily for simulating edge-case scenarios, but rather ensuring that our core offerings are stable.\nFor example, if your site requires signup, you want to make sure the workflow is behaving as expected - allowing valid information to go through signup, while invalid information does not let you progress.\n/*\n * This example uses Jasmine along with an add-on called jasmine-integration\n */\n\ndescribe(\"Acceptance tests\", function () {\n\n  // Go to our signup page\n  var page = visit(\"/signup\");\n\n  // Fill our signup form with invalid information\n  page.fill_in(\"input[name='email']\", \"Not An Email\");\n  page.fill_in(\"input[name='name']\", \"Alicia\");\n  page.click(\"button[type=submit]\");\n\n  // Check that we get an expected error message\n  it(\"Shouldn't allow signup with invalid information\", function () {\n    expect(page.find(\"#signupError\").hasClass(\"hidden\")).toBeFalsy();\n  });\n\n  // Now, fill our signup form with valid information\n  page.fill_in(\"input[name='email']\", \"thisismyemail@gmail.com\");\n  page.fill_in(\"input[name='name']\", \"Gerry\");\n  page.click(\"button[type=submit]\");\n\n  // Check that we get an expected success message and the error message is hidden\n  it(\"Should allow signup with valid information\", function () {\n    expect(page.find(\"#signupError\").hasClass(\"hidden\")).toBeTruthy();\n    expect(page.find(\"#thankYouMessage\").hasClass(\"hidden\")).toBeFalsy();\n  });\n});\nIn terms of visual design, we\u2019re now able to take snapshots of what our interfaces look like before and after any code changes to see what has changed. We call this visual regression testing. Rather than being a pass or fail test like our other examples thus far, this is more of an awareness test, intended to inform developers of all the visual differences that have occurred, intentional or not. Developers may accidentally introduce a styling change or fix that has unintended side effects on other areas of a website - visual regression testing helps us catch these sooner rather than later. These do require a bit more consistent grooming than other tests, but can be valuable in major CSS refactors or if your CSS is generally a bit like Jenga.\nTools like PhantomCSS will take screenshots of your pages, and do a visual comparison to check what has changed between two sets of images. The code would look something like this:\n/*\n * This example uses PhantomCSS\n */\n\ncasper.start(\"/home\").then(function(){\n\n  // Initial state of form\n  phantomcss.screenshot(\"#signUpForm\", \"sign up form\");\n\n  // Hit the sign up button (should trigger error)\n  casper.click(\"button#signUp\");\n\n  // Take a screenshot of the UI component\n  phantomcss.screenshot(\"#signUpForm\", \"sign up form error\");\n\n  // Fill in form by name attributes & submit\n  casper.fill(\"#signUpForm\", {\n    name: \"Alicia Sedlock\",\n    email: \"alicia@example.com\"\n  }, true);\n\n  // Take a second screenshot of success state\n  phantomcss.screenshot(\"#signUpForm\", \"sign up form success\");\n});\nYou run this code before starting any development, to create your baseline set of screen captures. After you\u2019ve completed a batch of work, you run PhantomCSS again. This will create a second batch of screenshots, which are then put through an image comparison tool to display any differences that occurred. Say you changed your margins on our form elements \u2013 your image diff would look something like this:\n\nThis is a great tool for ensuring not just your site retains its expected styling, but it\u2019s also great for ensuring nothing accidentally changes in the living style guide or modular components you may have developed. It\u2019s hard to keep eagle eyes on every visual aspect of your site or app, so visual regression testing helps to keep these things monitored.\nConclusion\nThe shape and size of what you\u2019re testing for your site or app will vary. You may not need lots of unit or integration tests if you don\u2019t write a lot of JavaScript. You may not need visual regression testing for a one page site. It\u2019s important to assess your codebase to see which tests would provide the most benefit for you and your team.\nWriting tests isn\u2019t a joy for most developers, myself included. But I end up thanking Past Alicia a lot when there are tests, because otherwise I would have introduced a lot of issues into codebases. Shipping code that\u2019s broken breaks trust with our users, and it\u2019s our responsibility as developers to make sure that trust isn\u2019t broken. Testing shouldn\u2019t be considered a \u201cnice to have\u201d - it should be an integral piece of our workflow and our day-to-day job.", "year": "2016", "author": "Alicia Sedlock", "author_slug": "aliciasedlock", "published": "2016-12-03T00:00:00+00:00", "url": "https://24ways.org/2016/a-favor-for-your-future-self/", "topic": "code"}
{"rowid": 292, "title": "Watch Your Language!", "contents": "I\u2019m bilingual. My first language is French. I learned English in my early 20s. Learning a new language later in life meant that I was able to observe my thought processes changing over time. It made me realize that some concepts can\u2019t be expressed in some languages, while other languages express these concepts with ease.\nIt also helped me understand the way we label languages. English: business. French: romance. Here\u2019s an example of how words, or the absence thereof, can affect the way we think:\nIn French we love everything. There\u2019s no straightforward way to say we like something, so we just end up loving everything. I love my sisters, I love broccoli, I love programming, I love my partner, I love doing laundry (this is a lie), I love my mom (this is not a lie). I love, I love, I love. It\u2019s no wonder French is considered romantic. When I first learned English I used the word love rather than like because I hadn\u2019t grasped the difference. Needless to say, I\u2019ve scared away plenty of first dates!\nLearning another language made me realize the limitations of my native language and revealed concepts I didn\u2019t know existed. Without the nuances a given language provides, we fail to express what we really think. The absence of words in our vocabulary gets in the way of effectively communicating and considering ideas.\nWhen I lived in Montr\u00e9al, most people in my circle spoke both French and English. I could switch between them when I could more easily express an idea in one language or the other. I liked (or should I say loved?) those conversations. They were meaningful. They were efficient.\n\nI\u2019m quadrilingual. I code in Ruby, HTML/CSS, JavaScript, Python. In the past couple of years I have been lucky enough to write code in these languages at a massive scale. In learning Ruby, much like learning English, I discovered the strengths and limitations of not only the languages I knew but the language I was learning. It taught me to choose the right tool for the job.\nWhen I started working at Shopify, making a change to a view involved copy/pasting HTML and ERB from one view to another. The CSS was roughly structured into modules, but those modules were not responsive to different screen sizes. Our HTML was complete mayhem, and we didn\u2019t consider accessibility. All this made editing views a laborious process.\nGrep. Replace all. Test. Ship it. Repeat.\nThis wasn\u2019t sustainable at Shopify\u2019s scale, so the newly-formed front end team was given two missions:\n\nMake the app responsive (AKA Let\u2019s Make This Thing Responsive ASAP)\nMake the view layer scalable and maintainable (AKA Let\u2019s Build a Pattern Library\u2026 in Ruby)\n\nLet\u2019s make this thing responsive ASAP\nThe year was 2015. The Shopify admin wasn\u2019t mobile friendly. Our browser support was set to IE10. We had the wind in our sails. We wanted to achieve complete responsiveness in the shortest amount of time. Our answer: container queries.\nIt seemed like the obvious decision at the time. We would be able to set rules for each component in isolation and the component would know how to lay itself out on the page regardless of where it was rendered. It would save us a ton of development time since we wouldn\u2019t need to change our markup, it would scale well, and we would achieve complete component autonomy by not having to worry about page layout. By siloing our components, we were going to unlock the ultimate goal of componentization, cutting the tie to external dependencies. We were cool.\nWriting the JavaScript handling container queries was my first contribution to Shopify. It was a satisfying project to work on. We could drop our components in anywhere and they would magically look good. It took us less than a couple weeks to push this to production and make our app mostly responsive.\nBut with time, it became increasingly obvious that this was not as performant as we had hoped. It wasn\u2019t performant at all. Components would jarringly jump around the page before settling in on first paint.\nIt was only when we started using the flex-wrap: wrap CSS property to build new components that we realized we were not using the right language for the job. So we swapped out JavaScript container queries for CSS flex-wrapping. Even though flex wasn\u2019t yet as powerful as we wanted it to be, it was still a good compromise. Our components stayed independent of the window size but took much less time to render. Best of all: they used CSS instead of relying on JavaScript for layout.\nIn other words: we were using the wrong language to express our layout to the browser, when another language could do it much more simply and elegantly.\nLet\u2019s build a pattern library\u2026 in Ruby\nIn order to make our view layer maintainable, we chose to build a comprehensive library of helpers. This library would generate our markup from a single source of truth, allowing us to make changes system-wide, in one place. No. More. Grepping.\nWhen I joined Shopify it was a Rails shop freshly wounded by a JavaScript framework (See: Batman.js). JavaScript was like Voldemort, the language that could not be named. Because of this baggage, the only way for us to build a pattern library that would get buyin from our developers was to use Rails view helpers. And for many reasons using Ruby was the right choice for us. The time spent ramping developers up on the new UI Components would be negligible since the Ruby API felt familiar. The transition would be simple since we didn\u2019t have to introduce any new technology to the stack. The components would be fast since they would be rendered on the server. We had a plan.\nWe put in place a set of Rails tools to make it easy to build components, then wrote a bunch of sweet, sweet components using our shiny new tools. To document our design, content and front end patterns we put together an interactive styleguide to demonstrate how every component works. Our research and development department loved it (and still do)! We continue to roll out new components, and generally the project has been successful, though it has had its drawbacks.\nSince the Shopify admin is mostly made up of a huge number of forms, most of the content is static. For this reason, using server-rendered components didn\u2019t seem like a problem at the time. With new app features increasing the amount of DOM manipulation needed on the client side, our early design decisions mean making requests to the server for each re-paint. This isn\u2019t going to cut it.\nI don\u2019t know the end of this story, because we haven\u2019t written it yet. We\u2019ve been exploring alternatives to our current system to facilitate the rendering of our components on the client, including React, Vue.js, and Web Components, but we haven\u2019t determined the winner yet. Only time (and data gathering) will tell.\nRuby is great but it doesn\u2019t speak the browser\u2019s language efficiently. It was not the right language for the job.\n\nLearning a new spoken language has had an impact on how I write code. It has taught me that you don\u2019t know what you don\u2019t know until you have the language to express it. Understanding the strengths and limitations of any programming language is fundamental to making good design decisions. At the end of the day, you make the best choices with the information you have. But if you still feel like you\u2019re unable to express your thoughts to the fullest with what you know, it might be time to learn a new language.", "year": "2016", "author": "Annie-Claude C\u00f4t\u00e9", "author_slug": "annieclaudecote", "published": "2016-12-10T00:00:00+00:00", "url": "https://24ways.org/2016/watch-your-language/", "topic": "code"}
{"rowid": 289, "title": "Front-End Developers Are Information Architects Too", "contents": "The theme of this year\u2019s World IA Day was \u201cInformation Everywhere, Architects Everywhere\u201d. This article isn\u2019t about what you may consider an information architect to be: someone in the user-experience field, who maybe studied library science, and who talks about taxonomies. This is about a realisation I had a couple of years ago when I started to run an increasing amount of usability-testing sessions with people who have disabilities: that the structure, labelling, and connections that can be made in front-end code is information architecture. People\u2019s ability to be successful online is unequivocally connected to the quality of the code that is written.\nPlaces made of information\nIn information architecture we talk about creating places made of information. These places are made of ones and zeros, but we talk about them as physical structures. We talk about going onto a social media platform, posting in blogs, getting locked out of an environment, and building applications. In 2002, Andrew Hinton stated:\n\nPeople live and work in these structures, just as they live and work in their homes, offices, factories and malls. These places are not virtual: they are as real as our own minds.\n25 Theses\n\nWe\u2019re creating structures which people rely on for significant parts of their lives, so it\u2019s critical that we carry out our work responsibly. This means we must use our construction materials correctly. Luckily, our most important material, HTML, has a well-documented specification which tells us how to build robust and accessible places. What is most important, I believe, is to understand the semantics of HTML.\nSemantics\nThe word \u201csemantic\u201d has its origin in Greek words meaning \u201csignificant\u201d, \u201csignify\u201d, and \u201csign\u201d. In the physical world, a structure can have semantic qualities that tell us something about it. For example, the stunning Westminster Abbey inspires awe and signifies much about the intent and purpose of the structure. The building\u2019s size; the quality of the stone work; the massive, detailed stained glass: these are all signs that this is a building meant for something the creators deemed important. Alternatively consider a set of large, clean, well-positioned, well-lit doors on the ground floor of an office block: they don\u2019t need an \u201centrance\u201d sign to communicate their use and to stop people trying to use a nearby fire exit to get into the building. The design of the doors signify their usage. Sometimes a more literal and less awe-inspiring approach to communicating a building\u2019s purpose happens, but the affect is similar: the building is signifying something about its purpose.\nHTML has over 115 elements, many of which have semantics to signify structure and affordance to people, browsers, and assistive technology. The HTML 5.1 specification mentions semantics, stating:\n\nElements, attributes, and attribute values in HTML are defined \u2026 to have certain meanings (semantics). For example, the <ol> element represents an ordered list, and the lang attribute represents the language of the content.\nHTML 5.1 Semantics, structure, and APIs of HTML documents\n\nHTML\u2019s baked-in semantics means that developers can architect their code to signify structure, create relationships between elements, and label content so people can understand what they\u2019re interacting with. Structuring and labelling information to make it available, usable, and understandable to people is what an information architect does. It\u2019s also what a front-end developer does, whether they realise it or not.\nA brief introduction to information architecture\nWe\u2019re going to start by looking at what an information architect is. There are many definitions, and I\u2019m going to quote Richard Saul Wurman, who is widely regarded as the father of information architecture. In 1976 he said an information architect is:\n\nthe individual who organizes the patterns inherent in data, making the complex clear; a person who creates the structure or map of information which allows others to find their personal paths to knowledge; the emerging 21st century professional occupation addressing the needs of the age focused upon clarity, human understanding, and the science of the organization of information.\nOf Patterns And Structures\n\nTo me, this clearly defines any developer who creates code that a browser, or other user agent (for example, a screen reader), uses to create a structured, navigable place for people.\nJust as there are many definitions of what an information architect is, there are for information architecture itself. I\u2019m going to use the definition from the fourth edition of Information Architecture For The World Wide Web, in which the authors define it as:\nThe structural design of shared information environments.\nThe synthesis of organization, labeling, search, and navigation systems within digital, physical, and cross-channel ecosystems.\nThe art and science of shaping information products and experiences to support usability, findability, and understanding.\nInformation Architecture For The World Wide Web, 4th Edition\nTo me, this describes front-end development. Done properly, there is an art to creating robust, accessible, usable, and findable spaces that delight all our users. For example, at 2015\u2019s State Of The Browser conference, Edd Sowden talked about the accessibility of <table>s. He discovered that by simply not using the semantically-correct <th> element to mark up <table> headings, in some situations browsers will decide that a <table> is being used for layout and essentially make it invisible to assistive technology. Another example of how coding practices can affect the usability and findability of content is shown by L\u00e9onie Watson in her How ARIA landmark roles help screen reader users video. By using ARIA landmark roles, people who use screen readers are quickly able to identify and jump to common parts of a web page.\nOur definitions of information architects and information architecture mention patterns, rules, organisation, labelling, structure, and relationships. There are numerous different models for how these elements get boiled down to their fundamentals. In his Understanding Context book, Andrew Hinton calls them Labels, Relationships, and Rules; Jorge Arango calls them Links, Nodes, And Order; and Dan Klyn uses Ontology, Taxonomy, and Choreography, which is the one we\u2019re going to use. Dan defines these terms as:\nOntology\nThe definition and articulation of the rules and patterns that govern the meaning of what we intend to communicate.\nWhat we mean when we say what we say.\nTaxonomy\nThe arrangements of the parts. Developing systems and structures for what everything\u2019s called, where everything\u2019s sorted, and the relationships between labels and categories\nChoreography\nRules for interaction among the parts. The structures it creates foster specific types of movement and interaction; anticipating the way users and information want to flow and making affordance for change over time.\n\nWe now have definitions of an information architect, information architecture, and a model of the elements of information architecture. But is writing HTML really creating information or is it just wrangling data and metadata? When does data turn into information? In his book Managing For The Future Peter Drucker states:\n\n\u2026 data is not information. Information is data endowed with relevance and purpose.\nManaging For The Future\n\nIf we use the correct semantic element to mark up content then we\u2019re developing with purpose and creating relevance. For example, if we follow the advice of the HTML 5.1 specification and mark up headings using heading rank instead of the outline algorithm, we\u2019re creating a structure where the depth of one heading is relevant to the previous one. Architected correctly, an <h2> element should be relevant to its parent, which should be the <h1>. By following the HTML specification we can create a structured, searchable, labeled document that will hopefully be relevant to what our users need to be successful. If you\u2019ve never used a screen reader, you might be wondering how the headings on a page are searchable. Screen readers give users the ability to interact with headings in a couple of ways:\n\nby creating a list of headings so users can quickly scan the page for information\nby using a keyboard command to cycle through one heading at a time\n\nIf we had a document for Christmas Day TV we might structure it something like this:\n<h1>Christmas Day TV schedule</h1>\n  <h2>BBC1</h2>\n    <h3>Morning</h3>\n      <h3>Evening</h3>\n  <h2>BBC2</h2>\n    <h3>Morning</h3>\n    <h3>Evening</h3>\n  <h2>ITV</h2>\n    <h3>Morning</h3>\n    <h3>Evening</h3>\n  <h2>Channel 4</h2>\n    <h3>Morning</h3>\n    <h3>Evening</h3>\nIf I use VoiceOver to generate a list of headings, I get this:\n\nOnce I have that list I can use keyboard commands to filter the list based on the heading level. For example, I can press 2 to hear just the <h2>s:\n\nIf we hadn\u2019t used headings, of if we\u2019d nested them incorrectly, our users would be frustrated.\nPutting this together\nLet\u2019s put this together with an example of a button that, when pressed, toggles the appearance of a panel of links. There are numerous ways we could create a button on a web page, but the best way is to just use a <button>. Every browser understands what a <button> is, how it works, and what keyboard shortcuts should be used with them. The HTML specification for the <button> element says:\n\nThe <button> element represents a button labeled by its contents.\n\nThe contents that a <button> can have include the type attribute, any relevant ARIA attributes, and the actual text label that the user sees. This information is more important than the visual design: it doesn\u2019t matter how beautiful or obtuse the design is, if the underlying code is non-semantic and poorly labelled, people are going to struggle to use it. Here are three buttons, each created with the same HTML but with different designs:\n\nRegardless of what they look like, because we\u2019ve used semantic HTML instead of a bunch of meaningless <div>s or <span>s, people who use assistive technology are going to benefit. Out of the box, without any extra development effort, a <button> is accessible and usable with a keyboard. We don\u2019t have to write event handlers to listen for people pressing the Enter key or the space bar, which we would have to do if we\u2019d faked a button with non-semantic elements. Our <button> can also be quickly findable: for example, in the same way it\u2019s possible to create a list of headings with a screen reader, I can also create a list of form elements and then quickly jump to the one I want.\nNow we have our <button>, let\u2019s add the panel we\u2019re toggling the appearance of. Here\u2019s our code:\n<button aria-controls=\"panel\" aria-expanded=\"false\" class=\"settings\" id=\"settings\" type=\"button\">Settings</button>\n\n<div class=\"panel hidden\" id=\"panel\">\n    <ul aria-labelledby=\"settings\">\n        <li><a href=\"\u2026\">Account</a></li>\n        <li><a href=\"\u2026\">Privacy</a></li>\n        <li><a href=\"\u2026\">Security</a></li>\n    </ul>\n</div>\nThere\u2019s quite a bit going on here. We\u2019re using the:\n\naria-controls attribute to architect a connection between the <button> element and the panel whose appearance it controls. When some assistive technology, for example the JAWS screen reader, encounters an element with aria-controls it audibly tells a user about the controlled expanded element and gives them the ability to move focus to it.\naria-expanded attribute to denote whether the panel is visible or not. We toggle this value using JavaScript to true when the panel is visible and false when it\u2019s not. This important attribute tells people who use screen readers about the state of the elements they\u2019re interacting with. For example, VoiceOver announces Settings expanded button when the panel is visible and Settings collapsed button when it\u2019s hidden.\naria-labelledby attribute to give the list a title of \u201cSettings\u201d. This can benefit some users of assistive technology. For example, screen readers can cycle through all the lists on a page, so being able to title them can improve findability. Being able to hear list Settings three items is, I\u2019d argue, more useful than list three items. By doing this we\u2019re supporting usability and findability.\n<ul> element to contain our list of links in our panel.\n\nLet\u2019s look at the choice of <ul> to contain our settings choices. Firstly, our settings are related items, so they belong in a structure that semantically groups things. This is something that a list can do that other elements or patterns can\u2019t. This pattern, for example, isn\u2019t semantic and has no structure:\n<div><a href=\"\u2026\">Account</a></div>\n<div><a href=\"\u2026\">Privacy</a></div>\n<div><a href=\"\u2026\">Security</a></div>\nAll we have there is three elements next to each other on the screen and in the DOM. That is not robust code that signifies anything.\nWhy are we using an unordered list as opposed to an ordered list or a definition list? A quick look at the HTML specification tells us why:\n\nThe <ul> element represents a list of items, where the order of the items is not important \u2014 that is, where changing the order would not materially change the meaning of the document.\nThe HTML 5.1 specification\u2019s description of the  element\n\nWill the meaning of our document materially change if we moved the order of our links around? Nope. Therefore, I\u2019d argue, we\u2019ve used the correct element to structure our content.\nThese coding decisions are information architecture\nI believe that what we\u2019ve done here is pure information architecture. Going back to Dan Klyn\u2019s model, we\u2019ve practiced ontology by looking at the meaning of what we\u2019re intending to communicate:\n\nwe want to communicate there is an interactive element that toggles the appearance of an element on a page so we\u2019ve used one, a <button>, with those semantics.\nprogrammatically we\u2019ve used the type='button' attribute to signify that the button isn\u2019t a menu, reset, or submit element.\nvisually we\u2019ve designed our <button> look like something that can be interacted with and, importantly, we haven\u2019t removed the focus ring.\nwe\u2019ve labelled the <button> with the word \u201cSettings\u201d so that our users will hopefully understand what the button is for.\nwe\u2019ve used an <ul> element to structure and communicate our list of related items.\n\nWe\u2019ve also practiced taxonomy by developing systems and structures and creating relationships between our elements:\n\nby connecting the <button> to the panel using the aria-controls attribute we\u2019ve programmatically created a relationship between two elements.\nwe\u2019ve developed a structure in our elements by labelling our <ul> with the same name as the <button> that controls its appearance.\n\nAnd finally we\u2019ve practiced choreography by creating elements that foster movement and interaction. We\u2019ve anticipated the way users and information want to flow:\n\nwe\u2019ve used a <button> element that is interactive and accessible out of the box.\nour aria-controls attribute can help some people who use screen readers move easily from the <button> to the panel it controls.\nby toggling the value of the aria-expanded attribute we\u2019ve developed a system that tells assistive technology about the status of the relationship between our elements: the panel is visible or the panel is hidden.\nwe\u2019ve made sure our information is more usable and findable no matter how our users want or need to interact with it. Regardless of how someone \u201csees\u201d our work they\u2019re going to be able to use it because we\u2019ve architected multiple ways to access our information.\n\nInformation architecture, robust code, and accessibility\nThe United Nations estimates that around 10% of the world\u2019s population has some form of disability which, at the time of writing, is around 740,000,000 people. That\u2019s a lot of people who rely on well-architected semantic code that can be interpreted by whatever assistive technology they may need to use.\nIf everyone involved in the creation of our places made of information practiced information architecture it would make satisfying the WCAG 2.0 POUR principles so much easier. Our digital construction practices directly affect the quality of life of millions of people, and we have a responsibility to make technology available to them. In her book How To Make Sense Of Any Mess, Abby Covert states:\nIf we\u2019re going to be successful in this new world, we need to see information as a workable material and learn to architect it in a way that gets us to our goals.\nHow To Make Sense Of Any Mess\nI believe that the world will be a better place if we start treating front-end development as information architecture.", "year": "2016", "author": "Francis Storr", "author_slug": "francisstorr", "published": "2016-12-17T00:00:00+00:00", "url": "https://24ways.org/2016/front-end-developers-are-information-architects-too/", "topic": "code"}
{"rowid": 288, "title": "Displaying Icons with Fonts and Data- Attributes", "contents": "Traditionally, bitmap formats such as PNG have been the standard way of delivering iconography on websites. They\u2019re quick and easy, and it also ensures they\u2019re as pixel crisp as possible. Bitmaps have two drawbacks, however: multiple HTTP requests, affecting the page\u2019s loading performance; and a lack of scalability, noticeable when the page is zoomed or viewed on a screen with a high pixel density, such as the iPhone 4 and 4S.\n\nThe requests problem is normally solved by using CSS sprites, combining the icon set into one (physically) large image file and showing the relevant portion via background-position. While this works well, it can get a bit fiddly to specify all the positions. In particular, scalability is still an issue. A vector-based format such as SVG sounds ideal to solve this, but browser support is still patchy.\n\n\n\nThe rise and adoption of web fonts have given us another alternative. By their very nature, they\u2019re not only scalable, but resolution-independent too. No need to specify higher resolution graphics for high resolution screens! \n\nThat\u2019s not all though:\n\n\n\tBrowser support: Unlike a lot of new shiny techniques, they have been supported by Internet Explorer since version 4, and, of course, by all modern browsers. We do need several different formats, however!\n\tDesign on the fly: The font contains the basic graphic, which can then be coloured easily with CSS \u2013 changing colours for themes or :hover and :focus styles is done with one line of CSS, rather than requiring a new graphic. You can also use CSS3 properties such as text-shadow to add further effects. Using -webkit-background-clip: text;, it\u2019s possible to use gradient and inset shadow effects, although this creates a bitmap mask which spoils the scalability.\n\tSmall file size: specially designed icon fonts, such as Drew Wilson\u2019s Pictos font, can be as little as 12Kb for the .woff font. This is because they contain fewer characters than a fully fledged font. You can see Pictos being used in the wild on sites like Garrett Murray\u2019s Maniacal Rage.\n\n\nAs with all formats though, it\u2019s not without its disadvantages: \n\n\n\tIcons can only be rendered in monochrome or with a gradient fill in browsers that are capable of rendering CSS3 gradients. Specific parts of the icon can\u2019t be a different colour.\n\tIt\u2019s only appropriate when there is an accompanying text to provide meaning. This can be alleviated by wrapping the text label in a tag (I like to use <b> rather than <span>, due to the fact that it\u2019s smaller and isn\u2019 t being used elsewhere) and then hiding it from view with text-indent:-999em.\n\tCreating an icon font can be a complex and time-consuming process. While font editors can carry out hinting automatically, the best results are achieved manually.\n\tUnless you\u2019re adept at creating your own fonts, you\u2019re restricted to what is available in the font. However, fonts like Pictos will cover the most common needs, and icons are most effective when they\u2019re using familiar conventions.\n\n\nThe main complaint about using fonts for icons is that it can mean adding a meaningless character to our markup. The good news is that we can overcome this by using one of two methods \u2013 CSS generated content or the data-icon attribute \u2013 in combination with the :before and :after pseudo-selectors, to keep our markup minimal and meaningful. \n\nOur simple markup looks like this:\n\n<a href=\"/basket\" class=\"icon basket\">View Basket</a>\n\nNote the multiple class attributes. Next, we\u2019ll import the Pictos font using the @font-face web fonts property in CSS:\n\n@font-face {\n    font-family: 'Pictos';\n    src: url('pictos-web.eot');\n    src: local('\u263a'), \n    url('pictos-web.woff') format('woff'), \n    url('pictos-web.ttf') format('truetype'),\n    url('pictos-web.svg#webfontIyfZbseF') format('svg');\n}\n\nThis rather complicated looking set of rules is (at the time of writing) the most bulletproof way of ensuring as many browsers as possible load the font we want.  We\u2019ll now use the content property applied to the :before pseudo-class selector to generate our icon. Once again, we\u2019ll use those multiple class attribute values to set common icon styles, then specific styles for .basket. This helps us avoid repeating styles:\n\n.icon {\n    font-family: 'Pictos';\n    font-size: 22px:\n}\n\n.basket:before {\n    content: \"$\";\n}\n\nWhat does the :before pseudo-class do? It generates the dollar character in a browser, even when it\u2019s not present in the markup. Using the generated content approach means our markup stays simple, but we\u2019ll need a new line of CSS, defining what letter to apply to each class attribute for every icon we add.\n\ndata-icon is a new alternative approach that uses the HTML5 data- attribute in combination with CSS attribute selectors. This new attribute lets us add our own metadata to elements, as long as its prefixed by data- and doesn\u2019t contain any uppercase letters. In this case, we want to use it to provide the letter value for the icon. Look closely at this markup and you\u2019ll see the data-icon attribute.\n\n<a href=\"/basket\" class=\"icon\" data-icon=\"$\">View Basket</a>\n\n\n\nWe could add others, in fact as many as we like.\n\n<a href=\"/\" class=\"icon\" data-icon=\"k\">Favourites</a>\n<a href=\"/\" class=\"icon\" data-icon=\"t\">History</a>\n<a href=\"/\" class=\"icon\" data-icon=\"@\">Location</a>\n\n\n\nThen, we need just one CSS attribute selector to style all our icons in one go:\n\n.icon:before {\n    content: attr(data-icon);\n    /* Insert your fancy colours here */\n    }\n\nBy placing our custom attribute data-icon in the selector in this way, we can enable CSS to read the value of that attribute and display it before the element (in this case, the anchor tag). It saves writing a lot of CSS rules. I can imagine that some may not like the extra attribute, but it does keep it out of the actual content \u2013 generated or not.\n\n\n\n\n\nThis could be used for all manner of tasks, including a media player and large simple illustrations. See the demo for live examples. Go ahead and zoom the page, and the icons will be crisp, with the exception of the examples that use -webkit-background-clip: text as mentioned earlier.\n\nFinally, it\u2019s worth pointing out that with both generated content and the data-icon method, the letter will be announced to people using screen readers. For example, with the shopping basket icon above, the reader will say \u201cdollar sign view basket\u201d. As accessibility issues go, it\u2019s not exactly the worst, but could be confusing. You would need to decide whether this method is appropriate for the audience. Despite the disadvantages, icon fonts have huge potential.", "year": "2011", "author": "Jon Hicks", "author_slug": "jonhicks", "published": "2011-12-12T00:00:00+00:00", "url": "https://24ways.org/2011/displaying-icons-with-fonts-and-data-attributes/", "topic": "code"}
{"rowid": 283, "title": "CSS3 Patterns, Explained", "contents": "Many of you have probably seen my CSS3 patterns gallery. It became very popular throughout the year and it showed many web developers how powerful CSS3 gradients really are. But how many really understand how these patterns are created? The biggest benefit of CSS-generated backgrounds is that they can be modified directly within the style sheet. This benefit is void if we are just copying and pasting CSS code we don\u2019t understand. We may as well use a data URI instead.\n\nImportant note\n\nIn all the examples that follow, I\u2019ll be using gradients without a vendor prefix, for readability and brevity. However, you should keep in mind that in reality you need to use all the vendor prefixes (-moz-, -ms-, -o-, -webkit-) as no browser currently implements them without a prefix. Alternatively, you could use -prefix-free and have the current vendor prefix prepended at runtime, only when needed.\n\nThe syntax described here is the one that browsers currently implement. The specification has since changed, but no browser implements the changes yet. If you are interested in what is coming, I suggest you take a look at the dev version of the spec.\n\nIf you are not yet familiar with CSS gradients, you can read these excellent tutorials by John Allsopp and return here later, as in the rest of the article I assume you already know the CSS gradient basics:\n\n\n\tCSS3 Linear Gradients\n\tCSS3 Radial Gradients\n\n\nThe main idea\n\nI\u2019m sure most of you can imagine the background this code generates:\n\nbackground: linear-gradient(left, white 20%, #8b0 80%);\n\nIt\u2019s a simple gradient from one color to another that looks like this:\n\n See this example live\n\nAs you probably know, in this case the first 20% of the container\u2019s width is solid white and the last 20% is solid green. The other 60% is a smooth gradient between these colors. Let\u2019s try moving these color stops closer to each other:\n\nbackground: linear-gradient(left, white 30%, #8b0 70%);\n\n See this example live\n\nbackground: linear-gradient(left, white 40%, #8b0 60%);\n\n See this example live\n\nbackground: linear-gradient(left, white 50%, #8b0 50%);\n\n See this example live\n\nNotice how the gradient keeps shrinking and the solid color areas expanding, until there is no gradient any more in the last example. We can even adjust the position of these two color stops to control where each color abruptly changes into another:\n\nbackground: linear-gradient(left, white 30%, #8b0 30%);\n\n See this example live\n\nbackground: linear-gradient(left, white 90%, #8b0 90%);\n\n See this example live\n\nWhat you need to take away from these examples is that when two color stops are at the same position, there is no gradient, only solid colors. Even without going any further, this trick is useful for a number of different use cases like faux columns or the effect I wanted to achieve in my homepage or the -prefix-free page where the background is only shown on one side and hidden on the other:\n\n\n\nCombining with background-size\n\nWe can do wonders, however, if we combine this with the CSS3 background-size property:\n\nbackground: linear-gradient(left, white 50%, #8b0 50%);\nbackground-size: 100px 100px;\n\n See this example live\n\nAnd there it is. We just created the simplest of patterns: (vertical) stripes. We can remove the first parameter (left) or replace it with top and we\u2019ll get horizontal stripes. However, let\u2019s face it: Horizontal and vertical stripes are kinda boring. Most stripey backgrounds we see on the web are diagonal. So, let\u2019s try doing that.\n\nOur first attempt would be to change the angle of the gradient to something like 45deg. However, this results in an ugly pattern like this: \n\n See this example live\n\nBefore reading on, think for a second: why didn\u2019t this produce the desired result? Can you figure it out?\n\nThe reason is that the gradient angle rotates the gradient inside each tile, not the tiled background as a whole. However, didn\u2019t we have the same problem the first time we tried to create diagonal stripes with an image? And then we learned that every stripe has to be included twice, like so:\n\n\n\nSo, let\u2019s try to create that effect with CSS gradients. It\u2019s essentially what we tried before, but with more color stops:\n\nbackground: linear-gradient(45deg, white 25%,\n    #8b0 25%, #8b0 50%, \n    white 50%, white 75%, \n    #8b0 75%);\nbackground-size:100px 100px;\n\n See this example live\n\nAnd there we have our stripes! An easy way to remember the order of the percentages and colors it is that you always have two of the same in succession, except the first and last color.\n\nNote: Firefox for Mac also needs an additional 100% color stop at the end of any pattern with more than two stops, like so: ..., white 75%, #8b0 75%, #8b0). The bug was reported in February 2011 and you can vote for it and track its progress at Bugzilla.\n\nUnfortunately, this is essentially a hack and we will realize that if we try to change the gradient angle to 60deg:\n\n See this example live\n\nNot that maintainable after all, eh? Luckily, CSS3 offers us another way of declaring such backgrounds, which not only helps this case but also results in much more concise code:\n\nbackground: repeating-linear-gradient(60deg, white, white 35px, #8b0 35px, #8b0 70px);\n\n See this example live\n\nIn this case, however, the size has to be declared in the color stop positions and not through background-size, since the gradient is supposed to cover the entire container. You might notice that the declared size is different from the one specified the previous way. This is because the size of the stripes is measured differently: in the first example we specify the dimensions of the tile itself; in the second, the width of the stripes (35px), which is measured diagonally.\n\nMultiple backgrounds\n\nUsing only one gradient you can create stripes and that\u2019s about it. There are a few more patterns you can create with just one gradient (linear or radial) but they are more or less boring and ugly. Almost every pattern in my gallery contains a number of different backgrounds. For example, let\u2019s create a polka dot pattern:\n\nbackground: radial-gradient(circle, white 10%, transparent 10%),\nradial-gradient(circle, white 10%, black 10%) 50px 50px;\nbackground-size:100px 100px;\n\n See this example live\n\nNotice that the two gradients are almost the same image, but positioned differently to create the polka dot effect. The only difference between them is that the first (topmost) gradient has transparent instead of black. If it didn\u2019t have transparent regions, it would effectively be the same as having a single gradient, as the topmost gradient would obscure everything beneath it.\n\nThere is an issue with this background. Can you spot it?\n\nThis background will be fine for browsers that support CSS gradients but, for browsers that don\u2019t, it will be transparent as the whole declaration is ignored. We have two ways to provide a fallback, each for different use cases. We have to either declare another background before the gradient, like so:\n\nbackground: black;\nbackground: radial-gradient(circle, white 10%, transparent 10%),\nradial-gradient(circle, white 10%, black 10%) 50px 50px;\nbackground-size:100px 100px;\n\nor declare each background property separately:\n\nbackground-color: black;\nbackground-image: radial-gradient(circle, white 10%, transparent 10%),\nradial-gradient(circle, white 10%, transparent 10%);\nbackground-size:100px 100px;\nbackground-position: 0 0, 50px 50px;\n\nThe vigilant among you will have noticed another change we made to our code in the last example: we altered the second gradient to have transparent regions as well. This way background-color serves a dual purpose: it sets both the fallback color and the background color of the polka dot pattern, so that we can change it with just one edit. Always strive to make code that can be modified with the least number of edits. You might think that it will never be changed in that way but, almost always, given enough time, you\u2019ll be proved wrong.\n\nWe can apply the exact same technique with linear gradients, in order to create checkerboard patterns out of right triangles:\n\nbackground-color: white;\nbackground-image: linear-gradient(45deg, black 25%, transparent 25%, transparent 75%, black 75%), \nlinear-gradient(45deg, black 25%, transparent 25%, transparent 75%, black 75%);\nbackground-size:100px 100px;\nbackground-position: 0 0, 50px 50px;\n\n See this example live\n\nUsing the right units\n\nDon\u2019t use pixels for the sizes without any thought. In some cases, ems make much more sense. For example, when you want to make a lined paper background, you want the lines to actually follow the text. If you use pixels, you have to change the size every time you change font-size. If you set the background-size in ems, it will naturally follow the text and you will only have to update it if you change line-height.\n\nIs it possible?\n\nThe shapes that can be achieved with only one gradient are:\n\n\n\tstripes\n\tright triangles\n\tcircles and ellipses\n\tsemicircles and other shapes formed from slicing ellipses horizontally or vertically\n\n\nYou can combine several of them to create squares and rectangles (two right triangles put together), rhombi and other parallelograms (four right triangles), curves formed from parts of ellipses, and other shapes.\n\nJust because you can doesn\u2019t mean you should\n\nTechnically, anything can be crafted with these techniques. However, not every pattern is suitable for it. The main advantages of this technique are:\n\n\n\tno extra HTTP requests\n\tshort code\n\thuman-readable code (unlike data URIs) that can be changed without even leaving the CSS file.\n\n\nComplex patterns that require a large number of gradients are probably better left to SVG or bitmap images, since they negate almost every advantage of this technique:\n\n\n\tthey are not shorter\n\tthey are not really comprehensible \u2013 changing them requires much more effort than using an image editor\n\n\nThey still save an HTTP request, but so does a data URI.\n\nI have included some very complex patterns in my gallery, because even though I think they shouldn\u2019t be used in production (except under very exceptional conditions), understanding how they work and coding them helps somebody understand the technology in much more depth.\n\nAnother rule of thumb is that if your pattern needs shapes to obscure parts of other shapes, like in the star pattern or the yin yang pattern, then you probably shouldn\u2019t use it. In these patterns, changing the background color requires you to also change the color of these shapes, making edits very tedious.\n\nIf a certain pattern is not practicable with a reasonable amount of CSS, that doesn\u2019t mean you should resort to bitmap images. SVG is a very good alternative and is supported by all modern browsers.\n\nBrowser support\n\nCSS gradients are supported by Firefox 3.6+, Chrome 10+, Safari 5.1+ and Opera 11.60+ (linear gradients since Opera 11.10). Support is also coming in Internet Explorer when IE10 is released. You can get gradients in older WebKit versions (including most mobile browsers) by using the proprietary -webkit-gradient(), if you really need them.\n\nEpilogue\n\nI hope you find these techniques useful for your own designs. If you come up with a pattern that\u2019s very different from the ones already included, especially if it demonstrates a cool new technique, feel free to send a pull request to the github repo of the patterns gallery. Also, I\u2019m always fascinated to see my techniques put in practice, so if you made something cool and used CSS patterns, I\u2019d love to know about it!\n\nHappy holidays!", "year": "2011", "author": "Lea Verou", "author_slug": "leaverou", "published": "2011-12-16T00:00:00+00:00", "url": "https://24ways.org/2011/css3-patterns-explained/", "topic": "code"}
{"rowid": 276, "title": "Your jQuery: Now With 67% Less Suck", "contents": "Fun fact: more websites are now using jQuery than Flash.\n\njQuery is an amazing tool that\u2019s made JavaScript accessible to developers and designers of all levels of experience. However, as Spiderman taught us, \u201cwith great power comes great responsibility.\u201d The unfortunate downside to jQuery is that while it makes it easy to write JavaScript, it makes it easy to write really really f*&#ing bad JavaScript. Scripts that slow down page load, unresponsive user interfaces, and spaghetti code knotted so deep that it should come with a bottle of whiskey for the next sucker developer that has to work on it. \n\nThis becomes more important for those of us who have yet to move into the magical fairy wonderland where none of our clients or users view our pages in Internet Explorer. The IE JavaScript engine moves at the speed of an advancing glacier compared to more modern browsers, so optimizing our code for performance takes on an even higher level of urgency.\n\nThankfully, there are a few very simple things anyone can add into their jQuery workflow that can clear up a lot of basic problems. When undertaking code reviews, three of the areas where I consistently see the biggest problems are: inefficient selectors; poor event delegation; and clunky DOM manipulation. We\u2019ll tackle all three of these and hopefully you\u2019ll walk away with some new jQuery batarangs to toss around in your next project.\n\nSelector optimization\n\nSelector speed: fast or slow?\n\nSaying that the power behind jQuery comes from its ability to select DOM elements and act on them is like saying that Photoshop is a really good tool for selecting pixels on screen and making them change color \u2013 it\u2019s a bit of a gross oversimplification, but the fact remains that jQuery gives us a ton of ways to choose which element or elements in a page we want to work with. However, a surprising number of web developers are unaware that all selectors are not created equal; in fact, it\u2019s incredible just how drastic the performance difference can be between two selectors that, at first glance, appear nearly identical. For instance, consider these two ways of selecting all paragraph tags inside a <div> with an ID.\n\n$(\"#id p\");\n\n$(\"#id\").find(\"p\");\n\nWould it surprise you to learn that the second way can be more than twice as fast as the first? Knowing which selectors outperform others (and why) is a pretty key building block in making sure your code runs well and doesn\u2019t frustrate your users waiting for things to happen.\n\nThere are many different ways to select elements using jQuery, but the most common ways can be basically broken down into five different methods. In order, roughly, from fastest to slowest, these are:\n\n\n\t$(\"#id\"); \nThis is without a doubt the fastest selector jQuery provides because it maps directly to the native document.getElementbyId() JavaScript method. If possible, the selectors listed below should be prefaced with an ID selector in conjunction with jQuery\u2019s .find() method to limit the scope of the page that has to be searched (as in the $(\"#id\").find(\"p\") example shown above).\n\t$(\"p\");, $(\"input\");, $(\"form\"); and so on\nSelecting elements by tag name is also fast, since it maps directly to the native document.getElementsByTagname() method.\n\t$(\".class\"); \nSelecting by class name is a little trickier. While still performing very well in modern browsers, it can cause some pretty significant slowdowns in IE8 and below. Why? IE9 was the first IE version to support the native document.getElementsByClassName() JavaScript method. Older browsers have to resort to using much slower DOM-scraping methods that can really impact performance.\n\t$(\"[attribute=value]\");\nThere is no native JavaScript method for this selector to use, so the only way that jQuery can perform the search is by crawling the entire DOM looking for matches. Modern browsers that support the querySelectorAll() method will perform better in certain cases (Opera, especially, runs these searches much faster than any other browser) but, generally speaking, this type of selector is Slowey McSlowersons.\n\t$(\":hidden\");\nLike attribute selectors, there is no native JavaScript method for this one to use. Pseudo-selectors can be painfully slow since the selector has to be run against every element in your search space. Again, modern browsers with querySelectorAll() will perform slightly better here, but try to avoid these if at all possible. If you must use one, try to limit the search space to a specific portion of the page: $(\"#list\").find(\":hidden\");\n\n\nBut, hey, proof is in the performance testing, right? It just so happens that said proof is sitting right here. Be sure to notice the class selector numbers beside IE7 and 8 compared to other browsers and then wonder how the people on the IE team at Microsoft manage to sleep at night. Yikes.\n\nChaining\n\nAlmost all jQuery methods return a jQuery object. This means that when a method is run, its results are returned and you can continue executing more methods on them. Rather than writing out the same selector multiple times over, just making a selection once allows multiple actions to be run on it.\n\nWithout chaining\n\n$(\"#object\").addClass(\"active\");\n$(\"#object\").css(\"color\",\"#f0f\");\n$(\"#object\").height(300);\n\nWith chaining\n\n$(\"#object\").addClass(\"active\").css(\"color\", \"#f0f\").height(300);\n\nThis has the dual effect of making your code shorter and faster. Chained methods will be slightly faster than multiple methods made on a cached selector, and both ways will be much faster than multiple methods made on non-cached selectors. Wait\u2026 \u201ccached selector\u201d? What is this new devilry? \n\nCaching\n\nAnother easy way to speed up your code that seems to be a mystery to developers is the idea of caching your selectors. Think of how many times you end up writing the same selector over and over again in any project. Every $(\".element\") selector has to search the entire DOM each time, regardless of whether or not that selector had been previously run. Running the selection once and then storing the results in a variable means that the DOM only has to be searched once. Once the results of a selector have been cached, you can do anything with them.\n\nFirst, run your search (here we\u2019re selecting all of the <li> elements inside <ul id=\"blocks\">): \n\nvar blocks = $(\"#blocks\").find(\"li\");\n\nNow, you can use the blocks variable wherever you want without having to search the DOM every time.\n\n$(\"#hideBlocks\").click(function() {\n    blocks.fadeOut();\n});\n$(\"#showBlocks\").click(function() {\n    blocks.fadeIn();\n});\n\nMy advice? Any selector that gets run more than once should be cached. This jsperf test shows just how much faster a cached selector runs compared to a non-cached one (and even throws some chaining love in to boot).\n\nEvent delegation\n\nEvent listeners cost memory. In complex websites and apps it\u2019s not uncommon to have a lot of event listeners floating around, and thankfully jQuery provides some really easy methods for handling event listeners efficiently through delegation.\n\nIn a bit of an extreme example, imagine a situation where a 10\u00d710 cell table needs to have an event listener on each cell; let\u2019s say that clicking on a cell adds or removes a class that defines the cell\u2019s background color. A typical way that this might be written (and something I\u2019ve often seen during code reviews) is like so:\n\n$('table').find('td').click(function() {\n    $(this).toggleClass('active');\n});\n\njQuery 1.7 has provided us with a new event listener method, .on(). It acts as a utility that wraps all of jQuery\u2019s previous event listeners into one convenient method, and the way you write it determines how it behaves. To rewrite the above .click() example using .on(), we\u2019d simply do the following:\n\n$('table').find('td').on('click',function() {\n    $(this).toggleClass('active');\n});\n\nSimple enough, right? Sure, but the problem here is that we\u2019re still binding one hundred event listeners to our page, one to each individual table cell. A far better way to do things is to create one event listener on the table itself that listens for events inside it. Since the majority of events bubble up the DOM tree, we can bind a single event listener to one element (in this case, the <table>) and wait for events to bubble up from its children. The way to do this using the .on() method requires only one change from our code above:\n\n$('table').on('click','td',function() {\n    $(this).toggleClass('active');\n});\n\nAll we\u2019ve done is moved the td selector to an argument inside the .on() method. Providing a selector to .on() switches it into delegation mode, and the event is only fired for descendants of the bound element (table) that match the selector (td). With that one simple change, we\u2019ve gone from having to bind one hundred event listeners to just one. You might think that the browser having to do one hundred times less work would be a good thing and you\u2019d be completely right. The difference between the two examples above is staggering.\n\n(Note that if your site is using a version of jQuery earlier than 1.7, you can accomplish the very same thing using the .delegate() method. The syntax of how you write the function differs slightly; if you\u2019ve never used it before, it\u2019s worth checking the API docs for that page to see how it works.)\n\nDOM manipulation\n\njQuery makes it very easy to manipulate the DOM. It\u2019s trivial to create new nodes, insert them, remove other ones, move things around, and so on. While the code to do this is simple to write, every time the DOM is manipulated, the browser has to repaint and reflow content which can be extremely costly. This is no more evident than in a long loop, whether it be a standard for() loop, while() loop, or jQuery $.each() loop.\n\nIn this case, let\u2019s say we\u2019ve just received an array full of image URLs from a database or Ajax call or wherever, and we want to put all of those images in an unordered list. Commonly, you\u2019ll see code like this to pull this off:\n\nvar arr = [reallyLongArrayOfImageURLs]; \n    $.each(arr, function(count, item) {\n        var newImg = '<li><img src=\"'+item+'\"></li>';\n        $('#imgList').append(newImg);\n    });\n\nThere are a couple of problems with this. For one (which you should have already noticed if you\u2019ve read the earlier part of this article), we\u2019re making the $(\"#imgList\") selection once for each iteration of our loop. The other problem here is that each time the loop iterates, it\u2019s adding a new <li> to the DOM. Each of those insertions is going to be costly, and if our array is quite large then this could lead to a massive slowdown or even the dreaded \u2018A script is causing this page to run slowly\u2019 warning.\n\nvar arr = [reallyLongArrayOfImageURLs],\n    tmp = ''; \n$.each(arr, function(count, item) {\n    tmp += '<li><img src=\"'+item+'\"></li>';\n});\n$('#imgList').append(tmp);\n\nAll we\u2019ve done here is create a tmp variable that each <li> is added to as it\u2019s created. Once our loop has finished iterating, that tmp variable will contain all of our list items in memory, and can be appended to our <ul> all in one go. Browsers work much faster when working with objects in memory rather than on screen, so this is a much faster, more CPU-cycle-friendly method of building a list.\n\nWrapping up\n\nThese are far from being the only ways to make your jQuery code run better, but they are among the simplest ones to implement. Though each individual change may only make a few milliseconds of difference, it doesn\u2019t take long for those milliseconds to add up. Studies have shown that the human eye can discern delays of as few as 100ms, so simply making a few changes sprinkled throughout your code can very easily have a noticeable effect on how well your website or app performs. Do you have other jQuery optimization tips to share? Leave them in the comments and help make us all better.\n\nNow go forth and make awesome!", "year": "2011", "author": "Scott Kosman", "author_slug": "scottkosman", "published": "2011-12-13T00:00:00+00:00", "url": "https://24ways.org/2011/your-jquery-now-with-less-suck/", "topic": "code"}
{"rowid": 271, "title": "Creating Custom Font Stacks with Unicode-Range", "contents": "Any web designer or front-end developer worth their salt will be familiar with the CSS @font-face rule used for embedding fonts in a web page. We\u2019ve all used it \u2014 either directly in our code ourselves, or via one of the web font services like Fontdeck, Typekit or Google Fonts.\n\nIf you\u2019re like me, however, you\u2019ll be used to just copying and pasting in a specific incantation of lines designed to get different formats of fonts working in different browsers, and may not have really explored all the capabilities of @font-face properties as defined by the spec.\n\nOne such property \u2014 the unicode-range descriptor \u2014 sounds pretty dull and is easily overlooked. It does, however, have some fairly interesting possibilities when put to use in creative ways.\n\nUnicode-range\n\nThe unicode-range descriptor is designed to help when using fonts that don\u2019t have full coverage of the characters used in a page. By adding a unicode-range property to a @font-face rule it is possible to specify the range of characters the font covers. \n\n@font-face {\n    font-family: BBCBengali;\n    src: url(fonts/BBCBengali.ttf) format(\"opentype\");\n    unicode-range: U+00-FF;\n}\n\nIn this example, the font is to be used for characters in the range of U+00 to U+FF which runs from the unexciting control characters at the start of the Unicode table (symbols like the exclamation mark start at U+21) right through to \u00ff at U+FF \u2013 the extent of the Basic Latin character range.\n\nBy adding multiple @font-face rules for the same family but with different ranges, you can build up complete coverage of the characters your page uses by using different fonts.\n\nWhen I say that it\u2019s possible to specify the range of characters the font covers, that\u2019s true, but what you\u2019re really doing with the unicode-range property is declaring which characters the font should be used for. This becomes interesting, because instead of merely working with the technical constraints of available characters in a given font, we can start picking and choosing characters to use and selectively mix fonts together.\n\nThe best available ampersand\n\nA few years back, Dan Cederholm wrote a post encouraging designers to use the best available ampersand. Dan went on to outline how this can be achieved by wrapping our ampersands in a <span> element with a class applied:\n\n<span class=\"amp\">&</span>\n\nA CSS rule can then be written to select the <span> and apply a different font:\n\nspan.amp {\n    font-family: Baskerville, Palatino, \"Book Antiqua\", serif;\n}\n\nThat\u2019s a perfectly serviceable technique, but the drawbacks are clear \u2014 you have to add extra markup which is borderline presentational, and you also have to be able to add that markup, which isn\u2019t always possible when working with a CMS.\n\nPerhaps we could do this with unicode-range.\n\nA better best available ampersand\n\nThe Unicode code point for an ampersand is U+26, so the ampersand font stack above can be created like so:\n\n@font-face {\n    font-family: 'Ampersand';\n    src: local('Baskerville'), local('Palatino'), local('Book Antiqua');\n    unicode-range: U+26;\n}\n\nWhat we\u2019ve done here is specify a new family called Ampersand and created a font stack for it with the user\u2019s locally installed copies of Baskerville, Palatino or Book Antiqua. We\u2019ve then limited it to a single character range \u2014 the ampersand. Of course, those don\u2019t need to be local fonts \u2014 they could be web font files, too. If you have a font with a really snazzy ampersand, go for your life.\n\nWe can then use that new family in a regular font stack.\n\nh1 {\n    font-family: Ampersand, Arial, sans-serif;\n}\n\nWith this in place, any <h1> elements in our page will use the Ampersand family (Baskerville, Palatino or Book Antiqua) for ampersands, and Arial for all other characters. If the user doesn\u2019t have any of the Ampersand family fonts available, the ampersand will fall back to the next item in the font stack, Arial.\n\nYou didn\u2019t think it was that easy, did you?\n\nOh, if only it were so. The problem comes, as ever, with the issue of browser support. The unicode-range property has good support in WebKit browsers (like Safari and Chrome, and the browsers on most popular smartphone platforms) and in recent versions of Internet Explorer. The big stumbling block comes in the form of Firefox, which has no support at all.\n\nIf you\u2019re familiar with how CSS works when it comes to unsupported properties, you\u2019ll know that if a browser encounters a property it doesn\u2019t implement, it just skips that declaration and moves on to the next. That works perfectly for things like border-radius \u2014 if the browser can\u2019t round off the corners, the declaration is skipped and the user sees square corners instead. Perfect.\n\nLess perfect when it comes to unicode-range, because if no range is specified then the default is that the font is applied for all characters \u2014 the whole range. If you\u2019re using a fancy font for flamboyant ampersands, you probably don\u2019t want that applied to all your text if unicode-range isn\u2019t supported. That would be bad. Really bad.\n\nEnsuring good fallbacks\n\nAs ever, the trick is to make sure that there\u2019s a sensible fallback in place if a browser doesn\u2019t have support for whatever technology you\u2019re trying to use. This is where being a super nerd about understanding the spec you\u2019re working with really pays off.\n\nWe can make use of the rules of the CSS cascade to make sure that if unicode-range isn\u2019t supported we get a sensible fallback font. What would be ideal is if we were able to follow up the @font-face rule with a second rule to override it if Unicode ranges aren\u2019t implemented.\n\n@font-face {\n    font-family: 'Ampersand';\n    src: local('Baskerville'), local('Palatino'), local('Book Antiqua');\n    unicode-range: U+26;\n}\n@font-face {\n    font-family: 'Ampersand';\n    src: local('Arial');\n}\n\nIn theory, this code should make sense for all browsers. For those that support unicode-range the two rules become cumulative. They specify different ranges for the same family, and in WebKit browsers this has the expected result of using Arial for most characters, but Baskerville and friends for the ampersand. For browsers that don\u2019t have support, the second rule should just supersede the first, setting the font to Arial. \n\nUnfortunately, this code causes current versions of Firefox to freak out and use the first rule, applying Baskerville to the entire range. That\u2019s both unexpected and unfortunate. Bad Firefox. On your rug.\n\nIf that doesn\u2019t work, what can we do? Well, we know that if given a unicode-range Firefox will ignore the range and apply the font to all characters. That\u2019s really what we\u2019re trying to achieve. So what if we specified a range for the fallback font, but made sure it only covers some obscure high-value Unicode character we\u2019re never going to use in our page? Then it wouldn\u2019t affect the outcome for browsers that do support ranges.\n\n@font-face {\n    font-family: 'Ampersand';\n    src: local('Baskerville'), local('Palatino'), local('Book Antiqua');\n    unicode-range: U+26;\n}\n@font-face {\n    /* Ampersand fallback font */\n    font-family: 'Ampersand';\n    src: local('Arial');\n    unicode-range: U+270C;\n}\n\nBy specifying a range on the fallback font, Firefox appears to correctly override the first based on the cascade sort order. Browsers that do support ranges take the second rule in addition, and apply Arial for that obscure character we\u2019re not using in any of our pages \u2014 U+270C.\n\nSo we get our nice ampersands in browsers that support unicode-range and, thanks to our styling of an obscure Unicode character, the font falls back to a perfectly acceptable Arial in browsers that do not offer support. Perfect!\n\nThat obscure character, my friends, is what Unicode defines as the VICTORY HAND.\n\n\u270c\n\nSo, how can we use this?\n\nAmpersands are a neat trick, and it works well in browsers that support ranges, but that\u2019s not really the point of all this. Styling ampersands is fun, but they\u2019re only really scratching the surface. Consider more involved examples, such as substituting a different font for numerals, or symbols, or even caps. Things certainly begin to get a bit more interesting.\n\nHow do you know what the codes are for different characters? Richard Ishida has a handy online conversion tool available where you can type in the characters and get the Unicode code points out the other end.\n\nOf course, the fact remains that browser support for unicode-range is currently limited, so any application needs to have fallbacks that you\u2019re still happy for a significant proportion of your visitors to see. In some cases, such as dedicated pages for mobile devices in an HTML-based phone app, this is immediately useful as support in WebKit browsers is already very good. In other cases, you\u2019ll have to use your own best judgement based on your needs and audience.\n\nOne thing to keep in mind is that if you\u2019re using web fonts, the entire font will be downloaded even if only one character is used. That said, the font shouldn\u2019t be downloaded if none of the characters within the Unicode range are present in a given page.\n\nAs ever, there are pros and cons to using unicode-range as well as varied but increasing support in browsers. It remains a useful tool to understand and have in your toolkit for when the right moment comes along.", "year": "2011", "author": "Drew McLellan", "author_slug": "drewmclellan", "published": "2011-12-01T00:00:00+00:00", "url": "https://24ways.org/2011/creating-custom-font-stacks-with-unicode-range/", "topic": "code"}
{"rowid": 264, "title": "Dynamic Social Sharing Images", "contents": "Way back when social media was new, you could be pretty sure that whatever you posted would be read by those who follow you. If you\u2019d written a blog post and you wanted to share it with those who follow you, you could post a link and your followers would see it in their streams. Oh heady days! \nWith so many social channels and a proliferation of content and promotions flying past in everyone\u2019s streams, it\u2019s no longer enough to share content on social media, you have to actively sell it if you want it to be seen. You really need to make the most of every opportunity to catch a reader\u2019s attention if you\u2019re trying to get as many eyes as possible on that sweet, sweet social content.\nOne of the best ways to grab attention with your posts or tweets is to include an image. There\u2019s heaps of research that says that having images in your posts helps them stand out to followers. Reports I found showed figures from anything from 35% to 150% improvement from just having image in a post. Unfortunately, the details were surrounded with gross words like engagement and visual marketing assets and so I had to close the page before I started to hate myself too much.\nSo without hard stats to quote, we\u2019ll call it a rule of thumb. The rule of thumb is that posts with images will grab more attention than those without, so it makes sense that when adding pages to a website, you should make sure that they have social media sharing images associated with them.\nAdding sharing images\nThe process for declaring an image to be used in places like Facebook and Twitter is very simple, and at this point is familiar to many of us. You add a meta tag to the head of the page to point to the location of the image to use. When a link to the page is added to a post, the social network will fetch the page, look for the meta tag and then use the image you specified.\n<meta property=\"og:image\" content=\"https://example.com/my_image.jpg\">\nThere\u2019s a good post on this over at CSS-Tricks if you need to bone up on the details of this and other similar meta tags for social media sharing.\nThis is all fine and well for content that has a very obvious choice of image to go along with it, but what if you don\u2019t necessarily have an image? One approach is to use stock photography, but that\u2019s not going to be right for every situation.\nThis was something we faced with 24 ways in 2017. We wanted to add images to the tweets we post each day announcing a new article. Some articles have images, but not all, and there tended not to be any consistency in terms of imagery from one article to the next. We always have an author photograph, but those don\u2019t usually lend themselves directly to being the main \u2018hero\u2019 image for an article.\nPutting his thinking cap on, Paul came up with a design for an image that used the author photo along with a quote extracted from the article.\nOne of the hand-made sharing images from 2017\nEach day we would pick a quote from the article, and Paul would manually compose an image to be uploaded to the site. The results were great, but the whole process was a bit too labour intensive and relied on an individual (Paul) being available each day to do the work. I thought we could probably improve this.\nHatching a new plan\nOne initial idea I came up with was to script the image editor to dynamically build a new image by pulling content from our database. Sketch has plugins available to pull JSON content into a design, and our CMS can easily output JSON data, so that was one possibility.\nThe more I thought about this and how much I wish graphic design tools worked just a little bit more like CSS, the obvious solution hit me. We should just build it with CSS!\nIn fact, as the author name and image already exist in our CMS, and the visual styling is based on the design of the website, couldn\u2019t this just be another page on the site generated by the CMS?\nBreaking it down, I figured the steps needed would be something like:\n\nCreate the CSS to lay out a component that could be turned into an image\nAdd a new field to articles in the CMS to hold a handpicked quote\nBuild a new article template in the CMS to output the author name and quote dynamically for any article\n\u2026 um \u2026 screenshot?\n\nI thought I\u2019d get cracking and see if I could figure out the final steps later.\nBuilding the page\nThe first thing to tackle was the basic HTML and CSS to lay out the components for our image. That bit was really easy, as I just asked Paul to do it. Everyone should have a Paul.\nPaul\u2019s code uses a fixed dimension container in the HTML, set to 600 \u00d7 315px. This is to make it the correct aspect ratio for Facebook\u2019s recommended image size. It\u2019s useful to remember here that it doesn\u2019t need to be responsive or robust, as the page only needs to lay out correctly for a screenshot and a fixed size in a known browser.\nWith the markup and CSS in place, I turned this into a new template. Our CMS can easily display content through any number of templates, so I created a version of the article template that was totally stripped down. It only included the author details and the quote, along with Paul\u2019s markup.\nI also added the quote as a new field on the article in the CMS, so each \u2018image\u2019 could be quickly and easily customised in the editing process.\nI added a new field to the article template to capture the quote.\nWith very little effort, we quickly had a page to dynamically generate our \u2018image\u2019 right from the CMS. You can see any of them by adding /sharing onto the end of an article URL for any 2018 article.\nOur automatically generated layout direct from the CMS\nIt soon became clear that the elusive Step 4 was going to be the tricky part. I can create a small page on the site that looks like an image, but how should I go about turning it into one? An obvious route is to screenshot the page by hand, but that\u2019s going back to some of the manual steps I was trying to eliminate, and also opens up a possibility for errors to be made. But it did lead me to the thought\u2026 how could I automatically take a screenshot?\nEnter Puppeteer\nPuppeteer is a Node.js library that provides a nice API onto Headless Chrome. What is Headless Chrome, you ask? It\u2019s just a version of the Chrome browser than runs from the command line without ever drawing anything to a user interface window. It loads pages, renders CSS, runs JavaScript, pretty much every normal thing that Chrome on the desktop does, but without a clicky user interface.\nHeadless Chrome can be used for all sorts of things such as running automated tests on front-end code after making changes, or\u2026 get this\u2026 rendering pages that can be used for screenshots. The actual process of writing some code to control Chrome and to take the screenshot is where Puppeteer comes in. Puppeteer puts a friendly layer in front of big old scary Chrome to enable us to interact with it using simple JavaScript code running in Node.\nUsing Puppeteer, I can write a small script that will repeatably turn a URL into an image. So simple is it to do this, that\u2019s it\u2019s actually Puppeteer\u2019s \u2018hello world\u2019 example.\nFirst you install Puppeteer. It downloads a compatible headless browser (actually Chromium) as a dependancy, so you don\u2019t need to worry about installing that. At the command line:\nnpm i puppeteer\nThen save a new file as example.js with this code:\nconst puppeteer = require('puppeteer');\n\n(async () => {\n  const browser = await puppeteer.launch();\n  const page = await browser.newPage();\n  await page.goto('https://example.com');\n  await page.screenshot({path: 'example.png'});\n  await browser.close();\n})();\nand then run it using Node:\nnode example.js\nThis will output an image file example.png to disk, which contains a screenshot of, in this case https://example.com. The logic of the code is reasonably easy to follow:\n\nLaunch a browser\nOpen up a new page\nGoto a URL\nTake a screenshot\nClose the browser\n\nThe async function and await keywords are a way to have the script pause and wait for normally asynchronous code to return before proceeding. That\u2019s useful with actions like loading a web page that might take some time to complete. They\u2019re used with Promises, and the effect is to make asynchronous code behave as if it\u2019s synchronous. You can read more about async and await at MDN if you\u2019re interested.\nThat\u2019s a good proof-of-concept using the basic Puppeteer example. I can take a screenshot of a URL! But what happens if I put the URL of my new special page in there?\nOur content is up in the corner of the image with lots of empty space.\nThat\u2019s not great. It\u2019s okay, but not great. It looks like that, by default, Puppeteer takes a screenshot with a resolution of 800 \u00d7 600, so we need to find out how to adjust that. Fortunately, the docs aren\u2019t the worst and I was able to find the page.setViewport() method pretty easily.\nconst puppeteer = require('puppeteer');\n\n(async () => {\n  const browser = await puppeteer.launch();\n  const page = await browser.newPage();\n  await page.goto('https://24ways.org/2018/clip-paths-know-no-bounds/sharing');\n  await page.setViewport({\n    width: 600,\n    height: 315\n  });\n  await page.screenshot({path: 'example.png'});\n  await browser.close();\n})();\nThis worked! The screenshot is now 600 \u00d7 315 as expected. That\u2019s exactly what we asked for. Trouble is, that\u2019s a bit low res and it is nearly 2019 after all. While in those docs, I noticed the deviceScaleFactor option that can be passed to page.setViewport(). Setting that to 2 gives us an image of the same area of the screen, but with twice as many pixels.\n  await page.setViewport({\n    width: 600,\n    height: 315,\n    deviceScaleFactor: 2\n  });\nPerfect! We now have a programmatic way of turning a URL into an image.\nImproving the script\nRather than having a script with a fixed URL in it that outputs an image called example.png, the next step is to make that a bit more dynamic. The aim here is to have a script that we can run with a URL as an argument and have it output an image for that one page. That way we can run it manually, or hook it into part of our site\u2019s build process to automate the generation of the image.\nOur goal is to call the script like this:\nnode shoot-sharing-image.js https://24ways.org/2018/clip-paths-know-no-bounds/\nAnd I want the image to come out with the name clip-paths-know-no-bounds.png. To do that, I need to have my script look for command arguments, and then to split the URL up to grab the slug from it.\n// Get the URL and the slug segment from it\nconst url = process.argv[2];\nconst segments = url.split('/');\n// Get the second-to-last segment (the slug)\nconst slug = segments[segments.length-2];\nWe can then use these variables later in the script, remembering to add sharing back onto the end of the URL to get our dedicated page.\n(async () => {\n  const browser = await puppeteer.launch();\n  const page = await browser.newPage();\n  await page.goto(url + 'sharing');\n  await page.setViewport({\n    width: 600,\n    height: 315,\n    deviceScaleFactor: 2\n  });\n  await page.screenshot({path: slug + '.png'});\n  await browser.close();\n})();\nOnce you\u2019re generating the image with Node, there\u2019s all sorts of things you can do with it. An obvious step is to move it to the correct location within your site or project.\nYou can also run optimisations on the file. I\u2019m using imagemin with pngquant to reduce the file size a little.\nconst imagemin = require('imagemin');\nconst imageminPngquant = require('imagemin-pngquant');\n\nawait imagemin([slug + '.png'], 'build', {\n  plugins: [\n    imageminPngquant({quality: '75-90'})\n  ]\n});\n\nYou can see the completed example as a gist.\nIntegrating it with your CMS\nSo we now have a command we can run to take a URL and generate a custom image for that URL. It\u2019s in a format that can be called by any sort of build script, or triggered from a publishing hook in a CMS. Exactly how you do that is going to depend on the way your site is built and the technology stack you\u2019re using, but it\u2019s likely not too hard as long as you can run a command as part of the process.\nFor 24 ways this year, I\u2019ve been running the script by hand once each article is ready. My script adds the file to a git repo and pushes to a deployment remote that is configured to automatically deploy static assets to our server. Along with our theme of making incremental improvements, next year I\u2019ll look to automate this one step further.\nWe may also look at having a few slightly different layouts to choose from, so that each day isn\u2019t exactly the same as the last. Interestingly, we could even try some A/B tests to see if there\u2019s any particular format of image or type of quote that does a better job of grabbing attention. There are lots of possibilities!\n\nBy using a bit of ingenuity, some custom CMS templates, and the very useful Puppeteer project, we\u2019ve been able to reliably produce dynamic social media sharing images for all of our articles. In doing so, we reduced the dependancy on any individual for producing those images, and opened up a world of possibilities in how we use those images.\nI hope you\u2019ll give it a try!", "year": "2018", "author": "Drew McLellan", "author_slug": "drewmclellan", "published": "2018-12-24T00:00:00+00:00", "url": "https://24ways.org/2018/dynamic-social-sharing-images/", "topic": "code"}
{"rowid": 263, "title": "Securing Your Site like It\u2019s 1999", "contents": "Running a website in the early years of the web was a scary business. The web was an evolving medium, and people were finding new uses for it almost every day. From book stores to online auctions, the web was an expanding universe of new possibilities.\nAs the web evolved, so too did the knowledge of its inherent security vulnerabilities. Clever tricks that were played on one site could be copied on literally hundreds of other sites. It was a normal sight to log in to a website to find nothing working because someone had breached its defences and deleted its database. Lessons in web security in those days were hard-earned.\nWhat follows are examples of critical mistakes that brought down several early websites, and how you can help protect yourself and your team from the same fate.\nBad input validation: Trusting anything the user sends you\nOur story begins in the most unlikely place: Animal Crossing. Animal Crossing was a 2001 video game set in a quaint town, filled with happy-go-lucky inhabitants that co-exist peacefully. Like most video games, Animal Crossing was the subject of many fan communities on the early web.\nOne such unofficial web forum was dedicated to players discussing their adventures in Animal Crossing. Players could trade secrets, ask for help, and share pictures of their virtual homes. This might sound like a model community to you, but you would be wrong.\nOne day, a player discovered a hidden field in the forum\u2019s user profile form. Normally, this page allows users to change their name, their password, or their profile photo. This person discovered that the hidden field contained their unique user ID, which identifies them when the forum\u2019s backend saves profile changes to its database. They discovered that by modifying the form to change the user ID, they could make changes to any other player\u2019s profile.\nNeedless to say, this idyllic online community descended into chaos. Users changed each other\u2019s passwords, deleted each other\u2019s messages, and attacked each-other under the cover of complete anonymity. What happened?\nThere aren\u2019t any official rules for developing software on the web. But if there were, my golden rule would be:\nNever trust user input. Ever.\nAlways ask yourself how users will send you data that isn\u2019t what it seems to be. If the nicest community of gamers playing the happiest game on earth can turn on each other, nowhere on the web is safe.\nMake sure you validate user input to make sure it\u2019s of the correct type (e.g. string, number, JSON string) and that it\u2019s the length that you were expecting. Don\u2019t forget that user input doesn\u2019t become safe once it is stored in your database; any data that originates from outside your network can still be dangerous and must be escaped before it is inserted into HTML.\nMake sure to check a user\u2019s actions against what they are allowed to do. Create a clear access control policy that defines what actions a user may take, and to whose data they are allowed access to. For example, a newly-registered user should not be allowed to change the user profile of a web forum\u2019s owner.\nFinally, never rely on client-side validation. Validating user input in the browser is a convenience to the user, not a security measure. Always assume the user has full control over any data sent from the browser and make sure you validate any data sent to your backend from the outside world.\nSQL injection: Allowing the user to run their own database queries\nA long time ago, my favourite website was a web forum dedicated to the Final Fantasy video game series. Like the users of the Animal Crossing forum, I\u2019d while away many hours arguing with other people on the internet about my favourite characters, my favourite stories, and the greatest controversies of the day.\nOne day, I noticed people were acting strangely. Users were being uncharacteristically nasty and posting in private areas of the forum they wouldn\u2019t normally have access to. Then messages started disappearing, and user accounts for well-respected people were banned.\nIt turns out someone had discovered a way of logging in to any other user account, using a secret password that allowed them to do literally anything they wanted. What was this password that granted untold power to those who wielded it?\n' OR '1'='1\nSQL is a computer language that is used to query databases. When you fill out a login form, just like the one above, your username and your password are usually inserted into an SQL query like this:\n\nSELECT COUNT(*)\nFROM USERS\nWHERE USERNAME='Alice'\nAND PASSWORD='hunter2'\nThis query selects users from the database that match the username Alice and the password hunter2. If there is at least one user matching record, the user will be granted access. Let\u2019s see what happens when we use our magic password instead!\n\nSELECT COUNT(*)\nFROM USERS\nWHERE USERNAME='Admin'\nAND PASSWORD='' OR '1'='1'\nDoes the password look like part of the query to you? That\u2019s because it is! This password is a deliberate attempt to inject our own SQL into the query, hence the term SQL injection. The query is now looking for users matching the username Admin, with a password that is blank, or 1=1. In an SQL query, 1=1 is always true, which makes this query select every single record in the database. As long as the forum software is checking for at least one matching user, it will grant the person logging in access. This password will work for any user registered on the forum!\nSo how can you protect yourself from SQL injection?\nNever build SQL queries by concatenating strings. Instead, use parameterised query tools. PHP offers prepared statements, and Node.JS has the knex package. Alternatively, you can use an ORM tool, such as Propel or sequelize.\nExpert help in the form of language features or software tools is a key ally for securing your code. Get all the help you can!\nCross site request forgery: Getting other users to do your dirty work for you\nDo you remember Netflix? Not the Netflix we have now, the Netflix that used to rent you DVDs by mailing them to you. My next story is about how someone managed to convince Netflix users to send him their DVDs - free of charge.\nHave you ever clicked on a hyperlink, only to find something that you weren\u2019t expecting? If you were lucky, you might have just gotten Rickrolled. If you were unlucky\u2026\nLet\u2019s just say there are older and fouler things than Rick Astley in the dark places of the web.\nWhat if you could convince people to visit a page you controlled? And what if those people were Netflix users, and they were logged in? In 2006, Dave Ferguson did just that. He created a harmless-looking page with an image on it:\n<img src=\"http://www.netflix.com/JSON/AddToQueue?movieid=70110672\" />\nDid you notice the source URL of the image? It\u2019s deliberately crafted to add a particular DVD to your queue. Sprinkle in a few more requests to change the user\u2019s name and shipping address, and you could ship yourself DVDs completely free of charge!\nThis attack is possible when websites unconditionally trust a user\u2019s session cookies without checking where HTTP requests come from.\nThe first check you can make is to verify that a request\u2019s origin and referer headers match the location of the website. These headers can\u2019t be programmatically set.\nAnother check you can use is to add CSRF tokens to your web forms, to verify requests have come from an actual form on your website. Tokens are long, unpredictable, unique strings that are generated by your server and inserted into web forms. When users complete a form, the form data sent to the server can be checked for a recently generated token. This is an effective deterrent of CSRF attacks because CSRF tokens aren\u2019t stored in cookies.\nYou can also set SameSite=Strict when setting cookies with the Set-Cookie HTTP header. This communicates to browsers that cookies are not to be sent with cross-site requests. This is a relatively new feature, though it is well supported in evergreen browsers.\nCross site scripting: Someone else\u2019s code running on your website\nIn 2005, Samy Kamkar became famous for having lots of friends. Lots and lots of friends.\nSamy enjoyed using MySpace which, at the time, was the world\u2019s largest social network. Social networks at that time were more limited than today. For instance, MySpace let you upload photos to your photo gallery, but capped the limit at twelve. Twelve photos. At least you didn\u2019t have to wade through photos of avocado toast back then\u2026\nSamy discovered that MySpace also locked down the kinds of content that you could post on your MySpace page. He discovered he could inject <img /> and <div /> tags into his headline, but <script /> was filtered. MySpace wasn\u2019t about to let someone else run their own code on MySpace.\nIntrigued, Samy set about finding out exactly what he could do with <img /> and <div /> tags. He found that you could add style properties to <div /> tags to style them with CSS.\n<div style=\"background:url('javascript:alert(1)')\">\nThis code only worked in Internet Explorer and in some versions of Safari, but that was plenty of people to befriend. However, MySpace was prepared for this: they also filtered the word javascript from <div />.\n<div style=\"background:url('java\nscript:alert(1)')\">\nSamy discovered that by inserting a line break into his code, MySpace would not filter out the word javascript. The browser would continue to run the code just fine! Samy had now broken past MySpace\u2019s first line of defence and was able to start running code on his profile page. Now he started looking at what he could do with that code.\nalert(document.body.innerHTML)\nSamy wondered if he could inspect the page\u2019s source to find the details of other MySpace users to befriend. To do this, you would normally use document.body.innerHTML, but MySpace had filtered this too.\nalert(eval('document.body.inne' + 'rHTML'))\nThis isn\u2019t a problem if you build up JavaScript code inside a string and execute it using the eval() function. This trick also worked with XMLHttpRequest.onReadyStateChange, which allowed Samy to send friend requests to the MySpace API and install the JavaScript code on his new friends\u2019 pages.\nOne final obstacle stood in his way. The same origin policy is a security mechanism that prevents scripts hosted on one domain interacting with sites hosted on another domain.\nif (location.hostname == 'profile.myspace.com') {\n  document.location = 'http://www.myspace.com'\n  + location.pathname + location.search\n}\nSamy discovered that only the http://www.myspace.com domain would accept his API requests, and requests from http://profile.myspace.com were being blocked by the browser\u2019s same-origin policy. By redirecting the browser to http://www.myspace.com, he discovered that he could load profile pages and successfully make requests to MySpace\u2019s API. Samy installed this code on his profile page, and he waited.\n\nOver the course of the next day, over a million people unwittingly installed Samy\u2019s code into their MySpace profile pages and invited their friends. The load of friend requests on MySpace was so large that the site buckled and shut down. It took them two hours to remove Samy\u2019s code and patch the security holes he exploited. Samy was raided by the United States secret service and sentenced to do 90 days of community service.\nThis is the power of installing a little bit of JavaScript on someone else\u2019s website. It is called cross site scripting, and its effects can be devastating. It is suspected that cross-site scripting was to blame for the 2018 British Airways breach that leaked the credit card details of 380,000 people.\nSo how can you help protect yourself from cross-site scripting?\nAlways sanitise user input when it comes in, using a library such as sanitize-html. Open source tools like this benefit from hundreds of hours of work from dozens of experienced contributors. Don\u2019t be tempted to roll your own protection. MySpace was prepared, but they were not prepared enough. It makes no sense to turn this kind of help down.\nYou can also use an auto-escaping templating language to make sure nobody else\u2019s HTML can get into your pages. Both Angular and React will do this for you, and they are extremely convenient to use.\nYou should also implement a content security policy to restrict the domains that content like scripts and stylesheets can be loaded from. Loading content from sites not under your control is a significant security risk, and you should use a CSP to lock this down to only the sources you trust. CSP can also block the use of the eval() function.\nFor content not under your control, consider setting up sub-resource integrity protection. This allows you to add hashes to stylesheets and scripts you include on your website. Hashes are like fingerprints for digital files; if the content changes, so does the fingerprint. Adding hashes will allow your browser to keep your site safe if the content changes without you knowing.\nnpm audit: Protecting yourself from code you don\u2019t own\nJavaScript and npm run the modern web. Together, they make it easy to take advantage of the world\u2019s largest public registry of open source software. How do you protect yourself from code written by someone you\u2019ve never met? Enter npm audit.\nnpm audit reviews the security of your website\u2019s dependency tree. You can start using it by upgrading to the latest version of npm:\nnpm install npm -g\nnpm audit\nWhen you run npm audit, npm submits a description of your dependencies to the Registry, which returns a report of known vulnerabilities for the packages you have installed.\n\nIf your website has a known cross-site scripting vulnerability, npm audit will tell you about it. What\u2019s more, if the vulnerability has been patched, running npm audit fix will automatically install the patched package for you!\nSecuring your site like it\u2019s 2019\nThe truth is that since the early days of the web, the stakes of a security breach have become much, much higher. The web is so much more than fandom and mailing DVDs - online banking is now mainstream, social media and dating websites store intimate information about our personal lives, and we are even inviting the internet into our homes.\nHowever, we have powerful new allies helping us stay safe. There are more resources than ever before to teach us how to write secure code. Tools like Angular and React are designed with security features baked-in from the start. We have a new generation of security tools like npm audit to watch over our dependencies.\nAs we roll over into 2019, let\u2019s take the opportunity to reflect on the security of the code we write and be grateful for the everything we\u2019ve learned in the last twenty years.", "year": "2018", "author": "Katie Fenn", "author_slug": "katiefenn", "published": "2018-12-01T00:00:00+00:00", "url": "https://24ways.org/2018/securing-your-site-like-its-1999/", "topic": "code"}
{"rowid": 260, "title": "The Art of Mathematics: A Mandala Maker Tutorial", "contents": "In front-end development, there\u2019s often a great deal of focus on tools that aim to make our work more efficient. But what if you\u2019re new to web development? When you\u2019re just starting out, the amount of new material can be overwhelming, particularly if you don\u2019t have a solid background in Computer Science. But the truth is, once you\u2019ve learned a little bit of JavaScript, you can already make some pretty impressive things.\nA couple of years back, when I was learning to code, I started working on a side project. I wanted to make something colorful and fun to share with my friends. This is what my app looks like these days:\nMandala Maker user interface\nThe coolest part about it is the fact that it\u2019s a tool: anyone can use it to create something original and brand new. \nIn this tutorial, we\u2019ll build a smaller version of this app \u2013 a symmetrical drawing tool in ES5, JavaScript and HTML5. The tutorial app will have eight reflections, a color picker and a Clear button. Once we\u2019re done, you\u2019re on your own and can tweak it as you please. Be creative!\nPreparations: a blank canvas\nThe first thing you\u2019ll need for this project is a designated drawing space. We\u2019ll use the HTML5 canvas element and give it a width and a height of 600px (you can set the dimensions to anything else if you like).\nFiles\nCreate 3 files: index.html, styles.css, main.js. Don\u2019t forget to include your JS and CSS files in your HTML. \n<!DOCTYPE html>\n<html>\n<head>\n    <meta charset=\"utf-8\">\n    <link rel=\"stylesheet\" type=\"text/css\" href=\"style.css\">\n    <script src=\"main.js\"></script>\n</head>\n<body onload=\"init()\">\n    <canvas width=\"600\" height=\"600\">\n        <p>Your browser doesn't support canvas.</p>\n    </canvas>\n</body>\n</html>\nI\u2019ll ask you to update your HTML file at a later point, but the CSS file we\u2019ll start with will stay the same throughout the project. This is the full CSS we are going to use:\nbody {\n    background-color: #ccc;\n    text-align: center;\n}\n\ncanvas {\n    touch-action: none;\n    background-color: #fff;\n}\n\nbutton {\n    font-size: 110%;\n}\nNext steps\nWe are done with our preparations and ready to move on to the actual tutorial, which is made up of 4 parts:\n\nBuilding a simple drawing app with one line and one color \nAdding a Clear button and a color picker\nAdding more functionality: 2 line drawing (add the first reflection)\nAdding more functionality: 8 line drawing (add 6 more reflections!)\n\nInteractive demos\nThis tutorial will be accompanied by four CodePens, one at the end of each section. In my own app I originally used mouse events, and only added touch events when I realized mobile device support was (A) possible, and (B) going to make my app way more accessible. For the sake of code simplicity, I decided that in this tutorial app I will only use one event type, so I picked a third option: pointer events. These are supported by some desktop browsers and some mobile browsers. An up-to-date version of Chrome is probably your best bet.\nPart 1: A simple drawing app\nLet\u2019s get started with our main.js file. Our basic drawing app will be made up of 6 functions: init, drawLine, stopDrawing, recordPointerLocation, handlePointerMove, handlePointerDown. It also has nine variables:\nvar canvas, context, w, h,\n    prevX = 0, currX = 0, prevY = 0, currY = 0,\n    draw = false;\nThe variables canvas and context let us manipulate the canvas. w is the canvas width and h is the canvas height. The four coordinates are used for tracking the current and previous location of the pointer. A short line is drawn between (prevX, prevY) and (currX, currY) repeatedly many times while we move the pointer upon the canvas. For your drawing to appear, three conditions must be met: the pointer (be it a finger, a trackpad or a mouse) must be down, it must be moving and the movement has to be on the canvas. If these three conditions are met, the boolean draw is set to true. \n1. init\nResponsible for canvas set up, this listens to pointer events and the location of their coordinates and sets everything in motion by calling other functions, which in turn handle touch and movement events. \nfunction init() {\n    canvas = document.querySelector(\"canvas\");\n    context = canvas.getContext(\"2d\");\n    w = canvas.width;\n    h = canvas.height;\n\n    canvas.onpointermove = handlePointerMove;\n    canvas.onpointerdown = handlePointerDown;\n    canvas.onpointerup = stopDrawing;\n    canvas.onpointerout = stopDrawing;\n}\n2. drawLine\nThis is called to action by handlePointerMove() and draws the pointer path. It only runs if draw = true. It uses canvas methods you can read about in the canvas API documentation. You can also learn to use the canvas element in this tutorial.\nlineWidth and linecap set the properties of our paint brush, or digital pen, but pay attention to beginPath and closePath. Between those two is where the magic happens: moveTo and lineTo take canvas coordinates as arguments and draw from (a,b) to (c,d), which is to say from (prevX,prevY) to (currX,currY).\nfunction drawLine() {\n    var a = prevX,\n        b = prevY,\n        c = currX,\n        d = currY;\n\n    context.lineWidth = 4;\n    context.lineCap = \"round\";\n\n    context.beginPath();\n    context.moveTo(a, b);\n    context.lineTo(c, d);\n    context.stroke();\n    context.closePath();\n}\n3. stopDrawing\nThis is used by init when the pointer is not down (onpointerup) or is out of bounds (onpointerout).\nfunction stopDrawing() {\n    draw = false;\n}\n4. recordPointerLocation\nThis tracks the pointer\u2019s location and stores its coordinates. Also, you need to know that in computer graphics the origin of the coordinate space (0,0) is at the top left corner, and all elements are positioned relative to it. When we use canvas we are dealing with two coordinate spaces: the browser window and the canvas itself. This function converts between the two: it subtracts the canvas offsetLeft and offsetTop so we can later treat the canvas as the only coordinate space. If you are confused, read more about it.\nfunction recordPointerLocation(e) {\n    prevX = currX;\n    prevY = currY;\n    currX = e.clientX - canvas.offsetLeft;\n    currY = e.clientY - canvas.offsetTop;\n}\n5. handlePointerMove\nThis is set by init to run when the pointer moves. It checks if draw = true. If so, it calls recordPointerLocation to get the path and drawLine to draw it.\nfunction handlePointerMove(e) {\n    if (draw) {\n        recordPointerLocation(e);\n        drawLine();\n    }\n}\n6. handlePointerDown\nThis is set by init to run when the pointer is down (finger is on touchscreen or mouse it clicked). If it is, calls recordPointerLocation to get the path and sets draw to true. That\u2019s because we only want movement events from handlePointerMove to cause drawing if the pointer is down.\nfunction handlePointerDown(e) {\n    recordPointerLocation(e);\n    draw = true;\n}\nFinally, we have a working drawing app. But that\u2019s just the beginning!\nSee the Pen Mandala Maker Tutorial: Part 1 by Hagar Shilo (@hagarsh) on CodePen.\n\nPart 2: Add a Clear button and a color picker\nNow we\u2019ll update our HTML file, adding a menu div with an input of the type and class color and a button of the class clear.\n<body onload=\"init()\">\n    <canvas width=\"600\" height=\"600\">\n        <p>Your browser doesn't support canvas.</p>\n    </canvas>\n    <div class=\"menu\">\n        <input type=\"color\" class=\"color\" />\n        <button type=\"button\" class=\"clear\">Clear</button>\n    </div>\n</body>\nColor picker\nThis is our new color picker function. It targets the input element by its class and gets its value. \nfunction getColor() {\n    return document.querySelector(\".color\").value;\n}\nUp until now, the app used a default color (black) for the paint brush/digital pen. If we want to change the color we need to use the canvas property strokeStyle. We\u2019ll update drawLine by adding strokeStyle to it and setting it to the input value by calling getColor.\nfunction drawLine() {\n    //...code...  \n    context.strokeStyle = getColor();\n    context.lineWidth = 4;\n    context.lineCap = \"round\";\n\n    //...code...  \n}\nClear button\nThis is our new Clear function. It responds to a button click and displays a dialog asking the user if she really wants to delete the drawing.\nfunction clearCanvas() {\n    if (confirm(\"Want to clear?\")) {\n        context.clearRect(0, 0, w, h);\n    }\n}\nThe method clearRect takes four arguments. The first two (0,0) mark the origin, which is actually the top left corner of the canvas. The other two (w,h) mark the full width and height of the canvas. This means the entire canvas will be erased, from the top left corner to the bottom right corner. \nIf we were to give clearRect a slightly different set of arguments, say (0,0,w/2,h), the result would be different. In this case, only the left side of the canvas would clear up.\nLet\u2019s add this event handler to init:\nfunction init() {\n    //...code...\n    canvas.onpointermove = handleMouseMove;\n    canvas.onpointerdown = handleMouseDown;\n    canvas.onpointerup = stopDrawing;\n    canvas.onpointerout = stopDrawing;\n    document.querySelector(\".clear\").onclick = clearCanvas;\n}\nSee the Pen Mandala Maker Tutorial: Part 2 by Hagar Shilo (@hagarsh) on CodePen.\n\nPart 3: Draw with 2 lines\nIt\u2019s time to make a line appear where no pointer has gone before. A ghost line! \nFor that we are going to need four new coordinates: a', b', c' and d' (marked in the code as a_, b_, c_ and d_). In order for us to be able to add the first reflection, first we must decide if it\u2019s going to go over the y-axis or the x-axis. Since this is an arbitrary decision, it doesn\u2019t matter which one we choose. Let\u2019s go with the x-axis. \nHere is a sketch to help you grasp the mathematics of reflecting a point across the x-axis. The coordinate space in my sketch is different from my explanation earlier about the way the coordinate space works in computer graphics (more about that in a bit!). \nNow, look at A. It shows a point drawn where the pointer hits, and B shows the additional point we want to appear: a reflection of the point across the x-axis. This is our goal.\nA sketch illustrating the mathematics of reflecting a point.\nWhat happens to the x coordinates?\nThe variables a/a' and c/c' correspond to prevX and currX respectively, so we can call them \u201cthe x coordinates\u201d. We are reflecting across x, so their values remain the same, and therefore a' = a and c' = c. \nWhat happens to the y coordinates?\nWhat about b' and d'? Those are the ones that have to change, but in what way? Thanks to the slightly misleading sketch I showed you just now (of A and B), you probably think that the y coordinates b' and d' should get the negative values of b and d respectively, but nope. This is computer graphics, remember? The origin is at the top left corner and not at the canvas center, and therefore we get the following values: b = h - b, d' = h - d, where h is the canvas height.\nThis is the new code for the app\u2019s variables and the two lines: the one that fills the pointer\u2019s path and the one mirroring it across the x-axis.\nfunction drawLine() {\n    var a = prevX, a_ = a,\n        b = prevY, b_ = h-b,\n        c = currX, c_ = c,\n        d = currY, d_ = h-d;\n\n    //... code ...\n\n    // Draw line #1, at the pointer's location\n    context.moveTo(a, b);\n    context.lineTo(c, d);\n\n    // Draw line #2, mirroring the line #1\n    context.moveTo(a_, b_);\n    context.lineTo(c_, d_);\n\n    //... code ...\n}\nIn case this was too abstract for you, let\u2019s look at some actual numbers to see how this works.\nLet\u2019s say we have a tiny canvas of w = h = 10. Now let a = 3, b = 2, c = 4 and d = 3.\nSo b' = 10 - 2 = 8 and d' = 10 - 3 = 7.\nWe use the top and the left as references. For the y coordinates this means we count from the top, and 8 from the top is also 2 from the bottom. Similarly, 7 from the top is 3 from the bottom of the canvas. That\u2019s it, really. This is how the single point, and a line (not necessarily a straight one, by the way) is made up of many, many small segments that are similar to point in behavior.\nIf you are still confused, I don\u2019t blame you. \nHere is the result. Draw something and see what happens.\nSee the Pen Mandala Maker Tutorial: Part 3 by Hagar Shilo (@hagarsh) on CodePen.\n\nPart 4: Draw with 8 lines\nI have made yet another confusing sketch, with points C and D, so you understand what we\u2019re trying to do. Later on we\u2019ll look at points E, F, G and H as well. The circled point is the one we\u2019re adding at each particular step. The circled point at C has the coordinates (-3,2) and the circled point at D has the coordinates (-3,-2). Once again, keep in mind that the origin in the sketches is not the same as the origin of the canvas. \nA sketch illustrating points C and D.\nThis is the part where the math gets a bit mathier, as our drawLine function evolves further. We\u2019ll keep using the four new coordinates: a', b', c' and d', and reassign their values for each new location/line. Let\u2019s add two more lines in two new locations on the canvas. Their locations relative to the first two lines are exactly what you see in the sketch above, though the calculation required is different (because of the origin points being different).\nfunction drawLine() {\n\n    //... code ... \n\n    // Reassign values\n    a_ = w-a; b_ = b;\n    c_ = w-c; d_ = d;\n\n    // Draw the 3rd line\n    context.moveTo(a_, b_);\n    context.lineTo(c_, d_);\n\n    // Reassign values\n    a_ = w-a; b_ = h-b;\n    c_ = w-c; d_ = h-d;\n\n    // Draw the 4th line\n    context.moveTo(a_, b_);\n    context.lineTo(c_, d_);\n\n    //... code ... \nWhat is happening?\nYou might be wondering why we use w and h as separate variables, even though we know they have the same value. Why complicate the code this way for no apparent reason? That\u2019s because we want the symmetry to hold for a rectangular canvas as well, and this way it will. \nAlso, you may have noticed that the values of a' and c' are not reassigned when the fourth line is created. Why write their value assignments twice? It\u2019s for readability, documentation and communication. Maintaining the quadruple structure in the code is meant to help you remember that all the while we are dealing with two y coordinates (current and previous) and two x coordinates (current and previous). \nWhat happens to the x coordinates?\nAs you recall, our x coordinates are a (prevX) and c (currX).\nFor the third line we are adding, a' = w - a and c' = w - c, which means\u2026\nFor the fourth line, the same thing happens to our x coordinates a and c.\nWhat happens to the y coordinates?\nAs you recall, our y coordinates are b (prevY) and d (currY).\nFor the third line we are adding, b' = b and d' = d, which means the y coordinates are the ones not changing this time, making this is a reflection across the y-axis. \nFor the fourth line, b' = h - b and d' = h - d, which we\u2019ve seen before: that\u2019s a reflection across the x-axis.\nWe have four more lines, or locations, to define. Note: the part of the code that\u2019s responsible for drawing a micro-line between the newly calculated coordinates is always the same:\n    context.moveTo(a_, b_);\n    context.lineTo(c_, d_);\nWe can leave it out of the next code snippets and just focus on the calculations, i.e, the reassignments. \nOnce again, we need some concrete examples to see where we\u2019re going, so here\u2019s another sketch! The circled point E has the coordinates (2,3) and the circled point F has the coordinates (2,-3). The ability to draw at A but also make the drawing appear at E and F (in addition to B, C and D that we already dealt with) is the functionality we are about to add to out code.\nA sketch illustrating points E and F.\nThis is the code for E and F:\n    // Reassign for 5\n    a_ = w/2+h/2-b; b_ = w/2+h/2-a;\n    c_ = w/2+h/2-d; d_ = w/2+h/2-c;\n\n    // Reassign for 6\n    a_ = w/2+h/2-b; b_ = h/2-w/2+a;\n    c_ = w/2+h/2-d; d_ = h/2-w/2+c;\nTheir x coordinates are identical and their y coordinates are reversed to one another.\nThis one will be out final sketch. The circled point G has the coordinates (-2,3) and the circled point H has the coordinates (-2,-3).\nA sketch illustrating points G and H.\nThis is the code:\n    // Reassign for 7\n    a_ = w/2-h/2+b; b_ = w/2+h/2-a;\n    c_ = w/2-h/2+d; d_ = w/2+h/2-c;\n\n    // Reassign for 8\n    a_ = w/2-h/2+b; b_ = h/2-w/2+a;\n    c_ = w/2-h/2+d; d_ = h/2-w/2+c;\n    //...code...  \n}\nOnce again, the x coordinates of these two points are the same, while the y coordinates are different. And once again I won\u2019t go into the full details, since this has been a long enough journey as it is, and I think we\u2019ve covered all the important principles. But feel free to play around with the code and change it. I really recommend commenting out the code for some of the points to see what your drawing looks like without them.\nI hope you had fun learning! This is our final app:\nSee the Pen Mandala Maker Tutorial: Part 4 by Hagar Shilo (@hagarsh) on CodePen.", "year": "2018", "author": "Hagar Shilo", "author_slug": "hagarshilo", "published": "2018-12-02T00:00:00+00:00", "url": "https://24ways.org/2018/the-art-of-mathematics/", "topic": "code"}
{"rowid": 258, "title": "Mistletoe Offline", "contents": "It\u2019s that time of year, when we gather together as families to celebrate the life of the greatest person in history. This man walked the Earth long before us, but he left behind words of wisdom. Those words can guide us every single day, but they are at the forefront of our minds during this special season.\nI am, of course, talking about Murphy, and the golden rule he gave unto us:\n\nAnything that can go wrong will go wrong.\n\nSo true! I mean, that\u2019s why we make sure we\u2019ve got nice 404 pages. It\u2019s not that we want people to ever get served a File Not Found message, but we acknowledge that, despite our best efforts, it\u2019s bound to happen sometime. Murphy\u2019s Law, innit?\nBut there are some Murphyesque situations where even your lovingly crafted 404 page won\u2019t help. What if your web server is down? What if someone is trying to reach your site but they lose their internet connection? These are all things than can\u2014and will\u2014go wrong.\nI guess there\u2019s nothing we can do about those particular situations, right?\nWrong!\nA service worker is a Murphy-battling technology that you can inject into a visitor\u2019s device from your website. Once it\u2019s installed, it can intercept any requests made to your domain. If anything goes wrong with a request\u2014as is inevitable\u2014you can provide instructions for the browser. That\u2019s your opportunity to turn those server outage frowns upside down. Take those network connection lemons and make network connection lemonade.\nIf you\u2019ve got a custom 404 page, why not make a custom offline page too?\nGet your server in order\nStep one is to make \u2026actually, wait. There\u2019s a step before that. Step zero. Get your site running on HTTPS, if it isn\u2019t already. You won\u2019t be able to use a service worker unless everything\u2019s being served over HTTPS, which makes sense when you consider the awesome power that a service worker wields.\nIf you\u2019re developing locally, service workers will work fine for localhost, even without HTTPS. But for a live site, HTTPS is a must.\nMake an offline page\nAlright, assuming your site is being served over HTTPS, then step one is to create an offline page. Make it as serious or as quirky as is appropriate for your particular brand. If the website is for a restaurant, maybe you could put the telephone number and address of the restaurant on the custom offline page (unsolicited advice: you could also put this on the home page, you know). Here\u2019s an example of the custom offline page for this year\u2019s Ampersand conference.\nWhen you\u2019re done, publish the offline page at suitably imaginative URL, like, say /offline.html.\nPre-cache your offline page\nNow create a JavaScript file called serviceworker.js. This is the script that the browser will look to when certain events are triggered. The first event to handle is what to do when the service worker is installed on the user\u2019s device. When that happens, an event called install is fired. You can listen out for this event using addEventListener:\naddEventListener('install', installEvent => {\n// put your instructions here.\n}); // end addEventListener\nIn this case, you want to make sure that your lovingly crafted custom offline page is put into a nice safe cache. You can use the Cache API to do this. You get to create as many caches as you like, and you can call them whatever you want. Here, I\u2019m going to call the cache Johnny just so I can refer to it as JohnnyCache in the code:\naddEventListener('install', installEvent => {\n  installEvent.waitUntil(\n    caches.open('Johnny')\n    .then( JohnnyCache => {\n      JohnnyCache.addAll([\n       '/offline.html'\n      ]); // end addAll\n    }) // end open.then\n  ); // end waitUntil\n}); // end addEventListener\nI\u2019m betting that your lovely offline page is linking to a CSS file, maybe an image or two, and perhaps some JavaScript. You can cache all of those at this point:\naddEventListener('install', installEvent => {\n  installEvent.waitUntil(\n    caches.open('Johnny')\n    .then( JohnnyCache => {\n      JohnnyCache.addAll([\n       '/offline.html',\n       '/path/to/stylesheet.css',\n       '/path/to/javascript.js',\n           '/path/to/image.jpg'\n      ]); // end addAll\n    }) // end open.then\n  ); // end waitUntil\n}); // end addEventListener\nMake sure that the URLs are correct. If just one of the URLs in the list fails to resolve, none of the items in the list will be cached.\nIntercept requests\nThe next event you want to listen for is the fetch event. This is probably the most powerful\u2014and, let\u2019s be honest, the creepiest\u2014feature of a service worker. Once it has been installed, the service worker lurks on the user\u2019s device, waiting for any requests made to your site. Every time the user requests a web page from your site, a fetch event will fire. Every time that page requests a style sheet or an image, a fetch event will fire. You can provide instructions for what should happen each time:\naddEventListener('fetch', fetchEvent => {\n// What happens next is up to you!\n}); // end addEventListener\nLet\u2019s write a fairly conservative script with the following logic:\n\nWhenever a file is requested,\nFirst, try to fetch it from the network,\nBut if that doesn\u2019t work, try to find it in the cache,\nBut if that doesn\u2019t work, and it\u2019s a request for a web page, show the custom offline page instead.\n\nHere\u2019s how that translates into JavaScript:\n// Whenever a file is requested\naddEventListener('fetch', fetchEvent => {\n  const request = fetchEvent.request;\n  fetchEvent.respondWith(\n    // First, try to fetch it from the network\n    fetch(request)\n    .then( responseFromFetch => {\n      return responseFromFetch;\n    }) // end fetch.then\n    // But if that doesn't work\n    .catch( fetchError => {\n      // try to find it in the cache\n      caches.match(request)\n      .then( responseFromCache => {\n        if (responseFromCache) {\n         return responseFromCache;\n       // But if that doesn't work\n       } else {\n         // and it's a request for a web page\n         if (request.headers.get('Accept').includes('text/html')) {\n           // show the custom offline page instead\n           return caches.match('/offline.html');\n         } // end if\n       } // end if/else\n     }) // end match.then\n   }) // end fetch.catch\n  ); // end respondWith\n}); // end addEventListener\nI am fully aware that I may have done some owl-drawing there. If you need a more detailed breakdown of what\u2019s happening at each point in the code, I\u2019ve written a whole book for you. It\u2019s the perfect present for Murphymas.\nHook up your service worker script\nYou can publish your service worker script at /serviceworker.js but you still need to tell the browser where to look for it. You can do that using JavaScript. Put this in an existing JavaScript file that you\u2019re calling in to every page on your site, or add this in a script element at the end of every page\u2019s HTML:\nif (navigator.serviceWorker) {\n  navigator.serviceWorker.register('/serviceworker.js');\n}\nThat tells the browser to start installing the service worker, but not without first checking that the browser understands what a service worker is. When it comes to JavaScript, feature detection is your friend.\nYou might already have some JavaScript files in a folder like /assets/js/ and you might be tempted to put your service worker script in there too. Don\u2019t do that. If you do, the service worker will only be able to handle requests made to for files within /assets/js/. By putting the service worker script in the root directory, you\u2019re making sure that every request can be intercepted.\nGo further!\nNicely done! You\u2019ve made sure that if\u2014no, when\u2014a visitor can\u2019t reach your website, they\u2019ll get your hand-tailored offline page. You have temporarily defeated the forces of chaos! You have briefly fought the tide of entropy! You have made a small but ultimately futile gesture against the inevitable heat-death of the universe!\nThis is just the beginning. You can do more with service workers.\nWhat if, every time you fetched a page from the network, you stored a copy of that page in a cache? Then if that person tries to reach that page later, but they\u2019re offline, you could show them the cached version.\nOr, what if instead of reaching out the network first, you checked to see if a file is in the cache first? You could serve up that cached version\u2014which would be blazingly fast\u2014and still fetch a fresh version from the network in the background to pop in the cache for next time. That might be a good strategy for images.\nSo many options! The hard part isn\u2019t writing the code, it\u2019s figuring out the steps you want to take. Once you\u2019ve got those steps written out, then it\u2019s a matter of translating them into JavaScript.\nInevitably there will be some obstacles along the way\u2014usually it\u2019s a misplaced curly brace or a missing parenthesis. Don\u2019t be too hard on yourself if your code doesn\u2019t work at first. That\u2019s just Murphy\u2019s Law in action.", "year": "2018", "author": "Jeremy Keith", "author_slug": "jeremykeith", "published": "2018-12-04T00:00:00+00:00", "url": "https://24ways.org/2018/mistletoe-offline/", "topic": "code"}
{"rowid": 257, "title": "The (Switch)-Case for State Machines in User Interfaces", "contents": "You\u2019re tasked with creating a login form. Email, password, submit button, done.\n\u201cThis will be easy,\u201d you think to yourself.\nLogin form by Selecto\nYou\u2019ve made similar forms many times in the past; it\u2019s essentially muscle memory at this point. You\u2019re working closely with a designer, who gives you a beautiful, detailed mockup of a login form. Sure, you\u2019ll have to translate the pixels to meaningful, responsive CSS values, but that\u2019s the least of your problems.\nAs you\u2019re writing up the HTML structure and CSS layout and styles for this form, you realize that you don\u2019t know what the successful \u201clogged in\u201d page looks like. You remind the designer, who readily gives it to you. But then you start thinking more and more about how the login form is supposed to work.\n\nWhat if login fails? Where do those errors show up?\nShould we show errors differently if the user forgot to enter their email, or password, or both?\nOr should the submit button be disabled?\nShould we validate the email field?\nWhen should we show validation errors \u2013 as they\u2019re typing their email, or when they move to the password field, or when they click submit? (Note: many, many login forms are guilty of this.)\nWhen should the errors disappear?\nWhat do we show during the login process? Some loading spinner?\nWhat if loading takes too long, or a server error occurs?\n\nMany more questions come up, and you (and your designer) are understandably frustrated. The lack of upfront specification opens the door to scope creep, which readily finds itself at home in all the unexplored edge cases.\nModeling Behavior\nDescribing all the possible user flows and business logic of an application can become tricky. Ironically, user stories might not tell the whole story \u2013 they often leave out potential edge-cases or small yet important bits of information.\nHowever, one important (and very old) mathematical model of computation can be used for describing the behavior and all possible states of a user interface: the finite state machine.\nThe general idea, as it applies to user interfaces, is that all of our applications can be described (at some level of abstraction) as being in one, and only one, of a finite number of states at any given time. For example, we can describe our login form above in these states:\n\nstart - not submitted yet\nloading - submitted and logging in\nsuccess - successfully logged in\nerror - login failed\n\nAdditionally, we can describe an application as accepting a finite number of events \u2013 that is, all the possible events that can be \u201csent\u201d to the application, either from the user or some other external entity:\n\nSUBMIT - pressing the submit button\nRESOLVE - the server responds, indicating that login is successful\nREJECT - the server responds, indicating that login failed\n\nThen, we can combine these states and events to describe the transitions between them. That is, when the application is in one state, an an event occurs, we can specify what the next state should be:\n\nFrom the start state, when the SUBMIT event occurs, the app should be in the loading state.\nFrom the loading state, when the RESOLVE event occurs, login succeeded and the app should be in the success state.\nIf login fails from the loading state (i.e., when the REJECT event occurs), the app should be in the error state.\nFrom the error state, the user should be able to retry login: when the SUBMIT event occurs here, the app should go to the loading state.\nOtherwise, if any other event occurs, don\u2019t do anything and stay in the same state.\n\nThat\u2019s a pretty thorough description, similar to a user story! It\u2019s also a bit more symbolic than a user story (e.g., \u201cwhen the SUBMIT event occurs\u201d instead of \u201cwhen the user presses the submit button\u201d), and that\u2019s for a reason. By representing states, events, and transitions symbolically, we can visualize what this state machine looks like:\n\nEvery state is represented by a box, and every event is connected to a transition arrow that connects two states. This makes it intuitive to follow the flow and understand what the next state should be given the current state and an event.\nFrom Visuals to Code\nDrawing a state machine doesn\u2019t require any special software; in fact, using paper and pencil (in case anything changes!) does the job quite nicely. However, one common problem is handoff: it doesn\u2019t matter how detailed a user story or how well-designed a visualization is, it eventually has to be coded in order for it to become part of a real application.\nWith the state machine model described above, the same visual description can be mapped directly to code. Traditionally, and as the title suggests, this is done using switch/case statements:\nfunction loginMachine(state, event) {\n    switch (state) {\n        case 'start':\n            if (event === 'SUBMIT') {\n                return 'loading';\n            }\n            break;\n        case 'loading':\n            if (event === 'RESOLVE') {\n                return 'success';\n            } else if (event === 'REJECT') {\n                return 'error';\n            }\n            break;\n        case 'success':\n            // Accept no further events\n            break;\n        case 'error':\n            if (event === 'SUBMIT') {\n                return 'loading';\n            }\n            break;\n        default:\n            // This should never occur\n            return undefined;\n    }\n}\n\nconsole.log(loginMachine('start', 'SUBMIT'));\n// => 'loading'\nThis is fine (I suppose) but personally, I find it much easier to use objects:\nconst loginMachine = {\n  initial: \"start\",\n  states: {\n    start: {\n      on: { SUBMIT: 'loading' }\n    },\n    loading: {\n      on: {\n        REJECT: 'error',\n        RESOLVE: 'success'\n      }\n    },\n    error: {\n      on: {\n        SUBMIT: 'loading'\n      }\n    },\n    success: {}\n  }\n};\n\nfunction transition(state, event) {\n  return machine\n    .states[state] // Look up the state\n    .on[event]     // Look up the next state based on the event\n    || state;      // If not found, return the current state\n}\n\nconsole.log(transition('start', 'SUBMIT'));\nAs you might have noticed, the loginMachine is a plain JS object, and can be written in JSON. This is important because it allows the machine to be visualized by a 3rd-party tool, as demonstrated here:\n\nA Common Language Between Designers and Developers\nAlthough finite state machines are a fundamental part of computer science, they have an amazing potential to bridge the application specification gap between designers and developers, as well as project managers, stakeholders, and more. By designing a state machine visually and with code, designers and developers alike can:\n\nidentify all possible states, and potentially missing states\ndescribe exactly what should happen when an event occurs on a given state, and prevent that event from having unintended side-effects in other states (ever click a submit button more than once?)\neliminate impossible states and identify states that are \u201cunreachable\u201d (have no entry transition) or \u201csunken\u201d (have no exit transition)\nadd features with full confidence of knowing what other states it might affect\nsimplify redundant states or complex user flows\ncreate test paths for almost every possible user flow, and easily identify edge cases\ncollaborate better by understanding the entire application model equally.\n\nNot a New Idea\nI\u2019m not the first to suggest that state machines can help bridge the gap between design and development.\n\nVince MingPu Shao wrote an article about designing UI states and communicating with developers effectively with finite state machines\nUser flow diagrams, which visually describe the paths that a user can take through an app to achieve certain goals, are essentially state machines. Numerous tools, from Sketch plugins to standalone apps, exist for creating them.\nIn 1999, Ian Horrocks wrote a book titled \u201cConstructing the User Interface with Statecharts\u201d, which takes state machines to the next level and describes the inherent difficulties (and solutions) with creating complex UIs. The ideas in the book are still relevant today.\nMore than a decade earlier, David Harel published \u201cStatecharts: A Visual Formalism for Complex Systems\u201d, in which the statechart - an extended hierarchical state machine model - is born.\n\nState machines and statecharts have been used for complex systems and user interfaces, both physical and digital, for decades, and are especially prevalent in other industries, such as game development and embedded electronic systems. Even NASA uses statecharts for the Curiosity Rover and more, citing many benefits:\n\nVisualized modeling\nPrecise diagrams\nAutomatic code generation\nComprehensive test coverage\nAccommodation of late-breaking requirements changes\n\nMoving Forward\nIt\u2019s time that we improve how we communicate between designers and developers, much less improve the way we develop UIs to deliver the best, bug-free, optimal user experience. There is so much more to state machines and statecharts than just being a different way of designing and coding. For more resources:\n\nThe World of Statecharts is a comprehensive guide by Erik Mogensen in using statecharts in your applications\nThe Statechart Community on Spectrum is always full of interesting ideas and questions related to state machines, statecharts, and software modeling\nI gave a talk at React Rally over a year ago about how state machines (finite automata) can improve the way we develop applications. The latest one is from Reactive Conf, where I demonstrate how statecharts can be used to automatically generate test cases.\nI have also been working on XState, which is a library for \u201cstate machines and statecharts for the modern web\u201d. You can create and visualize statecharts in JavaScript, and use them in any framework (and soon enough, multiple different languages).\n\nI\u2019m excited about the future of developing web and mobile applications with statecharts, especially with regard to faster design/development cycles, auto-generated testing, better error prevention, comprehensive analytics, and even the use of model-based reinforcement learning and artificial intelligence to greatly improve the user experience.", "year": "2018", "author": "David Khourshid", "author_slug": "davidkhourshid", "published": "2018-12-12T00:00:00+00:00", "url": "https://24ways.org/2018/state-machines-in-user-interfaces/", "topic": "code"}
{"rowid": 256, "title": "Develop Your Naturalist Superpowers with Observable Notebooks and iNaturalist", "contents": "We\u2019re going to level up your knowledge of what animals you might see in an area at a particular time of year - a skill every naturalist* strives for -  using technology! Using iNaturalist and Observable Notebooks we\u2019re going to prototype seasonality graphs for particular species in an area, and automatically create a guide to what animals you might see in each month.\n*(a Naturalist is someone who likes learning about nature, not someone who\u2019s a fan of being naked, that\u2019s a \u2018Naturist\u2019\u2026 different thing!)\nLooking for critters in rocky intertidal habitats\nOne of my favourite things to do is going rockpooling, or as we call it over here in California, \u2018tidepooling\u2019. Amounting to the same thing, it\u2019s going to a beach that has rocks where the tide covers then uncovers little pools of water at different times of the day. All sorts of fun creatures and life can be found in this \u2018rocky intertidal habitat\u2019\nA particularly exciting creature that lives here is the Nudibranch, a type of super colourful \u2018sea slug\u2019. There are over 3000 species of Nudibranch worldwide. (The word \u201cnudibranch\u201d comes from the Latin nudus, naked, and the Greek \u03b2\u03c1\u03b1\u03bd\u03c7\u03b9\u03b1 / brankhia, gills.)\n\u200b\n\nThey are however quite tricky to find! Even though they are often brightly coloured and interestingly shaped, some of them are very small, and in our part of the world in the Bay Area in California their appearance in our rockpools is seasonal. We see them more often in Summer months, despite the not-as-low tides as in our Winter and Spring seasons.\nMy favourite place to go tidepooling here is Pillar Point in Half Moon bay (at other times of the year more famously known for the surf competition \u2018Mavericks\u2019). The rockpools there are rich in species diversity, of varied types and water-coverage habitat zones as well as being relatively accessible.\n\u200b\n\nI was rockpooling at Pillar Point recently with my parents and we talked to a lady who remarked that she hadn\u2019t seen any Nudibranchs on her visit this time. I realised that having an idea of what species to find where, and at what time of year is one of the many superpower goals of every budding Naturalist. \nUsing technology and the croudsourced species observations of the iNaturalist community we can shortcut our way to this superpower!\nFinding nearby animals with iNaturalist\nWe\u2019re going to be getting our information about what animals you can see in Pillar Point using iNaturalist. iNaturalist is a really fun platform that helps connect people to nature and report their findings of life in the outdoors. It is also a community of nature-loving people who help each other identify and confirm those observations. iNaturalist is a project run as a joint initiative by the California Academy of Sciences and the National Geographic Society.\nI\u2019ve been using iNaturalist for over two years to record and identify plants and animals that I\u2019ve found in the outdoors. I use their iPhone app to upload my pictures, which then uses machine learning algorithms to make an initial guess at what it is I\u2019ve seen. The community is really active, and I often find someone else has verified or updated my species guess pretty soon after posting. \nThis process is great because once an observation has been identified by at least two people it becomes \u2018verified\u2019 and is considered research grade. Research grade observations get exported and used by scientists, as well as being indexed by the Global Biodiversity Information Facility, GBIF.\n\u200b\n\niNaturalist has a great API and API explorer, which makes interacting and prototyping using iNaturalist data really fun. For example, if you go to the API explorer and expand the Observations : Search and fetch section and then the GET /observations API, you get a selection of input boxes that allow you to play with options that you can then pass to the API when you click the \u2018Try it out\u2019 button.\n\u200b\n\nYou\u2019ll then get a URL that looks a bit like\nhttps://api.inaturalist.org/v1/observations?captive=false &geo=true&verifiable=true&taxon_id=47113&lat=37.495461&lng=-122.499584 &radius=5&order=desc&order_by=created_at \nwhich you can call and interrrogate using a programming language of your choice.\nIf you would like to see an all-JavaScript application that uses the iNaturalist API, take a look at OwlsNearMe.com which Simon and I built one weekend earlier this year. It gets your location and shows you all iNaturalist observations of owls near you and lists which species you are likely to see (not adjusted for season).\nRapid development using Observable Notebooks\nWe\u2019re going to be using Observable Notebooks to prototype our examples, pulling data down from iNaturalist. I really like using visual notebooks like Observable, they are great for learning and building things quickly. You may be familiar with Jupyter notebooks for Python which is similar but takes a bit of setup to get going - I often use these for prototyping too. Observable is amazing for querying and visualising data with JavaScript and since it is a hosted product it doesn\u2019t require any setup at all.\nYou can follow along and play with this example on my Observable notebook. If you create an account there you can fork my notebook and create your own version of this example. \nEach \u2018notebook\u2019 consists of a page with a column of \u2018cells\u2019, similar to what you get in a spreadsheet. A cell can contain Markdown text or JavaScript code and the output of evaluating the cell appears above the code that generated it. There are lots of tutorials out there on Observable Notebooks, I like this code introduction one from Observable (and D3) creator Mike Bostock.\nDeveloping your Naturalist superpowers\nIf you have an idea of what plants and critters you might see in a place at the time you visit, you can hone in on what you want to study and train your Naturalist eye to better identify the life around you.\nFor our example, we care about wildlife we can see at Pillar Point, so we need a way of letting the iNaturalist API know which area we are interested in.\nWe could use a latitide, longitude and radius for this, but a rectangular bounding box is a better shape for the reef. We can use this tool to draw the area we want to search within: boundingbox.klokantech.com\n\u200b\n\nThe tool lets you export the bounding box in several forms using the dropdown at the bottom left under the map givese We are going to use the \u2018DublinCore\u2019 format as it\u2019s closest to the format needed by the iNaturalist API.\n westlimit=-122.50542; southlimit=37.492805; eastlimit=-122.492738; northlimit=37.499811\nA quick map primer:\nThe higher the latitude the more north it is\nThe lower the latitude the more south it is\nLatitude 0 = the equator\n\nThe higher the longitude the more east it is of Greenwich\nThe lower the longitude the more west it is of Greenwich\nLongitude 0 = Greenwich\nIn the iNaturalst API we want to use the parameters nelat, nelng, swlat, swlng to create a query that looks inside a bounding box of Pillar Point near Half Moon Bay in California:\nnelat = highest latitude = north limit = 37.499811\nnelng = highest longitude = east limit = -122.492738\nswlat = smallest latitude = south limit = 37.492805\nswlng = smallest longitude = west limit = 122.50542\nAs API parameters these look like this:\n?nelat=37.499811&nelng=-122.492738&swlat=37.492805&swlng=122.50542\nThese parameters in this format can be used for most of the iNaturalist API methods.\nNudibranch seasonality in Pillar Point\nWe can use the iNaturalist observation_histogram API to get a count of Nudibranch observations per week-of-year across all time and within our Pillar Point bounding box.\nIn addition to the geographic parameters that we just worked out, we are also sending the taxon_id of 47113, which is iNaturalists internal number associated with the Nudibranch taxon. By using this we can get all species which are under the parent \u2018Order Nudibranchia\u2019. \nAnother useful piece of naturalist knowledge is understanding the biological classification scheme of Taxanomic Rank - roughly, when a species has a Latin name of two words eg \u2018Glaucus Atlanticus\u2019 the first Latin word is the \u2018Genus\u2019 like a family name \u2018Glaucus\u2019, and the second word identifies that particular species, like a given name \u2018Atlanticus\u2019. \nThe two Latin words together indicate a specific species, the term we use colloquially to refer to a type of animal often differs wildly region to region, and sometimes the same common name in two countries can refer to two different species. The common names for the Glaucus Atlanticus (which incidentally is my favourite sea slug) include: sea swallow, blue angel, blue glaucus, blue dragon, blue sea slug and blue ocean slug! Because this gets super confusing, Scientists like using this Latin name format instead.\nThe following piece of code asks the iNaturalist Histogram API to return per-week counts for verified observations of Nudibranchs within our Pillar Point bounding box:\npillar_point_counts_per_week = fetch(\n  \"https://api.inaturalist.org/v1/observations/histogram?taxon_id=47113&nelat=37.499811&nelng=-122.492738&swlat=37.492805&swlng=-122.50542&date_field=observed&interval=week_of_year&verifiable=true\"\n  ).then(response => {\n  return response.json();\n})\nOur next step is to take this data and draw a graph! We\u2019ll be using Vega-Lite for this, which is a fab JavaScript graphing libary that is also easy and fun to use with Observable Notebooks. \n(Here is a great tutorial on exploring data and drawing graphs with Observable and Vega-Lite)\nThe iNaturalist API returns data that looks like this:\n{\n  \"total_results\": 53,\n  \"page\": 1,\n  \"per_page\": 53,\n  \"results\": {\n    \"week_of_year\": {\n      \"1\": 136,\n      \"2\": 20,\n      \"3\": 150,\n      \"4\": 65,\n      \"5\": 186,\n      \"6\": 74,\n      \"7\": 47,\n      \"8\": 87,\n      \"9\": 64,\n      \"10\": 56,\nBut for our Vega-Lite graph we need data that looks like this:\n[{\n  \"week\": \"01\",\n  \"value\": 136\n}, {\n  \"week\": \"02\",\n  \"value\": 20\n}, ...]\nWe can convert what we get back from the API to the second format using a loop that iterates over the object keys:\nobjects_to_plot = {\n  let objects = [];\n  Object.keys(pillar_point_counts_per_week.results.week_of_year).map(function(week_index) {\n    objects.push({\n      week: `Wk ${week_index.toString()}`,\n      observations: pillar_point_counts_per_week.results.week_of_year[week_index]\n    });\n  })\n  return objects;\n}\nWe can then plug this into Vega-Lite to draw us a graph:\nvegalite({\n  data: {values: objects_to_plot},\n  mark: \"bar\",\n  encoding: {\n    x: {field: \"week\", type: \"nominal\", sort: null},\n    y: {field: \"observations\", type: \"quantitative\"}\n  },\n  width: width * 0.9\n})\n\nIt\u2019s worth noting that we have a lot of observations of Nudibranchs particularly at Pillar Point due in no small part to the intertidal monitoring research that Alison Young and Rebecca Johnson facilitate for the California Achademy of Sciences. \nSo, what if we want to look for the seasonality of observations of a particular species of adorable sea slug? We want our interface to have a select box with a list of all the species you might find at any time of year. We can do this using the species_counts API to create us an object with the iNaturalist species ID and common & Latin names.\npillar_point_nudibranches = {\n  let api_results = await fetch(\n  \"https://api.inaturalist.org/v1/observations/species_counts?taxon_id=47113&nelat=37.499811&nelng=-122.492738&swlat=37.492805&swlng=-122.50542&date_field=observed&verifiable=true\"\n  ).then(r => r.json())\n\n  let species_list = api_results.results.map(i => ({\n      value: i.taxon.id,\n      label: `${i.taxon.preferred_common_name} (${i.taxon.name})`\n  }));\n\n  return species_list\n}\nWe can create an interactive select box by importing code from Jeremy Ashkanas\u2019 Observable Notebook: add import {select} from \"@jashkenas/inputs\" to a cell anywhere in our notebook. Observable is magic: like a spreadsheet, the order of the cells doesn\u2019t matter - if one cell is referenced by any other cell then when that cell updates all the other cells refresh themselves. You can also import and reference one notebook from another!\nviewof select_species = select({\n    title: \"Which Nudibranch do you want to see seasonality for?\",\n    options: [{value: \"\", label: \"All the Nudibranchs!\"}, ...pillar_point_nudibranches],\n    value: \"\"\n})\nThen we go back to our old favourite, the histogram API just like before, only this time we are calling it with the value created by our select box ${select_species} as taxon_id instead of the number 47113.\npillar_point_counts_per_month_per_species = fetch(\n  `https://api.inaturalist.org/v1/observations/histogram?taxon_id=${select_species}&nelat=37.499811&nelng=-122.492738&swlat=37.492805&swlng=-122.50542&date_field=observed&interval=month_of_year&verifiable=true`\n).then(r => r.json())\nNow for the fun graph bit! As we did before, we re-format the result of the API into a format compatible with Vega-Lite:\nobjects_to_plot_species_month = {\n  let objects = [];\n  Object.keys(pillar_point_counts_per_month_per_species.results.month_of_year).map(function(month_index) {\n    objects.push({\n      month: (new Date(2018, (month_index - 1), 1)).toLocaleString(\"en\", {month: \"long\"}),\n      observations: pillar_point_counts_per_month_per_species.results.month_of_year[month_index]\n    });\n  })\n  return objects;\n}\n(Note that in the above code we are creating a date object with our specific month in, and using toLocalString() to get the longer English name for the month. Because the JavaScript Date object counts January as 0, we use month_index -1 to get the correct month)\nAnd we draw the graph as we did before, only now if you interact with the select box in Observable the graph will dynamically update!\nvegalite({\n  data: {values: objects_to_plot_species_month},\n  mark: \"bar\",\n  encoding: {\n    x: {field: \"month\", type: \"nominal\", sort:null},\n    y: {field: \"observations\", type: \"quantitative\"}\n  },\n  width: width * 0.9\n})\nNow we can see when is the best time of year to plan to go tidepooling in Pillar Point if we want to find a specific species of Nudibranch.\n\u200b\n\nThis tool is great for planning when we to go rockpooling at Pillar Point, but what about if you are going this month and want to pre-train your eye with what to look for in order to impress your friends with your knowledge of Nudibranchs?\nWell\u2026 we can create ourselves a dynamic guide that you can with a list of the species, their photo, name and how many times they have been observed in that month of the year!\nOur select box this time looks as follows, simpler than before but assigning the month value to the variable selected_month.\nviewof selected_month = select({\n    title: \"When do you want to see Nudibranchs?\",\n    options: [\n      { label: \"Whenever\", value: \"\" },\n      { label: \"January\", value: \"1\" },\n      { label: \"February\", value: \"2\" },\n      { label: \"March\", value: \"3\" },\n      { label: \"April\", value: \"4\" },\n      { label: \"May\", value: \"5\" },\n      { label: \"June\", value: \"6\" },\n      { label: \"July\", value: \"7\" },\n      { label: \"August\", value: \"8\" },\n      { label: \"September\", value: \"9\" },\n      { label: \"October\", value: \"10\" },\n      { label: \"November\", value: \"11\" },\n      { label: \"December\", value: \"12\" },\n    ],\n    value: \"\"\n })\nWe then can use the species_counts API to get all the relevant information about which species we can see in month=${selected_month}. We\u2019ll be able to reference this response object and its values later with the variable we just created, eg: all_species_data.results[0].taxon.name.\nall_species_data = fetch(\n    `https://api.inaturalist.org/v1/observations/species_counts?taxon_id=47113&month=${selected_month}&nelat=37.499811&nelng=-122.492738&swlat=37.492805&swlng=-122.50542&verifiable=true`\n).then(r => r.json())\nYou can render HTML directly in a notebook cell using Observable\u2019s html tagged template literal:\n<style> \n.collection { margin-top: 2em }\n.collection .species { display: inline-block; width: 9em; margin-bottom: 2em; }\n.collection .species-name { font-size: 1em; margin: 0; padding: 0 } \n.collection .species-count { margin: 0 0 0.3em 0; padding: 0; font-size: 0.75em; color: #999; font-style: italic; }\n.collection img { display: block; width: 100% }\n.collection select { font-size: 1.5em; }\n</style>\n\n<h2>If you go to Pillar Point ${\n  {\"\": \"\",\n   \"1\":\"in January\",\n   \"2\":\"in Febrary\",\n   \"3\":\"in March\",\n   \"4\":\"in April\",\n   \"5\":\"in May\",\n   \"6\":\"in June\",\n   \"7\":\"in July\",\n   \"8\":\"in August\",\n   \"9\":\"in September\",\n   \"10\":\"in October\",\n   \"11\":\"in November\",\n   \"12\":\"in December\",\n  }[selected_month]\n } you might see\u2026</h2>\n\n<div class=\"collection\">\n${all_species_data.results.map(s => `<div class=\"species\"><h3 class=\"species-name\">${s.taxon.name}</h3>\n  <p class=\"species-count\">Seen ${s.count} times</p>\n  <img src=\"${s.taxon.default_photo.medium_url}\"></div>\n`)}\n</div>\nThese few lines of HTML are all you need to get this exciting dynamic guide to what Nudibranchs you will see in each month!\n\u200b\n\nPlay with it yourself in this Observable Notebook.\nConclusion\nI hope by playing with these examples you have an idea of how powerful it can be to prototype using Observable Notebooks and how you can use the incredible crowdsourced community data and APIs from iNaturalist to augment your naturalist skills and impress your friends with your new \u2018knowledge of nature\u2019 superpower.\nLastly I strongly encourage you to get outside on a low tide to explore your local rocky intertidal habitat, and all the amazing critters that live there.\nHere is a great introduction video to tidepooling / rockpooling, by Rebecca Johnson and Alison Young from the California Academy of Sciences.", "year": "2018", "author": "Natalie Downe", "author_slug": "nataliedowne", "published": "2018-12-18T00:00:00+00:00", "url": "https://24ways.org/2018/observable-notebooks-and-inaturalist/", "topic": "code"}
{"rowid": 255, "title": "Inclusive Considerations When Restyling Form Controls", "contents": "I would like to begin by saying 2018 was the year that we, as developers, visual designers, browser implementers, and inclusive design and experience specialists rallied together and achieved a long-sought goal: We now have the ability to fully style form controls, across all modern browsers, while retaining their ease of declaration, native functionality and accessibility.\nI would like to begin by saying all these things. However, they\u2019re not true. I think we spent the year debating about what file extension CSS should be written in, or something. Or was that last year? Maybe I\u2019m thinking of next year.\nReturning to reality, styling form controls is more tricky and time consuming these days rather than flat out \u201chard\u201d. In fact, depending on the length of the styling-leash a particular browser provides, there are controls you can style quite a bit. As for browsers with shorter leashes, there are other options to force their controls closer to the visual design you\u2019re tasked to match.\nHowever, when striving for custom styled controls, one must be careful not to forget about the inherent functionality and accessibility that many provide. People expect and deserve the products and services they use and pay for to work for them. If these services are visually pleasing, but only function for those who fit the handful of personas they\u2019ve been designed for, then we\u2019ve potentially deprived many people the experiences they deserve.\nQuick level setting\nGetting down to brass tacks, when creating custom styled form controls that should retain their expected semantics and functionality, we have to consider the following:\n\nMany form elements can be styled directly through standard and browser specific selectors, as well as through some clever styling of markup patterns. We should leverage these native options before reinventing any wheels.\nIt is important to preserve the underlying semantics of interactive controls. We must not unintentionally exclude people who use assistive technologies (ATs) that rely on these semantics. \nMake sure you test what you create. There is a lot of underlying complexity to form controls which may not be immediately apparent if they\u2019re judged solely by their visual presentation in a single browser, or with limited AT testing.\n\nVisually resetting and restyling form controls\nOver the course of 2018, I worked on a project where I tested and reported on the accessibility impact of styling various form controls. In conducting my research, I reviewed many of the form controls available in HTML, testing to see how malleable they were to direct styling from standardized CSS selectors. \nAs I expected, controls such as the various text fields could be restyled rather easily. However, other controls like radio buttons and checkboxes, or sub-elements of special text fields like date, search, and number spinners were resistant to standard-based styling. These particular controls and their sub-elements required specific pseudo-elements to reset and allow for restyling of some of their default presentation.\nSee the Pen form control styling comparisons by Scott (@scottohara) on CodePen.\nhttps://codepen.io/scottohara/pen/gZOrZm/\nOver the years, the ability to directly style form controls has been something many people have clamored for. However, one should realize the benefits of being able to restyle some of these controls may involve more effort than originally anticipated. \nIf you want to restyle a control from the ground up, then you must also recreate any :active, :focus, and :hover states for the control\u2014all those things that were previously taken care of by browsers. Not only that, but anything you restyle should also work with Windows High Contrast mode, styling for dark mode, and other OS-level settings that browser respect without you even realizing.   \n\n            You ever try playing with the accessibility settings of your display on macOS, or similar Windows setting?\n    \nIt is also worth mentioning that any browser prefixed pseudo-elements are not standardized CSS selectors. As MDN mentions at the top of their pages documenting these pseudo-elements:\n\nNon-standard\nThis feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.\n\nWhile this may be a deterrent for some, it\u2019s my opinion the risks are often only skin-deep. By which I mean if a non-standard selector does change, the control may look a bit quirky, but likely won\u2019t cease to function. A bug report which requires a CSS selector change can be an easy JIRA ticket to close, after all.\nCan\u2019t make it? Fake it.\nInternet Explorer 11 (IE11) is still neck-and-neck with other browsers in vying for the number 2 spot in desktop browser share. Due to IE not recognizing vendor-prefixed appearance properties, some essential controls like checkboxes won\u2019t render as intended. \nAdditionally, some controls like select boxes, file uploads, and sub-elements of date fields (calendar popups) cannot be modified by just relying on styling their HTML selectors alone. This means that unless your company designs and develops with a progressive enhancement, or graceful degradation mindset, you\u2019ll need to take a different approach in styling.\nGetting clever with markup and CSS\nThe following CodePen demonstrates how we can create a custom checkbox markup pattern. By mindfully utilizing CSS sibling selectors and positioning of the native control, we can create custom visual styling while also retaining the functionality and accessibility expectations of a native checkbox.\nSee the Pen Accessible Styled Native Checkbox by Scott (@scottohara) on CodePen.\nhttps://codepen.io/scottohara/pen/RqEayN/\nCustomizing checkboxes by visually hiding the input and styling well-placed markup with sibling selectors may seem old hat to some. However, many variations of these patterns do not take into account how their method of visually hiding the checkboxes can create discovery issues for certain screen reader navigation methods. For instance, if someone is using a mobile device and exploring by touch, how will they be able to drag their finger over an input that has been reduced to a single pixel, or positioned off screen?\nAs we move away from the simplicity of declaring a single HTML element and using clever CSS and markup patterns to create restyled form controls, we increase the need for additional testing to ensure no expected behaviors are lost. In other words, what should work in theory may not work in practice when you introduce the various different ways people may engage with a form control. It\u2019s worth remembering: what might be typical interactions for ourselves may be problematic if not impossible for others.\nLimitations to cleverness\nCreative coding will allow us to apply more consistent custom styles to some of the more problematic form controls. There will be a varied amount of custom markup, CSS, and sometimes JavaScript that will be needed to preserve the control\u2019s inherent usability and accessibility for each control we take this approach to.\nHowever, this method of restyling still doesn\u2019t solve for the lack of feature parity across different browsers. Nor is it a means to account for controls which don\u2019t have a native HTML element equivalent, such as a switch or multi-thumb range slider? Maybe there\u2019s a control that calls for a visual design or proposed user experience that would require too much fighting with a native control\u2019s behavior to be worth the level of effort to implement. Here\u2019s where we need to take another approach.\nUsing ARIA when appropriate\nSometimes we have no other option than to roll up our sleeves and start building custom form controls from scratch. Fair warning though: just because we\u2019re not leveraging a native HTML control as our foundation, it doesn\u2019t mean we have carte blanche to throw semantics out the window. Enter Accessible Rich Internet Applications (ARIA).\nARIA is a set of attributes that can modify existing elements, or extend HTML to include roles, properties and states that aren\u2019t native to the language. While divs and spans have no meaningful semantic information for us to leverage, with help from the ARIA specification and ARIA Authoring Practices we can incorporate these elements to help create the UI that we need while still following the first rule of Using ARIA:\n\nIf you can use a native HTML element or attribute with the semantics and behavior you require already built in, instead of re-purposing an element and adding an ARIA role, state or property to make it accessible, then do so.\n\nBy using these documents as guidelines, and testing our custom controls with people of various abilities, we can do our best to make sure a custom control performs as expected for as many people as possible.\nExceptions to the rule\nOne example of a control that allows for an exception to the first rule of Using ARIA would be a switch control.\nSwitches and checkboxes are similar components, in that they have both on/checked and off/unchecked states. However, checkboxes are often expected within the context of forms, or used to filter search queries on e-commerce sites. Switches are typically used to instantly enable or deactivate a particular setting at a component or app-based level, as this is their behavior in the native mobile apps in which they were popularized.\nWhile a switch control could be created by visually restyling a checkbox, this does not automatically mean that the underlying semantics and functionality will match the visual representation of the control. For example, the following CodePen restyles checkboxes to look like a switch control, but the semantics of the checkboxes remain which communicate a different way of interacting with the control than what you might expect from a native switch control.\nSee the Pen Switch Boxes - custom styled checkboxes posing as switches by Scott (@scottohara) on CodePen.\nhttps://codepen.io/scottohara/pen/XyvoeE/\nBy adding a role=\"switch\" to these checkboxes, we can repurpose the inherent checked/unchecked states of the native control, it\u2019s inherent ability to be focused by Tab key, and Space key to toggle state.\nBut while this is a valid approach to take in building a switch, how does this actually match up to reality?\nDoes it pass the test(s)?\nWhether deconstructing form controls to fully restyle them, or leveraging them and other HTML elements as a base to expand on, or create, a non-native form control, building it is just the start. We must test that what we\u2019ve restyled or rebuilt works the way people expect it to, if not better.\nWhat we must do here is run a gamut of comparative tests to document the functionality and usability of native form controls.  For example:\n\n\nIs the control implemented in all supported browsers?\nIf not: where are the gaps? Will it be necessary to implement a custom solution for the situations that degrade to a standard text field?  \nIf so: is each browser\u2019s implementation a good user experience? Is there room for improvement that can be tested against the native baseline?  \n\n\nTest with multiple input devices.\nWhere the control is implemented, what is the quality of the user experience when using different input devices, such as mouse, touchscreen, keyboard, speech recognition or switch device, to name a few.  \nYou\u2019ll find some HTML5 controls (like date pickers and number spinners) have additional UI elements that may not be announced to AT, or even allow keyboard accessibility. Often these controls can be adjusted by other means, such as text entry, or using arrow keys to increase or decrease values.  If restyling or recreating a custom version of a control like these, it  may make sense to maintain these native experiences as well.\n\n\nHow well does the control take to custom styles?\nIf a control can be styled enough to not need to be rebuilt from scratch, that\u2019s great! But make sure that there are no adverse affects on the accessibility of it.  For instance, range sliders can be restyled and maintain their functionality and accessibility.  However, elements like progress bars can be negatively affected by direct styling.  \nAlways test with different browser and AT pairings to ensure nothing is lost when controls are restyled.  \n\n\nDo specifications match reality?\nIf recreating controls to get around native limitations, such as the inability to style the options of a select element, or requiring a Switch control which is not native to HTML, do your solutions match user expectations?  \nFor instance, selects have unique picker interfaces on touch devices.  And switches have varied levels of support for different browser and screen reader pairings.  Test with real people, and check your analytics.  If these experiences don\u2019t match people\u2019s expectations, then maybe another solution is in order?  \n\n\nWrapping up\nWhile styling form controls is definitely easier than it\u2019s ever been, that doesn\u2019t mean that it\u2019s at all simple, nor will it likely ever be. The level of difficulty you\u2019re going to face is going to depend entirely on what it is you\u2019re hoping to style, add-on to, or recreate. And even if you build your custom control exactly to specification, you\u2019ll still be reliant on browsers and assistive technologies being able to fully understand the component they\u2019ve been presented.\nForms and their controls are an incredibly important part of what we need the Internet for. Paying bills, scheduling appointments, ordering groceries, renewing your license or even ordering gifts for the holidays. These are all important tasks that people should be able to complete with as little effort as possible. Especially since for some, completing these tasks online might be their only option.\n2018 didn\u2019t end up being the year we got full customization of form controls sorted out. But that\u2019s OK. If we can continue to mindfully work with what we have, and instead challenge ourselves to follow inclusive design principles, well thought out Form Design Patterns, and solve problems with an accessibility first approach, we may come to realize that we can get along just fine without fully branded drop downs.  \nAnd hey. There\u2019s always next year, right?", "year": "2018", "author": "Scott O'Hara", "author_slug": "scottohara", "published": "2018-12-13T00:00:00+00:00", "url": "https://24ways.org/2018/inclusive-considerations-when-restyling-form-controls/", "topic": "code"}
{"rowid": 253, "title": "Clip Paths Know No Bounds", "contents": "CSS Shapes are getting a lot of attention as browser support has increased for properties like shape-outside and clip-path. There are a few ways that we can use CSS Shapes, in particular with the clip-path property, that are not necessarily evident at first glance.\nThe basics of a clip path\nBefore we dig into specific techniques to expand on clip paths, we should first take a look at a basic shape and clip-path. Clip paths can apply a CSS Shape such as a circle(), ellipse(), inset(), or the flexible polygon() to any element. Everywhere in the element that is not within the bounds of our shape will be visually removed.\nUsing the polygon shape function, for example, we can create triangles, stars, or other straight-edged shapes as on Bennett Feely\u2019s Clippy. While fixed units like pixels can be used when defining vertices/points (where the sides meet), percentages will give more flexibility to adapt to the element\u2019s dimensions.\nSee the Pen Clip Path Box by Dan Wilson (@danwilson) on CodePen.\n\nSo for an octagon, we can set eight x, y pairs of percentages to define those points. In this case we start 30% into the width of the box for the first x and at the top of the box for the y and go clockwise. The visible area becomes the interior of the shape made by connecting these points with straight lines.\nclip-path: polygon(\n  30% 0%,\n  70% 0%,\n  100% 30%,\n  100% 70%,\n  70% 100%,\n  30% 100%,\n  0% 70%,\n  0% 30%\n);\nA shape with less vertices than the eye can see\nIt\u2019s reasonable to look at the polygon() function and assume that we need to have one pair of x, y coordinates for every point in our shape. However, we gain some flexibility by thinking outside the box \u2014 or more specifically when we think outside the range of 0% - 100%.\nOur element\u2019s box model will be the ultimate boundary for a clip-path, but we can still define points that exist beyond that natural box for an element.\nSee the Pen CSS Shapes Know No Bounds by Dan Wilson (@danwilson) on CodePen.\n\nBy going beyond the 0% - 100% range we can turn a polygon with three points into a quadrilateral, a pentagon, or a hexagon. In this example the shapes used are all similar triangles defining three points, but due to exceeding the bounds for our element box we visually see one triangle and two pentagons.\nOur earlier octagon can similarly be made with only four points.\nSee the Pen Octagon with four points by Dan Wilson (@danwilson) on CodePen.\n\nMultiple shapes, one clip path\nWe can lean on this power of going beyond the bounds of our element to also create more than one visual shape with a single polygon().\nSee the Pen Multiple shapes from one clip-path by Dan Wilson (@danwilson) on CodePen.\n\nDepending on how we lay it out we can make each shape directly, but since we know we can move around in the space beyond the element\u2019s box, we can draw extra lines to help us get where we need to go next as needed.\nIt can also help us in slicing an element. Combined with CSS Variables, we can work with overlapping elements and clip each one into alternating strips. This example is two elements, each divided into a few rectangles.\nSee the Pen 24w: Sliced Icon by Dan Wilson (@danwilson) on CodePen.\n\nDifferent shapes with fill rules\nA polygon() is not just a collection of points. There is one more key piece to its puzzle according to the specification \u2014 the Fill Rule. The default value we have been using so far is nonzero, and the second option is evenodd. These two values help determine what is considered inside and outside the shape.\nSee the Pen A Star Multiways by Dan Wilson (@danwilson) on CodePen.\n\nAs lines intersect we can get into situations where pieces seemingly on the inside can be considered outside the shape boundary. When using the evenodd fill rule, we can determine if a given point is inside or outside the boundary by drawing a ray from the point in any direction. If the ray crosses an even number of the clip path\u2019s lines, the point is considered outside, and if it crosses an odd number the point is inside.\nOrder of operations\nIt is important to note that there are many CSS properties that affect the final composited appearance of an element via CSS Filters, Blend Modes, and more.\nThese compositing effects are applied in the order:\n\nCSS Filters (e.g. filter: blur(2px))\nClipping (e.g. what this article is about)\nMasking (Clipping\u2019s cousin)\nBlend Modes (e.g. mix-blend-mode: multiply)\nOpacity\n\nThis means if we want to have a star shape and blur it, the blur will happen before the clip. And since blurs are most noticeable around the edge of an element box, the effect might be completely lost since we have clipped away the element\u2019s box edges.\nSee the Pen Order of Filter + Clip by Dan Wilson (@danwilson) on CodePen.\n\nIf we want the edges of the star to be blurred, we do have the option to wrap our clipped element in a blurred parent element. The inner element will be rendered first (with its star clip) and then the parent will blur its contents normally.\nRevealing content with animation\nCSS Shapes can be transitioned and animated, allowing us to animate the visual area of our element without affecting the content within. For example, we can start with visually hidden content (fully clipped) and grow the clip path to reveal the content within. The important caveat for polygon() is that the number of points need to be the same for each keyframe, as well as the fill rule. Otherwise the browser will not have enough information to interpolate the intermediate values. \nSee the Pen Clip Path Shape Reveal by Dan Wilson (@danwilson) on CodePen.\n\nDon\u2019t keep CSS Shapes in a box\nClip paths give us some interesting new possibilities, especially when we think of them as more than just basic shapes. We may be heavily modifying the visual representation of our elements with clip-path, but the underlying content remains unchanged and accessible which makes this property fairly powerful.", "year": "2018", "author": "Dan Wilson", "author_slug": "danwilson", "published": "2018-12-20T00:00:00+00:00", "url": "https://24ways.org/2018/clip-paths-know-no-bounds/", "topic": "code"}
{"rowid": 249, "title": "Fast Autocomplete Search for Your Website", "contents": "Every website deserves a great search engine - but building a search engine can be a lot of work, and hosting it can quickly get expensive.\nI\u2019m going to build a search engine for 24 ways that\u2019s fast enough to support autocomplete (a.k.a. typeahead) search queries and can be hosted for free. I\u2019ll be using wget, Python, SQLite, Jupyter, sqlite-utils and my open source Datasette tool to build the API backend, and a few dozen lines of modern vanilla JavaScript to build the interface.\n\nTry it out here, then read on to see how I built it.\nFirst step: crawling the data\nThe first step in building a search engine is to grab a copy of the data that you plan to make searchable.\nThere are plenty of potential ways to do this: you might be able to pull it directly from a database, or extract it using an API. If you don\u2019t have access to the raw data, you can imitate Google and write a crawler to extract the data that you need.\nI\u2019m going to do exactly that against 24 ways: I\u2019ll build a simple crawler using wget, a command-line tool that features a powerful \u201crecursive\u201d mode that\u2019s ideal for scraping websites.\nWe\u2019ll start at the https://24ways.org/archives/ page, which links to an archived index for every year that 24 ways has been running.\nThen we\u2019ll tell wget to recursively crawl the website, using the --recursive flag.\nWe don\u2019t want to fetch every single page on the site - we\u2019re only interested in the actual articles. Luckily, 24 ways has nicely designed URLs, so we can tell wget that we only care about pages that start with one of the years it has been running, using the -I argument like this: -I /2005,/2006,/2007,/2008,/2009,/2010,/2011,/2012,/2013,/2014,/2015,/2016,/2017\nWe want to be polite, so let\u2019s wait for 2 seconds between each request rather than hammering the site as fast as we can: --wait 2\nThe first time I ran this, I accidentally downloaded the comments pages as well. We don\u2019t want those, so let\u2019s exclude them from the crawl using -X \"/*/*/comments\".\nFinally, it\u2019s useful to be able to run the command multiple times without downloading pages that we have already fetched. We can use the --no-clobber option for this.\nTie all of those options together and we get this command:\nwget --recursive --wait 2 --no-clobber \n  -I /2005,/2006,/2007,/2008,/2009,/2010,/2011,/2012,/2013,/2014,/2015,/2016,/2017 \n  -X \"/*/*/comments\" \n  https://24ways.org/archives/ \nIf you leave this running for a few minutes, you\u2019ll end up with a folder structure something like this:\n$ find 24ways.org\n24ways.org\n24ways.org/2013\n24ways.org/2013/why-bother-with-accessibility\n24ways.org/2013/why-bother-with-accessibility/index.html\n24ways.org/2013/levelling-up\n24ways.org/2013/levelling-up/index.html\n24ways.org/2013/project-hubs\n24ways.org/2013/project-hubs/index.html\n24ways.org/2013/credits-and-recognition\n24ways.org/2013/credits-and-recognition/index.html\n...\nAs a quick sanity check, let\u2019s count the number of HTML pages we have retrieved:\n$ find 24ways.org | grep index.html | wc -l\n328\nThere\u2019s one last step! We got everything up to 2017, but we need to fetch the articles for 2018 (so far) as well. They aren\u2019t linked in the /archives/ yet so we need to point our crawler at the site\u2019s front page instead:\nwget --recursive --wait 2 --no-clobber \n  -I /2018 \n  -X \"/*/*/comments\" \n  https://24ways.org/\nThanks to --no-clobber, this is safe to run every day in December to pick up any new content.\nWe now have a folder on our computer containing an HTML file for every article that has ever been published on the site! Let\u2019s use them to build ourselves a search index.\nBuilding a search index using SQLite\nThere are many tools out there that can be used to build a search engine. You can use an open-source search server like Elasticsearch or Solr, a hosted option like Algolia or Amazon CloudSearch or you can tap into the built-in search features of relational databases like MySQL or PostgreSQL.\nI\u2019m going to use something that\u2019s less commonly used for web applications but makes for a powerful and extremely inexpensive alternative: SQLite.\nSQLite is the world\u2019s most widely deployed database, even though many people have never even heard of it. That\u2019s because it\u2019s designed to be used as an embedded database: it\u2019s commonly used by native mobile applications and even runs as part of the default set of apps on the Apple Watch!\nSQLite has one major limitation: unlike databases like MySQL and PostgreSQL, it isn\u2019t really designed to handle large numbers of concurrent writes. For this reason, most people avoid it for building web applications.\nThis doesn\u2019t matter nearly so much if you are building a search engine for infrequently updated content - say one for a site that only publishes new content on 24 days every year.\nIt turns out SQLite has very powerful full-text search functionality built into the core database - the FTS5 extension.\nI\u2019ve been doing a lot of work with SQLite recently, and as part of that, I\u2019ve been building a Python utility library to make building new SQLite databases as easy as possible, called sqlite-utils. It\u2019s designed to be used within a Jupyter notebook - an enormously productive way of interacting with Python code that\u2019s similar to the Observable notebooks Natalie described on 24 ways yesterday.\nIf you haven\u2019t used Jupyter before, here\u2019s the fastest way to get up and running with it - assuming you have Python 3 installed on your machine. We can use a Python virtual environment to ensure the software we are installing doesn\u2019t clash with any other installed packages:\n$ python3 -m venv ./jupyter-venv\n$ ./jupyter-venv/bin/pip install jupyter\n# ... lots of installer output\n# Now lets install some extra packages we will need later\n$ ./jupyter-venv/bin/pip install beautifulsoup4 sqlite-utils html5lib\n# And start the notebook web application\n$ ./jupyter-venv/bin/jupyter-notebook\n# This will open your browser to Jupyter at http://localhost:8888/\nYou should now be in the Jupyter web application. Click New -> Python 3 to start a new notebook.\nA neat thing about Jupyter notebooks is that if you publish them to GitHub (either in a regular repository or as a Gist), it will render them as HTML. This makes them a very powerful way to share annotated code. I\u2019ve published the notebook I used to build the search index on my GitHub account. \n\u200b\n\nHere\u2019s the Python code I used to scrape the relevant data from the downloaded HTML files. Check out the notebook for a line-by-line explanation of what\u2019s going on.\nfrom pathlib import Path\nfrom bs4 import BeautifulSoup as Soup\nbase = Path(\"/Users/simonw/Dropbox/Development/24ways-search\")\narticles = list(base.glob(\"*/*/*/*.html\"))\n# articles is now a list of paths that look like this:\n# PosixPath('...24ways-search/24ways.org/2013/why-bother-with-accessibility/index.html')\ndocs = []\nfor path in articles:\n    year = str(path.relative_to(base)).split(\"/\")[1]\n    url = 'https://' + str(path.relative_to(base).parent) + '/'\n    soup = Soup(path.open().read(), \"html5lib\")\n    author = soup.select_one(\".c-continue\")[\"title\"].split(\n        \"More information about\"\n    )[1].strip()\n    author_slug = soup.select_one(\".c-continue\")[\"href\"].split(\n        \"/authors/\"\n    )[1].split(\"/\")[0]\n    published = soup.select_one(\".c-meta time\")[\"datetime\"]\n    contents = soup.select_one(\".e-content\").text.strip()\n    title = soup.find(\"title\").text.split(\" \u25c6\")[0]\n    try:\n        topic = soup.select_one(\n            '.c-meta a[href^=\"/topics/\"]'\n        )[\"href\"].split(\"/topics/\")[1].split(\"/\")[0]\n    except TypeError:\n        topic = None\n    docs.append({\n        \"title\": title,\n        \"contents\": contents,\n        \"year\": year,\n        \"author\": author,\n        \"author_slug\": author_slug,\n        \"published\": published,\n        \"url\": url,\n        \"topic\": topic,\n    })\nAfter running this code, I have a list of Python dictionaries representing each of the documents that I want to add to the index. The list looks something like this:\n[\n  {\n    \"title\": \"Why Bother with Accessibility?\",\n    \"contents\": \"Web accessibility (known in other fields as inclus...\",\n    \"year\": \"2013\",\n    \"author\": \"Laura Kalbag\",\n    \"author_slug\": \"laurakalbag\",\n    \"published\": \"2013-12-10T00:00:00+00:00\",\n    \"url\": \"https://24ways.org/2013/why-bother-with-accessibility/\",\n    \"topic\": \"design\"\n  },\n  {\n    \"title\": \"Levelling Up\",\n    \"contents\": \"Hello, 24 ways. Iu2019m Ashley and I sell property ins...\",\n    \"year\": \"2013\",\n    \"author\": \"Ashley Baxter\",\n    \"author_slug\": \"ashleybaxter\",\n    \"published\": \"2013-12-06T00:00:00+00:00\",\n    \"url\": \"https://24ways.org/2013/levelling-up/\",\n    \"topic\": \"business\"\n  },\n  ...\nMy sqlite-utils library has the ability to take a list of objects like this and automatically create a SQLite database table with the right schema to store the data. Here\u2019s how to do that using this list of dictionaries.\nimport sqlite_utils\ndb = sqlite_utils.Database(\"/tmp/24ways.db\")\ndb[\"articles\"].insert_all(docs)\nThat\u2019s all there is to it! The library will create a new database and add a table to it called articles with the necessary columns, then insert all of the documents into that table.\n(I put the database in /tmp/ for the moment - you can move it to a more sensible location later on.)\nYou can inspect the table using the sqlite3 command-line utility (which comes with OS X) like this:\n$ sqlite3 /tmp/24ways.db\nsqlite> .headers on\nsqlite> .mode column\nsqlite> select title, author, year from articles;\ntitle                           author        year      \n------------------------------  ------------  ----------\nWhy Bother with Accessibility?  Laura Kalbag  2013      \nLevelling Up                    Ashley Baxte  2013      \nProject Hubs: A Home Base for   Brad Frost    2013      \nCredits and Recognition         Geri Coady    2013      \nManaging a Mind                 Christopher   2013      \nRun Ragged                      Mark Boulton  2013      \nGet Started With GitHub Pages   Anna Debenha  2013      \nCoding Towards Accessibility    Charlie Perr  2013      \n...\n<Ctrl+D to quit>\nThere\u2019s one last step to take in our notebook. We know we want to use SQLite\u2019s full-text search feature, and sqlite-utils has a simple convenience method for enabling it for a specified set of columns in a table. We want to be able to search by the title, author and contents fields, so we call the enable_fts() method like this:\ndb[\"articles\"].enable_fts([\"title\", \"author\", \"contents\"])\nIntroducing Datasette\nDatasette is the open-source tool I\u2019ve been building that makes it easy to both explore SQLite databases and publish them to the internet.\nWe\u2019ve been exploring our new SQLite database using the sqlite3 command-line tool. Wouldn\u2019t it be nice if we could use a more human-friendly interface for that?\nIf you don\u2019t want to install Datasette right now, you can visit https://search-24ways.herokuapp.com/ to try it out against the 24 ways search index data. I\u2019ll show you how to deploy Datasette to Heroku like this later in the article.\nIf you want to install Datasette locally, you can reuse the virtual environment we created to play with Jupyter:\n./jupyter-venv/bin/pip install datasette\nThis will install Datasette in the ./jupyter-venv/bin/ folder. You can also install it system-wide using regular pip install datasette.\nNow you can run Datasette against the 24ways.db file we created earlier like so:\n./jupyter-venv/bin/datasette /tmp/24ways.db\nThis will start a local webserver running. Visit http://localhost:8001/ to start interacting with the Datasette web application.\nIf you want to try out Datasette without creating your own 24ways.db file you can download the one I created directly from https://search-24ways.herokuapp.com/24ways-ae60295.db\nPublishing the database to the internet\nOne of the goals of the Datasette project is to make deploying data-backed APIs to the internet as easy as possible. Datasette has a built-in command for this, datasette publish. If you have an account with Heroku or Zeit Now, you can deploy a database to the internet with a single command. Here\u2019s how I deployed https://search-24ways.herokuapp.com/ (running on Heroku\u2019s free tier) using datasette publish:\n$ ./jupyter-venv/bin/datasette publish heroku /tmp/24ways.db --name search-24ways\n-----> Python app detected\n-----> Installing requirements with pip\n\n-----> Running post-compile hook\n-----> Discovering process types\n       Procfile declares types -> web\n\n-----> Compressing...\n       Done: 47.1M\n-----> Launching...\n       Released v8\n       https://search-24ways.herokuapp.com/ deployed to Heroku\nIf you try this out, you\u2019ll need to pick a different --name, since I\u2019ve already taken search-24ways.\nYou can run this command as many times as you like to deploy updated versions of the underlying database.\nSearching and faceting\nDatasette can detect tables with SQLite full-text search configured, and will add a search box directly to the page. Take a look at http://search-24ways.herokuapp.com/24ways-b607e21/articles to see this in action.\n\u200b\n\nSQLite search supports wildcards, so if you want autocomplete-style search where you don\u2019t need to enter full words to start getting results you can add a * to the end of your search term. Here\u2019s a search for access* which returns articles on accessibility:\nhttp://search-24ways.herokuapp.com/24ways-ae60295/articles?_search=acces%2A\nA neat feature of Datasette is the ability to calculate facets against your data. Here\u2019s a page showing search results for svg with facet counts calculated against both the year and the topic columns:\nhttp://search-24ways.herokuapp.com/24ways-ae60295/articles?_search=svg&_facet=year&_facet=topic\nEvery page visible via Datasette has a corresponding JSON API, which can be accessed using the JSON link on the page - or by adding a .json extension to the URL:\nhttp://search-24ways.herokuapp.com/24ways-ae60295/articles.json?_search=acces%2A\nBetter search using custom SQL\nThe search results we get back from ../articles?_search=svg are OK, but the order they are returned in is not ideal - they\u2019re actually being returned in the order they were inserted into the database! You can see why this is happening by clicking the View and edit SQL link on that search results page.\nThis exposes the underlying SQL query, which looks like this:\nselect rowid, * from articles where rowid in (\n  select rowid from articles_fts where articles_fts match :search\n) order by rowid limit 101\nWe can do better than this by constructing a custom SQL query. Here\u2019s the query we will use instead:\nselect\n  snippet(articles_fts, -1, 'b4de2a49c8', '8c94a2ed4b', '...', 100) as snippet,\n  articles_fts.rank, articles.title, articles.url, articles.author, articles.year\nfrom articles\n  join articles_fts on articles.rowid = articles_fts.rowid\nwhere articles_fts match :search || \"*\"\n  order by rank limit 10;\nYou can try this query out directly - since Datasette opens the underling SQLite database in read-only mode and enforces a one second time limit on queries, it\u2019s safe to allow users to provide arbitrary SQL select queries for Datasette to execute.\nThere\u2019s a lot going on here! Let\u2019s break the SQL down line-by-line:\nselect\n  snippet(articles_fts, -1, 'b4de2a49c8', '8c94a2ed4b', '...', 100) as snippet,\nWe\u2019re using snippet(), a built-in SQLite function, to generate a snippet highlighting the words that matched the query. We use two unique strings that I made up to mark the beginning and end of each match - you\u2019ll see why in the JavaScript later on.\n  articles_fts.rank, articles.title, articles.url, articles.author, articles.year\nThese are the other fields we need back - most of them are from the articles table but we retrieve the rank (representing the strength of the search match) from the magical articles_fts table.\nfrom articles\n  join articles_fts on articles.rowid = articles_fts.rowid\narticles is the table containing our data. articles_fts is a magic SQLite virtual table which implements full-text search - we need to join against it to be able to query it.\nwhere articles_fts match :search || \"*\"\n  order by rank limit 10;\n:search || \"*\" takes the ?search= argument from the page querystring and adds a * to the end of it, giving us the wildcard search that we want for autocomplete. We then match that against the articles_fts table using the match operator. Finally, we order by rank so that the best matching results are returned at the top - and limit to the first 10 results.\nHow do we turn this into an API? As before, the secret is to add the .json extension. Datasette actually supports multiple shapes of JSON - we\u2019re going to use ?_shape=array to get back a plain array of objects:\nJSON API call to search for articles matching SVG\nThe HTML version of that page shows the time taken to execute the SQL in the footer. Hitting refresh a few times, I get response times between 2 and 5ms - easily fast enough to power a responsive autocomplete feature.\nA simple JavaScript autocomplete search interface\nI considered building this using React or Svelte or another of the myriad of JavaScript framework options available today, but then I remembered that vanilla JavaScript in 2018 is a very productive environment all on its own.\nWe need a few small utility functions: first, a classic debounce function adapted from this one by David Walsh:\nfunction debounce(func, wait, immediate) {\n  let timeout;\n  return function() {\n    let context = this, args = arguments;\n    let later = () => {\n      timeout = null;\n      if (!immediate) func.apply(context, args);\n    };\n    let callNow = immediate && !timeout;\n    clearTimeout(timeout);\n    timeout = setTimeout(later, wait);\n    if (callNow) func.apply(context, args);\n  };\n};\nWe\u2019ll use this to only send fetch() requests a maximum of once every 100ms while the user is typing.\nSince we\u2019re rendering data that might include HTML tags (24 ways is a site about web development after all), we need an HTML escaping function. I\u2019m amazed that browsers still don\u2019t bundle a default one of these:\nconst htmlEscape = (s) => s.replace(\n  />/g, '&gt;'\n).replace(\n  /</g, '&lt;'\n).replace(\n  /&/g, '&'\n).replace(\n  /\"/g, '&quot;'\n).replace(\n  /'/g, '&#039;'\n);\nWe need some HTML for the search form, and a div in which to render the results:\n<h1>Autocomplete search</h1>\n<form>\n  <p><input id=\"searchbox\" type=\"search\" placeholder=\"Search 24ways\" style=\"width: 60%\"></p>\n</form>\n<div id=\"results\"></div>\nAnd now the autocomplete implementation itself, as a glorious, messy stream-of-consciousness of JavaScript:\n// Embed the SQL query in a multi-line backtick string:\nconst sql = `select\n  snippet(articles_fts, -1, 'b4de2a49c8', '8c94a2ed4b', '...', 100) as snippet,\n  articles_fts.rank, articles.title, articles.url, articles.author, articles.year\nfrom articles\n  join articles_fts on articles.rowid = articles_fts.rowid\nwhere articles_fts match :search || \"*\"\n  order by rank limit 10`;\n\n// Grab a reference to the <input type=\"search\">\nconst searchbox = document.getElementById(\"searchbox\");\n\n// Used to avoid race-conditions:\nlet requestInFlight = null;\n\nsearchbox.onkeyup = debounce(() => {\n  const q = searchbox.value;\n  // Construct the API URL, using encodeURIComponent() for the parameters\n  const url = (\n    \"https://search-24ways.herokuapp.com/24ways-866073b.json?sql=\" +\n    encodeURIComponent(sql) +\n    `&search=${encodeURIComponent(q)}&_shape=array`\n  );\n  // Unique object used just for race-condition comparison\n  let currentRequest = {};\n  requestInFlight = currentRequest;\n  fetch(url).then(r => r.json()).then(d => {\n    if (requestInFlight !== currentRequest) {\n      // Avoid race conditions where a slow request returns\n      // after a faster one.\n      return;\n    }\n    let results = d.map(r => `\n      <div class=\"result\">\n        <h3><a href=\"${r.url}\">${htmlEscape(r.title)}</a></h3>\n        <p><small>${htmlEscape(r.author)} - ${r.year}</small></p>\n        <p>${highlight(r.snippet)}</p>\n      </div>\n    `).join(\"\");\n    document.getElementById(\"results\").innerHTML = results;\n  });\n}, 100); // debounce every 100ms\nThere\u2019s just one more utility function, used to help construct the HTML results:\nconst highlight = (s) => htmlEscape(s).replace(\n  /b4de2a49c8/g, '<b>'\n).replace(\n  /8c94a2ed4b/g, '</b>'\n);\nThis is what those unique strings passed to the snippet() function were for.\nAvoiding race conditions in autocomplete\nOne trick in this code that you may not have seen before is the way race-conditions are handled. Any time you build an autocomplete feature, you have to consider the following case:\n\nUser types acces\nBrowser sends request A - querying documents matching acces*\nUser continues to type accessibility\nBrowser sends request B - querying documents matching accessibility*\nRequest B returns. It was fast, because there are fewer documents matching the full term\nThe results interface updates with the documents from request B, matching accessibility*\nRequest A returns results (this was the slower of the two requests)\nThe results interface updates with the documents from request A - results matching access*\n\nThis is a terrible user experience: the user saw their desired results for a brief second, and then had them snatched away and replaced with those results from earlier on.\nThankfully there\u2019s an easy way to avoid this. I set up a variable in the outer scope called requestInFlight, initially set to null.\nAny time I start a new fetch() request, I create a new currentRequest = {} object and assign it to the outer requestInFlight as well.\nWhen the fetch() completes, I use requestInFlight !== currentRequest to sanity check that the currentRequest object is strictly identical to the one that was in flight. If a new request has been triggered since we started the current request we can detect that and avoid updating the results.\nIt\u2019s not a lot of code, really\nAnd that\u2019s the whole thing! The code is pretty ugly, but when the entire implementation clocks in at fewer than 70 lines of JavaScript, I honestly don\u2019t think it matters. You\u2019re welcome to refactor it as much you like.\nHow good is this search implementation? I\u2019ve been building search engines for a long time using a wide variety of technologies and I\u2019m happy to report that using SQLite in this way is genuinely a really solid option. It scales happily up to hundreds of MBs (or even GBs) of data, and the fact that it\u2019s based on SQL makes it easy and flexible to work with.\nA surprisingly large number of desktop and mobile applications you use every day implement their search feature on top of SQLite.\nMore importantly though, I hope that this demonstrates that using Datasette for an API means you can build relatively sophisticated API-backed applications with very little backend programming effort. If you\u2019re working with a small-to-medium amount of data that changes infrequently, you may not need a more expensive database. Datasette-powered applications easily fit within the free tier of both Heroku and Zeit Now.\nFor more of my writing on Datasette, check out the datasette tag on my blog. And if you do build something fun with it, please let me know on Twitter.", "year": "2018", "author": "Simon Willison", "author_slug": "simonwillison", "published": "2018-12-19T00:00:00+00:00", "url": "https://24ways.org/2018/fast-autocomplete-search-for-your-website/", "topic": "code"}
{"rowid": 247, "title": "Managing Flow and Rhythm with CSS Custom Properties", "contents": "An important part of designing user interfaces is creating consistent vertical rhythm between elements. Creating consistent, predictable space doesn\u2019t just make your web pages and views look better, but it can also improve the scan-ability. \nBrowsers ship with default CSS and these styles often create consistent rhythm for flow elements out of the box. The problem is though that we often reset these styles with a reset. Elements such as <div> and <section> also have no default margin or padding associated with them. \nI\u2019ve tried all sorts of weird and wonderful techniques to find a balance between using inherited CSS while also levelling the playing field for component driven front-ends with very little success. This experimentation is how I landed on the flow utility, though and I\u2019m going to show you how it works. Let\u2019s dive in!\nThe Flow utility\nWith the ever-growing number of folks working with component libraries and design systems, we could benefit from a utility that creates space for us, only when it\u2019s appropriate to do so. The problem with my previous attempts at fixing this is that the spacing values were very rigid. \nThat\u2019s fine for 90% of contexts, but sometimes, it\u2019s handy to be able to tweak the values based on the exact context of your component. This is where CSS Custom Properties come in handy.\nThe code\n.flow {\n  --flow-space: 1em;\n}  \n\n.flow > * + * { \n  margin-top: var(--flow-space);\n}\nWhat this code does is enable you to add a class of flow to an element which will then add margin-top to sibling elements within that element. We use the lobotomised owl selector to select these siblings. This approach enables an almost anonymous and automatic system which is ideal for component library based front-ends where components probably don\u2019t have any idea what surrounds them. \nThe other important part of this utility is the usage of the --flow-space custom property. We define it in the .flow component and each element within it will be spaced by --flow-space, by default. The beauty about setting this as a custom property is that custom properties also participate in the cascade, so we can utilise specificity to change it if we need it. Pretty cool, right? Let\u2019s look at some examples.\nA basic example\nSee the Pen CSS Flow Utility: Basic implementation by Andy Bell (@hankchizljaw) on CodePen.\nhttps://codepen.io/hankchizljaw/pen/LXqerj\nWhat we\u2019ve got in this example is some basic HTML content that has a class of flow on the parent article element. Because there\u2019s a very heavy-handed reset added as a dependency, all of the content would have been squished together without the flow utility. \nBecause our --flow-space custom property is set to 1em, the space between elements is 1X the font size of the element in question. This means that a <h2> in this context has a calculated margin-top value of 28.8px, because it has an assigned font size of 1.8rem. If we were to globally change the --flow-space value to 1.1em for example, we\u2019d affect everything because margin values would be calculated as 1.1X the font size. \nThis example looks great because using font size as the basis of rhythm works really well. What if we wanted to to tweak certain elements within this article, though? \nSee the Pen CSS Flow Utility: Tweaked Basic implementation by Andy Bell (@hankchizljaw) on CodePen.\nhttps://codepen.io/hankchizljaw/pen/qQgxaY\nI like lots of whitespace with my article layouts, so the 1em space isn\u2019t going to cut it for all elements. I like to provide plenty of space between headed sections, so I increase the --flow-space in these instances:\nh2 {\n  --flow-space: 3rem;\n}\nNotice also how I also switch over to using rem units? I want to make sure that these overrides are always based on the root font size. This is a personal preference of mine and you can use whatever units you want. Just be aware that it\u2019s better for accessibility to use flexible units like em, rem and %, so that a user\u2019s font size preferences are honoured. \nA more advanced example\nAlthough the flow utility is super useful for a plethora of contexts, it really shines when working with a few unrelated components. Instead of having to write specific layout CSS just for your particular context, you can use flow and --flow-space to create predictable and contextual space.\nSee the Pen CSS Flow Utility: Unrelated components by Andy Bell (@hankchizljaw) on CodePen.\nhttps://codepen.io/hankchizljaw/pen/ZmPGyL\nIn this example, we\u2019ve got ourselves a little prototype layout that features a media element, followed by a grid of features. By using flow, it was really quick and easy to generate space between those two main elements. It was also easy to create space within the components. For example, I added it to the .media__content element, so that the article\u2019s content would space itself:\n<article class=\"media__content flow\">\n  ...\n</article>\nSomething to remember though: the custom properties cascade in the same way that other CSS values do, so you\u2019ve got to keep that in mind. We\u2019ve got a great example of that in this example where because we\u2019ve got the flow utility on our .features component, which has a --flow-space override: the child elements of .features will inherit that value, so we\u2019ve had to set another value on the .features__list element.\n\u201cBut what about old browsers?\u201d, I hear you cry\nWe\u2019re using CSS Custom Properties that at the time of writing, have about 88% support. One thing we can do to remedy the other 12% of browsers is to set a default, traditional margin-top value of 1em, so it calculates itself based on the element\u2019s font-size:\n.flow {\n  --flow-space: 1em;\n}\n\n.flow > * + * { \n  margin-top: 1em;\n  margin-top: var(--flow-space);\n}\nThanks to the cascading and declarative nature of CSS, we can set that default margin-top value and then immediately set it to use the custom property instead. Browsers that understand Custom Properties will automatically apply them\u2014those that don\u2019t will ignore them. Yay for the cascade and progressive enhancement! \nWrapping up\nThis tiny little utility can bring great power for when you want to consistently space elements, vertically. It also\u2014thanks to the power of the modern web\u2014allows us to create contextual overrides without creating modifier classes or shame CSS. \nIf you\u2019ve got other methods of doing this sort of work, please let me know on Twitter. I\u2019d love to see what you\u2019re working on!", "year": "2018", "author": "Andy Bell", "author_slug": "andybell", "published": "2018-12-07T00:00:00+00:00", "url": "https://24ways.org/2018/managing-flow-and-rhythm-with-css-custom-properties/", "topic": "code"}
{"rowid": 246, "title": "Designing Your Site Like It\u2019s 1998", "contents": "It\u2019s 20 years to the day since my wife and I started Stuff & Nonsense, our little studio and my outlet for creative ideas on the web. To celebrate this anniversary\u2014and my fourteenth contribution to 24 ways\u2014 I\u2019d like to explain how I would\u2019ve developed a design for Planes, Trains and Automobiles, one of my favourite Christmas films.\nMy design for Planes, Trains and Automobiles is fixed at 800px wide.\nDeveloping a <frameset> framework\nI\u2019ll start by using frames to set up the framework for this new website. Frames are individual pages\u2014one for navigation, the other for my content\u2014pulled together to form a frameset. Space is limited on lower-resolution screens, so by using frames I can ensure my navigation always remains visible. I can include any number of frames inside a <frameset> element.\nI add two rows to my <frameset>; the first is for my navigation and is 50px tall, the second is for my content and will resize to fill any available space. As I don\u2019t want frame borders or any space between my frames, I set frameborder and framespacing attributes to 0:\n<frameset frameborder=\"0\" framespacing=\"0\" rows=\"50,*\">\n[\u2026]\n</frameset>\nNext I add the source of my two frame documents. I don\u2019t want people to be able to resize or scroll my navigation, so I add the noresize attribute to that frame:\n<frameset frameborder=\"0\" framespacing=\"0\" rows=\"50,*\">\n<frame noresize scrolling=\"no\" src=\"nav.html\">\n<frame src=\"content.html\">\n</frameset>\nI do want links from my navigation to open in the content frame, so I give each <frame> a name so I can specify where I want links to open:\n<frameset frameborder=\"0\" framespacing=\"0\" rows=\"50,*\">\n<frame name=\"navigation\" noresize scrolling=\"no\" src=\"nav.html\">\n<frame name=\"content\" src=\"content.html\">\n</frameset>\nThe framework for this website is simple as it contains only two horizontal rows. Should I need a more complex layout, I can nest as many framesets\u2014and as many individual documents\u2014as I need:\n<frameset rows=\"50,*\">\n <frame name=\"navigation\">\n <frameset cols=\"25%,*\">\n  <frame name=\"sidebar\">\n  <frame name=\"content\">\n </frameset>\n</frameset>\nLetterbox framesets were common way to deal with multiple screen sizes. In a letterbox, the central frameset had a fixed height and width, while the frames on the top, right, bottom, and left expanded to fill any remaining space.\nHandling older browsers\nSadly not every browser supports frames, so I should send a helpful message to people who use older browsers asking them to upgrade. Happily, I can do that using noframes content:\n<noframes>\n<body>\n<p>This page uses frames, but your browser doesn\u2019t support them. \n    Please upgrade your browser.</p>\n</body>\n</noframes>\nForcing someone back into a frame\nSometimes, someone may follow a link to a page from a portal or search engine, or they might attempt to open it in a new window or tab. If that page properly belongs inside a <frameset>, people could easily miss out on other parts of a design. This short script will prevent this happening and because it\u2019s vanilla Javascript, it doesn\u2019t require a library such as jQuery:\n<script type=\"text/javascript\">\nif (top == self) {\n  location = 'frameset.html';\n}\n</script>\n\nLaying out my page\nBefore starting my layout, I add a few basic background and colour styles. I must include these attributes in every page on my website:\n<body background=\"img/container.jpg\" bgcolor=\"#fef7fb\" \n    link=\"#245eab\" alink=\"#245eab\" vlink=\"#3c146e\" text=\"#000000\">\nI want absolute control over how people experience my design and don\u2019t want to allow it to stretch, so I first need a <table> which limits the width of my layout to 800px. The align attribute will keep this <table> in the centre of someone\u2019s screen:\n<table width=\"800\" align=\"center\">\n <tr>\n  <td>[\u2026]</td>\n </tr>\n</table>\nAlthough they were developed for displaying tabular information, the cells and rows which make up the <table> element make it ideal for the precise implementation of a design. I need several tables\u2014often nested inside each other\u2014to implement my design. These include tables for a banner and three rows of content:\n<table width=\"800\" align=\"center\">\n <table>[\u2026]</table>\n <table>\n  <table>\n   <table>[\u2026]</table>\n  </table>\n </table>\n <table>[\u2026]</table>\n <table>[\u2026]</table>\n</table>\nThe width of the first table\u2014used for my banner\u2014is fixed to match the logo it contains. As I don\u2019t need borders, padding, or spacing between these cells, I use attributes to remove them:\n<table border=\"0\" cellpadding=\"0\" cellspacing=\"0\" width=\"587\" align=\"center\">\n <tr>\n  <td><img src=\"logo.gif\" border=\"0\" width=\"587\" alt=\"Logo\"></td>\n </tr>\n</table>\nThe next table\u2014which contains the largest image, introduction, and a call-to-action\u2014is one of the most complex parts of my design, so I need to ensure its layout is pixel perfect. To do that I add an extra row at the top of this table and fill each of its cells with tiny transparent images:\n<tr>\n <td><img src=\"spacer.gif\" width=\"593\" height=\"1\"></td>\n <td><img src=\"spacer.gif\" width=\"207\" height=\"1\"></td>\n</tr>\nThe height and width of these \u201cshims\u201d or \u201cspacers\u201d is only 1px but they will stretch to any size without increasing their weight on the page. This makes them perfect for performant website development.\nFor the hero of this design, I splice up the large image into three separate files and apply each slice as a background to the table cells. I also match the height of those cells to the background images:\n<tr>\n <td background=\"slice-1.jpg\" height=\"473\">\u00a0</td>\n <td background=\"slice-2.jpg\" height=\"473\">[\u2026]</td>\n</tr>\n\n<tr>\n <td background=\"slice-3.jpg\" height=\"388\">\u00a0</td>\n</tr>\nI use tables and spacer images throughout the rest of this design to lay out the various types of content with perfect precision. For example, to add a single-pixel border around my two columns of content, I first apply a blue background to an outer table along with 1px of cellspacing, then simply nest an inner table\u2014this time with a white background\u2014inside it:\n<table border=\"0\" cellpadding=\"1\" cellspacing=\"0\">\n <tr>\n  <td>\n   <table bgcolor=\"#ffffff\" border=\"0\" cellpadding=\"0\" cellspacing=\"0\">\n[\u2026]\n   </table>\n  </td>\n </tr>\n</table>\nAdding details\nTables are fabulous tools for laying out a page, but they\u2019re also useful for implementing details on those pages. I can use a table to add a gradient background, rounded corners, and a shadow to the button which forms my \u201cBuy the DVD\u201d call-to-action. First, I splice my button graphic into three slices; two fixed-width rounded ends, plus a narrow gradient which stretches and makes this button responsive. Then, I add those images as backgrounds and use spacers to perfectly size my button:\n<table border=\"0\" cellpadding=\"0\" cellspacing=\"0\">\n <tr>\n  <td background=\"btn-1.jpg\" border=\"0\" height=\"48\" width=\"30\"><img src=\"spacer.gif\" width=\"30\" height=\"1\"></td>\n\n  <td background=\"btn-2.jpg\" border=\"0\" height=\"48\">\n   <center>\n    <a href=\"\" target=\"_blank\"><b>Buy the DVD</b></a>\n   </center>\n  </td>\n\n  <td background=\"btn-3.jpg\" border=\"0\" height=\"48\" width=\"30\"><img src=\"spacer.gif\" width=\"30\" height=\"1\"></td>\n </tr>\n</table>\nI use those same elements to add details to headlines and lists too. Adding a \u201cbullet\u201d to each item in a list needs only two additional table cells, a circular graphic, and a spacer:\n<table border=\"0\" cellpadding=\"0\" cellspacing=\"0\">\n <tr>\n  <td width=\"10\"><img src=\"li.gif\" border=\"0\" width=\"8\" height=\"8\">\u00a0</td>\n  <td><img src=\"spacer.gif\" width=\"10\" height=\"1\">\u00a0</td>\n  <td>Directed by John Hughes</td>\n </tr>\n</table>\nImplementing a typographic hierarchy\nSo far I\u2019ve explained how to use frames, tables, and spacers to develop a layout for my content, but what about styling that content? I use <font> elements to change the typeface from the browser\u2019s default to any font installed on someone\u2019s device:\n<font face=\"Arial\">Planes, Trains and Automobiles is a comedy film [\u2026]</font>\nTo adjust the size of those fonts, I use the size attribute and a value between the smallest (1) and the largest (7) where 3 is the browser\u2019s default. I use a size of 4 for this headline and 2 for the text which follows:\n<font face=\"Arial\" size=\"4\"><b>Steve Martin</b></font>\n\n<font face=\"Arial\" size=\"2\">An American actor, comedian, writer, producer, and musician.</font>\nWhen I need to change the typeface, perhaps from a sans-serif like Arial to a serif like Times New Roman, I must change the value of the face attribute on every element on all pages on my website.\nNB: I use as many <br> elements as needed to create space between headlines and paragraphs.\nView the final result (and especially the source.)\nMy modern day design for Planes, Trains and Automobiles.\nI can imagine many people reading this and thinking \u201cThis is terrible advice because we don\u2019t develop websites like this in 2018.\u201d That\u2019s true.\nWe have the ability to embed any number of web fonts into our products and websites and have far more control over type features, leading, ligatures, and sizes:\nfont-variant-caps: titling-caps;\nfont-variant-ligatures: common-ligatures;\nfont-variant-numeric: oldstyle-nums;\nGrid has simplified the implementation of even the most complex compound grid down to just a few lines of CSS:\nbody {\n  display: grid;\n  grid-template-columns: 3fr 1fr 2fr 2fr 1fr 3fr;\n  grid-template-rows: auto;\n  grid-column-gap: 2vw;\n  grid-row-gap: 1vh;\n}\nFlexbox has made it easy to develop flexible components such as navigation links:\nnav ul { display: flex; }\nnav li { flex: 1; }\nJust one line of CSS can create multiple columns of fluid type:\nmain { column-width: 12em; }\nCSS Shapes enable text to flow around irregular shapes including polygons:\n[src*=\"main-img\"] {\n  float: left;\n  shape-outside: polygon(\u2026);\n}\nToday, we wouldn\u2019t dream of using images and a table to add a gradient, rounded corners, and a shadow to a button or link, preferring instead:\n.btn {\n  background: linear-gradient(#8B1212, #DD3A3C);\n  border-radius: 1em;\n  box-shadow: 0 2px 4px 0 rgba(0,0,0,0.50), inset 0 -1px 1px 0 rgba(0,0,0,0.50);\n}\nCSS Custom Properties, feature and media queries, filters, pseudo-elements, and SVG; the list of advances in HTML, CSS, and other technologies goes on. So does our understanding of how best to use them by separating content, structure, presentation, and behaviour. As 2018 draws to a close, we\u2019re certain we know how to design and develop products and websites better than we did at the end of 1998.\nStrange as it might seem looking back, in 1998 we were also certain our techniques and technologies were the best for the job. That\u2019s why it\u2019s dangerous to believe with absolute certainty that the frameworks and tools we increasingly rely on today\u2014tools like Bootstrap, Bower, and Brunch, Grunt, Gulp, Node, Require, React, and Sass\u2014will be any more relevant in the future than <font> elements, frames, layout tables, and spacer images are today.\nI have no prediction for what the web will be like twenty years from now. However, I want to believe we\u2019ll build on what we\u2019ve learned during these past two decades about the importance of accessibility, flexibility, and usability, and that the mistakes we made while infatuated by technologies won\u2019t be repeated.\n\nHead over to my website if you\u2019d like to read about how I\u2019d implement my design for \u2018Planes, Trains and Automobiles\u2019 today.", "year": "2018", "author": "Andy Clarke", "author_slug": "andyclarke", "published": "2018-12-23T00:00:00+00:00", "url": "https://24ways.org/2018/designing-your-site-like-its-1998/", "topic": "code"}
{"rowid": 244, "title": "It\u2019s Beginning to Look a Lot Like XSSmas", "contents": "I dread the office Secret Santa. I have a knack for choosing well-meaning but inappropriate presents, like a bottle of port for a teetotaller, a cheese-tasting experience for a vegan, or heaven forbid, Spurs socks for an Arsenal supporter. Ok, the last one was intentional.\nIt\u2019s the same with gifting code. Once, I made a pattern library for A List Apart which I open sourced, and a few weeks later, a glaring security vulnerability was found in it. My gift was so generous that it enabled unrestricted access to any file on any public-facing server that hosted it.\nWith platforms like GitHub and npm, giving the gift of code is so easy it\u2019s practically a no-brainer. This giant, open source yankee swap helps us do our jobs without starting from scratch with every project. But like any gift-giving, it\u2019s also risky.\nVulnerabilities and Open Source\nOpen source code is not inherently more or less vulnerable than closed-source code. What makes it higher risk is that the same piece of code gets reused in lots of places, meaning a hacker can use the same exploit mechanism on the same vulnerable code in different apps.\nGraph showing the number of open source vulnerabilities published per year, from the State of Open Source Security 2017\nIn the first 24 ways article this year, Katie referenced a few different types of vulnerability:\n\nCross-site Request Forgery (also known as CSRF)\nSQL Injection\nCross-site Scripting (also known as XSS)\n\nThere are many more types of vulnerability, and those that live under the same category share similarities. \nFor example, my favourite \u2013 is it weird to have a favourite vulnerability? \u2013 is Cross Site Scripting (XSS), which allows for the injection of scripts into web pages. This is a really common vulnerability often unwittingly added by developers. OWASP (the Open Web Application Security Project) wrote a great article about how to prevent opening the door to XSS attacks \u2013 share it generously with your colleagues.\nMost vulnerabilities like this are not added intentionally \u2013 they\u2019re doors left ajar due to the way something has been scripted, like the over-generous code in my pattern library. \nOthers, though, are added intentionally. A few months ago, a hacker, disguised as a helpful elf, offered to take over the maintenance of a popular npm package that had been unmaintained for a couple of years. The owner had moved onto other projects, and was keen to see it continue to be maintained by someone else, so transferred ownership. Fast-forward 3 months, it was discovered that the individual had quietly added a malicious package to the codebase, and the obfuscated code in it had been unwittingly installed onto thousands of apps. The code added was designed to harvest Bitcoin if it was run alongside another application. It was only spotted due to a developer\u2019s curiosity.\nAnother tactic to get developers to unwittingly install malicious packages into their codebase is \u201ctyposquatting\u201d \u2013 back in August last year, npm reported that a user had been publishing packages with very similar names to popular packages (for example, crossenv instead of cross-env). \nThis is a big wakeup call for open source maintainers. Techniques like this are likely to be used more as the maintenance of open source libraries becomes an increasing burden to their owners. After all, starting a new project often has a greater reward than maintaining an existing one, but remember, an open source library is for life, not just for Christmas.\nSanta\u2019s on his sleigh\nIf you use open source libraries, chances are that these libraries also use open source libraries. Your app may only have a handful of dependencies, but tucked in the back of that sleigh may be a whole extra sack of dependencies known as deep dependencies (ones that you didn\u2019t directly install, but are dependencies of that dependency), and these can contain vulnerabilities too.\nLet\u2019s look at the npm package santa as an example. santa has 8 direct dependencies listed on npm. That seems pretty manageable. But that\u2019s just the tip of the iceberg \u2013 have a look at the full dependency tree which contains 109 dependencies \u2013 more dependencies than there are Christmas puns in this article. Only one of these direct dependencies has a vulnerability (at the time of writing), but there are actually 13 other known vulnerabilities in santa, which have been introduced through its deeper dependencies.\nFixing vulnerabilities \u2013 the ultimate christmas gift\nIf you\u2019re a maintainer of open source libraries, taking good care of them is the ultimate gift you can give. Keep your dependencies up to date, use a security tool to monitor and alert you when new vulnerabilities are found in your code, and fix or patch them promptly. This will help keep the whole open source ecosystem healthy.\nWhen you find out about a new vulnerability, you have some options:\nFix the vulnerability via an upgrade\nYou can often fix a vulnerability by upgrading the library to the latest version. Make sure you\u2019re using software that monitors your dependencies for new security issues and lets you know when a fix is ready, otherwise you may be unwittingly using a vulnerable version.\nPatch the vulnerable code\nSometimes, a fix for a vulnerable library isn\u2019t possible. This is often the case when a library is no longer being maintained, or the version of the library being used might be so out of date that upgrading it would cause a breaking change. Patches are bits of code that will fix that particular issue, but won\u2019t change anything else.\nSwitch to a different library\nIf the library you\u2019re using has no fix or patch, you may be better of switching it out for another one, particularly if it looks like it\u2019s being unmaintained.\nResponsibly disclosing vulnerabilities\nKnowing how to responsibly disclose vulnerabilities is something I\u2019m ashamed to admit that I didn\u2019t know about before I joined a security company. But it\u2019s so important! On discovering a new vulnerability, a developer has a few options: \n\nA malicious developer will exploit that vulnerability for their own gain. \nA reckless (or inexperienced) developer will disclose that vulnerability to the world without following a responsible disclosure process. This opens the door to an unethical developer exploiting the vulnerability. At Snyk, we monitor social media for mentions of newly found vulnerabilities so we can add them to our database and share fixes before they get exploited.\nAn ethical and aware developer will follow what\u2019s known as a \u201cresponsible disclosure process\u201d. They will contact the maintainer of the code privately, allowing reasonable time for them to release a fix for the issue and to give others who use that vulnerable code a chance to fix it too.\n\nIt\u2019s important to understand this process if you\u2019re a maintainer or contributor of code. It can be daunting when a report comes in, but understanding and following the right steps will help reduce the risk to the people who use that code.\nSo what does responsible disclosure look like? I\u2019ll take Node.js\u2019s security disclosure policy as an example. They ask that all security issues that are found in Node.js are reported there. (There\u2019s a separate process for bug found in third-party npm packages). Once you\u2019ve reported a vulnerability, they promise to acknowledge it within 24 hours, and to give a more detailed response within 48 hours. If they find that the issue is indeed a security bug, they\u2019ll give you regular updates about the progress they\u2019re making towards fixing it. As part of this, they\u2019ll figure out which versions are affected, and prepare fixes for them. They\u2019ll assign the vulnerability a CVE (Common Vulnerabilities and Exposures) ID and decide on an embargo date for public disclosure. On the date of the embargo, they announce the vulnerability in their Node.js security mailing list and deploy fixes to nodejs.org.\nTim Kadlec published an in-depth article about responsible disclosures if you\u2019re interested in knowing more. It has some interesting horror stories of what happened when the disclosure process was not followed.\nEncourage responsible disclosure\nAdd a SECURITY.md file to your project so someone who wants to message you about a vulnerability can do so without having to hunt around for contact details. Last year, Snyk published a State of Open Source Security report that found 79.5% of maintainers do not have a public disclosure policy. Those that did were considerably more likely to get notified privately about a vulnerability \u2013 73% of maintainers who had one had been notified, vs 21% of maintainers who hadn\u2019t published one one.\nStats from the State of Open Source Security 2017\nBug bounties\nSome companies run bug bounties to encourage the responsible disclosure of vulnerabilities. By offering a reward for finding and safely disclosing a vulnerability, it also reduces the enticement of exploiting a vulnerability over reporting it and getting a quick cash reward. Hackerone is a community of ethical hackers who pentest apps that have signed up for the scheme and get paid when they find a new vulnerability. Wordpress is one such participant, and you can see the long list of vulnerabilities that have been disclosed as part of that program.\nIf you don\u2019t have such a bounty, be prepared to get the odd vulnerability extortion email. Scott Helme, who founded securityheaders.com and report-uri.com, wrote a post about some of the requests he gets for a report about a critical vulnerability in exchange for money. \n\nOn one hand, I want to be as responsible as possible and if my users are at risk then I need to know and patch this issue to protect them. On the other hand this is such irresponsible and unethical behaviour that interacting with this person seems out of the question.\n\nA gift worth giving\nIt\u2019s time to brush the dust off those old gifts that we shared and forgot about. Practice good hygiene and run them through your favourite security tool \u2013 I\u2019m just a little biased towards Snyk, but as Katie mentioned, there\u2019s also npm audit if you use Node.js, and most source code managers like GitHub and GitLab have basic vulnerability alert capabilities.\nStats from the State of Open Source Security 2017\nMost importantly, patch or upgrade away those vulnerabilities away, and if you want to share that Christmas spirit, open fixes for your favourite open source projects, too.", "year": "2018", "author": "Anna Debenham", "author_slug": "annadebenham", "published": "2018-12-17T00:00:00+00:00", "url": "https://24ways.org/2018/its-beginning-to-look-a-lot-like-xssmas/", "topic": "code"}
{"rowid": 243, "title": "Researching a Property in the CSS Specifications", "contents": "I frequently joke that I\u2019m \u201creading the specs so you don\u2019t have to\u201d, as I unpack some detail of a CSS spec in a post on my blog, some documentation for MDN, or an article on Smashing Magazine. However waiting for someone like me to write an article about something is a pretty slow way to get the information you need. Sometimes people like me get things wrong, or specifications change after we write a tutorial. \nWhat if you could just look it up yourself? That\u2019s what you get when you learn to read the CSS specifications, and in this article my aim is to give you the basic details you need to grab quick information about any CSS property detailed in the CSS specs.\nWhere are the CSS Specifications?\nThe easiest way to see all of the CSS specs is to take a look at the Current Work page in the CSS section of the W3C Website. Here you can see all of the specifications listed, the level they are at and their status. There is also a link to the specification from this page. I explained CSS Levels in my article Why there is no CSS 4.\nWho are the specifications for?\nCSS specifications are for everyone who uses CSS. You might be a browser engineer - referred to as an implementor - needing to know how to implement a feature, or a web developer - referred to as an author - wanting to know how to use the feature. The fact that both parties are looking at the same document hopefully means that what the browser displays is what the web developer expected.\nWhich version of a spec should I look at?\nThere are a couple of places you might want to look. Each published spec will have the latest published version, which will have TR in the URL and can be accessed without a date (which is always the newest version) or at a date, which will be the date of that publication. If I\u2019m referring to a particular Working Draft in an article I\u2019ll typically link to the dated version. That way if the information changes it is possible for someone to see where I got the information from at the time of writing.\nIf you want the very latest additions and changes to the spec, then the Editor\u2019s Draft is the place to look. This is the version of the spec that the editors are committing changes to. If I make a change to the Multicol spec and push it to GitHub, within a few minutes that will be live in the Editor\u2019s Draft. So it is possible there are errors, bits of text that we are still working out and so on. The Editor\u2019s Draft however is definitely the place to look if you are wanting to raise an issue on a spec, as it may be that the issue you are about to raise is already fixed.\nIf you are especially keen on seeing updates to specifications keep an eye on https://drafts.csswg.org/ as this is a list of drafts, along with the date they were last updated.\nHow to approach a spec\nThe first thing to understand is that most CSS Specifications start with the most straightforward information, and get progressively further into the weeds. For an author the initial examples and explanations are likely to be of interest, and then the property definitions and examples. Therefore, if you are looking at a vast spec, know that you probably won\u2019t need to read all the way to the bottom, or read every section in detail.\nThe second thing that is useful to know about modern CSS specifications is how modularized they are. It really never is a case of finding everything you need in a single document. If we tried to do that, there would be a lot of repetition and likely inconsistency between specs. There are some key specifications that many other specifications draw on, such as:\n\nValues and Units\nIntrinsic and Extrinsic Sizing\nBox Alignment\n\nWhen something is defined in another specification the spec you are reading will link to it, so it is worth opening that other spec in a new tab in order that you can refer back to it as you explore.\nResearching your property\nAs an example we will take a look at the property grid-auto-rows, this property defines row tracks in the implicit grid when using CSS Grid Layout. The first thing you will need to do is find out which specification defines this property.\nYou might already know which spec the property is part of, and therefore you could go directly to the spec and search using your browser or look in the navigation for the spec to find it. Alternatively, you could take a look at the CSS Property Index, which is an automatically generated list of CSS Properties.\nClicking on a property will take you to the TR version of the spec, the latest published draft, and the definition of that property in it. This definition begins with a panel detailing the syntax of this property. For grid-auto-rows, you can see that it is listed along with grid-auto-columns as these two properties are essentially identical. They take the same values and work in the same way, one for rows and the other for columns.\nValue\nFor value we can see that the property accepts a value <track-size>. The next thing to do is to find out what that actually means, clicking  will take you to where it is defined in the Grid spec.\nThe <track-size> value is defined as accepting various values:\n\n<track-breadth>\nminmax( <inflexible-breadth> , <track-breadth> )\nfit-content( <length-percentage>\n\nWe need to head down the rabbit hole to find out what each of these mean. From here we essentially go down line by line until we have unpacked the value of track-size.\n<track-breadth> is defined just below <track-size> as:\n\n<length-percentage>\n<flex>\nmin-content\nmax-content\nauto\n\nSo these are all things that would be valid to use as a value for grid-auto-rows.\nThe first value of <length-percentage> is something you will see in many specifications as a value. It means that you can use a length unit - for example px or em - or a percentage. Some properties only accept a <length> in which case you know that you cannot use a percentage as the value. This means that you could have grid-auto-rows with any of the following values.\ngrid-auto-rows: 100px;\ngrid-auto-rows: 1em;\ngrid-auto-rows: 30%;\nWhen using percentages, it is important to know what it is a percentage of. As a percentage has to resolve from something. There is text in the spec which explains how column and row percentages work.\n\n\u201c<percentage> values are relative to the inline size of the grid container in column grid tracks, and the block size of the grid container in row grid tracks.\u201d\n\nThis means that in a horizontal writing mode such as when using English, a percentage when used as a track-size in grid-auto-columns would be a percentage of the width of the grid, and a percentage in grid-auto-rows a percentage of the height of the grid.\nThe second value of <flex> is also defined here, as \u201cA non-negative dimension with the unit fr specifying the track\u2019s flex factor.\u201d This is the fr unit, and the spec links to a fuller definition of fr as this unit is only used in Grid Layout so it is therefore defined in the grid spec. We now know that a valid value would be:\ngrid-auto-rows: 1fr;\nThere is some useful information about the fr unit in this part of the spec. It is noted that the fr unit has an automatic minimum. This means that 1fr is really minmax(auto, 1fr). This is why having a number of tracks all at 1fr does not mean that all are equal sized, as a larger item in any of the tracks would have a large auto size and therefore would be larger after spare space had been distributed.\nWe then have min-content and max-content. These keywords can be used for track sizing and the specification defines what they mean in the context of sizing a track, representing the min and max-sizing contributions of the grid tracks. You will see that there are various terms linked in the definition, so if you do not know what these mean you can follow them to find out.\nFor example the spec links max-content contribution to the CSS Intrinsic and Extrinsic Sizing specification. This is one of those specs which is drawn on by many other specifications. If we follow that link we can read the definition there and follow further links to understand what each term means. The more that you read specifications the more these terms will become familiar to you. Just like learning a foreign language, at first you feel like you have to look up every little thing. After a while you remember the vocabulary.\nWe can now add min-content and max-content to our available values.\ngrid-auto-rows: min-content;\ngrid-auto-rows: max-content;\nThe final item in our list is auto. If you are familiar with using Grid Layout, then you are probably aware that an auto sized track for will grow to fit the content used. There is an interesting note here in the spec detailing that auto sized rows will stretch to fill the grid container if there is extra space and align-content or justify-content have a value of stretch. As stretch is the default value, that means these tracks stretch by default. Tracks using other types of length will not behave like this.\ngrid-auto-rows: auto;\nSo, this was the list for <track-breadth>, the next possible value is minmax( <inflexible-breadth> , <track-breadth> ). So this is telling us that we can use minmax() as a value, the final (max) value will be <track-breadth> and we have already unpacked all of the allowable values there. The first value (min) is detailed as an <inflexible-breadth>. If we look at the values for this, we discover that they are the same as <track-breadth>, minus the <flex> value:\n\n<length-percentage>\nmin-content\nmax-content\nauto\n\nWe already know what all of these do, so we can add possible minmax() values to our list of values for <track-size>.\ngrid-auto-rows: minmax(100px, 200px);\ngrid-auto-rows: minmax(20%, 1fr);\ngrid-auto-rows: minmax(1em, auto);\ngrid-auto-rows: minmax(min-content, max-content);\nFinally we can use fit-content( <length-percentage>. We can see that fit-content takes a value of <length-percentage> which we already know to be either a length unit, or a percentage. The spec details how fit-content is worked out, and it essentially allows a track which acts as if you had used the max-content keyword, however the track stops growing when it hits the length passed to it.\ngrid-auto-rows: fit-content(200px);\ngrid-auto-rows: fit-content(20%);\nThose are all of our possible values, and to round things off, check again at the initial <track-size> value, you can see it has a little + sign next to it, click that and you will be taken to the CSS Values and Units module to find that, \u201cA plus (+) indicates that the preceding type, word, or group occurs one or more times.\u201d This means that we can pass a single track size to grid-auto-rows or multiple track sizes as a space separated list. Below the box is an explanation of what happens if you pass in more than one track size:\n\n\u201cIf multiple track sizes are given, the pattern is repeated as necessary to find the size of the implicit tracks. The first implicit grid track after the explicit grid receives the first specified size, and so on forwards; and the last implicit grid track before the explicit grid receives the last specified size, and so on backwards.\u201d\n\nTherefore with the following CSS, if five implicit rows were needed they would be as follows:\n\n100px\n1fr\nauto\n100px\n1fr\n\n.grid {\n    display: grid;\n    grid-auto-rows: 100px 1fr auto;\n}\nInitial\nWe can now move to the next line in the box, and you\u2019ll be glad to know that it isn\u2019t going to require as much unpacking! This simply defines the initial value for grid-auto-rows. If you do not specify anything, created rows will be auto sized. All CSS properties have an initial value that they will use if they are invoked as part of the usage of the specification they are in, but you do not set a value for them. In the case of grid-auto-rows it is used whenever rows are created in the implicit grid, so it needs to have a value to be used even if you do not set one.\nApplies to\nThis line tells us what this property is used for. Some properties are used in multiple places. For example if you look at the definition for justify-content in the Box Alignment specification you can see it is used in multicol containers, flex containers, and grid containers. In our case the property only applies for grid containers.\nInherited\nThis tells us if the property can be inherited from a parent element if it is not set. In the case of grid-auto-rows it is not inherited. A property such as color is inherited, so you do not need to set it on each element.\nPercentages\nAre percentages allowed for this property, and if so how are they calculated. In this case we are referred to the definition for grid-template-columns and grid-template-rows where we discover that the percentage is from the corresponding dimension of the content area.\nMedia\nThis defines the media group that the property belongs to. In this case visual.\nComputed Value\nThis details how the value is resolved. The grid-auto-rows property again refers to track sizing as defined for grid-template-columns and grid-template-rows, which tells us the computed value is as specified with lengths made absolute.\nCanonical Order\nIf you have a property\u2013generally a shorthand property\u2013which takes multiple values in a set order, then those values need to be serialized in the order detailed in the grammar for that property. In general you don\u2019t need to worry about this value in the table.\nAnimation Type\nThis details whether the property can be animated, and if so what type of animation. This is useful if you are trying to animate something and not getting the result that you expect. Note that just because something is listed in the spec as animatable does not mean that browsers will have implemented animation for that property yet!\nThat\u2019s (mostly) it!\nSometimes the property will have additional examples - there is one underneath the table for grid-auto-rows. These are worth looking at as they will highlight usage of the property that the spec editor has felt could use an example. There may also be some additional text explaining anythign specific to this property.\nIn selecting grid-auto-rows I chose a fairly complex property in terms of the work we needed to do to unpack the value. Many properties are far simpler than this. However ultimately, even when you come across a complex value, it really is just a case of stepping through the definitions until you come to the bottom of the rabbit hole.\nBeing able to work out what is valid for each property is incredibly useful. It means you don\u2019t waste time trying to use a value that doesn\u2019t work for that property. You also may find that there are values you weren\u2019t aware of, that solve problems for you.\nFurther reading\nSpecifications are not designed to be user manuals, and while they often contain examples, these are pretty terse as they need to be clear to demonstrate their particular point. The manual for the Web Platform is MDN Web Docs. Pairing reading a specification with the examples and information on an MDN property page such as the one for grid-auto-rows is a really great way to ensure that you have all the information and practical usage examples you might need.\nYou may also find useful:\n\nValue Definition Syntax on MDN.\nThe MDN Glossary defines many common terms.\nUnderstanding the CSS Property Value Syntax goes into more detail in terms of reading the syntax.\nHow to read W3C Specs - from 2001 but still relevant.\n\nI hope this article has gone some way to demystify CSS specifications for you. Even if the specifications are not your preferred first stop to learn about new CSS, being able to go directly to the source and avoid having your understanding filtered by someone else, can be very useful indeed.", "year": "2018", "author": "Rachel Andrew", "author_slug": "rachelandrew", "published": "2018-12-14T00:00:00+00:00", "url": "https://24ways.org/2018/researching-a-property-in-the-css-specifications/", "topic": "code"}
{"rowid": 242, "title": "Creating My First Chrome Extension", "contents": "Writing a Chrome Extension isn\u2019t as scary at it seems!\nNot too long ago, I used a Chrome extension called 20 Cubed. I\u2019m far-sighted, and being a software engineer makes it difficult to maintain distance vision. So I used 20 Cubed to remind myself to look away from my screen and rest my eyes. I loved its simple interface and design. I loved it so much, I often forgot to turn it off in the middle of presentations, where it would take over my entire screen. Oops.\nUnfortunately, the developer stopped updating the extension and removed it from Chrome\u2019s extension library. I was so sad. None of the other eye rest extensions out there matched my design aesthetic, so I decided to create my own! Want to do the same?\nFortunately, Google has some respectable documentation on how to create an extension. And remember, Chrome extensions are just HTML, CSS, and JavaScript. You can add libraries and frameworks, or you can just code the \u201cold-fashioned\u201d way. Sky\u2019s the limit!\nSetup\nBut first, some things you\u2019ll need to know about before getting started:\n\nCallbacks\nTimeouts\nChrome Dev Tools\n\nDeveloping with Chrome extension methods requires a lot of callbacks. If you\u2019ve never experienced the joy of callback hell, creating a Chrome extension will introduce you to this concept. However, things can get confusing pretty quickly. I\u2019d highly recommend brushing up on that subject before getting started.\nHyperbole and a Half\nTimeouts and Intervals are another thing you might want to brush up on. While creating this extension, I didn\u2019t consider the fact that I\u2019d be juggling three timers. And I probably would\u2019ve saved time organizing those and reading up on the Chrome extension Alarms documentation beforehand. But more on that in a bit.\nOn the note of organization, abstraction is important! You might have any combination of the following:\n\nThe Chrome extension options page\nThe popup from the Chrome Menu\nThe windows or tabs you create\nThe background scripts\n\nAnd that can get unwieldy. You might also edit the existing tabs or windows in the browser, which you\u2019ll probably want as a separate script too. Note that this tutorial only covers creating your own customized window rather than editing existing windows or tabs.\nAlright, now that you know all that up front, let\u2019s get going!\nDocumentation\nTL;DR READ THE DOCS.\nA few things to get started:\n\nRead Google\u2019s primer on browser extensions\nHave a look at their Getting started tutorial\nCheck out their overview on Chrome Extensions\n\nThis overview discusses the Chrome extension files, architecture, APIs, and communication between pages. Funnily enough, I only discovered the Overview page after creating my extension.\nThe manifest.json file gives the browser information about the extension, including general information, where to find your extension files and icons, and API permissions required. Here\u2019s what my manifest.json looked like, for example:\nhttps://github.com/jennz0r/eye-rest/blob/master/manifest.json\nBecause I\u2019m a visual learner, I found the images that describe the extension\u2019s architecture most helpful.\n\nTo clarify this diagram, the background.js file is the extension\u2019s event handler. It\u2019s constantly listening for browser events, which you\u2019ll feed to it using the Chrome Extension API. Google says that an effective background script is only loaded when it is needed and unloaded when it goes idle.\nThe Popup is the little window that appears when you click on an extension\u2019s icon in the Chrome Menu. It consists of markup and scripts, and you can tell the browser where to find it in the manifest.json under page_action: { \"default_popup\": FILE_NAME_HERE }.\nThe Options page is exactly as it says. This displays customizable options only visible to the user when they either right-click on the Chrome menu and choose \u201cOptions\u201d under an extension. This also consists of markup and scripts, and you can tell the browser where to find it in the manifest.json under options_page: FILE_NAME_HERE.\nContent scripts are any scripts that will interact with any web windows or tabs that the user has open. These scripts will also interact with any tabs or windows opened by your extension.\nDebugging\nA quick note: don\u2019t forget the debugging tutorial!\nJust like any other Chrome window, every piece of an extension has an inspector and dev tools. If (read: when) you run into errors (as I did), you\u2019re likely to have several inspector windows open \u2013 one for the background script, one for the popup, one for the options, and one for the window or tab the extension is interacting with.\nFor example, I kept seeing the error \u201cThis request exceeds the MAX_WRITE_OPERATIONS_PER_HOUR quota.\u201d Well, it turns out there are limitations on how often you can sync stored information.\nAnother error I kept seeing was \u201cAlarm delay is less than minimum of 1 minutes. In released .crx, alarm \u201cALARM_NAME_HERE\u201d will fire in approximately 1 minutes\u201d. Well, it turns out there are minimum interval times for alarms.\nChrome Extension creation definitely benefits from debugging skills. Especially with callbacks and listeners, good old fashioned console.log can really help!\nMe adding a ton of `console.log`s while trying to debug my alarms.\nEye Rest Functionality\nOk, so what is the extension I created? Again, it\u2019s a way to rest your eyes every twenty minutes for twenty seconds. So, the basic functionality should look like the following:\n\nIf the extension is running AND\nIf the user has not clicked Pause in the Popup HTML AND\nIf the counter in the Popup HTML is down to 00:00 THEN\n\nOpen a new window with Timer HTML AND\nStart a 20 sec countdown in Timer HTML AND\nReset the Popup HTML counter to 20:00\n\nIf the Timer HTML is down to 0 sec THEN\n\nClose that window. Rinse. Repeat.\n\n\nSounds simple enough, but wow, these timers became convoluted! Of all the Chrome extensions I decided to create, I decided to make one that\u2019s heavily dependent on time, intervals, and having those in sync with each other. In other words, I made this unnecessarily complicated and didn\u2019t realize until I started coding.\nFor visual reference of my confusion, check out the GitHub repository for Eye Rest. (And yes, it\u2019s a pun.)\nAPI\nNow let\u2019s discuss the APIs that I used to build this extension.\nAlarms\nWhat even are alarms? I didn\u2019t know either.\nAlarms are basically Chrome\u2019s setTimeout and setInterval. They exist because, as Google says\u2026\n\nDOM-based timers, such as window.setTimeout() or window.setInterval(), are not honored in non-persistent background scripts if they trigger when the event page is dormant.\n\nFor more information, check out this background migration doc.\nOne interesting note about alarms in Chrome extensions is that they are persistent. Garbage collection with Chrome extension alarms seems unreliable at best. I didn\u2019t have much luck using the clearAll method to remove alarms I created on previous extension loads or installs. A workaround (read: hack) is to specify a unique alarm name every time your extension is loaded and clearing any other alarms without that unique name.\nBackground Scripts\nFor Eye Rest, I have two background scripts. One is my actual initializer and event listener, and the other is a helpers file.\nI wanted to share a couple of functions between my Background and Popup scripts. Specifically, the clearAndCreateAlarm function. I wanted my background script to clear any existing alarms, create a new alarm, and add remaining time until the next alarm to local storage immediately upon extension load. To make the function available to the Background script, I added helpers.js as the first item under background > scripts in my manifest.json.\nI also wanted my Popup script to do the same things when the user has unpaused the extension\u2019s functionality. To make the function available to the Popup script, I just include the helpers script in the Popup HTML file.\nOther APIs\nWindows\nI use the Windows API to create the Timer window when the time of my alarm is up. The window creation is initiated by my Background script.\nOne day, while coding late into the evening, I found it very confusing that the window.create method included url as an option. I assumed it was meant to be an external web address. A friend pondered that there must be an option to specify the window\u2019s HTML. Until then, it hadn\u2019t dawned on me that the url could be relative. Duh. I was tired!\nI pass the timer.html as the url option, as well as type, size, position, and other visual options.\nStorage\nMaybe you want to pass information back and forth between the Background script and your Popup script? You can do that using Chrome or local storage. One benefit of using local storage over Chrome\u2019s storage is avoiding quotas and write operation maximums.\nI wanted to pass the time at which the latest alarm was set, the time to the next alarm, and whether or not the timer is paused between the Background and Popup scripts. Because the countdown should change every second, it\u2019s quite complicated and requires lots of writes. That\u2019s why I went with the user\u2019s local storage. You can see me getting and setting those variables in my Background, Helper, and Popup scripts. Just search for date, nextAlarmTime, and isPaused.\nDeclarative Content\nThe Declarative Content API allows you to show your extension\u2019s page action based on several type of matches, without needing to take a host permission or inject a content script. So you\u2019ll need this to get your extension to work in the browser!\nYou can see me set this in my Background script. Because I want my extension\u2019s popup to appear on every page one is browsing, I leave the page matchers empty.\nThere are many more APIs for Chrome apps and extensions, so make sure to surf around and see what features are available!\nThe Extension\nHere\u2019s what my original Popup looked like before I added styles.\nAnd here\u2019s what it looks like with new styles. I guess I\u2019m going for a Nickelodeon feel.\nAnd here\u2019s the Timer window and Popup together! \nPublishing\nPublishing is a cinch. You just zip up your files, create a new or use an existing Google Developer account, upload the files, add some details, and pay a one time $5 fee. That\u2019s all! Then your extension will be available on the Chrome extension store! Neato :D\nMy extension is now available for you to install.\nConclusion\nI thought creating a time based Chrome Extension would be quick and easy. I was wrong. It was more complicated than I thought! But it\u2019s definitely achievable with some time, persistence, and good ole Google searches.\nEventually, I\u2019d like to add more interactive elements to Eye Rest. For example, hitting the YouTube API to grab a silly or cute video as a reward for looking away during the 20 sec countdown and not closing the timer window. This harkens back to one of my first web projects, Toothtimer, from 2012. Or maybe a way to change the background colors of the Timer and Popup!\nEither way, with Eye Rest\u2019s framework built out, I\u2019m feeling fearless about future feature adds! Building this Chrome extension took some broken nails, achy shoulders, and tired eyes, but now Eye Rest can tell me to give my eyes a break every 20 minutes.", "year": "2018", "author": "Jennifer Wong", "author_slug": "jenniferwong", "published": "2018-12-05T00:00:00+00:00", "url": "https://24ways.org/2018/my-first-chrome-extension/", "topic": "code"}
{"rowid": 241, "title": "Jank-Free Image Loads", "contents": "There are a few fundamental problems with embedding images in pages of hypertext; perhaps chief among them is this: text is very light and loads rather fast; images are much heavier and arrive much later. Consequently, millions (billions?) of times a day, a hapless Web surfer will start reading some text on a page, and then \u2014\nYour browser doesn\u2019t support HTML5 video. Here is\n     a link to the video instead.\n\n\u2014 oops! \u2014 an image pops in above it, pushing said text down the page, and our poor reader loses their place.\nBy default, partially-loaded pages have the user experience of a slippery fish, or spilled jar of jumping beans. For the rest of this article, I shall call that jarring, no-good jumpiness by its name: jank. And I\u2019ll chart a path into a jank-free future \u2013 one in which it\u2019s easy and natural to author <img> elements that load like this:\nYour browser doesn\u2019t support HTML5 video. Here is\n     a link to the video instead.\n\nJank is a very old problem, and there is a very old solution to it: the width and height attributes on <img>. The idea is: if we stick an image\u2019s dimensions right into the HTML, browsers can know those dimensions before the image loads, and reserve some space on the layout for it so that nothing gets bumped down the page when the image finally arrives.\n\nwidth\nSpecifies the intended width of the image in pixels. When given together with the height, this allows user agents to reserve screen space for the image before the image data has arrived over the network.\n\n\u2014The HTML 3.2 Specification, published on January 14 1997\nUnfortunately for us, when width and height were first spec\u2019d and implemented, layouts were largely fixed and images were usually only intended to render at their fixed, actual dimensions. When image sizing gets fluid, width and height get weird:\nSee the Pen fluid width + fixed height = distortion by Eric Portis (@eeeps) on CodePen.\n\nwidth and height are too rigid for the responsive world. What we need, and have needed for a very long time, is a way to specify fixed aspect ratios, to pair with our fluid widths.\nI have good news, bad news, and great news.\nThe good news is, there are ways to do this, now, that work in every browser. Responsible sites, and responsible developers, go through the effort to do them.\nThe bad news is that these techniques are all terrible, cumbersome hacks. They\u2019re difficult to remember, difficult to understand, and they can interact with other pieces of CSS in unexpected ways.\nSo, the great news: there are two on-the-horizon web platform features that are trying to make no-jank, fixed-aspect-ratio, fluid-width images a natural part of the web platform.\naspect-ratio in CSS\nThe first proposed feature? An aspect-ratio property in CSS!\nThis would allow us to write CSS like this:\nimg {\n    width: 100%;\n}\n\n.thumb {\n    aspect-ratio: 1/1;\n}\n\n.hero {\n    aspect-ratio: 16/9;\n}\nThis\u2019ll work wonders when we need to set aspect ratios for whole classes of images, which are all sized to fit within pre-defined layout slots, like the .thumb and .hero images, above.\nAlas, the harder problem, in my experience, is not images with known-ahead-of-time aspect ratios. It\u2019s images \u2013 possibly user generated images \u2013 that can have any aspect ratio. The really tricky problem is unknown-when-you\u2019re-writing-your-CSS aspect ratios that can vary per-image. Using aspect-ratio to reserve space for images like this requires inline styles:\n<img src=\"image.jpg\" style=\"aspect-ratio: 5/4\" />\nAnd inline styles give me the heebie-jeebies! As a web developer of a certain age, I have a tiny man in a blue beanie permanently embedded deep within my hindbrain, who cries out in agony whenever I author a style=\"\" attribute. And you know what? The old man has a point! By sticking super-high-specificity inline styles in my content, I\u2019m cutting off my, (or anyone else\u2019s) ability to change those aspect ratios, for whatever reason, later.\nHow might we specify aspect ratios at a lower level? How might we give browsers information about an image\u2019s dimensions, without giving them explicit instructions about how to style it?\nI\u2019ll tell you: we could give browsers the intrinsic aspect ratio of the image in our HTML, rather than specifying an extrinsic aspect ratio!\nA brief note on intrinsic and extrinsic sizing\nWhat do I mean by \u201cintrinsic\u201d and \u201cextrinsic?\u201d\nThe intrinsic size of an image is, put simply, how big it\u2019d be if you plopped it onto a page and applied no CSS to it whatsoever. An 800\u00d7600 image has an intrinsic width of 800px.\nThe extrinsic size of an image, then, is how large it ends up after CSS has been applied. Stick a width: 300px rule on that same 800\u00d7600 image, and its intrinsic size (accessible via the Image.naturalWidth property, in JavaScript) doesn\u2019t change: its intrinsic size is still 800px. But this image now has an extrinsic size (accessible via Image.clientWidth) of 300px.\nIt surprised me to learn this year that height and width are interpreted as presentational hints and that they end up setting extrinsic dimensions (albeit ones that, unlike inline styles, have absolutely no specificity).\nCSS aspect-ratio lets us avoid setting extrinsic heights and widths \u2013 and instead lets us give images (or anything else) an extrinsic aspect ratio, so that as soon as we set one dimension (possibly to a fluid width, like 100%!), the other dimension is set automatically in relation to it.\nThe last tool I\u2019m going to talk about gets us out of the extrinsic sizing game all together \u2014 which, I think, is only appropriate for a feature that we\u2019re going to be using in HTML.\nintrinsicsize in HTML\nThe proposed intrinsicsize attribute will let you do this:\n<img src=\"image.jpg\" intrinsicsize=\"800x600\" />\nThat tells the browser, \u201chey, this image.jpg that I\u2019m using here \u2013 I know you haven\u2019t loaded it yet but I\u2019m just going to let you know right away that it\u2019s going to have an intrinsic size of 800\u00d7600.\u201d This gives the browser enough information to reserve space on the layout for the image, and ensures that any and all extrinsic sizing instructions, specified in our CSS, will layer cleanly on top of this, the image\u2019s intrinsic size.\nYou may ask (I did!): wait, what if my <img> references multiple resources, which all have different intrinsic sizes? Well, if you\u2019re using srcset, intrinsicsize is a bit of a misnomer \u2013 what the attribute will do then, is specify an intrinsic aspect ratio:\n<img\n    srcset=\"300x200.jpg 300w,\n            600x400.jpg 600w,\n            900x600.jpg 900w,\n            1200x800.jpg 1200w\"\n    sizes=\"75vw\"\n    intrinsicsize=\"3x2\" />\nIn the future (and behind the \u201cExperimental Web Platform Features\u201d flag right now, in Chrome 71+), asking this image for its .naturalWidth would not return 3 \u2013 it will return whatever 75vw is, given the current viewport width. And Image.naturalHeight will return that width, divided by the intrinsic aspect ratio: 3/2.\nCan\u2019t wait\nI seem to have gotten myself into the weeds a bit. Sizing on the web is complicated!\nDon\u2019t let all of these details bury the big takeaway here: sometime soon (\ud83e\udd1e 2019\u203d \ud83e\udd1e), we\u2019ll be able to toss our terrible aspect-ratio hacks into the dustbin of history, get in the habit of setting aspect-ratios in CSS and/or intrinsicsizes in HTML, and surf a less-frustrating, more-performant, less-janky web. I can\u2019t wait!", "year": "2018", "author": "Eric Portis", "author_slug": "ericportis", "published": "2018-12-21T00:00:00+00:00", "url": "https://24ways.org/2018/jank-free-image-loads/", "topic": "code"}
{"rowid": 240, "title": "My CSS Wish List", "contents": "I love Christmas. I love walking around the streets of London, looking at the beautifully decorated windows, seeing the shiny lights that hang above Oxford Street and listening to Christmas songs.\n\nI\u2019m not going to lie though. Not only do I like buying presents, I love receiving them too. I remember making long lists that I would send to Father Christmas with all of the Lego sets I wanted to get. I knew I could only get one a year, but I would spend days writing the perfect list.\n\nThe years have gone by, but I still enjoy making wish lists. And I\u2019ll tell you a little secret: my mum still asks me to send her my Christmas list every year.\n\nThis time I\u2019ve made my CSS wish list. As before, I\u2019d be happy with just one present.\n\nBefore I begin\u2026\n\n\u2026 this list includes:\n\n\n\tthings that don\u2019t exist in the CSS specification (if they do, please let me know in the comments \u2013 I may have missed them);\n\tothers that are in the spec, but it\u2019s incomplete or lacks use cases and examples (which usually means that properties haven\u2019t been implemented by even the most recent browsers).\n\n\nLike with any other wish list, the further down I go, the more unrealistic my expectations \u2013 but that doesn\u2019t mean I can\u2019t wish. Some of the things we wouldn\u2019t have thought possible a few years ago have been implemented and our wishes fulfilled (think multiple backgrounds, gradients and transformations, for example).\n\nThe list\n\nCross-browser implementation of font-size-adjust\n\nWhen one of the fall-back fonts from your font stack is used, rather than the preferred (first) one, you can retain the aspect ratio by using this very useful property. It is incredibly helpful when the fall-back fonts are smaller or larger than the initial one, which can make layouts look less polished.\n\nWhat font-size-adjust does is divide the original font-size of the fall-back fonts by the font-size-adjust value. This preserves the x-height of the preferred font in the fall-back fonts. Here\u2019s a simple example:\n\np {\n    font-family: Calibri, \"Lucida Sans\", Verdana, sans-serif;\n    font-size-adjust: 0.47;\n}\n\nIn this case, if the user doesn\u2019t have Calibri installed, both Lucida Sans and Verdana will keep Calibri\u2019s aspect ratio, based on the font\u2019s x-height. This property is a personal favourite and one I keep pointing to.\n\nFirefox supported this property from version three. So far, it\u2019s the only browser that does. Fontdeck provides the font-size-adjust value along with its fonts, and has a handy tool for calculating it.\n\nMore control over overflowing text\n\nThe text-overflow property lets you control text that overflows its container. The most common use for it is to show an ellipsis to indicate that there is more text than what is shown. To be able to use it, the container should have overflow set to something other than visible, and white-space: nowrap:\n\ndiv {\n    white-space: nowrap;\n    width: 100%;\n    overflow: hidden;\n    text-overflow: ellipsis;\n}\n\nThis, however, only works for blocks of text on a single line. In the wish list of many CSS authors (and in mine) is a way of defining text-overflow: ellipsis on a block of multiple text lines. Opera has taken the first step and added support for the -o-ellipsis-lastline property, which can be used instead of ellipsis. This property is not part of the CSS3 spec, but we could certainly make good use of it if it were\u2026\n\nWebKit has -webkit-line-clamp to specify how many lines to show before cutting with an ellipsis, but support is patchy at best and there is no control over where the ellipsis shows in the text. Many people have spent time wrangling JavaScript to do this for us, but the methods used are very processor intensive, and introduce a JavaScript dependency.\n\nIndentation and hanging punctuation properties\n\nYou might notice a trend here: almost half of the items in this list relate to typography. The lack of fine-grained control over typographical detail is a general concern among designers and CSS authors. Indentation and hanging punctuation fall into this category.\n\nThe CSS3 specification introduces two new possible values for the text-indent property: each-line; and hanging. each-line would indent the first line of the block container and each line after a forced line break; hanging would invert which lines are affected by the indentation.\n\nThe proposed hanging-punctuation property would allow us to specify whether opening and closing brackets and quotes should hang outside the edge of the first and last lines. The specification is still incomplete, though, and asks for more examples and use cases.\n\nText alignment and hyphenation properties\n\nFollowing the typographic trend of this list, I\u2019d like to add better control over text alignment and hyphenation properties. The CSS3 module on Generated Content for Paged Media already specifies five new hyphenation-related properties (namely: hyphenate-dictionary; hyphenate-before and hyphenate-after; hyphenate-lines; and hyphenate-character), but it is still being developed and lacks examples.\n\nIn the text alignment realm, the new text-align-last property allows you to define how the last line of a block (or a line just before a forced break) is aligned, if your text is set to justify. Its value can be: start; end; left; right; center; and justify. The text-justify property should also allow you to have more control over text set to text-align: justify but, for now, only Internet Explorer supports this.\n\ncalc()\n\nThis is probably my favourite item in the list: the calc() function. This function is part of the CSS3 Values and Units module, but it has only been implemented by Firefox (4.0). To take advantage of it now you need to use the Mozilla vendor code, -moz-calc().\n\nImagine you have a fluid two-column layout where the sidebar column has a fixed width of 240 pixels, and the main content area fills the rest of the width available. This is how you could create that using -moz-calc():\n\n#main {\n    width: -moz-calc(100% - 240px);\n}\n\nCan you imagine how many hacks and headaches we could avoid were this function available in more browsers? Transitions and animations are really nice and lovely but, for me, it\u2019s the ability to do the things that calc() allows you to that deserves the spotlight and to be pushed for implementation.\n\nSelector grouping with -moz-any()\n\nThe -moz-any() selector grouping has been introduced by Mozilla but it\u2019s not part of any CSS specification (yet?); it\u2019s currently only available on Firefox 4.\n\nThis would be especially useful with the way HTML5 outlines documents, where we can have any number of variations of several levels of headings within numerous types of containers (think sections within articles within sections\u2026).\n\nHere is a quick example (copied from the Mozilla blog post about the article) of how -moz-any() works. Instead of writing:\n\nsection section h1, section article h1, section aside h1,\nsection nav h1, article section h1, article article h1,\narticle aside h1, article nav h1, aside section h1,\naside article h1, aside aside h1, aside nav h1, nav section h1,\nnav article h1, nav aside h1, nav nav h1, {\n    font-size: 24px;\n}\n\nYou could simply write:\n\n-moz-any(section, article, aside, nav)\n-moz-any(section, article, aside, nav) h1 {\n    font-size: 24px;\n}\n\nNice, huh?\n\nMore control over styling form elements\n\nSome are of the opinion that form elements shouldn\u2019t be styled at all, since a user might not recognise them as such if they don\u2019t match the operating system\u2019s controls. I partially agree: I\u2019d rather put the choice in the hands of designers and expect them to be capable of deciding whether their particular design hampers or improves usability.\n\nI would say the same idea applies to font-face: while some fear designers might go crazy and litter their web pages with dozens of different fonts, most welcome the freedom to use something other than Arial or Verdana.\n\nThere will always be someone who will take this freedom too far, but it would be useful if we could, for example, style the default Opera date picker:\n\n<input type=\"date\" />\n\n\n\nor Safari\u2019s slider control (think star movie ratings, for example):\n\n<input type=\"range\" min=\"0\" max=\"5\" step=\"1\" value=\"3\" />\n\n\n\nParent selector\n\nI don\u2019t think there is one CSS author out there who has never come across a case where he or she wished there was a parent selector. There have been many suggestions as to how this could work, but a variation of the child selector is usually the most popular:\n\narticle < h1 {\n\u2026\n}\n\nOne can dream\u2026\n\nFlexible box layout\n\nThe Flexible Box Layout Module sounds a bit like magic: it introduces a new box model to CSS, allowing you to distribute and order boxes inside other boxes, and determine how the available space is shared.\n\nTwo of my favourite features of this new box model are:\n\n\n\tthe ability to redistribute boxes in a different order from the markup\n\tthe ability to create flexible layouts, where boxes shrink (or expand) to fill the available space\n\n\nLet\u2019s take a quick look at the second case. Imagine you have a three-column layout, where the first column takes up twice as much horizontal space as the other two:\n\n<body>\n        <section id=\"main\">\n        </section>\n        <section id=\"links\">\n        </section>\n        <aside>\n        </aside>\n</body>\n\nWith the flexible box model, you could specify it like this:\n\nbody {\n    display: box;\n    box-orient: horizontal;\n}\n#main {\n    box-flex: 2;\n}\n#links {\n    box-flex: 1;\n}\naside {\n    box-flex: 1;\n}\n\nIf you decide to add a fourth column to this layout, there is no need to recalculate units or percentages, it\u2019s as easy as that.\n\nBrowser support for this property is still in its early stages (Firefox and WebKit need their vendor prefixes), but we should start to see it being gradually introduced as more attention is drawn to it (I\u2019m looking at you\u2026). You can read a more comprehensive write-up about this property on the Mozilla developer blog.\n\nIt\u2019s easy to understand why it\u2019s harder to start playing with this module than with things like animations or other more decorative properties, which don\u2019t really break your layouts when users don\u2019t see them. But it\u2019s important that we do, even if only in very experimental projects.\n\nNested selectors\n\nAnyone who has never wished they could do something like the following in CSS, cast the first stone:\n\narticle {\n    h1 { font-size: 1.2em; }\n    ul { margin-bottom: 1.2em; }\n}\n\nEven though it can easily turn into a specificity nightmare and promote redundancy in your style sheets (if you abuse it), it\u2019s easy to see how nested selectors could be useful. CSS compilers such as Less or Sass let you do this already, but not everyone wants or can use these compilers in their projects.\n\nEvery wish list has an item that could easily be dropped. In my case, I would say this is one that I would ditch first \u2013 it\u2019s the least useful, and also the one that could cause more maintenance problems. But it could be nice.\n\nImplementation of the ::marker pseudo-element\n\nThe CSS Lists module introduces the ::marker pseudo-element, that allows you to create custom list item markers. When an element\u2019s display property is set to list-item, this pseudo-element is created.\n\nUsing the ::marker pseudo-element you could create something like the following:\n\nFootnote 1:  Both John Locke and his father, Anthony Cooper, are\nnamed after 17th- and 18th-century English philosophers; the real\nAnthony Cooper was educated as a boy by the real John Locke.\nFootnote 2:  Parts of the plane were used as percussion instruments\nand can be heard in the soundtrack.\n\nwhere the footnote marker is generated by the following CSS:\n\nli::marker {\n    content: \"Footnote \" counter(notes) \":\";\n    text-align: left;\n    width: 12em;\n}\nli {\n    counter-increment: notes;\n}\n\nYou can read more about how to use counters in CSS in my article from last year.\n\nBear in mind that the CSS Lists module is still a Working Draft and is listed as \u201cLow priority\u201d. I did say this wish list would start to grow more unrealistic closer to the end\u2026\n\nVariables\n\nThe sight of the word \u2018variables\u2019 may make some web designers shy away, but when you think of them applied to things such as repeated colours in your stylesheets, it\u2019s easy to see how having variables available in CSS could be useful.\n\nThink of a website where the main brand colour is applied to elements like the main text, headings, section backgrounds, borders, and so on. In a particularly large website, where the colour is repeated countless times in the CSS and where it\u2019s important to keep the colour consistent, using variables would be ideal (some big websites are already doing this by using server-side technology).\n\nAgain, Less and Sass allow you to use variables in your CSS but, again, not everyone can (or wants to) use these.\n\nIf you are using Less, you could, for instance, set the font-family value in one variable, and simply call that variable later in the code, instead of repeating the complete font stack, like so:\n\n@fontFamily: Calibri, \"Lucida Grande\", \"Lucida Sans Unicode\", Helvetica, Arial, sans-serif;\nbody {\n    font-family: @fontFamily;\n}\n\nOther features of these CSS compilers might also be useful, like the ability to \u2018call\u2019 a property value from another selector (accessors):\n\nheader {\n    background: #000000;\n}\nfooter {\n    background: header['background'];\n}\n\nor the ability to define functions (with arguments), saving you from writing large blocks of code when you need to write something like, for example, a CSS gradient:\n\n.gradient (@start:\"\", @end:\"\") {\n    background: -webkit-gradient(linear, left top, left bottom, from(@start), to(@end));\n    background: -moz-linear-gradient(-90deg,@start,@end);\n}\nbutton {\n    .gradient(#D0D0D0,#9F9F9F);\n}\n\nStandardised comments\n\nEach CSS author has his or her own style for commenting their style sheets. While this isn\u2019t a massive problem on smaller projects, where maybe only one person will edit the CSS, in larger scale projects, where dozens of hands touch the code, it would be nice to start seeing a more standardised way of commenting.\n\nOne attempt at creating a standard for CSS comments is CSSDOC, an adaptation of Javadoc (a documentation generator that extracts comments from Java source code into HTML). CSSDOC uses \u2018DocBlocks\u2019, a term borrowed from the phpDocumentor Project. A DocBlock is a human- and machine-readable block of data which has the following structure:\n\n/**\n * Short description\n *\n * Long description (this can have multiple lines and contain <p> tags\n *\n * @tags (optional)\n */\n\nCSSDOC includes a standard for documenting bug fixes and hacks, colours, versioning and copyright information, amongst other important bits of data.\n\nI know this isn\u2019t a CSS feature request per se; rather, it\u2019s just me pointing you at something that is usually overlooked but that could contribute towards keeping style sheets easier to maintain and to hand over to new developers.\n\nFinal notes\n\nI understand that if even some of these were implemented in browsers now, it would be a long time until all vendors were up to speed. But if we don\u2019t talk about them and experiment with what\u2019s available, then it will definitely never happen.\n\nWhy haven\u2019t I mentioned better browser support for existing CSS3 properties? Because that would be the same as adding chocolate to your Christmas wish list \u2013 you don\u2019t need to ask, everyone knows you want it.\n\nThe list could go on. There are dozens of other things I would love to see integrated in CSS or further developed. These are my personal favourites: some might be less useful than others, but I\u2019ve wished for all of them at some point.\n\nPart of the research I did while writing this article was asking some friends what they would add to their lists; other than a couple of items I already had in mine, everything else was different. I\u2019m sure your list would be different too. So tell me, what\u2019s on your CSS wish list?", "year": "2010", "author": "Inayaili de Le\u00f3n Persson", "author_slug": "inayailideleon", "published": "2010-12-03T00:00:00+00:00", "url": "https://24ways.org/2010/my-css-wish-list/", "topic": "code"}
{"rowid": 239, "title": "Using the WebFont Loader to Make Browsers Behave the Same", "contents": "Web fonts give us designers a whole new typographic palette with which to work. However, browsers handle the loading of web fonts in different ways, and this can lead to inconsistent user experiences.\n\nSafari, Chrome and Internet Explorer leave a blank space in place of the styled text while the web font is loading. Opera and Firefox show text with the default font which switches over when the web font has loaded, resulting in the so-called Flash of Unstyled Text (aka FOUT). Some people prefer Safari\u2019s approach as it eliminates FOUT, others think the Firefox way is more appropriate as content can be read whilst fonts download. Whatever your preference, the WebFont Loader can make all browsers behave the same way.\n\nThe WebFont Loader is a JavaScript library that gives you extra control over font loading. It was co-developed by Google and Typekit, and released as open source. The WebFont Loader works with most web font services as well as with self-hosted fonts.\n\nThe WebFont Loader tells you when the following events happen as a browser downloads web fonts (or loads them from cache):\n\n\n\twhen fonts start to download (\u2018loading\u2019)\n\twhen fonts finish loading (\u2018active\u2019)\n\tif fonts fail to load (\u2018inactive\u2019)\n\n\nIf your web page requires more than one font, the WebFont Loader will trigger events for individual fonts, and for all the fonts as a whole. This means you can find out when any single font has loaded, and when all the fonts have loaded (or failed to do so).\n\nThe WebFont Loader notifies you of these events in two ways: by applying special CSS classes when each event happens; and by firing JavaScript events. For our purposes, we\u2019ll be using just the CSS classes.\n\nImplementing the WebFont Loader\n\nAs stated above, the WebFont Loader works with most web font services as well as with self-hosted fonts.\n\nSelf-hosted fonts\n\nTo use the WebFont Loader when you are hosting the font files on your own server, paste the following code into your web page:\n\n<script type=\"text/javascript\">\nWebFontConfig = {\n\tcustom: { families: ['Font Family Name', 'Another Font Family'],\n\turls: [ 'http://yourwebsite.com/styles.css' ] }\n};\n(function() {\n\tvar wf = document.createElement('script');\n\twf.src = ('https:' == document.location.protocol ? 'https' : 'http') + '://ajax.googleapis.com/ajax/libs/webfont/1/webfont.js';\n\twf.type = 'text/javascript';\n\twf.async = 'true';\n\tvar s = document.getElementsByTagName('script')[0];\n\ts.parentNode.insertBefore(wf, s);\n})();\n</script>\n\nReplace Font Family Name and Another Font Family with a comma-separated list of the font families you want to check against, and replace http://yourwebsite.com/styles.css with the URL of the style sheet where your @font-face rules reside.\n\nFontdeck\n\nAssuming you have added some fonts to a website project in Fontdeck, use the afore-mentioned code for self-hosted solutions and replace http://yourwebsite.com/styles.css with the URL of the <link> tag in your Fontdeck website settings page. It will look something like http://f.fontdeck.com/s/css/xxxx/domain/nnnn.css.\n\nTypekit\n\nTypekit\u2019s JavaScript-based implementation incorporates the WebFont Loader events by default, so you won\u2019t need to include any WebFont Loader code.\n\nMaking all browsers behave like Safari\n\nTo make Firefox and Opera work in the same way as WebKit browsers (Safari, Chrome, etc.) and Internet Explorer, and thus minimise FOUT, you need to hide the text while the fonts are loading.\n\nWhile fonts are loading, the WebFont Loader adds a class of wf-loading to the <html> element. Once the fonts have loaded, the wf-loading class is removed and replaced with a class of wf-active (or wf-inactive if all of the fonts failed to load). This means you can style elements on the page while the fonts are loading and then style them differently when the fonts have finished loading.\n\nSo, let\u2019s say the text you need to hide while fonts are loading is contained in all paragraphs and top-level headings. By writing the following style rule into your CSS, you can hide the text while the fonts are loading:\n\n.wf-loading h1, .wf-loading p {\n\tvisibility:hidden;\n}\n\nBecause the wf-loading class is removed once the the fonts have loaded, the visibility:hidden rule will stop being applied, and the text revealed. You can see this in action on this simple example page.\n\nThat works nicely across the board, but the situation is slightly more complicated. WebKit doesn\u2019t wait for all fonts to load before displaying text: it displays text elements as soon as the relevant font is loaded. \n\nTo emulate WebKit more accurately, we need to know when individual fonts have loaded, and apply styles accordingly. Fortunately, as mentioned earlier, the WebFont Loader has events for individual fonts too.\n\nWhen a specific font is loading, a class of the form wf-fontfamilyname-n4-loading is applied. Assuming headings and paragraphs are styled in different fonts, we can make our CSS more specific as follows:\n\n.wf-fontfamilyname-n4-loading h1, \n.wf-anotherfontfamily-n4-loading p {\n\tvisibility:hidden;\n}\n\nNote that the font family name is transformed to lower case, with all spaces removed. The n4 is a shorthand for the weight and style of the font family. In most circumstances you\u2019ll use n4 but refer to the WebFont Loader documentation for exceptions.\n\nYou can see it in action on this Safari example page (you\u2019ll probably need to disable your cache to see any change occur).\n\nMaking all browsers behave like Firefox\n\nTo make WebKit browsers and Internet Explorer work like Firefox and Opera, you need to explicitly show text while the fonts are loading. In order to make this happen, you need to specify a font family which is not a web font while the fonts load, like this:\n\n.wf-fontfamilyname-n4-loading h1 { \n    font-family: 'arial narrow', sans-serif; \n}\n.wf-anotherfontfamily-n4-loading p { \n    font-family: arial, sans-serif; \n}\n\nYou can see this in action on the Firefox example page (again you\u2019ll probably need to disable your cache to see any change occur).\n\nAnd there\u2019s more\n\nThat\u2019s just the start of what can be done with the WebFont Loader. More areas to explore would be tweaking font sizes to reduce the impact of reflowing text and to better cater for very narrow fonts. By using the JavaScript events much more can be achieved too, such as fading in text as the fonts load.", "year": "2010", "author": "Richard Rutter", "author_slug": "richardrutter", "published": "2010-12-02T00:00:00+00:00", "url": "https://24ways.org/2010/using-the-webfont-loader-to-make-browsers-behave-the-same/", "topic": "code"}
{"rowid": 238, "title": "Everything You Wanted To Know About Gradients (And a Few Things You Didn\u2019t)", "contents": "Hello. I am here to discuss CSS3 gradients. Because, let\u2019s face it, what the web really needed was more gradients.\n\nStill, despite their widespread use (or is it overuse?), the smartly applied gradient can be a valuable contributor to a designer\u2019s vocabulary. There\u2019s always been a tension between the inherently two-dimensional nature of our medium, and our desire for more intensity, more depth in our designs. And a gradient can evoke so much: the splay of light across your desk, the slow decrease in volume toward the end of your favorite song, the sunset after a long day. When properly applied, graded colors bring a much needed softness to our work.\n\nOf course, that whole \u2018proper application\u2019 thing is the tricky bit.\n\nBut given their place in our toolkit and their prominence online, it really is heartening to see we can create gradients directly with CSS. They\u2019re part of the draft images module, and implemented in two of the major rendering engines.\n\nStill, I\u2019ve always found CSS gradients to be one of the more confusing aspects of CSS3. So if you\u2019ll indulge me, let\u2019s take a quick look at how to create CSS gradients\u2014hopefully we can make them seem a bit more accessible, and bring a bit more art into the browser.\n\nGradient theory 101 (I hope that\u2019s not really a thing)\n\nRight. So before we dive into the code, let\u2019s cover a few basics. Every gradient, no matter how complex, shares a few common characteristics. Here\u2019s a straightforward one:\n\n I spent seconds hours designing this gradient. I hope you like it.\n\nAt either end of our image, we have a final color value, or color stop: on the left, our stop is white; on the right, black. And more color-rich gradients are no different:\n\n (Don\u2019t ever really do this. Please. I beg you.)\n\nIt\u2019s visually more intricate, sure. But at the heart of it, we have just seven color stops (red, orange, yellow, and so on), making for a fantastic gradient all the way.\n\nNow, color stops alone do not a gradient make. Between each is a transition point, the fail-over point between the two stops. Now, the transition point doesn\u2019t need to fall exactly between stops: it can be brought closer to one stop or the other, influencing the overall shape of the gradient.\n\nA tale of two syntaxes\n\nArmed with our new vocabulary, let\u2019s look at a CSS gradient in the wild. Behold, the simple input button:\n\n\n\nThere\u2019s a simple linear gradient applied vertically across the button, moving from a bright sunflowerish hue (#FAA51A, for you hex nuts in the audience) to a much richer orange (#F47A20). And here\u2019s the CSS that makes it happen:\n\ninput[type=submit] {\n\tbackground-color: #F47A20;\n\tbackground-image: -moz-linear-gradient(\n\t\t#FAA51A,\n\t\t#F47A20\n\t\t);\n\tbackground-image: -webkit-gradient(linear, 0 0, 0 100%,\n\t\tcolor-stop(0, #FAA51A),\n\t\tcolor-stop(1, #F47A20)\n\t\t);\n}\n\nI\u2019ve borrowed David DeSandro\u2019s most excellent formatting suggestions for gradients to make this snippet a bit more legible but, still, the code above might have turned your stomach a bit. And that\u2019s perfectly understandable\u2014heck, it sort of turned mine. But let\u2019s step through the CSS slowly, and see if we can\u2019t make it a little less terrifying.\n\nVerbose WebKit is verbose\n\nHere\u2019s the syntax for our little gradient on WebKit:\n\nbackground-image: -webkit-gradient(linear, 0 0, 0 100%,\n\tcolor-stop(0, #FAA51A),\n\tcolor-stop(1, #F47A20)\n\t);\n\nWoof. Quite a mouthful, no? Well, here\u2019s what we\u2019re looking at:\n\n\n\tWebKit has a single -webkit-gradient property, which can be used to create either linear or radial gradients.\n\tThe next two values are the starting and ending positions for our gradient (0 0 and 0 100%, respectively). Linear gradients are simply drawn along the path between those two points, which allows us to change the direction of our gradient simply by altering its start and end points.\n\tAfterward, we specify our color stops with the oh-so-aptly named color-stop parameter, which takes the stop\u2019s position on the gradient (0 being the beginning, and 100% or 1 being the end) and the color itself.\n\n\nFor a simple two-color gradient like this, -webkit-gradient has a bit of shorthand notation to offer us:\n\nbackground-image: -webkit-gradient(linear, 0 0, 0 100%,\n\tfrom(#FAA51A),\n\tto(#FAA51A)\n\t);\n\nfrom(#FAA51A) is equivalent to writing color-stop(0, #FAA51A), and to(#FAA51A) is the same as color-stop(1, #FAA51A) or color-stop(100%, #FAA51A)\u2014in both cases, we\u2019re simply declaring the first and last color stops in our gradient.\n\nTerse Gecko is terse\n\nWebKit proposed its syntax back in 2008, heavily inspired by the way gradients are drawn in the canvas specification. However, a different, leaner syntax came to the fore, eventually appearing in a draft module specification in CSS3.\n\nNaturally, because nothing on the web was meant to be easy, this is the one that Mozilla has implemented.\n\nHere\u2019s how we get gradient-y in Gecko:\n\nbackground-image: -moz-linear-gradient(\n\t#FAA51A,\n\t#F47A20\n\t);\n\nWait, what? Done already? That\u2019s right. By default, -moz-linear-gradient assumes you\u2019re trying to create a vertical gradient, starting from the top of your element and moving to the bottom. And, if that\u2019s the case, then you simply need to specify your color stops, delimited with a few commas.\n\nI know: that was almost\u2026 painless. But the W3C/Mozilla syntax also affords us a fair amount of flexibility and control, by introducing features as we need them.\n\nWe can specify an origin point for our gradient:\n\nbackground-image: -moz-linear-gradient(50% 100%,\n\t#FAA51A,\n\t#F47A20\n\t);\n\nAs well as an angle, to give it a direction:\n\nbackground-image: -moz-linear-gradient(50% 100%, 45deg,\n\t#FAA51A,\n\t#F47A20\n\t);\n\nAnd we can specify multiple stops, simply by adding to our comma-delimited list:\n\nbackground-image: -moz-linear-gradient(50% 100%, 45deg,\n\t#FAA51A,\n\t#FCC,\n\t#F47A20\n\t);\n\nBy adding a percentage after a given color value, we can determine its position along the gradient path:\n\nbackground-image: -moz-linear-gradient(50% 100%, 45deg,\n\t#FAA51A,\n\t#FCC 20%,\n\t#F47A20\n\t);\n\nSo that\u2019s some of the flexibility implicit in the W3C/Mozilla-style syntax.\n\nNow, I should note that both syntaxes have their respective fans. I will say that the W3C/Mozilla-style syntax makes much more sense to me, and lines up with how I think about creating gradients. But I can totally understand why some might prefer WebKit\u2019s more verbose approach to the, well, looseness behind the -moz syntax. \u00c0 chacun son gradient syntax.\n\nStill, as the language gets refined by the W3C, I really hope some consensus is reached by the browser vendors. And with Opera signaling that it will support the W3C syntax, I suppose it falls on WebKit to do the same.\n\nReusing color stops for fun and profit\n\nBut CSS gradients aren\u2019t all simple colors and shapes and whatnot: by getting inventive with individual color stops, you can create some really complex, compelling effects.\n\nTim Van Damme, whose brain, I believe, should be posthumously donated to science, has a particularly clever application of gradients on The Box, a site dedicated to his occasional podcast series. Now, there are a fair number of gradients applied throughout the UI, but it\u2019s the feature image that really catches the eye.\n\nYou see, there\u2019s nothing that says you can\u2019t reuse color stops. And Tim\u2019s exploited that perfectly.\n\nHe\u2019s created a linear gradient, angled at forty-five degrees from the top left corner of the photo, starting with a fully transparent white (rgba(255, 255, 255, 0)). At the halfway mark, he\u2019s established another color stop at an only slightly more opaque white (rgba(255, 255, 255, 0.1)), making for that incredibly gradual brightening toward the middle of the photo.\n\n\n\nBut then he has set another color stop immediately on top of it, bringing it back down to rgba(255, 255, 255, 0) again. This creates that fantastically hard edge that diagonally bisects the photo, giving the image that subtle gloss.\n\n\n\nAnd his final color stop ends at the same fully transparent white, completing the effect. Hot? I do believe so.\n\nRocking the radials\n\nWe\u2019ve been looking at linear gradients pretty exclusively. But I\u2019d be remiss if I didn\u2019t at least mention radial gradients as a viable option, including a modest one as a link accent on a navigation bar:\n\n\n\nAnd here\u2019s the relevant CSS:\n\nbackground: -moz-radial-gradient(50% 100%, farthest-side,\n\trgb(204, 255, 255) 1%,\n\trgb(85, 85, 85) 15%,\n\trgba(85, 85, 85, 0)\n\t);\nbackground: -webkit-gradient(radial, 50% 100%, 0, 50% 100%, 15,\n\tfrom(rgb(204, 255, 255)),\n\tto(rgba(85, 85, 85, 0))\n\t);\n\nNow, the syntax builds on what we\u2019ve already learned about linear gradients, so much of it might be familiar to you, picking out color stops and transition points, as well as the two syntaxes\u2019 reliance on either a separate property (-moz-radial-gradient) or parameter (-webkit-gradient(radial, \u2026)) to shift into circular mode.\n\nMozilla introduces another stand-alone property (-moz-radial-gradient), and accepts a starting point (50% 100%) from which the circle radiates. There\u2019s also a size constant defined (farthest-side), which determines the reach and shape of our gradient.\n\nWebKit is again the more verbose of the two syntaxes, requiring both starting and ending points (50% 100% in both cases). Each also accepts a radius in pixels, allowing you to control the skew and breadth of the circle.\n\nAgain, this is a fairly modest little radial gradient. Time and article length (and, let\u2019s be honest, your author\u2019s completely inadequate grasp of geometry) prevent me from covering radial gradients in much more detail, because they are incredibly powerful. For those interested in learning more, I can\u2019t recommend the references at Mozilla and Apple strongly enough.\n\nLeave no browser behind\n\nBut no matter the kind of gradients you\u2019re working with, there is a large swathe of browsers that simply don\u2019t support gradients. Thankfully, it\u2019s fairly easy to declare a sensible fallback\u2014it just depends on the kind of fallback you\u2019d like. Essentially, gradient-blind browsers will disregard any properties containing references to either -moz-linear-gradient, -moz-radial-gradient, or -webkit-gradient, so you simply need to keep your fallback isolated from those properties.\n\nFor example: if you\u2019d like to fall back to a flat color, simply declare a separate background-color:\n\n.nav {\n\tbackground-color: #000;\n\tbackground-image: -moz-linear-gradient(rgba(0, 0, 0, 0), rgba(255, 255, 255, 0.45));\n\tbackground-image: -webkit-gradient(linear, 0 0, 0 100%, from(rgba(0, 0, 0, 0)), to(rgba(255, 255, 255, 0.45)));\n}\n\nOr perhaps just create three separate background properties.\n\n.nav {\n\tbackground: #000;\n\tbackground: #000 -moz-linear-gradient(rgba(0, 0, 0, 0), rgba(255, 255, 255, 0.45));\n\tbackground: #000 -webkit-gradient(linear, 0 0, 0 100%, from(rgba(0, 0, 0, 0)), to(rgba(255, 255, 255, 0.45)));\n}\n\nWe can even build on this to fall back to a non-gradient image:\n\n.nav {\n\tbackground: #000 <strong>url(\"faux-gradient-lol.png\") repeat-x</strong>;\n\tbackground: #000 -moz-linear-gradient(rgba(0, 0, 0, 0), rgba(255, 255, 255, 0.45));\n\tbackground: #000 -webkit-gradient(linear, 0 0, 0 100%, from(rgba(0, 0, 0, 0)), to(rgba(255, 255, 255, 0.45)));\n}\n\nNo matter the approach you feel most appropriate to your design, it\u2019s really just a matter of keeping your fallback design quarantined from its CSS3-ified siblings.\n\n(If you\u2019re feeling especially masochistic, there\u2019s even a way to get simple linear gradients working in IE via Microsoft\u2019s proprietary filters. Of course, those come with considerable performance penalties that even Microsoft is quick to point out, so I\u2019d recommend avoiding those.\n\nAnd don\u2019t tell Andy Clarke I told you, or he\u2019ll probably unload his Derringer at me. Or something.)\n\nGo forth and, um, gradientify!\n\nIt\u2019s entirely possible your head\u2019s spinning. Heck, mine is, but that might be the effects of the \u2019nog. But maybe you\u2019re wondering why you should care about CSS gradients. After all, images are here right now, and work just fine. \n\nWell, there are some quick benefits that spring to mind: fewer HTTP requests are needed; CSS3 gradients are easily made scalable, making them ideal for variable widths and heights; and finally, they\u2019re easily modifiable by tweaking a few CSS properties. Because, let\u2019s face it, less time spent yelling at Photoshop is a very, very good thing.\n\nOf course, CSS-generated gradients are not without their drawbacks. The syntax can be confusing, and it\u2019s still under development at the W3C. As we\u2019ve seen, browser support is still very much in flux. And it\u2019s possible that gradients themselves have some real performance drawbacks\u2014so test thoroughly, and gradient carefully.\n\nBut still, as syntaxes converge, and support improves, I think generated gradients can make a compelling tool in our collective belts. The tasteful design is, of course, entirely up to you.\n\nSo have fun, and get gradientin\u2019.", "year": "2010", "author": "Ethan Marcotte", "author_slug": "ethanmarcotte", "published": "2010-12-22T00:00:00+00:00", "url": "https://24ways.org/2010/everything-you-wanted-to-know-about-gradients/", "topic": "code"}
{"rowid": 235, "title": "Real Animation Using JavaScript, CSS3, and HTML5 Video", "contents": "When I was in school to be a 3-D animator, I read a book called Timing for Animation. Though only 152 pages long, it\u2019s essentially the bible for anyone looking to be a great animator. In fact, Pixar chief creative officer John Lasseter used the first edition as a reference when he was an animator at Walt Disney Studios in the early 1980s.\n\nIn the book, authors John Halas and Harold Whitaker advise:\n\n\n\tTiming is the part of animation which gives meaning to movement. Movement can easily be achieved by drawing the same thing in two different positions and inserting a number of other drawings between the two. The result on the screen will be movement; but it will not be animation.\n\n\nBut that\u2019s exactly what we\u2019re doing with CSS3 and JavaScript: we\u2019re moving elements, not animating them. We\u2019re constantly specifying beginning and end states and allowing the technology to interpolate between the two. And yet, it\u2019s the nuances within those middle frames that create the sense of life we\u2019re looking for.\n\nAs bandwidth increases and browser rendering grows more consistent, we can create interactions in different ways than we\u2019ve been able to before. We\u2019re encountering motion more and more on sites we\u2019d generally label \u2018static.\u2019 However, this motion is mostly just movement, not animation. It\u2019s the manipulation of an element\u2019s properties, most commonly width, height, x- and y-coordinates, and opacity.\n\nSo how do we create real animation?\n\nThe metaphor\n\nIn my experience, animation is most believable when it simulates, exaggerates, or defies the real world. A bowling ball falls differently than a racquetball. They each have different weights and sizes, which affect the way they land, bounce, and impact other objects.\n\nThis is a major reason that JavaScript animation frequently feels mechanical; it doesn\u2019t complete a metaphor. Expanding and collapsing a <div> feels very different than a opening a door or unfolding a piece of paper, but it often shouldn\u2019t. The interaction itself should tie directly to the art direction of a page.\n\nPhysics\n\nUnderstanding the physics of a situation is key to creating convincing animation, even if your animation seeks to defy conventional physics. Isaac Newton\u2019s first law of motion\u2019s_laws_of_motion states, \u201cEvery body remains in a state of rest or uniform motion (constant velocity) unless it is acted upon by an external unbalanced force.\u201d Once a force acts upon an object, the object\u2019s shape can change accordingly, depending on the strength of the force and the mass of the object. Another nugget of wisdom from Halas and Whitaker:\n\n\n\tAll objects in nature have their own weight, construction, and degree of flexibility, and therefore each behaves in its own individual way when a force acts upon it. This behavior, a combination of position and timing, is the basis of animation. The basic question which an animator is continually asking himself is this: \u201cWhat will happen to this object when a force acts upon it?\u201d And the success of his animation largely depends on how well he answers this question.\n\n\nIn animating with CSS3 and JavaScript, keep physics in mind. How \u2018heavy\u2019 is the element you\u2019re interacting with? What kind of force created the action? A gentle nudge? A forceful shove? These subtleties will add a sense of realism to your animations and make them much more believable to your users.\n\nMisdirection\n\nMagicians often use misdirection to get their audience to focus on one thing rather than another. They fool us into thinking something happened that actually didn\u2019t.\n\nAnimation is the same, especially on a screen. By changing the arrangement of pixels on screen at a fast enough rate, your eyes fool your mind into thinking an object is actually in motion. \n\nAnother important component of misdirecting in animation is the use of multiple objects. Try to recall a cartoon where a character vanishes. More often, the character makes some sort of exaggerated motion (this is called anticipation) then disappears, and a puff a smoke follows. That smoke is an extra element, but it goes a long way into make you believe that character actually disappeared.\n\nVery rarely does a vanishing character\u2019s opacity simply go from one hundred per cent to zero. That\u2019s not believable. So why do we do it with <div>s?\n\nArmed with the ammunition of metaphors and misdirection, let\u2019s code an example.\n\nShake, rattle, and roll\n\n(These demos require at least a basic understanding of jQuery and CSS3. Run away if your\u2019re afraid, or brush up on CSS animation and resources for learning jQuery. Also, these demos use WebKit-specific features and are best viewed in the latest version of Safari, so performance in other browsers may vary.)\n\nWe often see the design pattern of clicking a link to reveal content. Our \u201cfirst demo\u201d:\u201d/examples/2010/real-animation/demo1/ shows us exactly that. It uses jQuery\u2019s \u201c slideDown()\u201d:http://api.jquery.com/slideDown/ method, as many instances do.\n\nBut what force acted on the <div> that caused it to open? Did pressing the button unlatch some imaginary hook? Did it activate an unlocking sequence with some gears?\n\nTake 2\n\nOur second demo is more explicit about what happens: the button fell on the <div> and shook its content loose. Here\u2019s how it\u2019s done. \n\nfunction clickHandler(){\n\t$('#button').addClass('animate');\n\treturn false;\n}\n\nClicking the link adds a class of animate to our button. That class has the following CSS associated with it:\n\n<style>\n\t.animate {\n\t\t-webkit-animation-name: ANIMATE;\n\t\t-webkit-animation-duration: 0.25s;\n\t\t-webkit-animation-iteration-count: 1;\n\t\t-webkit-animation-timing-function: ease-in;\n\t}\n\t@-webkit-keyframes ANIMATE {\n\t\tfrom {\n\t\ttop: 72px;\n\t\t}\n\t\tto {\n\t\t\ttop: 112px;\n\t\t}\n\t}\n</style>\n\nIn our keyframe definition, we\u2019ve specified from and to states. This is great, because we can be explicit about how an object starts and finishes moving. \n\nWhat\u2019s also extra handy is that these CSS keyframes broadcast events that you can react to with JavaScript. In this example, we\u2019re listening to the webkitAnimationEnd event and opening the <div> only when the sequence is complete. Here\u2019s that code.\n\nfunction attachAnimationEventHandlers(){\n\tvar wrap = document.getElementById('wrap');\n\twrap.addEventListener('webkitAnimationEnd', function($e) {\n\t\tswitch($e.animationName){\n\t\t\tcase \"ANIMATE\" :\n\t\t\topenMain();\n\t\t\tbreak;\n\t\t\tdefault:\n\t\t}\n\t}, false);\n}\nfunction openMain(){\n\t$('#main .inner').slideDown('slow');\n}\n\n(For more info on handling animation events, check out the documentation at the Safari Reference Library.)\n\nTake 3\n\nThe problem with the previous demo is that the subtleties of timing aren\u2019t evident. It still feels a bit choppy.\n\nFor our third demo, we\u2019ll use percentages instead of keywords so that we can insert as many points as we need to communicate more realistic timing. The percentages allow us to add the keys to well-timed animation: anticipation, hold, release, and reaction. \n\n<style>\n\t@-webkit-keyframes ANIMATE {\n\t\t0% {\n\t\t\ttop: 72px;\n\t\t}\n\t\t40% { /* anticipation */\n\t\t\ttop: 57px;\n\t\t}\n\t\t70% { /* hold */\n\t\t\ttop: 56px;\n\t\t}\n\t\t80% { /* release */\n\t\t\ttop: 112px;\n\t\t}\n\t\t100% { /* return */\n\t\t\ttop: 72px;\n\t\t}\n\t}\n</style>\n\nTake 4\n\nThe button animation is starting to feel much better, but the reaction of the <div> opening seems a bit slow.\n\nThis fourth demo uses jQuery\u2019s delay() method to time the opening precisely when we want it. Since we know the button\u2019s animation is one second long and its reaction starts at eighty per cent of that, that puts our delay at 800ms (eighty per cent of one second). However, here\u2019s a little pro tip: let\u2019s start the opening at 750ms instead. The extra fifty milliseconds makes it feel more like the opening is a reaction to the exact hit of the button. Instead of listening for the webkitAnimationEnd event, we can start the opening as soon as the button is clicked, and the movement plays on the specified delay.\n\nfunction clickHandler(){\n\t$('#button').addClass('animate');\n\topenMain();\n\treturn false;\n}\nfunction openMain(){\n\t$('#main .inner').delay(750).slideDown('slow');\n}\n\nTake 5\n\nWe can tweak the timing of that previous animation forever, but that\u2019s probably as close as we\u2019re going to get to realistic animation with CSS and JavaScript. However, for some extra sauce, we could relegate the whole animation in our final demo to a video sequence which includes more nuances and extra elements for misdirection.\n\nHere\u2019s the basis of video replacement. Add a <video> element to the page and adjust its opacity to zero. Once the button is clicked, fade the button out and start playing the video. Once the video is finished playing, fade it out and bring the button back.\n\nfunction clickHandler(){\n\tif($('#main .inner').is(':hidden')){\n\t\t$('#button').fadeTo(100, 0);\n\t\t$('#clickVideo').fadeTo(100, 1, function(){\n\t\t\tvar clickVideo = document.getElementById('clickVideo');\n\t\t\tclickVideo.play();\n\t\t\tsetTimeout(removeVideo, 2400);\n\t\t\topenMain();\n\t\t});\n\t}\n\treturn false;\n}\nfunction removeVideo(){\n\t$('#button').fadeTo(500, 1);\n\t$('#clickVideo').fadeOut('slow');\n}\nfunction openMain(){\n\t$('#main .inner').delay(1100).slideDown('slow');\n}\n\nWrapping up\n\nI\u2019m no JavaScript expert by any stretch. I\u2019m sure a lot of you scripting wizards out there could write much cleaner and more efficient code, but I hope this gives you an idea of the theory behind more realistic motion with the technology we\u2019re using most. This is just one model of creating more convincing animation, but you can create countless variations of this, including\u2026\n\n\n\tExporting <video> animations in 3-D animation tools or 2-D animation tools like Flash or After Effects\n\tUsing <canvas> or SVG instead of <video>\n\tEmploying specific JavaScript animation frameworks\n\tMaking use of all the powerful properties of CSS Transforms and CSS Animation\n\tTrying out emerging CSS3 animation tools like Sencha Animator\n\n\nIf it wasn\u2019t already apparent, these demos show an exaggerated example and probably aren\u2019t practical in a lot of environments. However, there are a handful of great sites out there that honor animation techniques\u2014metaphor, physics, and misdirection, among others\u2014like Benjamin De Cock\u2019s vCard, 20 Things I Learned About Browsers and the Web by Fantasy Interactive, and the Nike Snowboarding site by Ian Coyle and HEGA. They\u2019re wonderful testaments to what you can do to aid interaction for users.\n\nMy goal was to show you the \u2018why\u2019 and the \u2018how.\u2019 Your charge is to discern the \u2018where\u2019 and the \u2018when.\u2019 Happy animating!", "year": "2010", "author": "Dan Mall", "author_slug": "danmall", "published": "2010-12-15T00:00:00+00:00", "url": "https://24ways.org/2010/real-animation-using-javascript-css3-and-html5-video/", "topic": "code"}
{"rowid": 234, "title": "An Introduction to CSS 3-D Transforms", "contents": "Ladies and gentlemen, it is the second decade of the third millennium and we are still kicking around the same 2-D interface we got three decades ago. Sure, Apple debuted a few apps for OSX 10.7 that have a couple more 3-D flourishes, and Microsoft has had that Flip 3D for a while. But c\u2019mon \u2013 2011 is right around the corner. That\u2019s Twenty Eleven, folks. Where is our 3-D virtual reality? By now, we should be zipping around the Metaverse on super-sonic motorbikes.\n\nGranted, the capability of rendering complex 3-D environments has been present for years. On the web, there are already several solutions: Flash; three.js in <canvas>; and, eventually, WebGL. Finally, we meagre front-end developers have our own three-dimensional jewel: CSS 3-D transforms!\n\nRationale\n\nLike a beautiful jewel, 3-D transforms can be dazzling, a true spectacle to behold. But before we start tacking 3-D diamonds and rubies to our compositions like Liberace\u2018s tailor, we owe it to our users to ask how they can benefit from this awesome feature. \n\nAn entire application should not take advantage of 3-D transforms. CSS was built to style documents, not generate explorable environments. I fail to find a benefit to completing a web form that can be accessed by swivelling my viewport to the Sign-Up Room (although there have been proposals to make the web just that). Nevertheless, there are plenty of opportunities to use 3-D transforms in between interactions with the interface, via transitions.\n\nTake, for instance, the Weather App on the iPhone. The application uses two views: a details view; and an options view. Switching between these two views is done with a 3-D flip transition. This informs the user that the interface has two \u2013 and only two \u2013 views, as they can exist only on either side of the same plane.\n\n Flipping from details view to options view via a 3-D transition\n\nAlso, consider slide shows. When you\u2019re looking at the last slide, what cues tip you off that advancing will restart the cycle at the first slide? A better paradigm might be achieved with a 3-D transform, placing the slides side-by-side in a circle (carousel) in three-dimensional space; in that arrangement, the last slide obviously comes before the first.\n\n3-D transforms are more than just eye candy. We can also use them to solve dilemmas and make our applications more intuitive. \n\nCurrent support\n\nThe CSS 3D Transforms module has been out in the wild for over a year now. Currently, only Safari supports the specification \u2013 which includes Safari on Mac OS X and Mobile Safari on iOS. \n\nThe support roadmap for other browsers varies. The Mozilla team has taken some initial steps towards implementing the module. Mike Taylor tells me that the Opera team is keeping a close eye on CSS transforms, and is waiting until the specification is fleshed out. And our best friend Internet Explorer still needs to catch up to 2-D transforms before we can talk about the 3-D variety.\n\nTo make matters more perplexing, Safari\u2019s WebKit cousin Chrome currently accepts 3-D transform declarations, but renders them in 2-D space. Chrome team member Paul Irish, says that 3-D transforms are on the horizon, perhaps in one of the next 8.0 releases.\n\nThis all adds up to a bit of a challenge for those of us excited by 3-D transforms. I\u2019ll give it to you straight: missing the dimension of depth can make degradation a bit ungraceful. Unless the transform is relatively simple and holds up in non-3D-supporting browsers, you\u2019ll most likely have to design another solution. But what\u2019s another hurdle in a steeplechase? We web folk have had our mettle tested for years. We\u2019re prepared to devise multiple solutions.\n\nHere\u2019s the part of the article where I mention Modernizr, and you brush over it because you\u2019ve read this part of an article hundreds of times before. But seriously, it\u2019s the best way to test for CSS 3-D transform support. Use it.\n\nEven with these difficulties mounting up, trying out 3-D transforms today is the right move. The CSS 3-D transforms module was developed by the same team at Apple that produced the CSS 2D Transforms and Animation modules. Both specifications have since been adopted by Mozilla and Opera. Transforming in three-dimensions now will guarantee you\u2019ll be ahead of the game when the other browsers catch up.\n\nThe choice is yours. You can make excuses and pooh-pooh 3-D transforms because they\u2019re too hard and only snobby Apple fans will see them today. Or, with a tip of the fedora to Mr Andy Clarke, you can get hard-boiled and start designing with the best features out there right this instant.\n\nSo, I bid you, in the words of the eternal Optimus Prime\u2026\n\n\n\tTransform and roll out.\n\n\nLet\u2019s get coding.\n\nPerspective\n\nTo activate 3-D space, an element needs perspective. This can be applied in two ways: using the transform property, with the perspective as a functional notation:\n\n-webkit-transform: perspective(600);\n\nor using the perspective property: \n\n-webkit-perspective: 600;\n\nSee example: Perspective 1.\n\n\n\n The red element on the left uses transform: perspective() functional notation; the blue element on the right uses the perspective property\n\n\n\nThese two formats both trigger a 3-D space, but there is a difference. The first, functional notation is convenient for directly applying a 3-D transform on a single element (in the previous example, I use it in conjunction with a rotateY transform). But when used on multiple elements, the transformed elements don\u2019t line up as expected. If you use the same transform across elements with different positions, each element will have its own vanishing point. To remedy this, use the perspective property on a parent element, so each child shares the same 3-D space.\n\nSee Example: Perspective 2.\n\n\n\n Each red box on the left has its own vanishing point within the parent container; the blue boxes on the right share the vanishing point of the parent container\n\n\n\nThe value of perspective determines the intensity of the 3-D effect. Think of it as a distance from the viewer to the object. The greater the value, the further the distance, so the less intense the visual effect. perspective: 2000; yields a subtle 3-D effect, as if we were viewing an object from far away. perspective: 100; produces a tremendous 3-D effect, like a tiny insect viewing a massive object.\n\nBy default, the vanishing point for a 3-D space is positioned at its centre. You can change the position of the vanishing point with perspective-origin property.\n\n-webkit-perspective-origin: 25% 75%;\n\nSee Example: Perspective 3.\n\n\n\n\n\n\n\n3-D transform functions\n\nAs a web designer, you\u2019re probably well acquainted with working in two dimensions, X and Y, positioning items horizontally and vertically. With a 3-D space initialised with perspective, we can now transform elements in all three glorious spatial dimensions, including the third Z dimension, depth. \n\n3-D transforms use the same transform property used for 2-D transforms. If you\u2019re familiar with 2-D transforms, you\u2019ll find the basic 3D transform functions fairly similar. \n\n\n\trotateX(angle)\n\trotateY(angle)\n\trotateZ(angle)\n\ttranslateZ(tz)\n\tscaleZ(sz)\n\n\nWhereas translateX() positions an element along the horizontal X-axis, translateZ() positions it along the Z-axis, which runs front to back in 3-D space. Positive values position the element closer to the viewer, negative values further away.\n\nThe rotate functions rotate the element around the corresponding axis. This is somewhat counter-intuitive at first, as you might imagine that rotateX will spin an object left to right. Instead, using rotateX(45deg) rotates an element around the horizontal X-axis, so the top of the element angles back and away, and the bottom gets closer to the viewer.\n\nSee Example: Transforms 1.\n\n\n\n3-D rotate() and translate() functions around each axis\n\n\n\nThere are also several shorthand transform functions that require values for all three dimensions:\n\n\n\ttranslate3d(tx,ty,tz)\n\tscale3d(sx,sy,sz)\n\trotate3d(rx,ry,rz,angle)\n\n\nPro-tip: These foo3d() transform functions also have the benefit of triggering hardware acceleration in Safari. Dean Jackson, CSS 3-D transform spec author and main WebKit dude, writes (to Thomas Fuchs):\n\n\n\tIn essence, any transform that has a 3D operation as one of its functions will trigger hardware compositing, even when the actual transform is 2D, or not doing anything at all (such as translate3d(0,0,0)). Note this is just current behaviour, and could change in the future (which is why we don\u2019t document or encourage it). But it is very helpful in some situations and can significantly improve redraw performance.\n\n\nFor the sake of simplicity, my demos will use the basic transform functions, but if you\u2019re writing production-ready CSS for iOS or Safari-only, make sure to use the foo3d() functions to get the best rendering performance.\n\nCard flip\n\nWe now have all the tools to start making 3-D objects. Let\u2019s get started with something simple: flipping a card.\n\nHere\u2019s the basic markup we\u2019ll need:\n\n<section class=\"container\">\n  <div id=\"card\">\n    <figure class=\"front\">1</figure>\n    <figure class=\"back\">2</figure>\n  </div>\n</section>\n\nThe .container will house the 3-D space. The #card acts as a wrapper for the 3-D object. Each face of the card has a separate element: .front; and .back. Even for such a simple object, I recommend using this same pattern for any 3-D transform. Keeping the 3-D space element and the object element(s) separate establishes a pattern that is simple to understand and easier to style.\n\nWe\u2019re ready for some 3-D stylin\u2019. First, apply the necessary perspective to the parent 3-D space, along with any size or positioning styles.\n\n.container { \n  width: 200px;\n  height: 260px;\n  position: relative;\n  -webkit-perspective: 800;\n}\n\nNow the #card element can be transformed in its parent\u2019s 3-D space. We\u2019re combining absolute and relative positioning so the 3-D object is removed from the flow of the document. We\u2019ll also add width: 100%;  and height: 100%;. This ensures the object\u2019s transform-origin will occur in the centre of .container. More on transform-origin later. \n\nLet\u2019s add a CSS3 transition so users can see the transform take effect. \n\n#card {\n  width: 100%;\n  height: 100%;\n  position: absolute;\n  -webkit-transform-style: preserve-3d;\n  -webkit-transition: -webkit-transform 1s;\n}\n\nThe .container\u2019s perspective only applies to direct descendant children, in this case #card. In order for subsequent children to inherit a parent\u2019s perspective, and live in the same 3-D space, the parent can pass along its perspective with transform-style: preserve-3d. Without 3-D transform-style, the faces of the card would be flattened with its parents and the back face\u2019s rotation would be nullified. \n\nTo position the faces in 3-D space, we\u2019ll need to reset their positions in 2-D with position: absolute. In order to hide the reverse sides of the faces when they are faced away from the viewer, we use backface-visibility: hidden. \n\n#card figure {\n  display: block;\n  position: absolute;\n  width: 100%;\n  height: 100%;\n  -webkit-backface-visibility: hidden;\n}\n\nTo flip the .back face, we add a basic 3-D transform of rotateY(180deg). \n\n#card .front {\n  background: red;\n}\n#card .back {\n  background: blue;\n  -webkit-transform: rotateY(180deg);\n}\n\nWith the faces in place, the #card requires a corresponding style for when it is flipped.\n\n#card.flipped {\n  -webkit-transform: rotateY(180deg);\n}\n\nNow we have a working 3-D object. To flip the card, we can toggle the flipped class. When .flipped, the #card will rotate 180 degrees, thus exposing the .back face.\n\nSee Example: Card 1.\n\n\n\nFlipping a card in three dimensions\n\n\n\nSlide-flip\n\nTake another look at the Weather App 3-D transition. You\u2019ll notice that it\u2019s not quite the same effect as our previous demo. If you follow the right edge of the card, you\u2019ll find that its corners stay within the container. Instead of pivoting from the horizontal centre, it pivots on that right edge. But the transition is not just a rotation \u2013 the edge moves horizontally from right to left. We can reproduce this transition just by modifying a couple of lines of CSS from our original card flip demo.\n\nThe pivot point for the rotation occurs at the right side of the card. By default, the transform-origin of an element is at its horizontal and vertical centre (50% 50% or center center). Let\u2019s change it to the right side:\n\n#card { -webkit-transform-origin: right center; }\n\nThat flip now needs some horizontal movement with translateX. We\u2019ll set the rotation to -180deg so it flips right side out.\n\n#card.flipped {\n  -webkit-transform: translateX(-100%) rotateY(-180deg);\n}\n\nSee Example: Card 2.\n\n\n\nCreating a slide-flip from the right edge of the card\n\n\n\nCube\n\nCreating 3-D card objects is a good way to get started with 3-D transforms. But once you\u2019ve mastered them, you\u2019ll be hungry to push it further and create some true 3-D objects: prisms. We\u2019ll start out by making a cube.\n\nThe markup for the cube is similar to the card. This time, however, we need six child elements for all six faces of the cube:\n\n<section class=\"container\">\n  <div id=\"cube\">\n    <figure class=\"front\">1</figure>\n    <figure class=\"back\">2</figure>\n    <figure class=\"right\">3</figure>\n    <figure class=\"left\">4</figure>\n    <figure class=\"top\">5</figure>\n    <figure class=\"bottom\">6</figure>\n  </div>\n</section>\n\nBasic position and size styles set the six faces on top of one another in the container.\n\n.container {\n  width: 200px;\n  height: 200px;\n  position: relative;\n  -webkit-perspective: 1000;\n}\n#cube {\n  width: 100%;\n  height: 100%;\n  position: absolute;\n  -webkit-transform-style: preserve-3d;\n}\n#cube figure {\n  width: 196px;\n  height: 196px;\n  display: block;\n  position: absolute;\n  border: 2px solid black;\n}\n\nWith the card, we only had to rotate its back face. The cube, however, requires that five of the six faces to be rotated. Faces 1 and 2 will be the front and back. Faces 3 and 4 will be the sides. Faces 5 and 6 will be the top and bottom.\n\n#cube .front { -webkit-transform: rotateY(0deg); }\n#cube .back { -webkit-transform: rotateX(180deg); }\n#cube .right { -webkit-transform: rotateY(90deg); }\n#cube .left { -webkit-transform: rotateY(-90deg); }\n#cube .top { -webkit-transform: rotateX(90deg); }\n#cube .bottom { -webkit-transform: rotateX(-90deg); }\n\nWe could remove the first #cube .front style declaration, as this transform has no effect, but let\u2019s leave it in to keep our code consistent.\n\nNow each face is rotated, and only the front face is visible. The four side faces are all perpendicular to the viewer, so they appear invisible. To push them out to their appropriate sides, they need to be translated out from the centre of their positions. Each side of the cube is 200 pixels wide. From the cube\u2019s centre they\u2019ll need to be translated out half that distance, 100px.\n\n#cube .front { -webkit-transform: rotateY(0deg) translateZ(100px); }\n#cube .back { -webkit-transform: rotateX(180deg) translateZ(100px); }\n#cube .right { -webkit-transform: rotateY(90deg) translateZ(100px); }\n#cube .left { -webkit-transform: rotateY(-90deg) translateZ(100px); }\n#cube .top { -webkit-transform: rotateX(90deg) translateZ(100px); }\n#cube .bottom { -webkit-transform: rotateX(-90deg) translateZ(100px); }\n\nNote here that the translateZ function comes after the rotate. The order of transform functions is important. Take a moment and soak this up. Each face is first rotated towards its position, then translated outward in a separate vector.\n\nWe have a working cube, but we\u2019re not done yet.\n\nReturning to the Z-axis origin\n\nFor the sake of our users, our 3-D transforms should not distort the interface when the active panel is at its resting position. But once we start pushing elements off their Z-axis origin, distortion is inevitable. \n\nIn order to keep 3-D transforms snappy, Safari composites the element, then applies the transform. Consequently, anti-aliasing on text will remain whatever it was before the transform was applied. When transformed forward in 3-D space, significant pixelation can occur. \n\nSee Example: Transforms 2.\n\n\n\n\n\n\n\nLooking back at the Perspective 3 demo, note that no matter how small the perspective value is, or wherever the transform-origin may be, the panel number 1 always returns to its original position, as if all those funky 3-D transforms didn\u2019t even matter.\n\nTo resolve the distortion and restore pixel perfection to our #cube, we can push the 3-D object back, so that the front face will be positioned back to the Z-axis origin.\n\n#cube { -webkit-transform: translateZ(-100px); }\n\nSee Example: Cube 1.\n\n\n\nRestoring the front face to the original position on the Z-axis\n\n\n\nRotating the cube\n\nTo expose any face of the cube, we\u2019ll need a style that rotates the cube to expose any face. The transform values are the opposite of those for the corresponding face. We toggle the necessary class on the #box to apply the appropriate transform.\n\n#cube.show-front { -webkit-transform: translateZ(-100px) rotateY(0deg); }\n#cube.show-back { -webkit-transform: translateZ(-100px) rotateX(-180deg); }\n#cube.show-right { -webkit-transform: translateZ(-100px) rotateY(-90deg); }\n#cube.show-left { -webkit-transform: translateZ(-100px) rotateY(90deg); }\n#cube.show-top { -webkit-transform: translateZ(-100px) rotateX(-90deg); }\n#cube.show-bottom { -webkit-transform: translateZ(-100px) rotateX(90deg); }\n\nNotice how the order of the transform functions has reversed. First, we push the object back with translateZ, then we rotate it.\n\nFinishing up, we can add a transition to animate the rotation between states. \n\n#cube { -webkit-transition: -webkit-transform 1s; }\n\nSee Example: Cube 2.\n\n\n\nRotating the cube with a CSS transition\n\n\n\nRectangular prism\n\nCubes are easy enough to generate, as we only have to worry about one measurement. But how would we handle a non-regular rectangular prism? Let\u2019s try to make one that\u2019s 300 pixels wide, 200 pixels high, and 100 pixels deep. \n\nThe markup remains the same as the #cube, but we\u2019ll switch the cube id for #box. The container styles remain mostly the same:\n\n.container {\n  width: 300px;\n  height: 200px;\n  position: relative;\n  -webkit-perspective: 1000;\n}\n#box {\n  width: 100%;\n  height: 100%;\n  position: absolute;\n  -webkit-transform-style: preserve-3d;\n}\n\nNow to position the faces. Each set of faces will need their own sizes. The smaller faces (left, right, top and bottom) need to be positioned in the centre of the container, where they can be easily rotated and then shifted outward. The thinner left and right faces get positioned left: 100px ((300\u2009\u2212\u2009100)\u2009\u00f7\u20092), The stouter top and bottom faces get positioned top: 50px ((200\u2009\u2212\u2009100)\u2009\u00f7\u20092).\n\n#box figure {\n  display: block;\n  position: absolute;\n  border: 2px solid black;\n}\n#box .front,\n#box .back {\n  width: 296px;\n  height: 196px;\n}\n#box .right,\n#box .left {\n  width: 96px;\n  height: 196px;\n  left: 100px;\n}\n#box .top,\n#box .bottom {\n  width: 296px;\n  height: 96px;\n  top: 50px;\n}\n\nThe rotate values can all remain the same as the cube example, but for this rectangular prism, the translate values do differ. The front and back faces are each shifted out 50 pixels since the #box is 100 pixels deep. The translate value for the left and right faces is 150 pixels for their 300 pixels width. Top and bottom panels take 100 pixels for their 200 pixels height:\n\n#box .front { -webkit-transform: rotateY(0deg) translateZ(50px); }\n#box .back { -webkit-transform: rotateX(180deg) translateZ(50px); }\n#box .right { -webkit-transform: rotateY(90deg) translateZ(150px); }\n#box .left { -webkit-transform: rotateY(-90deg) translateZ(150px); }\n#box .top { -webkit-transform: rotateX(90deg) translateZ(100px); }\n#box .bottom { -webkit-transform: rotateX(-90deg) translateZ(100px); }\n\nSee Example: Box 1.\n\n\n\n\n\n\n\nJust like the cube example, to expose a face, the #box needs to have a style to reverse that face\u2019s transform. Both the translateZ and rotate values are the opposites of the corresponding face.\n\n#box.show-front { -webkit-transform: translateZ(-50px) rotateY(0deg); }\n#box.show-back { -webkit-transform: translateZ(-50px) rotateX(-180deg); }\n#box.show-right { -webkit-transform: translateZ(-150px) rotateY(-90deg); }\n#box.show-left { -webkit-transform: translateZ(-150px) rotateY(90deg); }\n#box.show-top { -webkit-transform: translateZ(-100px) rotateX(-90deg); }\n#box.show-bottom { -webkit-transform: translateZ(-100px) rotateX(90deg); }\n\nSee Example: Box 2.\n\n\n\nRotating the rectangular box with a CSS transition\n\n\n\nCarousel\n\nFront-end developers have a myriad of choices when it comes to content carousels. Now that we have 3-D capabilities in our browsers, why not take a shot at creating an actual 3-D carousel?\n\nThe markup for this demo takes the same form as the box, cube and card. Let\u2019s make it interesting and have a carousel with nine panels.\n\n<div class=\"container\">\n  <div id=\"carousel\">\n    <figure>1</figure>\n    <figure>2</figure>\n    <figure>3</figure>\n    <figure>4</figure>\n    <figure>5</figure>\n    <figure>6</figure>\n    <figure>7</figure>\n    <figure>8</figure>\n    <figure>9</figure>\n  </div>\n</div>\n\nNow, apply basic layout styles. Let\u2019s give each panel of the #carousel 20 pixel gaps between one another, done here with left: 10px; and top: 10px;. The effective width of each panel is 210 pixels.\n\n.container {\n  width: 210px;\n  height: 140px;\n  position: relative;\n  -webkit-perspective: 1000;\n}\n#carousel {\n  width: 100%;\n  height: 100%;\n  position: absolute;\n  -webkit-transform-style: preserve-3d;\n}\n#carousel figure {\n  display: block;\n  position: absolute;\n  width: 186px;\n  height: 116px;\n  left: 10px;\n  top: 10px;\n  border: 2px solid black;\n}\n\nNext up: rotating the faces. This #carousel has nine panels. If each panel gets an equal distribution on the carousel, each panel would be rotated forty degrees from its neighbour (360\u2009\u00f7\u20099).\n\n#carousel figure:nth-child(1) { -webkit-transform: rotateY(0deg); }\n#carousel figure:nth-child(2) { -webkit-transform: rotateY(40deg); }\n#carousel figure:nth-child(3) { -webkit-transform: rotateY(80deg); }\n#carousel figure:nth-child(4) { -webkit-transform: rotateY(120deg); }\n#carousel figure:nth-child(5) { -webkit-transform: rotateY(160deg); }\n#carousel figure:nth-child(6) { -webkit-transform: rotateY(200deg); }\n#carousel figure:nth-child(7) { -webkit-transform: rotateY(240deg); }\n#carousel figure:nth-child(8) { -webkit-transform: rotateY(280deg); }\n#carousel figure:nth-child(9) { -webkit-transform: rotateY(320deg); }\n\nNow, the outward shift. Back when we were creating the cube and box, the translate value was simple to calculate, as it was equal to one half the width, height or depth of the object. With this carousel, there is no size we can automatically use as a reference. We\u2019ll have to calculate the distance of the shift by other means.\n\n\n\nDrawing a diagram of the carousel, we can see that we know only two things: the width of each panel is 210 pixels; and the each panel is rotated forty degrees from the next. If we split one of these segments down its centre, we get a right-angled triangle, perfect for some trigonometry.\n\nWe can determine the length of r in this diagram with a basic tangent equation:\n\n\n\nThere you have it: the panels need to be translated 288 pixels in 3-D space. \n\n#carousel figure:nth-child(1) { -webkit-transform: rotateY(0deg) translateZ(288px); }\n#carousel figure:nth-child(2) { -webkit-transform: rotateY(40deg) translateZ(288px); }\n#carousel figure:nth-child(3) { -webkit-transform: rotateY(80deg) translateZ(288px); }\n#carousel figure:nth-child(4) { -webkit-transform: rotateY(120deg) translateZ(288px); }\n#carousel figure:nth-child(5) { -webkit-transform: rotateY(160deg) translateZ(288px); }\n#carousel figure:nth-child(6) { -webkit-transform: rotateY(200deg) translateZ(288px); }\n#carousel figure:nth-child(7) { -webkit-transform: rotateY(240deg) translateZ(288px); }\n#carousel figure:nth-child(8) { -webkit-transform: rotateY(280deg) translateZ(288px); }\n#carousel figure:nth-child(9) { -webkit-transform: rotateY(320deg) translateZ(288px); }\n\nIf we decide to change the width of the panel or the number of panels, we only need to plug in those two variables into our equation to get the appropriate translateZ value. In JavaScript terms, that equation would be:\n\nvar tz = Math.round( ( panelSize / 2 ) / \n  Math.tan( ( ( Math.PI * 2 ) / numberOfPanels ) / 2 ) );\n// or simplified to\nvar tz = Math.round( ( panelSize / 2 ) / \n  Math.tan( Math.PI / numberOfPanels ) );\n\nJust like our previous 3-D objects, to show any one panel we need only apply the reverse transform on the carousel. Here\u2019s the style to show the fifth panel:\n\n-webkit-transform: translateZ(-288px) rotateY(-160deg);\n\nSee Example: Carousel 1.\n\n\n\n\n\n\n\nBy now, you probably have two thoughts: \n\n\n\tRewriting transform styles for each panel looks tedious.\n\tWhy bother doing high school maths? Aren\u2019t robots supposed to be doing all this work for us?\n\n\nAnd you\u2019re absolutely right. The repetitive nature of 3-D objects lends itself to scripting. We can offload all the monotonous transform styles to our dynamic script, which, if done correctly, will be more flexible than the hard-coded version.\n\nSee Example: Carousel 2.\n\nConclusion\n\n3-D transforms change the way we think about the blank canvas of web design. Better yet, they change the canvas itself, trading in the flat surface for voluminous depth.\n\nMy hope is that you took at least one peak at a demo and were intrigued. We web designers, who have rejoiced for border-radius, box-shadow and background gradients, now have an incredible tool at our disposal in 3-D transforms. They deserve just the same enthusiasm, research and experimentation we have seen on other CSS3 features. Now is the perfect time to take the plunge and start thinking about how to use three dimensions to elevate our craft. I\u2019m breathless waiting for what\u2019s to come. \n\nSee you on the flip side.", "year": "2010", "author": "David DeSandro", "author_slug": "daviddesandro", "published": "2010-12-14T00:00:00+00:00", "url": "https://24ways.org/2010/intro-to-css-3d-transforms/", "topic": "code"}
{"rowid": 233, "title": "Wrapping Things Nicely with HTML5 Local Storage", "contents": "HTML5 is here to turn the web from a web of hacks into a web of applications \u2013 and we are well on the way to this goal. The coming year will be totally and utterly awesome if you are excited about web technologies.\n\nThis year the HTML5 revolution started and there is no stopping it. For the first time all the browser vendors are rallying together to make a technology work. The new browser war is fought over implementation of the HTML5 standard and not over random additions. We live in exciting times.\n\nStarting with a bang\n\nAs with every revolution there is a lot of noise with bangs and explosions, and that\u2019s the stage we\u2019re at right now. HTML5 showcases are often CSS3 showcases, web font playgrounds, or video and canvas examples.\n\nThis is great, as it gets people excited and it gives the media something to show. There is much more to HTML5, though. Let\u2019s take a look at one of the less sexy, but amazingly useful features of HTML5 (it was in the HTML5 specs, but grew at such an alarming rate that it warranted its own spec): storing information on the client-side.\n\nWhy store data on the client-side?\n\nStoring information in people\u2019s browsers affords us a few options that every application should have:\n\n\n\tYou can retain the state of an application \u2013 when the user comes back after closing the browser, everything will be as she left it. That\u2019s how \u2018real\u2019 applications work and this is how the web ones should, too.\n\tYou can cache data \u2013 if something doesn\u2019t change then there is no point in loading it over the Internet if local access is so much faster\n\tYou can store user preferences \u2013 without needing to keep that data on your server at all.\n\n\nIn the past, storing local data wasn\u2019t much fun.\n\nThe pain of hacky browser solutions\n\nIn the past, all we had were cookies. I don\u2019t mean the yummy things you get with your coffee, endorsed by the blue, furry junkie in Sesame Street, but the other, digital ones. Cookies suck \u2013 it isn\u2019t fun to have an unencrypted HTTP overhead on every server request for storing four kilobytes of data in a cryptic format. It was OK for 1994, but really neither an easy nor a beautiful solution for the task of storing data on the client.\n\nThen came a plethora of solutions by different vendors \u2013 from Microsoft\u2019s userdata to Flash\u2019s LSO, and from Silverlight isolated storage to Google\u2019s Gears. If you want to know just how many crazy and convoluted ways there are to store a bit of information, check out Samy\u2019s evercookie.\n\nClearly, we needed an easier and standardised way of storing local data.\n\nKeeping it simple \u2013 local storage\n\nAnd, lo and behold, we have one. The local storage API (or session storage, with the only difference being that session data is lost when the window is closed) is ridiculously easy to use. All you do is call a few methods on the window.localStorage object \u2013 or even just set the properties directly using the square bracket notation:\n\nif('localStorage' in window && window['localStorage'] !== null){\n\tvar store = window.localStorage;\n\n\t// valid, API way\n\t\tstore.setItem(\u2018cow\u2019,\u2018moo\u2019);\n\t\tconsole.log(\n\t\tstore.getItem(\u2018cow\u2019)\n\t); // => \u2018moo\u2019\n\n\t// shorthand, breaks at keys with spaces\n\t\tstore.sheep = \u2018baa\u2019 \n\t\tconsole.log(\n\t\tstore.sheep \n\t); // \u2018baa\u2019\n\n\t// shorthand for all\n\t\tstore[\u2018dog\u2019] = \u2018bark\u2019\n\t\tconsole.log(\n\t\tstore[\u2018dog\u2019]\n\t); // => \u2018bark\u2019\n\n}\n\nBrowser support is actually pretty good: Chrome 4+; Firefox 3.5+; IE8+; Opera 10.5+; Safari 4+; plus iPhone 2.0+; and Android 2.0+. That should cover most of your needs. Of course, you should check for support first (or use a wrapper library like YUI Storage Utility or YUI Storage Lite).\n\nThe data is stored on a per domain basis and you can store up to five megabytes of data in localStorage for each domain.\n\nStrings attached\n\nBy default, localStorage only supports strings as storage formats. You can\u2019t store results of JavaScript computations that are arrays or objects, and every number is stored as a string. This means that long, floating point numbers eat into the available memory much more quickly than if they were stored as numbers.\n\nvar cowdesc = \"the cow is of the bovine ilk, \"+\n\t\t\"one end is for the moo, the \"+\n\t\t\"other for the milk\";\n\nvar cowdef = {\n\tilk\u201cbovine\u201d,\n\tlegs,\n\tudders,\n\tpurposes\n\t\tfront\u201cmoo\u201d,\n\t\tend\u201cmilk\u201d\n\t}\n};\n\nwindow.localStorage.setItem(\u2018describecow\u2019,cowdesc);\nconsole.log(\n\twindow.localStorage.getItem(\u2018describecow\u2019)\n); // => the cow is of the bovine\u2026 \n\nwindow.localStorage.setItem(\u2018definecow\u2019,cowdef);\nconsole.log(\n\twindow.localStorage.getItem(\u2018definecow\u2019)\n); // => [object Object] = bad!\n\nThis limits what you can store quite heavily, which is why it makes sense to use JSON to encode and decode the data you store:\n\nvar cowdef = {\n\t\"ilk\":\"bovine\",\n\t\"legs\":4,\n\t\"udders\":4,\n\t\"purposes\":{\n\t\"front\":\"moo\",\n\t\"end\":\"milk\"\n\t}\n};\n\nwindow.localStorage.setItem(\u2018describecow\u2019,JSON.stringify(cowdef));\nconsole.log(\n\tJSON.parse(\n\t\twindow.localStorage.getItem(\u2018describecow\u2019)\n\t)\n); // =>  Object { ilk=\u201cbovine\u201d,  more\u2026}\n\nYou can also come up with your own formatting solutions like CSV, or pipe | or tilde ~ separated formats, but JSON is very terse and has native browser support.\n\nSome use case examples\n\nThe simplest use of localStorage is, of course, storing some data: the current state of a game; how far through a multi-form sign-up process a user is; and other things we traditionally stored in cookies. Using JSON, though, we can do cooler things.\n\nSpeeding up web service use and avoiding exceeding the quota\n\nA lot of web services only allow you a certain amount of hits per hour or day, and can be very slow. By using localStorage with a time stamp, you can cache results of web services locally and only access them after a certain time to refresh the data.\n\nI used this technique in my An Event Apart 10K entry, World Info, to only load the massive dataset of all the world information once, and allow for much faster subsequent visits to the site. The following screencast shows the difference:\n\n\n\nFor use with YQL (remember last year\u2019s 24 ways entry?), I\u2019ve built a small script called YQL localcache that wraps localStorage around the YQL data call. An example would be the following:\n\nyqlcache.get({\n\tyql: 'select * from flickr.photos.search where text=\"santa\"',\n\tid: 'myphotos',\n\tcacheage: ( 60*60*1000 ),\n\tcallback: function(data) {\n\t\tconsole.log(data);\n\t}\n});\n\nThis loads photos of Santa from Flickr and stores them for an hour in the key myphotos of localStorage. If you call the function at various times, you receive an object back with the YQL results in a data property and a type property which defines where the data came from \u2013 live is live data, cached means it comes from cache, and freshcache indicates that it was called for the first time and a new cache was primed. The cache will work for an hour (60\u00d760\u00d71,000 milliseconds) and then be refreshed. So, instead of hitting the YQL endpoint over and over again, you hit it once per hour.\n\nCaching a full interface\n\nAnother use case I found was to retain the state of a whole interface of an application by caching the innerHTML once it has been rendered. I use this in the Yahoo Firehose search interface, and you can get the full story about local storage and how it is used in this screencast:\n\n\n\nThe stripped down code is incredibly simple (JavaScript with PHP embed):\n\n// test for localStorage support\nif(('localStorage' in window) && window['localStorage'] !== null){\n\nvar f = document.getElementById(\u2018mainform\u2019);\n// test with PHP if the form was sent (the submit button has the name \u201csent\u201d)\n\n\n\t// get the HTML of the form and cache it in the property \u201cstate\u201d\n\tlocalStorage.setItem(\u2018state\u2019,f.innerHTML);\n\n// if the form hasn\u2019t been sent\u2026\n\n\n\t// check if a state property exists and write back the HTML cache\n\tif(\u2018state\u2019 in localStorage){\n\t\tf.innerHTML = localStorage.getItem(\u2018state\u2019);  \n\t}\n\n\t\n\n}\n\nOther ideas\n\nIn essence, you can use local storage every time you need to speed up access. For example, you could store image sprites in base-64 encoded datasets instead of loading them from a server. Or you could store CSS and JavaScript libraries on the client. Anything goes \u2013 have a play.\n\nIssues with local and session storage\n\nOf course, not all is rainbows and unicorns with the localStorage API. There are a few niggles that need ironing out. As with anything, this needs people to use the technology and raise issues. Here are some of the problems:\n\n\n\tInadequate information about storage quota \u2013 if you try to add more content to an already full store, you get a QUOTA_EXCEEDED_ERR and that\u2019s it. There\u2019s a great explanation and test suite for localStorage quota available.\n\tLack of automatically expiring storage \u2013 a feature that cookies came with. Pamela Fox has a solution (also available as a demo and source code)\n\tLack of encrypted storage \u2013 right now, everything is stored in readable strings in the browser.\n\n\nBigger, better, faster, more!\n\nAs cool as the local and session storage APIs are, they are not quite ready for extensive adoption \u2013 the storage limits might get in your way, and if you really want to go to town with accessing, filtering and sorting data, real databases are what you\u2019ll need. And, as we live in a world of client-side development, people are moving from heavy server-side databases like MySQL to NoSQL environments.\n\nOn the web, there is also a lot of work going on, with Ian Hickson of Google proposing the Web SQL database, and Nikunj Mehta, Jonas Sicking (Mozilla), Eliot Graff (Microsoft) and Andrei Popescu (Google) taking the idea beyond simply replicating MySQL and instead offering Indexed DB as an even faster alternative.\n\nOn the mobile front, a really important feature is to be able to store data to use when you are offline (mobile coverage and roaming data plans anybody?) and you can use the Offline Webapps API for that.\n\nAs I mentioned at the beginning, we have a very exciting time ahead \u2013 let\u2019s make this web work faster and more reliably by using what browsers offer us. For more on local storage, check out the chapter on Dive into HTML5.", "year": "2010", "author": "Christian Heilmann", "author_slug": "chrisheilmann", "published": "2010-12-06T00:00:00+00:00", "url": "https://24ways.org/2010/html5-local-storage/", "topic": "code"}
{"rowid": 231, "title": "Designing for iOS: Life Beyond Media Queries", "contents": "Although not a new phenomenon, media queries seem to be getting a lot attention online recently and for the right reasons too \u2013 it\u2019s great to be able to adapt a design with just a few lines of CSS \u2013 but many people are relying only on them to create an iPhone-specific version of their website. \n\nI was pleased to hear at FOWD NYC a few weeks ago that both myself and Aral Balkan share the same views on why media queries aren\u2019t always going to be the best solution for mobile. Both of us specialise in iPhone design ourselves and we opt for a different approach to media queries. The trouble is, regardless of what you have carefully selected to be display:none; in your CSS, the iPhone still loads everything in the background; all that large imagery for your full scale website also takes up valuable mobile bandwidth and time.\n\nYou can greatly increase the speed of your website by creating a specific site tailored to mobile users with just a few handy pointers \u2013 media queries, in some instances, might be perfectly suitable but, in others, here\u2019s what you can do.\n\nRedirect your iPhone/iPod Touch users\n\nTo detect whether someone is viewing your site on an iPhone or iPod Touch, you can either use JavaScript or PHP. \n\nThe JavaScript \n\nif((navigator.userAgent.match(/iPhone/i)) || (navigator.userAgent.match(/iPod/i))) { \n    if (document.cookie.indexOf(\"iphone_redirect=false\") == -1) window.location = \"http://mobile.yoursitehere.com\"; \n}\n\nThe PHP\n\nif(strstr($_SERVER['HTTP_USER_AGENT'],'iPhone') || strstr($_SERVER['HTTP_USER_AGENT'],'iPod')) \n{\n    header('Location: http://mobile.yoursitehere.com');\n    exit();\n}\n\nBoth of these methods redirect the user to a site that you have made specifically for the iPhone. At this point, be sure to provide a link to the full version of the website, in case the user wishes to view this and not be thrown into an experience they didn\u2019t want, with no way back.\n\nTailoring your site\n\nSo, now you\u2019ve got 320\u2009\u00d7\u2009480 pixels of screen to play with \u2013 and to create a style sheet for, just as you would for any other site you build. There are a few other bits and pieces that you can add to your code to create a site that feels more like a fully immersive iPhone app rather than a website.\n\nRetina display\n\nWhen building your website specifically tailored to the iPhone, you might like to go one step further and create a specific style sheet for iPhone 4\u2019s Retina display. Because there are four times as many pixels on the iPhone 4 (640\u2009\u00d7\u2009960 pixels), you\u2019ll find specifics such as text shadows and borders will have to be increased. \n\n<link rel=\"stylesheet\" \n   media=\"only screen and (-webkit-min-device-pixel-ratio: 2)\" \n   type=\"text/css\" href=\"../iphone4.css\" />\n\n(Credit to Thomas Maier)\n\nPrevent user scaling\n\nThis declaration, added into the <head>, stops the user being able to pinch-zoom in and out of your design, which is perfect if you are designing to the exact pixel measurements of the iPhone screen. \n\n<meta name=\"viewport\" \n   content=\"width=device-width; initial-scale=1.0; maximum-scale=1.0;\">\n\nDesigning for orientation \n\nAs iPhones aren\u2019t static devices, you\u2019ll also need to provide a style sheet for horizontal orientation. We can do this by inserting some JavaScript into the <head> as follows: \n\n<script type=\"text/javascript\">\nfunction orient() {\n    switch(window.orientation) {\n        case 0: \n            document.getElementById(\"orient_css\").href = \"css/iphone_portrait.css\";\n            break;\n        case -90: \n            document.getElementById(\"orient_css\").href = \"css/iphone_landscape.css\";\n            break;\n        case 90: \n            document.getElementById(\"orient_css\").href = \"css/iphone_landscape.css\";\n            break;\n    }\n}\nwindow.onload = orient();\n</script>\n\nYou can also specify orientation styles using media queries. This is absolutely fine, as by this point you\u2019ll already be working with mobile-specific graphics and have little need to set a lot of things to display:none;\n\n<link rel=\"stylesheet\" \n   media=\"only screen and (max-device-width: 480px)\" href=\"/iphone.css\">\n<link rel=\"stylesheet\" \n   media=\"only screen and (orientation: portrait)\" href=\"/portrait.css\">\n<link rel=\"stylesheet\" \n   media=\"only screen and (orientation: landscape)\u201d href=\"/landscape.css\">\n\nRemove the address and status bars, top and bottom\n\nTo give you more room on-screen and to make your site feel more like an immersive web app, you can place the following declaration into the <head> of your document\u2019s code to remove the address and status bars at the top and bottom of the screen. \n\n<meta name=\"apple-mobile-web-app-capable\" content=\"yes\" />\n\nMaking the most of inbuilt functions\n\nSimilar to mailto: e-mail links, the iPhone also supports another two handy URI schemes which are great for enhancing contact details. When tapped, the following links will automatically bring up the appropriate call or text interface:\n\n<a href=\"tel:01234567890\">Call us</a>\n<a href=\"sms:01234567890\">Text us</a>\n\niPhone-specific Web Clip icon\n\nAlthough I believe them to be fundamentally flawed, since they rely on the user bookmarking your site, iPhone Web Clip icons are still a nice touch. You need just two declarations, again in the <head> of your document:\n\n<link rel=\"apple-touch-icon\" href=\"icons/regular_icon.png\" />\n<link rel=\"apple-touch-icon\" sizes=\"114x114\" href=\"icons/retina_icon.png\" />\n\nFor iPhone 4 you\u2019ll need to create a 114\u2009\u00d7\u2009114 pixels icon; for a non-Retina display, a 57\u2009\u00d7\u200957 pixels icon will do the trick.\n\nPrecomposed \n\nApple adds its standard gloss \u2018moon\u2019 over the top of any icon. If you feel this might be too much for your particular icon and would prefer a matte finish, you can add precomposed to the end of the apple-touch-icon declaration to remove the standard gloss. \n\n<link rel=\"apple-touch-icon-precomposed\" href=\"/images/touch-icon.png\" />\n\nWrapping up\n\nMedia queries definitely have their uses. They make it easy to build a custom experience for your visitor, regardless of their browser\u2019s size. For more complex sites, however, or where you have lots of imagery and other content that isn\u2019t necessary on the mobile version, you can now use these other methods to help you out. Remember, they are purely for presentation and not optimisation; for busy people on the go, optimisation and faster-running mobile experiences can only be a good thing. \n\nHave a wonderful Christmas fellow Webbies!", "year": "2010", "author": "Sarah Parmenter", "author_slug": "sarahparmenter", "published": "2010-12-17T00:00:00+00:00", "url": "https://24ways.org/2010/life-beyond-media-queries/", "topic": "code"}
{"rowid": 223, "title": "Calculating Color Contrast", "contents": "Some websites and services allow you to customize your profile by uploading pictures, changing the background color or other aspects of the design. As a customer, this personalization turns a web app into your little nest where you store your data. As a designer, letting your customers have free rein over the layout and design is a scary prospect. So what happens to all the stock text and images that are designed to work on nice white backgrounds? Even the Mac only lets you choose between two colors for the OS, blue or graphite! Opening up the ability to customize your site\u2019s color scheme can be a recipe for disaster unless you are flexible and understand how to find maximum color contrasts.\n\nIn this article I will walk you through two simple equations to determine if you should be using white or black text depending on the color of the background. The equations are both easy to implement and produce similar results. It isn\u2019t a matter of which is better, but more the fact that you are using one at all! That way, even with the craziest of Geocities color schemes that your customers choose, at least your text will still be readable.\n\nLet\u2019s have a look at a range of various possible colors. Maybe these are pre-made color schemes, corporate colors, or plucked from an image.\n\n\n\nNow that we have these potential background colors and their hex values, we need to find out whether the corresponding text should be in white or black, based on which has a higher contrast, therefore affording the best readability. This can be done at runtime with JavaScript or in the back-end before the HTML is served up.\n\nThere are two functions I want to compare. The first, I call \u201950%\u2019. It takes the hex value and compares it to the value halfway between pure black and pure white. If the hex value is less than half, meaning it is on the darker side of the spectrum, it returns white as the text color. If the result is greater than half, it\u2019s on the lighter side of the spectrum and returns black as the text value.\n\nIn PHP:\n\nfunction getContrast50($hexcolor){\n    return (hexdec($hexcolor) > 0xffffff/2) ? 'black':'white';\n}\n\nIn JavaScript:\n\nfunction getContrast50(hexcolor){\n    return (parseInt(hexcolor, 16) > 0xffffff/2) ? 'black':'white';\n}\n\nIt doesn\u2019t get much simpler than that! The function converts the six-character hex color into an integer and compares that to one half the integer value of pure white. The function is easy to remember, but is naive when it comes to understanding how we perceive parts of the spectrum. Different wavelengths have greater or lesser impact on the contrast.\n\nThe second equation is called \u2018YIQ\u2019 because it converts the RGB color space into YIQ, which takes into account the different impacts of its constituent parts. Again, the equation returns white or black and it\u2019s also very easy to implement.\n\nIn PHP:\n\nfunction getContrastYIQ($hexcolor){\n\t$r = hexdec(substr($hexcolor,0,2));\n\t$g = hexdec(substr($hexcolor,2,2));\n\t$b = hexdec(substr($hexcolor,4,2));\n\t$yiq = (($r*299)+($g*587)+($b*114))/1000;\n\treturn ($yiq >= 128) ? 'black' : 'white';\n}\n\nIn JavaScript:\n\nfunction getContrastYIQ(hexcolor){\n\tvar r = parseInt(hexcolor.substr(0,2),16);\n\tvar g = parseInt(hexcolor.substr(2,2),16);\n\tvar b = parseInt(hexcolor.substr(4,2),16);\n\tvar yiq = ((r*299)+(g*587)+(b*114))/1000;\n\treturn (yiq >= 128) ? 'black' : 'white';\n}\n\nYou\u2019ll notice first that we have broken down the hex value into separate RGB values. This is important because each of these channels is scaled in accordance to its visual impact. Once everything is scaled and normalized, it will be in a range between zero and 255. Much like the previous \u201950%\u2019 function, we now need to check if the input is above or below halfway. Depending on where that value is, we\u2019ll return the corresponding highest contrasting color.\n\nThat\u2019s it: two simple contrast equations which work really well to determine the best readability.\n\nIf you are interested in learning more, the W3C has a few documents about color contrast and how to determine if there is enough contrast between any two colors. This is important for accessibility to make sure there is enough contrast between your text and link colors and the background.\n\nThere is also a great article by Kevin Hale on Particletree about his experience with choosing light or dark themes. To round it out, Jonathan Snook created a color contrast picker which allows you to play with RGB sliders to get values for YIQ, contrast and others. That way you can quickly fiddle with the knobs to find the right balance.\n\nComparing results\n\nLet\u2019s revisit our color schemes and see which text color is recommended for maximum contrast based on these two equations.\n\n\n\nIf we use the simple \u201950%\u2019 contrast function, we can see that it recommends black against all the colors except the dark green and purple on the second row. In general, the equation feels the colors are light and that black is a better choice for the text.\n\n\n\nThe more complex \u2018YIQ\u2019 function, with its weighted colors, has slightly different suggestions. White text is still recommended for the very dark colors, but there are some surprises. The red and pink values show white text rather than black. This equation takes into account the weight of the red value and determines that the hue is dark enough for white text to show the most contrast.\n\nAs you can see, the two contrast algorithms agree most of the time. There are some instances where they conflict, but overall you can use the equation that you prefer. I don\u2019t think it is a major issue if some edge-case colors get one contrast over another, they are still very readable.\n\nNow let\u2019s look at some common colors and then see how the two functions compare. You can quickly see that they do pretty well across the whole spectrum.\n\n\n\nIn the first few shades of grey, the white and black contrasts make sense, but as we test other colors in the spectrum, we do get some unexpected deviation. Pure red #FF0000 has a flip-flop. This is due to how the \u2018YIQ\u2019 function weights the RGB parts. While you might have a personal preference for one style over another, both are justifiable.\n\n\n\nIn this second round of colors, we go deeper into the spectrum, off the beaten track. Again, most of the time the contrasting algorithms are in sync, but every once in a while they disagree. You can select which you prefer, neither of which is unreadable.\n\nConclusion\n\nContrast in color is important, especially if you cede all control and take a hands-off approach to the design. It is important to select smart defaults by making the contrast between colors as high as possible. This makes it easier for your customers to read, increases accessibility and is generally just easier on the eyes. \n\nSure, there are plenty of other equations out there to determine contrast; what is most important is that you pick one and implement it into your system.\n\nSo, go ahead and experiment with color in your design. You now know how easy it is to guarantee that your text will be the most readable in any circumstance.", "year": "2010", "author": "Brian Suda", "author_slug": "briansuda", "published": "2010-12-24T00:00:00+00:00", "url": "https://24ways.org/2010/calculating-color-contrast/", "topic": "code"}
{"rowid": 221, "title": "\u201cProbably, Maybe, No\u201d: The State of HTML5 Audio", "contents": "With the hype around HTML5 and CSS3 exceeding levels not seen since 2005\u2019s Ajax era, it\u2019s worth noting that the excitement comes with good reason: the two specifications render many years of feature hacks redundant by replacing them with native features. For fun, consider how many CSS2-based rounded corners hacks you\u2019ve probably glossed over, looking for a magic solution. These days, with CSS3, the magic is border-radius (and perhaps some vendor prefixes) followed by a coffee break.\n\nCSS3\u2019s border-radius, box-shadow, text-shadow and gradients, and HTML5\u2019s <canvas>, <audio> and <video> are some of the most anticipated features we\u2019ll see put to creative (ab)use as adoption of the \u2018new shiny\u2019 grows. Developers jumping on the cutting edge are using subsets of these features to little detriment, in most cases. The more popular CSS features are design flourishes that can degrade nicely, but the current audio and video implementations in particular suffer from a number of annoyances.\n\nThe new shiny: how we got here\n\nSound involves one of the five senses, a key part of daily life for most \u2013 and yet it has been strangely absent from HTML and much of the web by default. From a simplistic perspective, it seems odd that HTML did not include support for the full multimedia experience earlier, despite the CD-ROM-based craze of the early 1990s. In truth, standards like HTML can take much longer to bake, but eventually deliver the promise of a lowered barrier to entry, consistent implementations and shiny new features now possible \u2018for free\u2019 just about everywhere.\n\n<img> was introduced early and naturally to HTML, despite having some opponents at the time. Perhaps <audio> and <video> were avoided, given the added technical complexity of decoding various multi-frame formats, plus the hardware and bandwidth limitations of the era. Perhaps there were quarrels about choosing a standard format or \u2013 more simply \u2013 maybe these elements just weren\u2019t considered to be applicable to the HTML-based web at the time. In any event, browser plugins from programs like RealPlayer and QuickTime eventually helped to fill the in-page audio/video gap, handling <object> and <embed> markup which pointed to .wav, .avi, .rm or .mov files. Suffice it to say, the experience was inconsistent at best and, on the standards side of the fence right now, so is HTML5 in terms of audio and video.\n\n: the theory\n\nAs far as HTML goes, the code for <audio> is simple and logical. Just as with <img>, a src attribute specifies the file to load. Pretty straightforward \u2013 sounds easy, right?\n\n<audio src=\"mysong.ogg\" controls>\n\t<!-- alternate content for unsupported case -->\n\tDownload <a href=\"mysong.ogg\">mysong.ogg</a>;\n</audio>\n\nAh, if only it were that simple. The first problem is that the OGG audio format, while \u2018free\u2019, is not supported by some browsers. Conversely, nor is MP3, despite being a de facto standard used in all kinds of desktop software (and hardware). In fact, as of November 2010, no single audio format is commonly supported across all major HTML5-enabled browsers.\n\nWhat you end up writing, then, is something like this:\n\n<audio controls>\n\t<source src=\"mysong.mp3\" />\n\t<source src=\"mysong.ogg\" />\n\t<!-- alternate content for unsupported case, maybe Flash, etc. -->\n\tDownload <a href=\"mysong.ogg\">mysong.ogg</a> or <a href=\"mysong.mp3\">mysong.mp3</a>\n</audio>\n\nKeep in mind, this is only a \u2018first class\u2019 experience for the HTML5 case; also, for non-supported browsers, you may want to look at another inline player (object/embed, or a JavaScript plus Flash API) to have inline audio. You can imagine the added code complexity in the case of supporting \u2018first class\u2019 experiences for older browsers, too.\n\n: the caveats\n\nWith <img>, you typically don\u2019t have to worry about format support \u2013 it just works \u2013 and that\u2019s part of what makes a standard wonderful. JPEG, PNG, BMP, GIF, even TIFF images all render just fine if for no better reason, perhaps, than being implemented during the \u2018wild west\u2019 days of the web. The situation with <audio> today reflects a very different \u2013 read: business-aware \u2013 environment in 2010. (Further subtext: There\u2019s a lot of [potential] money involved.) Regrettably, this is a collision of free and commercial interests, where the casualty is ultimately the user. Second up in the casualty list is you, the developer, who has to write additional code around this fragmented support.\n\nThe HTML5 audio API as implemented in JavaScript has one of the most un-computer-like responses I\u2019ve ever seen, and inspired the title of this post. Calling new Audio().canPlayType('audio/mp3'), which queries the system for format support according to a MIME type, is supposed to return one of \u201cprobably\u201d, \u201cmaybe\u201d, or \u201cno\u201d. Sometimes, you\u2019ll just get a null or empty string, which is also fun. A \u201cmaybe\u201d response does not guarantee that a format will be supported; sometimes audio/mp3 gives \u201cmaybe,\u201d but then audio/mpeg; codecs=\"mp3\" will give a more-solid \u201cprobably\u201d response. This can vary by browser or platform, too, depending on native support \u2013 and finally, the user may also be able to install codecs, extending support to include other formats. (Are you excited yet?)\n\nDamn you, warring formats!\n\nNew market and business opportunities go hand-in-hand with technology developments. What we have here is certainly not failure to communicate; rather, we have competing parties shouting loudly in public in attempts to influence mindshare towards a de facto standard for audio and video. Unfortunately, the current situation means that at least two formats are effectively required to serve the majority of users correctly.\n\nAs it currently stands, we have the free and open source software camp of OGG Vorbis/WebM and its proponents (notably, Mozilla, Google and Opera in terms of browser makers), up against the non-free, proprietary and \u2018closed\u2019 camp of MP3 and MPEG4/HE-AAC/H.264 \u2013 which is where you\u2019ll find commitments from Apple and Microsoft, among others. Apple is likely in with H.264 for the long haul, given its use of the format for its iTunes music store and video offerings.\n\nIt is generally held that H.264 is a technically superior format in terms of file size versus quality, but it involves intellectual property and, in many use cases, requires licensing fees. To be fair, there is a business model with H.264 and much has been invested in its development, but this approach is not often the kind that wins over the web. On that front, OGG/WebM may eventually win for being a \u2018free\u2019 format that does not involve a licensing scheme.\n\nClosed software and tools ideologically clash with the open nature of the web, which exists largely thanks to free and open technology. Because of philosophical and business reasons, support for audio and video is fragmented across browsers adopting HTML5 features. It does not help that a large amount of audio and video currently exists in non-free MP3 and MPEG-4 formats. Adoption of <audio> and <video> may be slowed, since it is more complex than <img> and may feel \u2018broken\u2019 to developers when edge cases are encountered. Furthermore, the HTML5 spec does not mandate a single required format. The end result is that, as a developer, you must currently provide at least both MP3 and OGG, for example, to serve most existing HTML5-based user agents.\n\nTransitioning to \n\n\n\nThere will be some growing pains as developers start to pick up the new HTML5 shiny, while balancing the needs of current and older agents that don\u2019t support either <audio> or the preferred format you may choose (for example, MP3). In either event, Flash or other plugins can be used as done traditionally within HTML4 documents to embed and play the relevant audio.\n\n\n\nThe SoundManager 2 page player demo in action.\n\n\n\nIdeally, HTML5 audio should be used whenever possible with Flash as the backup option. A few JavaScript/Flash-based audio player projects exist which balance the two; in attempting to tackle this problem, I develop and maintain SoundManager 2, a JavaScript sound API which transparently uses HTML5 Audio() and, if needed, Flash for playing audio files. The internals can get somewhat ugly, but the transition between HTML4 and HTML5 is going to be just that \u2013 and even with HTML5, you will need some form of format fall-back in addition to graceful degradation.\n\nIt may be safest to fall back to MP3/MP4 formats for inline playback at this time, given wide support via Flash, some HTML5-based browsers and mobile devices. Considering the amount of MP3/MP4 media currently available, it is wiser to try these before falling through to a traditional file download process.\n\nEarly findings\n\nHere is a brief list of behavioural notes, annoyances, bugs, quirks and general weirdness I have found while playing with HTML5-based audio at time of writing (November 2010):\n\nApple iPad/iPhone (iOS 4, iPad 3.2+)\n\n\n\tOnly one sound can be played at a time. If a second sound starts, the first is stopped.\n\tNo auto-play allowed. Sounds follow the pop-up window security model and can only be started from within a user event handler such as onclick/touch, and so on. Otherwise, playback attempts silently fail.\n\tOnce started, a sequence of sounds can be created or played via the \u2018finish\u2019 event of the previous sound (for example, advancing through a playlist without interaction after first track starts).\n\tiPad, iOS 3.2: Occasional \u2018infinite loop\u2019 bug seen where audio does not complete and stop at a sound\u2019s logical end \u2013 instead, it plays again from the beginning. Might be specific to example file format (HE-AAC) encoded from iTunes.\n\n\nApple Safari, OS X Snow Leopard 10.6.5\n\n\n\tCritical bug: Safari 4 and 5 intermittently fail to load or play HTML5 audio on Snow Leopard due to bug(s) in QuickTime X and/or other underlying frameworks. Known Apple \u2018radar\u2019 bug: bugs.webkit.org #32159 (see also, test case.) Amusing side note: Safari on Windows is fine.\n\n\nApple Safari, Windows\n\n\n\tFood for thought: if you download \u201cSafari\u201d alone on Windows, you will not get HTML5 audio/video support (tested in WinXP). You need to download \u201cSafari + QuickTime\u201d to get HTML5 audio/video support within Safari. (As far as I\u2019m aware, Chrome, Firefox and Opera either include decoders or use system libraries accordingly. Presumably IE 9 will use OS-level APIs.)\n\n\nGeneral Quirks\n\n\n\tSeeking and loading, \u2018progress\u2019 events, and calculating bytes loaded versus bytes total should not be expected to be linear, as users can arbitrarily seek within a sound. It appears that some support for HTTP ranges exists, which adds a bit of logic to UI code. Browsers seem to vary slightly in their current implementations of these features.\n\tThe onload event of a sound may be of little relevance, if non-linear loading is involved (see above note re: seeking).\n\tInterestingly (perhaps I missed it), the current spec does not seem to specify a panning or left/right channel mix option.\n\tThe preload attribute values may vary slightly between browsers at this time.\n\n\nUpcoming shiny: HTML5 Audio Data API\n\n\n\n\n\tWith access to audio data, you can incorporate waveform and spectrum elements that make your designs react to music.\n\n\n\nThe HTML5 audio spec does a good job covering the basics of playback, but did not initially get into manipulation or generation of audio on-the-fly, something Flash has had for a number of years now. What if JavaScript could create, monitor and change audio dynamically, like a sort of audio <canvas> element? With that kind of capability, many dynamic audio processing features become feasible and, when combined with other media, can make for some impressive demos.\n\nWhat started as a small idea among a small group of audio and programming enthusiasts grew to inspire a W3C audio incubator group, and continued to establish the Mozilla Audio Data API. Contributors wrote a patch for Firefox which was reviewed and revised, and is now slated to be in the public release of Firefox 4. Some background and demos are also detailed in an article from the BBC R&D blog.\n\nThere are plenty of live demos to see, which give an impression of the new creative ideas this API enables. Many concepts are not new in themselves, but it is exciting to see this sort of thing happening within the native browser context.\n\nMozilla is not alone in this effort; the WebKit folks are also working on a JavaScriptAudioNode interface, which implements similar audio buffering and sample elements.\n\nThe future?\n\nIt is my hope that we\u2019ll see a common format emerge in terms of support across the major browsers for both audio and video; otherwise, support will continue to be fragmented and mildly frustrating to develop for, and that can impede growth of the feature. It\u2019s a big call, but if <img> had lacked a common format back in the wild west era, I doubt the web would have grown to where it is today.\n\nComplaints and nitpicks aside, HTML5 brings excellent progress on the browser multimedia front, and the first signs of native support are a welcome improvement given all audio and video previously relied on plugins. There is good reason to be excited. While there is room for more, support could certainly be much worse \u2013 and as tends to happen with specifications, the implementations targeting them should improve over time.\n\nNote: Thanks to Nate Koechley, who suggested the Audio().canPlayType() response be part of the article title.", "year": "2010", "author": "Scott Schiller", "author_slug": "scottschiller", "published": "2010-12-08T00:00:00+00:00", "url": "https://24ways.org/2010/the-state-of-html5-audio/", "topic": "code"}
{"rowid": 220, "title": "Finding Your Way with Static Maps", "contents": "Since the introduction of the Google Maps service in 2005, online maps have taken off in a way not really possible before the invention of slippy map interaction. Although quickly followed by a plethora of similar services from both commercial and non-commercial parties, Google\u2019s first-mover advantage, and easy-to-use developer API saw Google Maps become pretty much the de facto mapping service.\n\n\n\nIt\u2019s now so easy to add a map to a web page, there\u2019s no reason not to. Dropping an iframe map into your page is as simple as embedding a YouTube video.\n\nBut there\u2019s one crucial drawback to both the solution Google provides for you to drop into your page and the code developers typically implement themselves \u2013 they don\u2019t work without JavaScript.\n\nA bit about JavaScript\n\nBack in October of this year, The Yahoo! Developer Network blog ran some tests to measure how many visitors to the Yahoo! home page didn\u2019t have JavaScript available or enabled in their browser. It\u2019s an interesting test when you consider that the audience for the Yahoo! home page (one of the most visited pages on the web) represents about as mainstream a sample as you\u2019ll find. If there\u2019s any such thing as an \u2018average Web user\u2019 then this is them.\n\nThe results surprised me. It varied from region to region, but at most just two per cent of visitors didn\u2019t have JavaScript running. To be honest, I was expecting it to be higher, but this quote from the article caught my attention:\n\n\n\tWhile the percentage of visitors with JavaScript disabled seems like a low number, keep in mind that small percentages of big numbers are also big numbers.\n\n\nThat\u2019s right, of course, and it got me thinking about what that two per cent means. For many sites, two per cent is the number of visitors using the Opera web browser, using IE6, or using Mobile Safari. \n\nSo, although a small percentage of the total, users without JavaScript can\u2019t just be forgotten about, and catering for them is at the very heart of how the web is supposed to work.\n\nStarting with content in HTML, we layer on presentation with CSS and then enhance interactivity with JavaScript. If anything fails along the way or the network craps out, or a browser just doesn\u2019t support one of the technologies, the user still gets something they can work with. \n\nIt\u2019s progressive enhancement \u2013 also known as doing our jobs properly.\n\nSorry, wasn\u2019t this about maps?\n\nAs I was saying, the default code Google provides, and the example code it gives to developers (which typically just gets followed \u2018as is\u2019) doesn\u2019t account for users without JavaScript. No JavaScript, no content.\n\nWhen adding the ability to publish maps to our small content management system Perch, I didn\u2019t want to provide a solution that only worked with JavaScript. I had to go looking for a way to provide maps without JavaScript, too.\n\nThere\u2019s a simple solution, fortunately, in the form of static map tiles. All the various slippy map services use a JavaScript interface on top of what are basically rendered map image tiles. Dragging the map loads in more image tiles in the direction you want to view. If you\u2019ve used a slippy map on a slow connection, you\u2019ll be familiar with seeing these tiles load in one by one.\n\nThe Static Map API\n\nThe good news is that these tiles (or tiles just like them) can be used as regular images on your site. Google has a Static Map API which not only gives you a handy interface to retrieve a tile for the exact area you need, but also allows you to place pins, and zoom and centre the tile so that the image looks just so. \n\nThis means that you can create a static, non-JavaScript version of your slippy map\u2019s initial (or ideal) state to load into your page as a regular image, and then have the JavaScript map hijack the image and make it slippy.\n\nClearly, that\u2019s not going to be a perfect solution for every map\u2019s requirements. It doesn\u2019t allow for panning, zooming or interrogation without JavaScript. However, for the majority of straightforward map uses online, a static map makes a great alternative for those visitors without JavaScript.\n\n\n\nHere\u2019s the how\n\nRetrieving a static map tile is staggeringly easy \u2013 it\u2019s just a case of forming a URL with the correct arguments and then using that as the src of an image tag.\n\n<img src=\"http://maps.google.com/maps/api/staticmap\n\t?center=Bethlehem+Israel\n\t&zoom=5\n\t&size=540x280\n\t&maptype=satellite\n\t&markers=color:red|31.4211,35.1144\n\t&sensor=false\" \n\twidth=\"540\" height=\"280\" alt=\"Map of Bethlehem, Israel\" />\n\nAs you can see, there are a few key options that we pass along to the base URL. All of these should be familiar to anyone who\u2019s worked with the JavaScript API.\n\n\n\tcenter determines the point on which the map is centred. This can be latitude and longitude values, or simply an address which is then geocoded.\n\tzoom sets the zoom level.\n\tsize is the pixel dimensions of the image you require.\n\tmaptype can be roadmap, satellite, terrain or hybrid.\n\tmarkers sets one or more pin locations. Markers can be labelled, have different colours, and so on \u2013 there\u2019s quite a lot of control available.\n\tsensor states whether you are using a sensor to determine the user\u2019s location. When just embedding a map in a web page, set this to false.\n\n\nThere are many options, including plotting paths and setting the image format, which can all be found in the straightforward documentation.\n\nAdding to your page\n\nIf you\u2019ve worked with the JavaScript API, you\u2019ll know that it needs a container element which you inject the map into:\n\n<div id=\"map\"></div>\n\nAll you need to do is put your static image inside that container:\n\n<div id=\"map\">\n   <img src=\"http://maps.google.com/maps/api/staticmap[...]\" />\n </div>\n\nAnd then, in your JavaScript, find the image and remove it. For example, with jQuery you\u2019d simply use:\n\n$('#map img').remove();\n\nWhy not use a <noscript> element around the image? You could, and that would certainly work fine for browsers that do not support JavaScript. What that won\u2019t cover, however, is the situation where the browser has JavaScript support but, for whatever reason, the JavaScript doesn\u2019t run. This could be due to network issues, an aggressive corporate firewall, or even just a bug in your code. So for that reason, we put the image in for all browsers that show images, and then remove it when the JavaScript is  successfully running.\n\nSee an example in action\n\nAbout rate limits\n\nThe Google Static Map API limits the requests per site viewer \u2013 currently at one thousand distinct maps per day per viewer. So, for most sites you really don\u2019t need to worry about the rate limit. Requests for the same tile aren\u2019t normally counted, as the tile has already been generated and is cached. You can embed the images direct from Google and let it worry about the distribution and caching.\n\nIn conclusion\n\nAs you can see, adding a static map alongside your dynamic map for those users without JavaScript is very easy indeed. There may not be a huge percentage of web visitors browsing without JavaScript but, as we\u2019ve seen, a small percentage of a big number is still a big number. When it\u2019s so easy to add a static map, can you really justify not doing it?", "year": "2010", "author": "Drew McLellan", "author_slug": "drewmclellan", "published": "2010-12-01T00:00:00+00:00", "url": "https://24ways.org/2010/finding-your-way-with-static-maps/", "topic": "code"}
{"rowid": 216, "title": "Styling Components - Typed CSS With Stylable", "contents": "There\u2019s been a lot of debate recently about how best to style components for web apps so that styles don\u2019t accidentally \u2018leak\u2019 out of the component they\u2019re meant for, or clash with other styles on the page.\nElaborate CSS conventions have sprung up, such as OOCSS, SMACSS, BEM, ITCSS, and ECSS. These work well, but they are methodologies, and require everyone in the team to know them and follow them, which can be a difficult undertaking across large or distributed teams.\nOthers just give up on CSS and put all their styles in JavaScript. Now, I\u2019m not bashing JS, especially so close to its 22nd birthday, but CSS-in-JS has problems of its own. Browsers have 20 years experience in optimising their CSS engines, so JavaScript won\u2019t be as fast as using real CSS, and in any case, this requires waiting for JS to download, parse, execute then render the styles.\nThere\u2019s another problem with CSS-in-JS, too. Since Responsive Web Design hit the streets, most designers no longer make comps in Photoshop or its equivalents; instead, they write CSS. Why hire an expensive design professional and require them to learn a new way of doing their job? \nA recent thread on Twitter asked \u201cWhat\u2019s your biggest gripe with CSS-in-JS?\u201d, and the replies were illuminating: \u201cAlways having to remember to camelCase properties then spending 10min pulling hair out when you do forget\u201d, \u201cthe cryptic domain-specific languages that each of the frameworks do just ever so slightly differently\u201d, \u201cWhen I test look and feel in browser, then I copy paste from inspector, only to have to re-write it as a JSON object\u201d, \u201cLack of linting, autocomplete, and css plug-ins for colors/ incrementing/ etc\u201d. \nIf you\u2019re a developer, and you\u2019re still unconvinced, I challenge you to let designers change the font in your IDE to Zapf Chancery and choose a new colour scheme, simply because they like it better. Does that sound like fun? Will that boost your productivity? Thought not.\nSome chums at Wix Engineering and I wanted to see if we could square this circle. Wix-hosted sites have always used CSS-in-JS (the concept isn\u2019t new; it was in Netscape 4!) but that was causing performance problems. Could we somehow devise a method of extending CSS (like SASS and LESS do) that gives us styles that are guaranteed not to leak or clash, that is compatible with code editors\u2019 autocompletion, and which could be pre-processed at build time to valid, cross-browser, static CSS?\nAfter a few months and a few proofs of concept later (drumroll), yes \u2013 we could! We call it Stylable.\nIntroducing Stylable\nStylable is a CSS pre-processor, like SASS or LESS. It uses CSS syntax so all your development tools will work. At build time, the Stylable CSS extensions are transpiled to flat, valid, cross-browser vanilla CSS for maximum performance. There\u2019s quite a bit to it, and this is a short article, so let\u2019s look at the basic concepts.\nComponents all the way down\nStylable is designed for component-based systems. Imagine you have a Gallery component. Within that, there is a Navigation component (for example, containing a \u2018next\u2019, \u2018previous\u2019, \u2018show all thumbnails\u2019, and \u2018show all albums\u2019 controls), and within that there are NavButton components. Each component is discrete, used elsewhere in the system in different contexts, perhaps maintained by different team members or even different organisations \u2014 you can use Stylable to add a typed interface to non-Stylable component libraries, as well as using it to build an app from scratch.\nFirstly, Stylable will automatically namespace styles so they only apply inside that component, by rewriting them at build time with a unique (but human-readable) prefix. So, for example,\n<div className=\"jingle bells\" /> might be re-written as <div class=\"header183--jingle header183--bells\"></div>. \nSo far, so BEM-like (albeit without the headache of remembering a convention). But what else can it do?\nCustom pseudo-elements\nAn important feature of Stylable is the ability to reach into a component and style it from the outside, without having to know about its internal structure. Let\u2019s see the guts of a simple JSX button component in the file button.jsx:\nrender () {\n    return (\n        <button>\n            <span className=\"icon\" />\n            <span className=\"label\">Submit</span>\n        </button>\n    );\n}\n(Note:className is the JSX way of setting a class on an element; this example uses React, but Stylable itself is framework-agnostic.)\nI style it using a Stylable stylesheet (the .st.css suffix tells the preprocessor to process this file):\n/* button.st.css */\n\n/* note that the root class is automatically placed on the root HTML \nelement by Stylable React integration */\n.root {\n  background: #b0e0e6;\n}\n\n.icon {\n  display: block; \n  height: 2em;\n  background-image: url('./assets/btnIcon.svg');\n}\n\n.label {\n  font-size: 1.2em;\n  color: rgba(81, 12, 68, 1.0);\n}\nNote that Stylable allows all the CSS that you know and love to be included. As Drew Powers wrote in his review:\n\nwith Stylable, you get CSS, and every part of CSS. This seems like a \u201cduh\u201d observation, but this is significant if you\u2019ve ever battled with a CSS-in-JS framework over a lost or \u201chacky\u201d implementation of a basic CSS feature.\n\nI can import my Button component into another component - this time, panel.jsx:\n/* panel.jsx */\nimport * as React from 'react';\nimport {properties, stylable} from 'wix-react-tools';\nimport {Button} from '../button';\nimport style from './panel.st.css';\n\nexport const Panel = stylable(style)(() => (\n    <div>\n        <Button className=\"cancelBtn\" />\n    </div>\n));\nIn panel.st.css: \n/* panel.st.css */\n:import {\n  -st-from: './button.st.css';\n  -st-default: Button;\n}\n\n/* cancelBtn is of type Button */\n.cancelBtn {\n  -st-extends: Button;\n  background: cornflowerblue;\n}\n\n/* targets the label of <Button className=\"cancelBtn\" /> */\n.cancelBtn::label {\n  color: honeydew;\n  font-weight: bold;\n}\nHere, we\u2019re reaching into the Button component from the Panel component. Buttons that are not inside a Panel won\u2019t be affected.\nWe do this by extending the CSS concept of pseudo-elements. As MDN says \u201cA CSS pseudo-element is a keyword added to a selector that lets you style a specific part of the selected element(s)\u201d. We don\u2019t use a descendant selector because the label isn\u2019t part of the Panel component, it\u2019s part of the Button component. \nThis syntax allows us three important features: \nPiercing the Shadow Boundary\nBecause, like a Matroshka doll of code, you can have components inside components inside components, you can chain pseudo-elements. In Stylable, Gallery::NavigationPanel::Button::Icon is a legitimate selector. We were worried by this (even though all Stylable CSS is transpiled to flat, valid CSS) because it\u2019s not allowed in CSS, albeit with the note \u201cA future version of this specification may allow multiple pseudo-elements per selector\u201d. So I asked the CSS Working Group and was told \u201cwe intend to only allow specific combinations\u201d, so we feel this extension to CSS is in the spirit of the language.\nWhile we\u2019re on the subject of those pesky Web Standards, note that the proposed ::part and ::theme pseudo-elements are meant to fulfil the same function. However, those are coming in two years (YouTube link) and, when they do, Stylable will support them.\nStructure-agnostic\nThe second totez-groovy\u2122 feature of Stylable\u2019s pseudo-element syntax is that you don\u2019t have to care about the internal structure of the component whose boundary you\u2019re piercing. Any element with a class attribute is exposed as a pseudo-element to any component that imports it. It acts as an interface on any component, whether written in-house or by a third party.\nCode completion\nWhen we started writing Stylable, our objective was to do for CSS what TypeScript does for JavaScript. Wikipedia says\n\nChallenges with dealing with complex JavaScript code led to demand for custom tooling to ease developing of components in the language. TypeScript developers sought a solution that would not break compatibility with the standard and its cross-platform support \u2026 [with]  static typing that enables static language analysis, which facilitates tooling and IDE support.\n\nSimilarly, because Stylable knows about components, their stylable parts and states, and how they inter-relate, we can develop language services like code completion and validation. That means we can see our errors at build time or even while working in our IDE. Wave goodbye to silent run-time breakage misery, with the Stylable Intelligence VS Code extension !\nAn action replay of Visual Studio Code offering code completion etc, filmed in super StyloVision.\nPseudo-classes for state\nStylable makes it easy to apply styles to custom states (as well as the usual :active, :checked, :visited etc) by extending the CSS pseudo-class syntax. \nWe do this by declaring the possible custom states on the component:\n/* Gallery.st.css */\n.root {\n  -st-states: toggled, loading;\n}\n\n.root:toggled {\n  color: red;\n}\n\n.root:loading {\n  color: green;\n}\n\n.root:loading:toggled {\n  color: blue;\n}\nThe -st-states \u201cproperty\u201d is actually a directive for the transpiler, so Stylable knows about possible pseudo-elements and can offer code completion etc. It looks like a vendor prefix by design, because it\u2019s therefore valid CSS syntax and IDEs won\u2019t flag it as an error, but is removed at build time. Remember, Stylable resolves to flat, valid, cross-browser CSS.\nAs with plain CSS, it can\u2019t set a state, but can only react to states set externally. In the case of custom pseudo-classes, your JavaScript logic is responsible for maintaining state \u2014 by default, by setting a data-* attribute.\nAnd there\u2019s more!\nHopefully, I\u2019ve shown you how Stylable extends CSS to allow you to style components and sub-components without worrying about that styles will leak, or knowing too much about internal structure. There isn\u2019t time to tell you about mixins (CSS macros in JavaScript), variables or our theming capabilities, because I have wine to wrap and presents to mull.\nWe made Stylable because we \u2665 CSS. But there\u2019s a practical reason, too. As James Kyle, a core team member of Yarn, Babel and TC39 (the JavaScript Standards Technical Committee), said of Styable \u201cpretty sure all the CSS-in-JS libraries just died for me\u201d,\nexplaining\n\nCSS could be perfectly static if given the right tools, that\u2019s exactly what stylable does. It gives you the tools you need in CSS so that you don\u2019t need to do a bunch of dynamic shit in JS.\nMaking it static is a huge performance win.\n\nWix is currently battle-testing Stylable in its back-office systems, before rolling it out to power Wix-hosted sites to make them more performant. There are 110 million Wix-hosted sites, so there will be a lot of Stylable on the web in a few months. And it\u2019s open-sourced so you, dear Reader, can try it out and use it too. There\u2019s a Stylable boilerplate based on create-react-app to get you started (more integrations are in the pipeline).\nHappy Hols \u2018n\u2019 Hugz from the Stylable team: Bruce, Arnon, Tom, Ido.\n\nRead more\n\nStylable documentation centre\nStylable on Twitter\nA nice picture of a hedgehog", "year": "2017", "author": "Bruce Lawson", "author_slug": "brucelawson", "published": "2017-12-09T00:00:00+00:00", "url": "https://24ways.org/2017/styling-components-typed-css-with-stylable/", "topic": "code"}
{"rowid": 215, "title": "Teach the CLI to Talk Back", "contents": "The CLI is a daunting tool. It\u2019s quick, powerful, but it\u2019s also incredibly easy to screw things up in \u2013 either with a mistyped command, or a correctly typed command used at the wrong moment. This puts a lot of people off using it, but it doesn\u2019t have to be this way.\nIf you\u2019ve ever interacted with Slack\u2019s Slackbot to set a reminder or ask a question, you\u2019re basically using a command line interface, but it feels more like having a conversation. (My favourite Slack app is Lunch Train which helps with the thankless task of herding colleagues to a particular lunch venue on time.)\nSame goes with voice-operated assistants like Alexa, Siri and Google Home. There are even games, like Lifeline, where you interact with a stranded astronaut via pseudo SMS, and KOMRAD where you chat with a Soviet AI.\nI\u2019m not aiming to build an AI here \u2013 my aspirations are a little more down to earth. What I\u2019d like is to make the CLI a friendlier, more forgiving, and more intuitive tool for new or reluctant users. I want to teach it to talk back.\nInteractive command lines in the wild\nIf you\u2019ve used dev tools in the command line, you\u2019ve probably already used an interactive prompt \u2013 something that asks you questions and responds based on your answers. Here are some examples:\nYeoman\nIf you have Yeoman globally installed, running yo will start a command prompt.\n\nThe prompt asks you what you\u2019d like to do, and gives you options with how to proceed. Seasoned users will run specific commands for these options rather than go through this prompt, but it\u2019s a nice way to start someone off with using the tool.\nnpm\nIf you\u2019re a Node.js developer, you\u2019re probably familiar with typing npm init to initialise a project. This brings up prompts that will populate a package.json manifest file for that project.\n\nThe alternative would be to expect the user to craft their own package.json, which is more error-prone since it\u2019s in JSON format, so something as trivial as an extraneous comma can throw an error.\nSnyk\nSnyk is a dev tool that checks for known vulnerabilities in your dependencies. Running snyk wizard in the CLI brings up a list of all the known vulnerabilities, and gives you options on how to deal with it \u2013 such as patching the issue, applying a fix by upgrading the problematic dependency, or ignoring the issue (you are then prompted for a reason).\n\nThese decisions get mapped to the manifest and a .snyk file, and committed into the repo so that the settings are the same for everyone who uses that project.\nI work at Snyk, and running the wizard is what made me think about building my own personal assistant in the command line to help me with some boring, repetitive tasks.\nWriting your own\nSomething I do a lot is add bookmarks to styleguides.io \u2013 I pull down the entire repo, copy and paste a template YAML file, and edit to contents. Sometimes I get it wrong and break the site. So I\u2019ve been putting together a tool to help me add bookmarks.\nIt\u2019s called bookmarkbot \u2013 it\u2019s a personal assistant squirrel called Mark who will collect and bury your bookmarks for safekeeping.*\n\n*Fortunately, this metaphor also gives me a charming excuse for any situation where bookmarks sometimes get lost \u2013 it\u2019s not my poorly-written code, honest, it\u2019s just being realistic because sometimes squirrels forget where they buried things!\nWhen you run bookmarkbot, it will ask you for some information, and save that information as a Markdown file in YAML format.\nFor this demo, I\u2019m going to use a Node.js package called inquirer, which is a well supported tool for creating command line prompts. I like it because it has a bunch of different question types; from input, which asks for some text back, confirm which expects a yes/no response, or a list which gives you a set of options to choose from. You can even nest questions, Choose Your Own Adventure style.\nPrerequisites\n\nNode.js\nnpm\nRubyGems (Only if you want to go as far as serving a static site for your bookmarks, and you want to use Jekyll for it)\n\nDisclaimer\nBear in mind that this is a really simplified walkthrough. It doesn\u2019t have any error states, and it doesn\u2019t handle the situation where we save a file with the same name. But it gets you in a good place to start building out your tool.\nLet\u2019s go!\nCreate a new folder wherever you keep your projects, and give it an awesome name (I\u2019ve called mine bookmarks and put it in the Sites directory because I\u2019m unimaginative). Now cd to that directory. \ncd Sites/bookmarks\nLet\u2019s use that example I gave earlier, the trusty npm init.\nnpm init\nPop in the information you\u2019d like to provide, or hit ENTER to skip through and save the defaults. Your directory should now have a package.json file in it. Now let\u2019s install some of the dependencies we\u2019ll need.\nnpm install --save inquirer\nnpm install --save slugify\nNext, add the following snippet to your package.json to tell it to run this file when you run npm start.\n\"scripts\": {\n  \u2026\n  \"start\": \"node index.js\"\n}\nThat index.js file doesn\u2019t exist yet, so let\u2019s create it in the root of our folder, and add the following:\n// Packages we need\nvar fs = require('fs'); // Creates our file (part of Node.js so doesn't need installing)\nvar inquirer = require('inquirer'); // The engine for our questions prompt\nvar slugify = require('slugify'); // Will turn a string into a usable filename\n\n// The questions\nvar questions = [\n  {\n    type: 'input',\n    name: 'name',\n    message: 'What is your name?',\n  },\n];\n\n// The questions prompt\nfunction askQuestions() {\n\n  // Ask questions\n  inquirer.prompt(questions).then(answers => {\n\n    // Things we'll need to generate the output\n    var name = answers.name;\n\n    // Finished asking questions, show the output\n    console.log('Hello ' + name + '!');\n\n  });\n\n}\n\n// Kick off the questions prompt\naskQuestions();\nThis is just some barebones where we\u2019re including the inquirer package we installed earlier. I\u2019ve stored the questions in a variable, and the askQuestions function will prompt the user for their name, and then print \u201cHello <your name>\u201d in the console.\nEnough setup, let\u2019s see some magic. Save the file, go back to the command line and run npm start.\n\nExtending what we\u2019ve learnt\nAt the moment, we\u2019re just saving a name to a file, which isn\u2019t really achieving our goal of saving bookmarks. We don\u2019t want our tool to forget our information every time we talk to it \u2013 we need to save it somewhere. So I\u2019m going to add a little function to write the output to a file.\nSaving to a file\nCreate a folder in your project\u2019s directory called _bookmarks. This is where the bookmarks will be saved.\nI\u2019ve replaced my questions array, and instead of asking for a name, I\u2019ve extended out the questions, asking to be provided with a link and title (as a regular input type), a list of tags (using inquirer\u2019s checkbox type), and finally a description, again, using the input type.\nSo this is how my code looks now:\n// Packages we need\nvar fs = require('fs'); // Creates our file\nvar inquirer = require('inquirer'); // The engine for our questions prompt\nvar slugify = require('slugify'); // Will turn a string into a usable filename\n\n// The questions\nvar questions = [\n  {\n    type: 'input',\n    name: 'link',\n    message: 'What is the url?',\n  },\n  {\n    type: 'input',\n    name: 'title',\n    message: 'What is the title?',\n  },\n  {\n    type: 'checkbox',\n    name: 'tags',\n    message: 'Would you like me to add any tags?',\n    choices: [\n      { name: 'frontend' },\n      { name: 'backend' },\n      { name: 'security' },\n      { name: 'design' },\n      { name: 'process' },\n      { name: 'business' },\n    ],\n  },\n  {\n    type: 'input',\n    name: 'description',\n    message: 'How about a description?',\n  },\n];\n\n// The questions prompt\nfunction askQuestions() {\n\n  // Say hello\n  console.log('\ud83d\udc3f  Oh, hello! Found something you want me to bookmark?\\n');\n\n  // Ask questions\n  inquirer.prompt(questions).then((answers) => {\n\n    // Things we'll need to generate the output\n    var title = answers.title;\n    var link = answers.link;\n    var tags = answers.tags + '';\n    var description = answers.description;\n    var output = '---\\n' +\n                 'title: \"' + title + '\"\\n' +\n                 'link: \"' + link + '\"\\n' +\n                 'tags: [' + tags + ']\\n' +\n                 '---\\n' + description + '\\n';\n\n    // Finished asking questions, show the output\n    console.log('\\n\ud83d\udc3f  All done! Here is what I\\'ve written down:\\n');\n    console.log(output);\n\n    // Things we'll need to generate the filename\n    var slug = slugify(title);\n    var filename = '_bookmarks/' + slug + '.md';\n\n    // Write the file\n    fs.writeFile(filename, output, function () {\n      console.log('\\n\ud83d\udc3f  Great! I have saved your bookmark to ' + filename);\n    });\n\n  });\n\n}\n\n// Kick off the questions prompt\naskQuestions();\nThe output is formatted into YAML metadata as a Markdown file, which will allow us to turn it into a static HTML file using a build tool later. Run npm start again and have a look at the file it outputs.\n\nGetting confirmation\nBefore the user makes critical changes, it\u2019s good to verify those changes first. We\u2019re going to add a confirmation step to our tool, before writing the file. More seasoned CLI users may favour speed over a \u201chey, can you wait a sec and just check this is all ok\u201d step, but I always think it\u2019s worth adding one so you can occasionally save someone\u2019s butt.\nSo, underneath our questions array, let\u2019s add a confirmation array.\n// Packages we need\n\u2026\n// The questions\n\u2026\n\n// Confirmation questions\nvar confirm = [\n  {\n    type: 'confirm',\n    name: 'confirm',\n    message: 'Does this look good?',\n  },\n];\n\n// The questions prompt\n\u2026\n\nAs we\u2019re adding the confirm step before the file gets written, we\u2019ll need to add the following inside the askQuestions function:\n// The questions prompt\nfunction askQuestions() {\n  // Say hello\n  \u2026\n  // Ask questions\n  inquirer.prompt(questions).then((answers) => {\n    \u2026\n    // Things we'll need to generate the output\n    \u2026\n    // Finished asking questions, show the output\n    \u2026\n\n    // Confirm output is correct\n    inquirer.prompt(confirm).then(answers => {\n\n      // Things we'll need to generate the filename\n      var slug = slugify(title);\n      var filename = '_bookmarks/' + slug + '.md';\n\n      if (answers.confirm) {\n        // Save output into file\n        fs.writeFile(filename, output, function () {\n          console.log('\\n\ud83d\udc3f  Great! I have saved your bookmark to ' +\n          filename);\n        });\n      } else {\n        // Ask the questions again\n        console.log('\\n\ud83d\udc3f  Oops, let\\'s try again!\\n');\n        askQuestions();\n      }\n\n    });\n\n  });\n}\n\n// Kick off the questions prompt\naskQuestions();\nNow run npm start and give it a go!\n\nTyping y will write the file, and n will take you back to the start. Ideally, I\u2019d store the answers already given as defaults so the user doesn\u2019t have to start from scratch, but I want to keep this demo simple.\nServing the files\nNow that your bookmarking tool is successfully saving formatted Markdown files to a folder, the next step is to serve those files in a way that lets you share them online. The easiest way to do this is to use a static-site generator to convert your YAML files into HTML, and pop them all on one page. Now, you\u2019ve got a few options here and I don\u2019t want to force you down any particular path, as there are plenty out there \u2013 it\u2019s just a case of using the one you\u2019re most comfortable with.\nI personally favour Jekyll because of its tight integration with GitHub Pages \u2013 I don\u2019t want to mess around with hosting and deployment, so it\u2019s really handy to have my bookmarks publish themselves on my site as soon as I commit and push them using Git.\nI\u2019ll give you a very brief run-through of how I\u2019m doing this with bookmarkbot, but I recommend you read my Get Started With GitHub Pages (Plus Bonus Jekyll) guide if you\u2019re unfamiliar with them, because I\u2019ll be glossing over some bits that are already covered in there.\nSetting up a build tool\nIf you haven\u2019t already, install Jekyll and Bundler globally through RubyGems. Jekyll is our static-site generator, and Bundler is what we use to install Ruby dependencies.\ngem install jekyll bundler\nIn my project folder, I\u2019m going to run the following which will install the Jekyll files we\u2019ll need to build our listing page. I\u2019m using --force, otherwise it will complain that the directory isn\u2019t empty.\njekyll new . --force\nIf you check your project folder, you\u2019ll see a bunch of new files. Now run the following to start the server:\nbundle exec jekyll serve\nThis will build a new directory called _site. This is where your static HTML files have been generated. Don\u2019t touch anything in this folder because it will get overwritten the next time you build.\nNow that serve is running, go to http://127.0.0.1:4000/ and you\u2019ll see the default Jekyll page and know that things are set up right. Now, instead, we want to see our list of bookmarks that are saved in the _bookmarks directory (make sure you\u2019ve got a few saved). So let\u2019s get that set up next.\nOpen up the _config.yml file that Jekyll added earlier. In here, we\u2019re going to tell it about our bookmarks. Replace everything in your _config.yml file with the following:\ntitle: My Bookmarks\ndescription: These are some of my favourite articles about the web.\nmarkdown: kramdown\nbaseurl: /bookmarks # This needs to be the same name as whatever you call your repo on GitHub.\ncollections:\n  - bookmarks\nThis will make Jekyll aware of our _bookmarks folder so that we can call it later. Next, create a new directory and file at _layouts/home.html and paste in the following.\n<!doctype html>\n<html lang=\"en\">\n<head>\n  <meta charset=\"UTF-8\" />\n  <title>{{site.title}}</title>\n  <meta name=\"description\" content=\"{{site.description}}\">\n</head>\n\n<body>\n\n  <h1>{{site.title}}</h1>\n  <p>{{site.description}}</p>\n\n  <ul>\n    {% for bookmark in site.bookmarks %}\n    <li>\n      <a href=\"{{bookmark.link}}\">\n        <h2>{{bookmark.title}}</h2>\n      </a>\n      {{bookmark.content}}\n      {% if bookmark.tags %}\n      <ul>\n        {% for tags in bookmark.tags %}<li>{{tags}}</li>{% endfor %}\n      </ul>\n      {% endif %}\n    </li>\n    {% endfor %}\n  </ul>\n\n</body>\n\n</html>\nRestart Jekyll for your config changes to kick in, and go to the url it provides you (probably http://127.0.0.1:4000/bookmarks, unless you gave something different as your baseurl).\n\nIt\u2019s a decent start \u2013 there\u2019s a lot more we can do in this area but now we\u2019ve got a nice list of all our bookmarks, let\u2019s get it online!\nIf you want to use GitHub Pages to host your files, your first step is to push your project to GitHub. Go to your repository and click \u201csettings\u201d. Scroll down to the section labelled \u201cGitHub Pages\u201d, and from here you can enable it. Select your master branch, and it will provide you with a url to view your published pages.\n\nWhat next?\nNow that you\u2019ve got a framework in place for publishing bookmarks, you can really go to town on your listing page and make it your own. First thing you\u2019ll probably want to do is add some CSS, then when you\u2019ve added a bunch of bookmarks, you\u2019ll probably want to have some filtering in place for the tags, perhaps extend the types of questions that you ask to include an image (if you\u2019re feeling extra-fancy, you could just ask for a url and pull in metadata from the site itself). Maybe you\u2019ve got an idea that doesn\u2019t involve bookmarks at all.\nYou could use what you\u2019ve learnt to build a place where you can share quotes, a list of your favourite restaurants, or even Christmas gift ideas.\nHere\u2019s one I made earlier\n\nMy demo, bookmarkbot, is on GitHub, and I\u2019ve reused a lot of the code from styleguides.io. Feel free to grab bits of code from there, and do share what you end up making!", "year": "2017", "author": "Anna Debenham", "author_slug": "annadebenham", "published": "2017-12-11T00:00:00+00:00", "url": "https://24ways.org/2017/teach-the-cli-to-talk-back/", "topic": "code"}
{"rowid": 214, "title": "Christmas Gifts for Your Future Self: Testing the Web Platform", "contents": "In the last year I became a CSS specification editor, on a mission to revitalise CSS Multi-column layout. This has involved learning about many things, one of which has been the Web Platform Tests project. In this article, I\u2019m going to share what I\u2019ve learned about testing the web platform. I\u2019m also going to explain why I think you might want to get involved too.\nWhy test?\nAt one time or another it is likely that you have been frustrated by an issue where you wrote some valid CSS, and one browser did one thing with it and another something else entirely. Experiences like this make many web developers feel that browser vendors don\u2019t work together, or they are actively doing things in a different way to one another to the detriment of those of us who use the platform. You\u2019ll be glad to know that isn\u2019t the case, and that the people who work on browsers want things to be consistent just as much as we do. It turns out however that interoperability, which is the official term for \u201cworks in all browsers\u201d, is hard.\nThanks to web-platform-tests, a test from another browser vendor just found genuine bug in our code before we shipped \ud83d\ude3b\u2014 Brian Birtles (@brianskold) February 10, 2017\n\nIn order for W3C Specifications to move on to become W3C Recommendations we need to have interoperable implementations.\n\n6.2.4 Implementation Experience\nImplementation experience is required to show that a specification is sufficiently clear, complete, and relevant to market needs, to ensure that independent interoperable implementations of each feature of the specification will be realized. While no exhaustive list of requirements is provided here, when assessing that there is adequate implementation experience the Director will consider (though not be limited to):\nis each feature of the current specification implemented, and how is this demonstrated?\nare there independent interoperable implementations of the current specification?\nare there implementations created by people other than the authors of the specification?\nare implementations publicly deployed?\nis there implementation experience at all levels of the specification\u2019s ecosystem (authoring, consuming, publishing\u2026)?\nare there reports of difficulties or problems with implementation?\nhttps://www.w3.org/2017/Process-20170301/#transition-reqs\n\nWe all want interoperability, achieving interoperability is part of the standards process. The next question is, how do we make sure that we get it?\nUnimplemented vs uninteroperable implementations\nBefore looking at how we can try to improve interoperability, I\u2019d like to look at the reasons we don\u2019t always meet that aim. There are a couple of reasons why browser X is not doing the same thing as browser Y.\nThe first reason is that browser X has not implemented that feature yet. Relatively small teams of people work on browser engines, and their resources are spread as thinly as those of any company. Behind those browsers are business or organisational goals which may not match our desire for a shiny feature to be made available. There are ways in which we as the web community can help gently encourage implementations - by requesting the feature, by using it so it shows up in usage reports, or writing about it to show interest. However, there will always be some degree of lag based on priorities.\nA browser not supporting a feature at all, is reasonably easy to deal with these days. We can test for support with Feature Queries, and create sensible fallbacks. What is harder to deal with is when a feature is implemented in different ways by different browsers. In that situation you use the feature, perhaps referring to the specification to ensure that you are writing your CSS correctly. It looks exactly as you expect in one browser and it\u2019s all broken when you test in another.\nA frequent cause of this kind of issue is that the specification is not well defined in a particular area or that the specification has changed since one or other browser implemented it. CSS specifications are not developed in a darkened room, then presented to browser vendors to implement as a completed document. It would be nice if it worked like that, however the web platform is a gnarly thing. Before we can be sure that a specification is correct, it needs implementing in order that we can get the interoperable implementations I described earlier. A circular process has to happen. Specifications have to be written, browsers have to implement and find the problems, and then the specification has to be revised.\nMany people reading this will be familiar with how flexbox changed three times in browsers, leaving us with a mess of incompatibilities and the need to use at least two versions of the spec. This story was an example of this circular process, in this case the specification was flagged as experimental using vendor prefixes. We had become used to using vendor prefixes in production and early adopters of flexbox were bitten by this. Today, specifications are developed behind experimental flags as we saw with CSS Grid Layout. Yet there has to come a time when implementations ship, and remove those flags, and it may be that knowingly or unknowingly some interop issues slip through.\nYou will know these interop issues as \u201cbrowser bugs\u201d, perhaps you have even reported one (thank you!) and none of us want them, so how do we make the platform as robust as possible?\nHow do we ensure we have interoperability?\nIf you were working on a large web application, with several people committing code, it would be very easy for one person to make a change that inadvertently broke some part of the application. They might not realise the fact that their change would cause a problem, due to not having a complete understanding of the entire codebase. To prevent this from happening, it is accepted good practice to write tests as well as code. The tests can then be run before the application is deployed.\nUnless you start out from the beginning writing tests, and are very good at writing a test for every bit of code, it is likely that some issues do slip through from time to time. When this happens, a good approach is to not only fix the issue but also to write a test that would stop it ever happening again. That way the test suite improves over time and hopefully fewer issues happen.\nThe web platform is essentially a giant, sprawling application, with a huge range of people working on it in different ways. There is therefore plenty of opportunity for issues to creep in, so it seems like having some way of writing tests and automating those tests on browsers would be a good thing. That, is what the Web Platform Tests project has set out to achieve.\nWeb Platform Tests\nWeb Platform Tests is the test suite for the web platform. It is set of tests for all parts of the web platform, which can be run in any browser and the results reported. This article mostly discusses CSS tests, because I work on CSS. You will find that there are tests covering the full platform, and you can look into whichever area you have the most interest and experience in.\nIf we want to create a test suite for a CSS specification then we need to ensure that every feature of the specification has a related test. If a change is made to the spec, and a test committed that reflects that change, then it should be straightforward to run that test against each browser and see if it passes.\nCurrently, at the CSS Working Group, specifications that are at Candidate Recommendation Status should commit at test with every normative change to the spec. To explain the terminology, a normative change is one that changes some of the normative text of a specification - text that contains instructions as to how a browser should render a certain thing. A Candidate Recommendation is the status at which the Working Group officially request implementations of the spec, therefore it is reasonable to assume that any change may cause an interoperability issue. It is usually the case that representatives from all browsers will have discussed the change, so anyone who needs to change code will be aware. In this case the test allows them to check that their change passes and matches everyone else. Tests would also highlight the situation where a change to the spec caused an issue in a browser that otherwise wouldn\u2019t be aware if it. Just as a test suite for your web application should alert a person committing code, that their change will cause a problem elsewhere.\nDiscovering the tests\nI\u2019ve found that the more I have understood the effort that goes into interoperability, and the reasons why creating an interoperable web is so hard, running into browser issues has become less frustrating. I have somewhere to go, even if all I can do is log the bug.\nIf you are even slightly interested in the subject, go have a poke around wpt.fyi. You can explore the various parts of the web platform and see how many tests have been committed. All the the CSS tests are under the directory /css where you will find each specification. Find a specification you are interested in, and look at the tests. Each test has a link to run it in your own browser to see if it passes. This can be useful in itself, if you are battling with an issue and have reduced it down to something specific, you can go and look to see if there is a test covering that and whether it appears to pass or fail in the browser you are battling with. If it turns out that the test fails, it\u2019s probably not you!\nA test on the wpt.fyi dashboard\nNote: In some tests you will come across mention of a font called Ahem. This is a font designed for testing which contains consistent glyphs. You can read about how to use the font and download it here.\nContributing to Web Platform Tests\nYou can also become involved with Web Platform Tests. People often ask me how they can become involved in CSS, and I can think of no better way than by writing tests. You need to really understand a feature to accurately come up with a method of testing if it works or not in the different engines. This is not glamorous work, it is however a very useful thing to be involved with.\nIn addition to helping yourself, and developing the sort of deep knowledge of the platform that enables contribution, you will really help the progress of specifications. There are only a very few people writing specs. If those people also have to write and review all of the tests it slows down their work. If you want a better, more interoperable web, and to massively improve your ability to have nerdy conversations about highly specific things, testing is the place to start.\nA local testing setup\nYour first stop should be to visit the home of Web Platform Tests. There is some documentation here, which does tend to assume you know about the tests and what you are looking for - having read this article you know as much as I do. To be able to work on tests you will want to:\n\nClone the WPT repo, this is where all the tests are stored\nInstall some tools so you can run up a local copy of the tests\n\nThe instructions on the Readme in the repo should get you up and running, you can then load your own version of the test suite in a browser at http://web-platform-test:8000, or whichever port you set up.\nRunning tests locally\nFinding things to test\nIt\u2019s currently not straightforward to locate low-hanging fruit in order to start committing tests. There are some issues flagged up as a good first issue in the GitHub repo, if any of those match your interest and knowledge. Otherwise, a good place to start is where you know of existing interoperability issues. If you are aware of a browser bug, have a look and see if there is a test that addresses it. If not, then a test highlights the interoperability issue, and if it is an issue that you are running into means that you have a nice way to see if it has been fixed!\nTalk to people\nThere is an IRC channel at irc://irc.w3.org:6667/testing, where you will find people who are writing tests as well as people who are working on the test suite framework itself. They have always been very friendly, and are likely to welcome people with a real interest in creating tests.\nGathering information\nFirst you need to read the spec. To be able to create a test you need to know and to understand what the specification says should be happening. As I mentioned, writing tests will improve your knowledge dramatically! In general I find that web developers assume their favourite browser has got it right, this isn\u2019t about right or wrong however, or good browsers versus bad ones. The browser with the incorrect implementation may have had a perfect, as per the spec implementation, until something changed. Do some investigation and work out what the spec says, and which \u2013 if any \u2013 browser is doing it correctly.\nAnother good place to look when trying to create a test for an interop issue, is to look at the browser issue trackers. It is quite likely that someone has already logged the issue, and detailed what it is, and even which browsers are as per the spec. This is useful information, as you then have a clue as to which browsers should pass your test. Remember to check version numbers - an issue may well be fixed in a pre-release version of Chrome for example, but not in the public release.\n\nEdge Issue Tracker\nMozilla Issue Tracker\nWebKit Issue Tracker\nChromium Issue Tracker\n\nWriting the test\nIf you\u2019ve ever created a Reduced Test Case to isolate a browser issue, you already have some idea of what we are trying to do with a test. We want to test one thing, in isolation, and to be able to confirm \u201cyes this works as per the spec\u201d or \u201cno, this does not\u201d.\nThe main two types of test are:\n\ntestharness.js tests\nreftests\n\nThe testharness.js tests use JavaScript to test an assertion, this framework is designed as a way to test Web APIs and as this quickly gets fairly complicated - and I\u2019m a complete beginner myself at writing these - I\u2019ll refer you to the excellent tutorial Using testharness.js.\nMany CSS tests will be reftests. A reftest involves getting two pages to lay out in the same way, so that they are visually the same. For example, you can find a reftest for Grid Layout at:https://w3c-test.org/css/css-grid/alignment/grid-gutters-001.html or at http://web-platform.test:8000/css/css-grid/alignment/grid-gutters-001.html if you have run up your own copy of WPT.\n<!DOCTYPE html>\n<meta charset=\"utf-8\">\n<title>CSS Grid Layout Test: Support for gap shorthand property of row-gap and column-gap</title>\n<link rel=\"help\" href=\"https://www.w3.org/TR/css-grid-1/#gutters\">\n<link rel=\"help\" href=\"https://www.w3.org/TR/css-align-3/#gap-shorthand\">\n<link rel=\"match\" href=\"../reference/grid-equal-gutters-ref.html\">\n<link rel=\"author\" title=\"Rachel Andrew\" href=\"mailto:me@rachelandrew.co.uk\">\n<style>\n    #grid {\n        display: grid;\n        width:200px;\n        gap: 20px;\n        grid-template-columns: 90px 90px;\n        grid-template-rows: 90px 90px;\n        background-color: green;\n    }\n\n    #grid > div {\n        background-color: silver;\n    }\n</style>\n\n<p>The test passes if it has the same visual effect as reference.</p>\n<div id=\"grid\">\n    <div></div>\n    <div></div>\n    <div></div>\n    <div></div>\n</div>\nI am testing the new gap property (renamed grid-gap). The reference file can be found by looking for the line:\n<link rel=\"match\" href=\"../reference/grid-equal-gutters-ref.html\">\nIn that file, I am using absolute positioning to mock up the way the file would look if gap is implemented correctly.\n<!DOCTYPE html>\n<meta charset=\"utf-8\">\n<title>CSS Grid Layout Reference: a square with a green cross</title>\n<link rel=\"author\" title=\"Rachel Andrew\" href=\"mailto:me@rachelandrew.co.uk\" />\n<style>\n    #grid {\n        width:200px;\n        height: 200px;\n        background-color: green;\n        position: relative;\n    }\n\n    #grid > div {\n        background-color: silver;\n        width: 90px;\n        height: 90px;\n        position: absolute;\n    }\n\n    #grid :nth-child(1) {\n        top: 0;\n        left: 0;\n    }\n\n    #grid :nth-child(2) {\n        top: 0;\n        left: 110px;\n    }\n\n    #grid :nth-child(3) {\n        top: 110px;\n        left: 0;\n    }\n\n    #grid :nth-child(4) {\n        top: 110px;\n        left: 110px;\n    }\n</style>\n\n<div id=\"grid\">\n    <div></div>\n    <div></div>\n    <div></div>\n    <div></div>\n</div>\nThe tests are compared in an automated way by taking screenshots of the test and reference.\nThese are relatively simple tests to write, you will find the work is not in writing the test however. The work is really in doing the research, and making sure you understand what is supposed to happen so you can write the test. Which is why, if you really want to get your hands dirty in the web platform, this is a good place to start.\nCommitting a test\nOnce you have written a test you can run the lint tool to make sure that everything is tidy. This tool is run automatically after you submit your pull request, and reviewers won\u2019t accept a test with lint errors, so do this locally first to catch anything obvious.\nTests are added as a pull request, once you have your test ready to go you can create a pull request to add it to the repository. Your test will be tested and it will then wait for a review.\nYou may well then find yourself in a bit of a waiting game, as the test needs to be reviewed. How long that takes will depend on how active work is on that spec. People who are in the OWNERS file for that spec should be notified. You can always ask in IRC to see if someone is available who can look at and potentially merge your test.\nUsually the reviewer will have some comments as to how the test can be improved, in the same as the owner of an open source project you submit a PR to might ask you to change some things. Work with them to make your test as good as it can be, the things you learn on the first test you submit will make future ones easier. You can then bask in the glow of knowing you have done something towards the aim of a more interoperable web for all of us.\nChristmas gifts for your future self\nI have been a web developer for over 20 years. I have no idea what the web platform will look like in 20 more years, but for as long as I\u2019m working on it I\u2019ll keep on trying to make it better. Making the web more interoperable makes it a better place to be a web developer, storing up some Christmas gifts for my future self, while learning new things as I do so.\nResources\nI rounded up everything I could find on WPT while researching this article. As well as some other links that might be helpful for you. These links are below. Happy testing!\n\nWeb Platform Tests\nUsing testharness.js\nIRC Channel irc://irc.w3.org:6667/testing\nEdge Issue Tracker\nMozilla Issue Tracker\nWebKit Issue Tracker\nChromium Issue Tracker\nReducing an Issue - guide to created a reduced test case\nEffectively Using Web Platform Tests: Slides and Video\nAn excellent walkthrough from Lyza Gardner on her working on tests for the HTML specification - Moving Targets: a case study on testing web standards.\nImproving interop with web-platform-tests: Slides and Video", "year": "2017", "author": "Rachel Andrew", "author_slug": "rachelandrew", "published": "2017-12-10T00:00:00+00:00", "url": "https://24ways.org/2017/testing-the-web-platform/", "topic": "code"}
{"rowid": 213, "title": "Accessibility Through Semantic HTML", "contents": "Working on Better, a tracker blocker, I spend an awful lot of my time with my nose in other people\u2019s page sources. I\u2019m mostly there looking for harmful tracking scripts, but often notice the HTML on some of the world\u2019s most popular sites is in a sad state of neglect.\nWhat does neglected HTML look like? Here\u2019s an example of the markup I found on a news site just yesterday. There\u2019s a bit of text, a few links, and a few images. But mostly it\u2019s div elements.\n<div class=\"block_wrapper\">\n  <div class=\"block_content\">\n    <div class=\"box\">\n      <div id=\"block1242235\">\n        <div class=\"column\">\n          <div class=\"column_content\">\n            <a class=\"close\" href=\"#\"><i class=\"fa\"></i></a>\n          </div>\n          <div class=\"btn account_login\"></div>\n          Some text <span>more text</span>\n        </div>\n      </div>\n    </div>\n  </div>\n</div>\ndivs and spans, why do we use them so much?\nWhile I find tracking scripts completely inexcusable, I do understand why people write HTML like the above. As developers, we like to use divs and spans as they\u2019re generic elements. They come with no associated default browser styles or behaviour except that div displays as a block, and span displays inline. If we make our page up out of divs and spans, we know we\u2019ll have absolute control over styles and behaviour cross-browser, and we won\u2019t need a CSS reset.\nAbsolute control may seem like an advantage, but there\u2019s a greater benefit to less generic, more semantic elements. Browsers render semantic elements with their own distinct styles and behaviours. For example, button looks and behaves differently from a. And ul is different from ol. These defaults are shortcuts to a more usable and accessible web. They provide consistent and well-tested components for common interactions.\nSemantic elements aid usability\nA good example of how browser defaults can benefit the usability of an element is in the <select> option menu. In Safari on the desktop, the browser renders <select> as a popover-style menu. On a touchscreen, Safari overlays the same menu over the lower half of the screen as a \u201cpicker view.\u201d\nOption menu in Safari on macOS.\nOption menu picker in Safari on iOS.\nThe iOS picker is a much better experience than struggling to pick from a complicated interface inside the page. The menu is shown more clearly than in the confined space on the page, which makes the options easier to read. The required swipe and tap gestures are consistent with the rest of the operating system, making the expected interaction easier to understand. The whole menu is scaled up, meaning the gestures don\u2019t need such fine motor control. Good usability is good accessibility.\nWhen we choose to use a div or span over a more semantic HTML element, we\u2019re also doing hard work the browser could be doing for us. We don\u2019t need to tie ourselves in knots making a custom div into a keyboard navigable option menu. Using select passes the bulk of the responsibility over to the browser.\u00a0\nLetting the browser do most of the work is also more future-friendly. More devices, with different expected interactions, will be released in the future. When that happens, the devices\u2019 browsers can adapt our sites according to those interactions. Then we can spend our time doing something more fun than rewriting cross-browser JavaScript for each new device.\nHTML\u2019s impact on accessibility\nAssistive technology also uses semantic HTML to understand how best to convey each element to its user.\nFor screen readers\nSemantic HTML gives context to screen readers. Screen readers are a type of assistive technology that reads the content of the screen to the person using it. All sites have a linear page source. Sighted visitors can use visual cues on the page to navigate to their desired content in a non-linear fashion. As screen readers output audio (and sometimes braille), those visual cues aren\u2019t usable in the same way.\nScreen readers provide alternative means of navigation, enabling people to jump between different types of content, such as links, forms, headings, lists, and paragraphs. If all our content is marked up using divs and spans, we\u2019re not giving screen readers a chance to index the valuable content.\nFor keyboard navigation\nKeyboard-only navigation is also aided by semantic HTML. Forms, option menus, navigation, video, and audio are particularly hard for people relying on a keyboard to access. For instance, option menus and navigation can be very fiddly if you need to use a mouse to hover a menu open and move to select the desired item at the same time.\u00a0\nAgain, we can leave much of the interaction to the browser through semantic HTML. Semantic form elements can convey if a check box has been checked, or which label is associated with which input field. These default behaviours can make the difference between a person being able to use a form or leaving the site out of frustration.\nDid I convince you yet? I hope so. Let\u2019s finish with some easy guidelines to follow.\n1. Use the most semantic HTML element for the job\nWhen you reach for a div, first check if there\u2019s a better element to do the job. What is the role of that element? How should a person be interacting with the element?\nAre you using class names like nav, header, or main? There are HTML5 elements for those sections! Using specific elements can also make writing CSS simpler, and ensure a consistent design with minimal effort.\n2. Separate structure and style\nDon\u2019t choose HTML elements based on how they\u2019re styled in your CSS. Nowadays, common practice is to use class names rather than elements for CSS selectors. You\u2019re unlikely to wrap all your page content in an <h1> element because you want all the text to be big and bold. Still, it can be easy to choose an HTML element because it will be the easiest to style. Focusing on content without style will help us choose the most semantic HTML element without that temptation. For example, you could add a class of .btn to a div to make it look like a button. But we all know that only a button will really behave like a button.\n3. Use progressive enhancement for enhanced functionality\nAirbnb and Groupon recently proved we\u2019re not past the laziness of \u201cthis site only works in X browser.\u201d Baffling disregard for the open web aside, making complex interactive experiences work cross-browser and cross-device is not easy. We can use progressive enhancement to layer fancy or unsupported features on top of a baseline \u201cit works\u201d experience.\u00a0\nWe should build the baseline experience on a foundation of accessible, semantic HTML. Then, if you really want to add a specific feature for a proprietary browser, you can layer that on top, without breaking the underlying experience.\n4. Test your work\nValidators are always valuable for checking the browser will be able to correctly interpret your markup. Document outline checkers can be valuable for testing your structure, but be aware that the HTML5 document outline is not actually implemented in browsers.\nOnce you\u2019ve got something resembling a web page, test the experience! Ensure that semantic HTML element you chose looks and behaves in a predictable manner consistent with its use across the web. Test cross-browser, test cross-device, and test with assistive technology. Testing with assistive technology is not as expensive as it used to be, you can even use your smartphone for testing on iOS and Android. Your visitors will thank you!\nFurther reading\n\nAccessibility For Everyone by Laura Kalbag\nHTML5 Doctor\nHTML5 Accessibility\nAn overview of HTML5 Semantics\nHTML reference on MDN\u00a0\nHeydon Pickering\u2019s Inclusive Design Checklist\nThe Paciello Group\u2019s Inclusive Design Principles", "year": "2017", "author": "Laura Kalbag", "author_slug": "laurakalbag", "published": "2017-12-15T00:00:00+00:00", "url": "https://24ways.org/2017/accessibility-through-semantic-html/", "topic": "code"}
{"rowid": 212, "title": "Refactoring Your Way to a Design System", "contents": "I love refactoring code. Absolutely love it. There\u2019s something about taking a piece of UI or a bit of code and reworking it in a way that is simpler, modular, and reusable that makes me incredibly happy.\nI also love design systems work. It gives hybrids like me a home. It seems like everyone is talking about design systems right now. Design systems teams are perfect for those who enjoy doing architectural work and who straddle the line between designer and developer. \nUna Kravets recently identified some of the reasons that design systems fail, and chief among them are lack of buy-in, underlying architecture, and communication. While it\u2019s definitely easier to establish these before project work begins, that doesn\u2019t mean it is the only path to success. \nIt\u2019s a privilege to work on a greenfield project, and one that is not afforded to many. Companies with complex and/or legacy codebases may not be able to support a full rewrite of their product. In addition, many people feel overwhelmed at the thought of creating a complete system and are at a loss of how or where to even begin the process. \nThis is where refactoring comes into play.\nAccording to Martin Fowler, \u201crefactoring is the process of changing a software system in such a way that it does not alter the external behavior of the code yet improves its internal structure.\u201d It\u2019s largely invisible work, and if you do it right, the end user will never know the difference. What it will do is provide a decent foundation to begin more systematic work.\nBuild a solid foundation\nWhen I was first asked to create Pantsuit, the design system for Hillary for America, I was tasked with changing our codebase to be more modular and scalable, without changing the behavior or visual design of the UI. We needed a system in place that would allow for the rapid creation of new projects while maintaining a consistent visual language. In essence, I was asked to refactor our code into a design system.\nDuring that refactor, I focused the majority of my efforts on creating a scalable architecture based on the UI components in a single workflow. Since I needed to maintain a 1:1 parity with production, the only changes I could create were under-the-hood. I started with writing coding standards and deciding on a CSS architecture that I would then use as I rewrote sections of the codebase. \nIf you already have these in place, great! If not, then this is an excellent place to start. Even if your dream of a design system is never fully realized, having a coding philosophy and architecture in place will still have far-reaching benefits and implications.\nI want to note that if your refactor includes creating new coding standards or a CSS architecture, don\u2019t try to switch everything over right away. Instead, focus on a single new feature and isolate/encapsulate your work from the rest of the codebase.\nFocus on the features\n\nThe key principle to cleaning up a complex codebase is to always refactor in the service of a feature. \n\u2014 Max Kanat-Alexander\n\nRefactoring for the sake of refactoring can easily lead to accusations of misused time and lack of results. Another danger of refactoring is that it can turn into yak-shaving if you aren\u2019t disciplined in your approach. To that end, tying your refactored components to feature work is a great way to limit scope and reduce the rest of unintended changes.\nFor example, the initial work on Pantsuit focused only on components related to the donations flow. Every line of code I wrote was in service to improving the maintainability and modularity of that UI. Because we didn\u2019t have any standards in place, I started with those. From there, I identified all the components present in every step of the donations flow, which included some type styles, buttons, form inputs and error states. Then came the refactor of each individual component. Finally, I reintegrated the newly refactored components into the existing donations flow and tested it against production, checking for visual and behavioral diffs. At the end of this process, I had the beginning of a design system that would grow to serve over 50 applications, and a case study to demonstrate its effectiveness.\nIdeally, you\u2019ll want to get buy-in from your stakeholders and product owners before you begin any design systems work. However, in the absence of buy-in, linking your work to new feature development is a good way to both limit the scope of your refactor and jump start component creation.\nIn addition, if you\u2019re still trying to convince your team of the benefits of a design system, starting small and using the newly refactored, feature-driven work as a case study is one way showcase a design systems\u2019 value. By providing a concrete example of how working towards a design system contributed to the project\u2019s success, you\u2019re gathering the data necessary to secure buy-in for a larger-scale effort. It\u2019s a great way to show value, rather than just talking about it.\nShow, don\u2019t tell\nPerhaps the most important thing you can do for any design system is to document it. The key is to create a frictionless way to keep the documentation up-to-date, otherwise no one will contribute to it, and in turn, it will become obsolete and useless. \nThere are lots of tools out there to help you get started documenting your new system. One of my favorites is KSS, which parses comments in the code and uses them to generate a style guide. For Pantsuit, I used the node version of KSS, along with a template to quickly spin up a documentation site.\nI\u2019ve listed just a few tools below; for even more, check out the tools sections of styleguides.io.\n\nFractal\nPattern Lab\nDrizzle\nFabricator\nAstrum\nCatalog\n\nRegardless of what tool you settle on, it needs to integrate well with your current workflow. \nConclusion: always be refactoring\nIf you\u2019re not lucky enough to be able to start a new design system from scratch, you can start small and work on a single feature or component. With each new project comes a new opportunity to flesh out a new part of the system, and another potential case study to secure buy-in and showcase its value. Make sure to carefully and thoroughly document each new portion of the system as it\u2019s built. After a few projects, you\u2019ll find yourself with a decent start to a design system. \nGood luck, and happy holidays!\nFurther reading:\n\nWhy Design Systems Fail\nCSS Architecture for Design Systems\nRefactoring: Improving the Design of Existing Code\nRefactoring CSS: The Three I\u2019s\nRefactoring is About Features", "year": "2017", "author": "Mina Markham", "author_slug": "minamarkham", "published": "2017-12-23T00:00:00+00:00", "url": "https://24ways.org/2017/refactoring-your-way-to-a-design-system/", "topic": "code"}
{"rowid": 211, "title": "Automating Your Accessibility Tests", "contents": "Accessibility is one of those things we all wish we were better at. It can lead to a bunch of questions like: how do we make our site better? How do we test what we have done? Should we spend time each day going through our site to check everything by hand? Or just hope that everyone on our team has remembered to check their changes are accessible?\nThis is where automated accessibility tests can come in. We can set up automated tests and have them run whenever someone makes a pull request, and even alongside end-to-end tests, too.\nAutomated tests can\u2019t cover everything however; only 20 to 50% of accessibility issues can be detected automatically. For example, we can\u2019t yet automate the comparison of an alt attribute with an image\u2019s content, and there are some screen reader tests that need to be carried out by hand too. To ensure our site is as accessible as possible, we will still need to carry out manual tests, and I will cover these later.\nFirst, I\u2019m going to explain how I implemented automated accessibility tests on Elsevier\u2019s ecommerce pages, and share some of the lessons I learnt along the way.\nPicking the right tool\nOne of the hardest, but most important parts of creating our automated accessibility tests was choosing the right tool.\nWe began by investigating aXe CLI, but soon realised it wouldn\u2019t fit our requirements. It couldn\u2019t check pages that required a visitor to log in, so while we could test our product pages, we couldn\u2019t test any customer account pages. Instead we moved over to Pa11y. Its beforeScript step meant we could log into the site and test pages such as the order history. \nThe example below shows the how the beforeScript step completes a login form and then waits for the login to complete before testing the page:\nbeforeScript: function(page, options, next) {\n  // An example function that can be used to make sure changes have been confirmed before continuing to run Pa11y\n  function waitUntil(condition, retries, waitOver) {\n    page.evaluate(condition, function(err, result) {\n      if (result || retries < 1) {\n        // Once the changes have taken place continue with Pa11y testing\n        waitOver();\n      } else {\n        retries -= 1;\n        setTimeout(function() {\n          waitUntil(condition, retries, waitOver);\n        }, 200);\n      }\n    });\n  }\n\n  // The script to manipulate the page must be run with page.evaluate to be run within the context of the page\n  page.evaluate(function() {\n    const user = document.querySelector('#login-form input[name=\"email\"]');\n    const password = document.querySelector('#login-form input[name=\"password\"]');\n    const submit = document.querySelector('#login-form input[name=\"submit\"]');\n    user.value = 'user@example.com';\n    password.value = 'password';\n    submit.click();\n  }, function() {\n    // Use the waitUntil function to set the condition, number of retries and the callback\n    waitUntil(function() {\n      return window.location.href === 'https://example.com';\n    }, 20, next);\n  });\n}\nThe waitUntil callback allows the test to be delayed until our test user is successfully logged in.\nAnother thing to consider when picking a tool is the type of error messages it produces. aXe groups all elements with the same error together, so the list of issues is a lot easier to read, and it\u2019s easier to identify the most commons problems. For example, here are some elements that have insufficient colour contrast:\nViolation of \"color-contrast\" with 8 occurrences!\nEnsures the contrast between foreground and background colors meets\nWCAG 2 AA contrast ratio thresholds. Correct invalid elements at:\n  - #maincontent > .make_your_mark > div:nth-child(2) > p > span > span\n  - #maincontent > .make_your_mark > div:nth-child(4) > p > span > span\n  - #maincontent > .inform_your_decisions > div:nth-child(2) > p > span > span\n  - #maincontent > .inform_your_decisions > div:nth-child(4) > p > span > span\n  - #maincontent > .inform_your_decisions > div:nth-child(6) > p > span > span\n  - #maincontent > .inform_your_decisions > div:nth-child(8) > p > span > span\n  - #maincontent > .inform_your_decisions > div:nth-child(10) > p > span > span\n  - #maincontent > .inform_your_decisions > div:nth-child(12) > p > span > span\nFor details, see: https://dequeuniversity.com/rules/axe/2.5/color-contrast\naXe also provides links to their site where they discuss the best way to fix the problem.\nIn comparison, Pa11y lists each individual error which can lead to a very verbose list. However, it does provide helpful suggestions of how to fix problems, such as suggesting an alternative shade of a colour to use:\n\u2022 Error: This element has insufficient contrast at this conformance level.\n  Expected a contrast ratio of at least 4.5:1, but text in this element has a contrast ratio of 2.96:1.\n  Recommendation: change text colour to #767676.\n  \u23a3 WCAG2AA.Principle1.Guideline1_4.1_4_3.G18.Fail\n  \u23a3 #maincontent > div:nth-child(10) > div:nth-child(8) > p > span > span\n  \u23a3 <span style=\"color:#969696\">Featured products:</span>\nIntegrating into our build pipeline\nWe decided the perfect time to run our accessibility tests would be alongside our end-to-end tests. We have a Jenkins job that detects changes to our staging site and then triggers the end-to-end tests, and in turn our accessibility tests. Our Jenkins job retrieves the contents of a GitHub repository containing our Pa11y script file and npm package manifest.\nOnce Jenkins has cloned the repository, it installs any dependencies and executes the tests via:\nnpm install && npm test\nBundling the URLs to be tested into our test script means we don\u2019t have a command line style test where we list each URL we wish to test in the Jenkins CLI. It\u2019s an effective method but can also be cluttered, and obscure which URLs are being tested.\nIn the middle of the office we have a monitor displaying a Jenkins dashboard and from this we can see if the accessibility tests are passing or failing. Everyone in the team has access to the Jenkins logs and when the build fails they can see why and fix the issue.\nFixing the issues\nAs mentioned earlier, Pa11y can generate a long list of areas for improvement which can be very verbose and quite overwhelming. I recommend going through the list to see which issues occur most frequently and fix those first. For example, we initially had a lot of errors around colour contrast, and one shade of grey in particular. By making this colour darker, the number of errors decreased, and we could focus on the remaining issues.\nAnother thing I like to do is to tackle the quick fixes, such as adding alt text to images. These are small things that allow us to make an impact instantly, giving us time to fix more detailed concerns such as addressing tabindex issues, or speaking to our designers about changing the contrast of elements on the site.\nManual testing\nAdding automated tests to check our site for accessibility is great, but as I mentioned earlier, this can only cover 20-50% of potential issues. To improve on this, we need to test by hand too, either by ourselves or by asking others.\nOne way we can test our site is to throw our mouse or trackpad away and interact with the site using only a keyboard. This allows us to check items such as tab order, and ensure menu items, buttons etc. can be used without a mouse. The commands may be different on different operating systems, but there are some great guides online for learning more about these. \nIt\u2019s tempting to add alt text and aria-labels to make errors go away, but if they don\u2019t make any sense, what use are they really? Using a screenreader we can check that alt text accurately represents the image. This is also a great way to double check that our ARIA roles make sense, and that they correctly identify elements and how to interact with them. When testing our site with screen readers, it\u2019s important to remember that not all screen readers are the same and some may interact with our site differently to others. \nConsider asking a range of people with different needs and abilities to test your site, too. People experience the web in numerous ways, be they permanent, temporary or even situational. They may interact with your site in ways you hadn\u2019t even thought about, so this is a good way to broaden your knowledge and awareness.\nTips and tricks\nOne of our main issues with Pa11y is that it may find issues we don\u2019t have the power to solve. A perfect example of this is the one pixel image Facebook injects into our site. So, we wrote a small function to go though such errors and ignore the ones that we cannot fix.\nconst test = pa11y({\n  ....\n  hideElements: '#ratings, #js-bigsearch',\n  ...\n});\n\nconst ignoreErrors: string[] = [\n  '<img src=\"https://books.google.com/intl/en/googlebooks/images/gbs_preview_button1.gif\" border=\"0\" style=\"cursor: pointer;\" class=\"lightbox-is-image\">',\n  '<script type=\"text/javascript\" id=\"\">var USI_orderID=google_tag_mana...</script>',\n  '<img height=\"1\" width=\"1\" style=\"display:none\" src=\"https://www.facebook.com/tr?id=123456789012345&ev=PageView&noscript=1\">'\n  ];\n  const filterResult = result => {\n    if (ignoreErrors.indexOf(result.context) > -1) {\n      return false;\n    }\n    return true;\n  };\nInitially we wanted to focus on fixing the major problems, so we added a rule to ignore notices and warnings. This made the list or errors much smaller and allowed us focus on fixing major issues such as colour contrast and missing alt text. The ignored notices and warnings can be added in later after these larger issues have been resolved. \nconst test = pa11y({\n  ignore: [\n    'notice',\n    'warning'\n  ],\n...\n});\nJenkins gotchas\nWhile using Jenkins we encountered a few problems. Sometimes Jenkins would indicate a build had passed when in reality it had failed. This was because Pa11y had timed out due to PhantomJS throwing an error, or the test didn\u2019t go past the first URL. Pa11y has recently released a new beta version that uses headless Chrome instead of PhantomJS, so hopefully these issues will less occur less often. \nWe tried a few approaches to solve these issues. First we added error handling, iterating over the array of test URLs so that if an unexpected error happened, we could catch it and exit the process with an error indicating that the job had failed (using process.exit(1)). \nfor (const url of urls) {\n  try {\n    console.log(url);\n    let urlResult = await run(url);\n    urlResult = urlResult.filter(filterResult);\n    urlResult.forEach(result => console.log(result));\n  }\n  catch (e) {\n    console.log('Error:', e);\n    process.exit(1);\n  }\n}\nWe also had issues with unhandled rejections sometimes caused by a session disconnecting or similar errors. To avoid Jenkins indicating our site was passing with 100% accessibility, when in reality it had not executed any tests, we instructed Jenkins to fail the job when an unhandled rejection or uncaught exception occurred:\nprocess.on('unhandledRejection', (reason, p) => {\n  console.log('Unhandled Rejection at:', p, 'reason:', reason);\n  process.exit(1);\n});\nprocess.on('uncaughtException', (err) => {\n  console.log('Caught exception: ${err}n');\n  process.exit(1);\n});\nNow it\u2019s your turn\nThat\u2019s it! That\u2019s how we automated accessibility testing for Elsevier ecommerce pages, allowing us to improve our site and make it more accessible for everyone. I hope our experience can help you automate accessibility tests on your own site, and bring the web a step closer to being accessible to all.", "year": "2017", "author": "Seren Davies", "author_slug": "serendavies", "published": "2017-12-07T00:00:00+00:00", "url": "https://24ways.org/2017/automating-your-accessibility-tests/", "topic": "code"}
{"rowid": 209, "title": "Feeding the Audio Graph", "contents": "In 2004, I was given an iPod.\nI count this as one of the most intuitive pieces of technology I\u2019ve ever owned.  It wasn\u2019t because of the the snazzy (colour!) menus or circular touchpad.  I loved how smoothly it fitted into my life. I could plug in my headphones and listen to music while I was walking around town.  Then when I got home, I could plug it into an amplifier and carry on listening there.\nThere was no faff. It didn\u2019t matter if I could find my favourite mix tape, or if my WiFi was flakey - it was all just there.\nNowadays, when I\u2019m trying to pair my phone with some Bluetooth speakers, or can\u2019t find my USB-to-headphone jack, or even access any music because I don\u2019t have cellular reception; I really miss this simplicity.\nThe Web Audio API\nI think the Web Audio API feels kind of like my iPod did.\nIt\u2019s different from most browser APIs - rather than throwing around data, or updating DOM elements - you plug together a graph of audio nodes, which the browser uses to generate, process, and play sounds.\nThe thing I like about it is that you can totally plug it into whatever you want, and it\u2019ll mostly just work.\nSo, let\u2019s get started. First of all we want an audio source.\n<audio src=\"night-owl.mp3\" controls />\n\n(Song - Night Owl by Broke For Free)\nThis totally works. However, it\u2019s not using the Web Audio API, so we can\u2019t access or modify the sound it makes.\nTo hook this up to our audio graph, we can use an AudioSourceNode.  This captures the sound from the element, and lets us connect to other nodes in a graph.\nconst audioCtx = new AudioContext()\n\nconst audio = document.querySelector('audio')\nconst input = audioCtx.createAudioSourceNode(audio)\n\ninput.connect(audioCtx.destination)\n\nGreat. We\u2019ve made something that looks and sounds exactly the same as it did before. Go us.\nGain\nLet\u2019s plug in a GainNode - this allows you to alter the amplitude (volume) of an an audio stream.\nWe can hook this node up to an <input> element by setting the gain property of the node.  (The syntax for this is kind of weird because it\u2019s an AudioParam which has options to set values at precise intervals).\nconst node = audioCtx.createGain()\n\nconst input = document.querySelector('input')\ninput.oninput = () => node.gain.value = parseFloat(input.value)\n\ninput.connect(node)\nnode.connect(audioCtx.destination)\n\nYou can now see a range input, which can be dragged to update the state of our graph. This input could be any kind of element, so now you\u2019ll be free to build the volume control of your dreams.\nThere\u2019s a number of nodes that let you modify/filter an audio stream in more interesting ways.  Head over to the MDN Web Audio page for a list of them.\nAnalysers\nSomething else we can add to our graph is an AnalyserNode. This doesn\u2019t modify the audio at all, but allows us to inspect the sounds that are flowing through it. We can put this into our graph between our AudioSourceNode and the GainNode.\nconst analyser = audioCtx.createAnalyser()\n\ninput.connect(analyser)\nanalyser.connect(gain)\ngain.connect(audioCtx.destination)\nAnd now we have an analyser. We can access it from elsewhere to drive any kind of visuals.  For instance, if we wanted to draw lines on a canvas we could totally do that:\nconst waveform = new Uint8Array(analyser.fftSize)\nconst frequencies = new Uint8Array(analyser.frequencyBinCount)\nconst ctx = canvas.getContext('2d')\n\nconst loop = () => {\n    requestAnimationFrame(loop)\n    analyser.getByteTimeDomainData(waveform)\n    analyser.getByteFrequencyData(frequencies)\n\n    ctx.beginPath()\n    waveform.forEach((f, i) => ctx.lineTo(i, f))\n    ctx.lineTo(0,255)\n    frequencies.forEach((f, i) => ctx.lineTo(i, 255-f))\n    ctx.stroke()\n}\nloop()\n\nYou can see that we have two arrays of data available (I added colours for clarity):\n\nThe waveform - the raw samples of the audio being played.\nThe frequencies - a fourier transform of the audio passing through the node.\n\nWhat\u2019s cool about this is that you\u2019re not tied to any specific functionality of the Web Audio API.  If it\u2019s possible for you to update something with an array of numbers, then you can just apply it to the output of the analyser node.\nFor instance, if we wanted to, we could definitely animate a list of emoji in time with our music.\nspans.forEach(\n  (s, i) => s.style.transform = `scale(${1 + (frequencies[i]/100)})`\n)\n\n\ud83d\udd08\ud83c\udfa4\ud83c\udfa4\ud83c\udfa4\ud83c\udfba\ud83c\udfb7\ud83d\udcef\ud83c\udfb6\ud83d\udd0a\ud83c\udfb8\ud83c\udfba\ud83c\udfa4\ud83c\udfb8\ud83c\udfbc\ud83c\udfb7\ud83c\udfba\ud83c\udfbb\ud83c\udfb8\ud83c\udfbb\ud83c\udfba\ud83c\udfb8\ud83c\udfb6\ud83e\udd41\ud83c\udfb6\ud83c\udfb5\ud83c\udfb5\ud83c\udfb7\ud83d\udcef\ud83c\udfb8\ud83c\udfb9\ud83c\udfa4\ud83c\udfb7\ud83c\udfbb\ud83c\udfb7\ud83d\udd08\ud83d\udd0a\ud83d\udcef\ud83c\udfbc\ud83c\udfa4\ud83c\udfb5\ud83c\udfbc\ud83d\udcef\ud83e\udd41\ud83c\udfbb\ud83c\udfbb\ud83c\udfa4\ud83d\udd09\ud83c\udfb5\ud83c\udfb9\ud83c\udfb8\ud83c\udfb7\ud83d\udd09\ud83d\udd08\ud83d\udd09\ud83c\udfb7\ud83c\udfb6\ud83d\udd08\ud83c\udfb8\ud83c\udfb8\ud83c\udfbb\ud83c\udfa4\ud83e\udd41\ud83c\udfbc\ud83d\udcef\ud83c\udfb8\ud83c\udfb8\ud83c\udfbc\ud83c\udfb8\ud83e\udd41\ud83c\udfbc\ud83c\udfb6\ud83c\udfb6\ud83e\udd41\ud83c\udfa4\ud83d\udd0a\ud83c\udfb7\ud83d\udd0a\ud83d\udd08\ud83c\udfba\ud83d\udd0a\ud83c\udfbb\ud83c\udfb5\ud83c\udfbb\ud83c\udfb8\ud83c\udfb5\ud83c\udfba\ud83c\udfa4\ud83c\udfb7\ud83c\udfb8\ud83c\udfb6\ud83c\udfbc\ud83d\udcef\ud83d\udd08\ud83c\udfba\ud83c\udfa4\ud83c\udfb5\ud83c\udfb8\ud83c\udfb8\ud83d\udd0a\ud83c\udfb6\ud83c\udfa4\ud83e\udd41\ud83c\udfb5\ud83c\udfb9\ud83c\udfb8\ud83d\udd08\ud83c\udfbb\ud83d\udd09\ud83e\udd41\ud83d\udd09\ud83c\udfba\ud83d\udd0a\ud83c\udfb9\ud83e\udd41\ud83c\udfb7\ud83d\udcef\ud83c\udfb7\ud83c\udfb7\ud83c\udfa4\ud83c\udfb8\ud83d\udd09\ud83c\udfb9\ud83c\udfb7\ud83c\udfb8\ud83c\udfba\ud83c\udfbc\ud83c\udfa4\ud83c\udfbc\ud83c\udfb6\ud83c\udfb7\ud83c\udfa4\ud83c\udfb7\ud83d\udcef\ud83d\udcef\ud83c\udfbb\ud83c\udfa4\ud83c\udfb7\ud83d\udcef\ud83c\udfb9\ud83d\udd08\ud83c\udfb5\ud83c\udfb9\ud83c\udfbc\ud83d\udd0a\ud83d\udd09\ud83d\udd09\ud83d\udd08\ud83c\udfb6\ud83c\udfb8\ud83e\udd41\ud83c\udfba\ud83d\udd08\ud83c\udfb7\ud83c\udfb5\ud83d\udd09\ud83e\udd41\ud83c\udfb7\ud83c\udfb9\ud83c\udfb7\ud83d\udd0a\ud83c\udfa4\ud83c\udfa4\ud83d\udd0a\ud83c\udfa4\ud83c\udfa4\ud83c\udfb9\ud83c\udfb8\ud83c\udfb9\ud83d\udd09\ud83c\udfb7\n\n\nGenerating Audio\nSo far, we\u2019ve been using the <audio> element as a source of sound.\nThere\u2019s a few other sources of audio that we can use.  We\u2019ll look at the AudioBufferNode - which allows you to manually generate a sound sample, and then connect it to our graph.\nFirst we have to create an AudioBuffer, which holds our raw data, then we pass that to an AudioBufferNode which we can then treat just like our AudioSource node. This can get a bit boring, so we\u2019ll use a helper method that makes it simpler to generate sounds.\nconst generator = (audioCtx, target) => (seconds, fn) => {\n  const { sampleRate } = audioCtx\n\n  const buffer = audioCtx.createBuffer(\n      1, sampleRate * seconds, sampleRate\n  )\n  const data = buffer.getChannelData(0)\n\n  for (var i = 0; i < data.length; i++) {\n    data[i] = fn(i / sampleRate, seconds)\n  }\n\n  return () => {\n    const source = audioCtx.createBufferSource()\n    source.buffer = audioBuffer\n\n    source.connect(target || audioCtx.destination)\n    source.start()  \n  }\n}\n\nconst sound = generator(audioCtx, gain)\nOur wrapper will let us provide a function that maps time (in seconds) to a sample (between 1 and -1). This generates a waveform, like we saw before with the analyser node.\nFor example, the following will generate 0.75 seconds of white noise at 20% volume.\nconst noise = sound(0.75, t => Math.random() * 0.2)\n\nbutton.onclick = noise\n\nNoise\n\n\nNow we\u2019ve got a noisy button! Handy.\nRather than having a static set of audio nodes, each time we click the button, we add a new node to our graph. Although this feels inefficient, it\u2019s not actually too bad - the browser can do a good job of cleaning up old nodes once they\u2019ve played.\nAn interesting property of defining sounds as functions is that we can combine multiple function to generate new sounds. So if we wanted to fade our noise in and out, we could write a higher order function that does that.\nconst ease = fn => (t, s) =>\n  fn(t) * Math.sin((t / s) * Math.PI)\n\nconst noise = sound(0.75, ease(t => Math.random() * 0.2))\n\nease(noise)\n\n\nAnd we can do more than just white noise - if we use Math.sin, we can generate some nice pure tones.\n// Math.sin with period of 0..1\nconst wave = v => Math.sin(Math.PI * 2 * v)\nconst hz = f => t => wave(t * f)\n\nconst _440hz = sound(0.75, ease(hz(440)))\nconst _880hz = sound(0.75, ease(hz(880)))\n\n440Hz\n880Hz\n\n\nWe can also make our functions more complex. Below we\u2019re combining several frequencies to make a richer sounding tone.\nconst harmony = f => [4, 3, 2, 1].reduce(\n    (v, h, i) => (sin(f * h) * (i+1) ) + v\n)\n\nconst a440 = sound(0.75, ease(harmony(440)))\n\n440Hz\n880Hz\n\n\nCool.\nWe\u2019re still not using any audio-specific functionality, so we can repurpose anything that does an operation on data. For example, we can use d3.js - usually used for interactive data visualisations - to generate a triangular waveform.\nconst triangle = d3.scaleLinear()\n    .domain([0, .5,  1])\n    .range([-1,  1, -1])\n\nconst wave = t => triangle(t % 1)\n\nconst a440 = sound(0.75, ease(harmony(440)))\n\n440Hz\n880Hz\n\n\nIt\u2019s pretty interesting to play around with different functions. I\u2019ve plonked everything in jsbin if you want to have a play yourself.\nA departure from best practice\nWe\u2019ve been generating our audio from scratch, but most of what we\u2019ve looked at can be implemented by a series of native Web Audio nodes. This would be way performant (because it\u2019s not happening on the main thread), and more flexible in some ways (because you can set timings dynamically whilst the note is playing). But we\u2019re going to stay with this approach because it\u2019s fun, and sometimes the fun thing to do might not technically be the best thing to do.\nMaking a keyboard\nHaving a button that makes a sound is totally great, but how about lots of buttons that make lots of sounds?  Yup, totally greater-er.\nThe first thing we need to know is the frequency of each note. I thought this would be awkward because pianos were invented more than 250 years before the Hz unit was defined, so surely there wouldn\u2019t be a simple mapping between the two?\nconst freq = note => 27.5 * Math.pow(2, (note - 21) / 12)\nThis equation blows my mind; I\u2019d never really figured how tightly music and maths fit together.  When you see a chord or melody, you can directly map it back to a mathematical pattern.\nOur keyboard is actually an SVG picture of a keyboard, so we can traverse the elements of it and map each element to a sound generated by one of the functions that we came up with before.\nArray.from(svg.querySelector('rect'))\n  .sort((a, b) => + a.x - b.x)\n  .forEach((key, i) =>\n    key.addEventListener('touchstart',\n      sound(0.75, ease(harmony(freq(i + 48))))\n    )\n  )\n\nrect {stroke: #ddd;}\nrect:hover {opacity: 0.8; stroke: #000}\n\nEt voil\u00e0. We have a keyboard.\nWhat I like about this is that it\u2019s completely pure - there\u2019s no lookup tables or hardcoded attributes; we\u2019ve just defined a mapping from SVG elements to the sound they should probably make.\nDoing better in the future\nAs I mentioned before, this could be implemented more performantly with Web Audio nodes, or even better - use something like Tone.js to be performant for you.\nWeb Audio has been around for a while, though we\u2019re getting new challenges with immersive WebXR experiences, where spatial audio becomes really important. There\u2019s also always support and API improvements (if you like AudioBufferNode, you\u2019re going to love AudioWorklet)\nConclusion\nAnd that\u2019s about it. Web Audio isn\u2019t some black box, you can easily link it with whatever framework, or UI that you\u2019ve built (whether you should is an entirely different question).\nIf anyone ever asks you \u201ccould you turn this SVG into a musical instrument?\u201d you don\u2019t have to stare blankly at them any more.\n(function(a,c){var b=a.createElement(\"script\");if(!(\"noModule\"in b)&&\"on\"+c in b){var d=!1;a.addEventListener(c,function(a){if(a.target===b)d=!0;else if(!a.target.hasAttribute(\"nomodule\")||!d)return;a.preventDefault()},!0);b.type=\"module\";b.src=\".\";a.head.appendChild(b);b.remove()}})(document,\"beforeload\");", "year": "2017", "author": "Ben Foxall", "author_slug": "benfoxall", "published": "2017-12-17T00:00:00+00:00", "url": "https://24ways.org/2017/feeding-the-audio-graph/", "topic": "code"}
{"rowid": 206, "title": "Getting Hardboiled with CSS Custom Properties", "contents": "Custom Properties are a fabulous new feature of CSS and have widespread support in contemporary browsers. But how do we handle browsers without support for CSS Custom Properties? Do we wait until those browsers are lying dead in a ditch before we use them? Do we tool up and prop up our CSS using a post-processor? Or do we get tough? Do we get hardboiled?\nPreviously only pre-processing tools like LESS and Sass enabled developers to use variables in their stylesheets, but now Custom Properties have brought variables natively to CSS.\nHow do you write a custom property? It\u2019s hardly a mystery. Simply add two dashes to the start of a style rule. Like this:\n--color-text-default : black;\nIf you\u2019re more the underscore type, try this:\n--color_text_default : black;\nHyphens or underscores are allowed in property names, but don\u2019t be a chump and try to use spaces. \nCustom property names are also case-sensitive, so --color-text-default and --Color_Text_Default are two distinct properties.\nTo use a custom property in your style rules, var() tells a browser to retrieve the value of a property. In the next example, the browser retrieves the black colour from the color-text-default variable and applies it to the body element:\nbody {\n    color : var(--color-text-default); \n}\nLike variables in LESS or Sass, CSS Custom Properties mean you don\u2019t have to be a dumb mug and repeat colour, font, or size values multiple times in your stylesheets. Unlike a preprocessor variable though, CSS Custom Properties use the cascade, can be modified by media queries and other state changes, and can also be manipulated by Javascript.\n(Serg Hospodarets wrote a fabulous primer on CSS Custom Properties where he dives deeper into the code and possible applications.)\nBrowser support\nNow it\u2019s about this time that people normally mention browser support. So what about support for CSS Custom Properties? Current versions of Chrome, Edge, Firefox, Opera, and Safari are all good. Internet Explorer 11 and before? Opera Mini? Nasty.\nSound familiar?\n\n  Can I Use css-variables? Data on support for the css-variables feature across the major browsers from caniuse.com.\n\nNot to worry, we can manually check for Custom Property support in a browser by using an @support directive, like this:\n--color-text-default : black;\n\nbody {\n    color : black;  \n}\n\n@supports ((--foo : bar)) {\n    body {\n        color : var(--color-text-default); \n    }\n}\nIn that example we first set body element text to black and then override that colour with a Custom Property value when the browser supports our fictitious foo bar variable.\nSubstitutions\nIf we reference a variable that hasn\u2019t been defined, that won\u2019t be a problem as browsers are smart enough to ignore the value altogether. If we need a cast iron alibi, use substitutions to specify a fall-back value.\nbody {\n    color : var(--color-text-default, black); \n}\nSubstitutions are similar to font stacks in that they contain a comma separated list of values. If there\u2019s no value associated with a property, a browser will ignore it and move onto the next value in the list.\nPost-processing\nOf course we could use a post-processor plugin to turn Custom Properties into plain CSS, but hang on one goddam minute kiddo.\nHaven\u2019t we been down this road before? Didn\u2019t we engineer elaborate workarounds to enable us to use \u2018advanced\u2019 CSS3 properties like border-radius, CSS columns, and Flexbox in the past? We did what we had to do to get the job done, but came away feeling dirty.\nI think there\u2019s a better way, one that allows us to enjoy the benefits of CSS Custom Properties in browsers that support them, while providing an appropriate, but not identical experience, for people who use less capable browsers. Guess what, I\u2019ve been down this road before too. \n2Tone Stuff & Nonsense\nWhen Internet Explorer 6 was the big dumb browser everyone hated, I served two different designs on my website. \nFor the modern browsers of the time, mod arrows and targets were everywhere in glorious red, white, and blue, and I implemented all of them using CSS attribute selectors which were considered advanced at the time:\n[class=\"banner\"] {\n    background-colour : red; \n}\nInternet Explorer 6 ignored any selectors it didn\u2019t understand, so people using that browser saw a simpler black and white, 2Tone-based design that I\u2019d implemented for them using class selectors:\n.banner {\n    background-colour : black; \n}\n\n[class=\"banner\"] {\n    background-colour : red; \n}\n\nYou don\u2019t have to be a detective to find out that most people thought I\u2019d lost my wits, but Microsoft even used my website as a reference when they tested attribute selectors in Internet Explorer 7. They did, as I suggested, \u201cStomp to da betta browser.\u201d\nDumb browsers look the other way\nSo how does this approach relate to tackling any lack of support for CSS Custom Properties? How can we take advantage of them without worrying about browsers with no support and having to implement complex workarounds, or spending hours specifying fallbacks that perfectly match our designs?\nTurns out, the answer is built into CSS, and always has been, because when browsers don\u2019t know what they\u2019re looking at, they look away. \nAll we have to do is first specify values for a simpler design first, and then follow that up with the values in our CSS Custom Properties:\nbody {\n    color : black;\n    color : var(--color-text-default, black); \n}\nAll browsers understand the first value (black,) and if they\u2018re smart enough to understand the second (var(--color-text-default)), they\u2019ll use it and override the first. If they\u2019re too damn stupid to understand the custom property value, they\u2019ll ignore it. Nobody dies.\nRepeat this for every style that contains a variable, baking an alternative, perhaps simpler design into your stylesheets for people who use less capable browsers, just like I did with Stuff & Nonsense.\nConclusion\nI doubt that anyone agrees with presenting a design that looks broken or unloved\u2014and I\u2019m not advocating for that\u2014but websites need not look the same in every browser. We can use substitutions to present a simpler design to people using less capable browsers.\nThe decision when to start using new CSS properties isn\u2018t always a technical one. Sometimes a change in attitude about browser support is all that\u2019s required. So get tough with dumb browsers and benefit from all the advantages that CSS Custom Properties offer. Get hardboiled.\nResources:\n\nIt\u2019s Time To Start Using CSS Custom Properties\u2014Smashing Magazine\nUsing CSS variables correctly\u2014Mike Riethmuller\nDeveloping Inspired Guides with CSS Custom Properties (variables)\u2014Andy Clarke", "year": "2017", "author": "Andy Clarke", "author_slug": "andyclarke", "published": "2017-12-13T00:00:00+00:00", "url": "https://24ways.org/2017/getting-hardboiled-with-css-custom-properties/", "topic": "code"}
{"rowid": 204, "title": "Cascading Web Design with Feature Queries", "contents": "Feature queries, also known as the @supports rule, were introduced as an extension to the CSS2 as part of the CSS Conditional Rules Module Level 3, which was first published as a working draft in 2011. It is a conditional group rule that tests if the browser\u2019s user agent supports CSS property:value pairs, and arbitrary conjunctions (and), disjunctions (or), and negations (not) of them.\nThe motivation behind this feature was to allow authors to write styles using new features when they were supported but degrade gracefully in browsers where they are not. Even though the nature of CSS already allows for graceful degradation, for example, by ignoring unsupported properties or values without disrupting other styles in the stylesheet, sometimes we need a bit more than that.\nCSS is ultimately a holistic technology, in that, even though you can use properties in isolation, the full power of CSS shines through when used in combination. This is especially evident when it comes to building web layouts. Having native feature detection in CSS makes it much more convenient to build with cutting-edge CSS for the latest browsers while supporting older browsers at the same time.\nBrowser support\nOpera first implemented feature queries in November 2012, both Chrome and Firefox had it since May 2013. There have been several articles about feature queries written over the years, however, it seems that awareness of its broad support isn\u2019t that well-known. Much of the earlier coverage on feature queries was not written in English, and perhaps that was a limiting factor.\n\n@supports \u2015 CSS\u306eFeature Queries by Masataka Yakura, August 8 2012\nNative CSS Feature Detection via the @supports Rule by Chris Mills, December 21 2012\nCSS @supports by David Walsh, April 3 2013\nResponsive typography with CSS Feature Queries by Aral Balkan, April 9 2013\nHow to use the @supports rule in your CSS by Lea Verou, January 31 2014\nCSS Feature Queries by Amit Tal, June 2 2014\nComing Soon: CSS Feature Queries by Adobe Web Platform Team, August 21 2014\nCSS feature queries mittels @supports by Daniel Erlinger, November 27 2014\n\nAs of December 2017, all current major browsers and their previous 2 versions support feature queries. Feature queries are also supported on Opera Mini, UC Browser and Samsung Internet. The only browsers that do not support feature queries are Internet Explorer and Blackberry Mobile, but that may be less of an issue than you might think.\n\n  Can I Use css-featurequeries? Data on support for the css-featurequeries feature across the major browsers from caniuse.com.\n\nGranted, there is still a significant number of organisations that require support of Internet Explorer. Microsoft still continues to support IE11 for the life-cycle of Windows 7, 8 and 10. They have, however, stopped supporting older versions since January 12, 2016. It is inevitable that there will be organisations that, for some reason or another, make it mandatory to support IE, but as time goes on, this number will continue to shrink.\nJen Simmons wrote an extensive article called Using Feature Queries in CSS which discussed a matrix of potential situations when it comes to the usage of feature queries. The following image is a summary of the aforementioned matrix.\n\nThe most tricky situation we have to deal with is the box in the top-left corner, which are \u201cbrowsers that don\u2019t support feature queries, yet do support the feature in question\u201d. For cases like those, it really depends on the specific CSS feature you want to use and a subsequent evaluation of the pros and cons of not including that feature in spite of the fact the browser (most likely Internet Explorer) supports it.\nThe basics of feature queries\nAs with any conditional, feature queries operate on boolean logic, in other words, if the query resolves to true, apply the CSS properties within the block, or else just ignore the entire block altogether. The syntax of a simple feature query is as follows:\n.selector {\n  /* Styles that are supported in old browsers */\n}\n\n@supports (property:value) {\n  .selector {\n    /* Styles for browsers that support the specified property */\n  }\n}\nNote that the parentheses around the property:value pair are mandatory and the rule is invalid without them. Styles that apply to older browsers, i.e. fallback styles, should come first, followed by the newer properties, which are contained within the @supports conditional. Because of the cascade, fallback styles will be overridden by the newer properties in the modern browsers that support them.\nmain {\n  background-color: red;\n}\n\n@supports (display:grid) {\n  main {\n    background-color: green;\n  }\n}\nIn this example, browsers that support CSS grid will have a main element with a green background colour because the conditional resolves to true, while browsers that do not support grid will have a main element with a red background colour.\nThe implication of such behaviour means that we can layer on enhanced styles based on the features we want to use and these styles will show up in browsers that support them. But for those that do not, they will get a more basic look that still works anyway. And that will be our approach moving forward.\nBoolean operators for feature queries\nThe and operator allows us to test for support of multiple properties within a single conditional. This would be useful for cases where the desired output requires multiple cutting-edge features to be supported at the same time to work. All the property:value pairs listed in the conditional must resolve to true for the styles within the rule to be applied.\n@supports (transform: rotate(45deg)) and\n          (writing-mode: vertical-rl) {\n  /* Some CSS styles */\n}\nThe or operator allows us to list multiple property:value pairs in the conditional and as long as one of them resolves to true, the styles within the block will be applied. A relevant use-case would be for properties with vendor-prefixes.\n@supports (background: -webkit-gradient(linear, left top, left bottom, from(white), to(black))) or\n          (background: -o-linear-gradient(top, white, black)) or\n          (background: linear-gradient(to bottom, white, black)) {\n  /* Some CSS styles */\n}\nThe not operator negates the resolution of the property:value pair in the conditional, resolving to false when the property is supported and vice versa. This is useful when there are two distinct sets of styles to be applied depending on the support of a specific feature. However, we do need to keep in mind the case where a browser does not support feature queries, and handle the styles for those browsers accordingly.\n@supports not (shape-outside: polygon(100% 80%,20% 0,100% 0)) {\n  /* Some CSS styles */\n}\nTo avoid confusion between and and or, these operators must be explicitly declared as opposed to using commas or spaces. To prevent confusion caused by precedence rules, and, or and not operators cannot be mixed without a layer of parentheses.\nThis rule is not valid and the styles within the block will be ignored.\n@supports (transition-property: background-color) or\n          (animation-name: fade) and\n          (transform: scale(1.5)) {\n  /* Some CSS styles */\n}\nTo make it work, parentheses must be added either around the two properties adjacent to the or or the and operator like so:\n@supports ((transition-property: background-color) or\n          (animation-name: fade)) and\n          (transform: scale(1.5)) {\n  /* Some CSS styles */\n}\n@supports (transition-property: background-color) or\n          ((animation-name: fade) and\n          (transform: scale(1.5))) {\n  /* Some CSS styles */\n}\nThe current specification states that whitespace is required after a not and on both sides of an and or or, but this may change in a future version of the specification. It is acceptable to add extra parentheses even when they are not needed, but omission of parentheses is considered invalid.\nCascading web design\nI\u2019d like to introduce the concept of cascading web design, an approach made possible with feature queries. Browser update cycles are much shorter these days, so new features and bug fixes are being pushed out a lot more frequently as compared to the early days of the web.\nWith the maturation of web standards, browser behaviour is less unpredictable than before, but each browser will still have their respective quirks. Chances are, the latest features will not ship across all browsers at the same time. But you know what? That\u2019s perfectly fine. If we accept this as a feature of the web, instead of a bug, we\u2019ve just opened up a lot more web design possibilities.\nThe following example is a basic, responsive grid layout of items laid out with flexbox, as viewed on IE11.\n\nWe can add a block of styles within an @supports rule to apply CSS grid properties for browsers that support them to enhance this layout, like so:\n\nThe web is not a static medium. It is dynamic and interactive and we manipulate this medium by writing code to tell the browser what we want it to do. Rather than micromanaging the pixels in our designs, maybe it\u2019s time we cede control of our designs to the browsers that render them. This means being okay with your designs looking different across browsers and devices.\nAs mentioned earlier, CSS works best when various properties are combined. It\u2019s one of those things whose whole is greater than the sum of its parts. So feature queries, when combined with media queries, allow us to design layouts that are most effective in the environment they have to perform in.\nSuch an approach requires interpolative thinking, on multiple levels. As web designers and developers, we don\u2019t just think in one fixed dimension, we get to think about how our design will morph on a narrow screen, or on an older browser, in addition to how it will appear on a browser with the latest features.\nIn the following example, the layout on the left is what IE11 users will see, the one in the middle is what Firefox users will see, because Firefox doesn\u2019t support CSS shapes yet, but once it does, it will then look like the layout on the right, which is what Chrome users see now.\n\nWith the release of CSS Grid this year, we\u2019ve hit another milestone in the evolution of the web as a medium. The beauty of the web is its backwards compatibility and generous fault tolerance. Browser features are largely additive, holding onto the good parts and building on top of them, while deprecating the bits that didn\u2019t work well.\nFeature queries allow us to progressively enhance our CSS, establishing a basic level of user experience across the widest range of browsers, while building in more advanced functionality for browsers who can use them. And hopefully, this will allow more of us to create designs that truly embrace the nature of the web.", "year": "2017", "author": "Chen Hui Jing", "author_slug": "chenhuijing", "published": "2017-12-01T00:00:00+00:00", "url": "https://24ways.org/2017/cascading-web-design/", "topic": "code"}
{"rowid": 202, "title": "Design Systems and CSS Grid", "contents": "Recently, my client has been looking at creating a few new marketing pages for their website. They currently have a design system in place but they\u2019re looking to push this forward into 2018 with some small and possibly some larger changes.\nTo start with we are creating a couple of new marketing pages. As well as making use of existing components within the design systems component library there are a couple of new components. Looking at the first couple of sketch files I felt this would be a great opportunity to use CSS Grid, to me the newer components need to be laid out on that page and grid would help with this perfectly.\n\nAs well as this layout of the new components and the text within it, imagery would be used that breaks out of the grid and pushes itself into the spaces where the text is aligned.\nThe existing grid system\nWhen the site was rebuilt in 2015 the team decided to make use of Sass and Susy, a \u201clightweight grid-layout engine using Sass\u201d.  It was built separating the grid system from the components that would be laid out on the page with a container, a row, an optional column, and a block.\nTo make use of the grid system on a page for a component that would take the full width of the row you would have to write something like this:\n<div class=\"grid-container\">\n  <div class=\"grid-row\">\n    <div class=\"grid-column-4\">\n      <div class=\"grid-block\">\n        <!-- component code here -->\n      </div>\n    </div>\n  </div>\n</div>\nUsing a grid system similar to this can easily create quite the tag soup. It could fill the HTML full of divs that may become complex to understand and difficult to edit.\nAlthough there is this reliance on several <div>s to lay out the components on a page it does allow a tidy way to place the component code within that page. It abstracts the layout of the page to its own code, its own system, so the components can \u2018fit\u2019 where needed.\nThe requirements of the new grid system\nMoving forward I set myself some goals for what I\u2019d like to have achieved in this new grid system:\nIt needs to behave like the existing grid systems\nWe are not ripping up the existing grid system, it would be too much work, for now,  to retrofit all of the existing components to work in a grid that has a different amount of columns, and spacing at various viewport widths.\nAllow full-width components\nCurrently the grid system is a 14 column grid that becomes centred on the page when viewport is wide enough. We have, in the past, written some CSS that would allow for a full-width component, but his had always felt like a hack. We want the option to have a full-width element as part of the new grid system, not something that needs CSS to fight against.\nLess of a tag soup\nIdeally we want to end up writing less HTML to layout the page. Although the existing system can be quite clear as to what each element is doing, it can also become a little laborious in working out what each grid row or block is doing where.\nI would like to move the layout logic to CSS as much as is possible, potentially creating some utility classes or additional \u2018layout classes\u2019 for the components.\nEasier for people to use and author\nWith many people using the existing design systems codebase  we need to create a new grid system that is as easy or easier to use than the existing one. I think and hope this would be helped by removing as many <div>s as needed and would require new documentation and examples, and potentially some initial training.\nSeparating layout from style\nThere still needs to be a separation of layout from the styles for the component. To allow for the component itself to be placed wherever needed in the page we need to make sure that the CSS for the layout is a separate entity to the CSS for that styling.\nWith these base requirements I took to CodePen and started working on some throwaway code to get started.\nMaking the new grid(s)\nThe Full-Width Grid\nTo start with I created a grid that had three columns, one for the left, one for the middle, and one for the right. This would give the full-width option to components.\nThankfully, one of Rachel Andrew\u2019s many articles on Grid discussed this exact requirement of the new grid system to break out with Grid.\nI took some of the code in the examples and edited to make grid we needed.\n.container {\n  display: grid;\n  grid-template-columns:\n    [full-start]\n      minmax(.75em, 1fr)\n        [main-start]\n          minmax(0, 1008px)\n        [main-end]\n      minmax(.75em, 1fr)\n    [full-end];\n}\nWe are declaring a grid, we have four grid column lines which we name and we define how the three columns they create react to the viewport width. We have a left and right column that have a minimum of 12px, and a central column with a maximum width of 1008px.\nBoth left and right columns fill up any additional space if the viewport is wider that 1032px wide. We are also not declaring any gutters to this grid, the left and right columns would act as gutters at smaller viewports.\nAt this point I noticed that older versions of Sass cannot parse the brackets in this code. To combat this I used Sass\u2019 unquote method  to wrap around the value of the grid-template-column.\n.container {\n  display: grid;\n  grid-template-columns:\n  unquote(\"\n    [full-start]\n      minmax(.75em, 1fr)\n        [main-start]\n          minmax(0, 1008px)\n        [main-end]\n      minmax(.75em, 1fr)\n    [full-end]\n  \");\n}\nThe existing codebase makes use of Sass variables, mixins and functions so to remove that would be a problem, but luckily the version of Sass used is up-to-date (note: example CodePens will be using CSS).\nThe initial full-width grid displays on a webpage as below:\n\nThe 14 column grid\nI decided to work out the 14 column grid as a separate prototype before working out how it would fit within the full-width grid. This grid is very similar to the 12 column grids that have been used in web design. Here we need 14 columns with a gutter between each one.\nAlong with the many other resources on Grid, Mozilla\u2019s MDN site had a page on common layouts using CSS Grid. This gave me the perfect CSS I needed to create my grid and I edited it as required:\n.inner {\n  display: grid;\n  grid-template-columns: repeat(14, [col-start] 1fr);\n  grid-gap: .75em;\n}\nWe, again, are declaring a grid, and we are splitting up the available space by creating 14 columns with 1 fr-unit and giving each one a starting line named col-start.\nThis grid would display on web page as below:\n\nBringing the grids together\nNow that we have got the two grids we need to help fulfil our requirements we need to put them together so that they are actually we we need.\nThe subgrid\nThere is no subgrid in CSS, yet. To workaround this for the new grid system we could nest the 14 column grid inside the full-width grid.\nIn the HTML we nest the 14 column inner grid inside the full-width container.\n<div class=\"container\">\n  <div class=\"inner\">\n  </div>\n</div>\nSo that the inner knows where to be laid out within the container we tell it what column to start and end with, with this code it would be the start and end of the main column.\n.inner {\n  display: grid;\n  grid-column: main-start / main-end;\n  grid-template-columns: repeat(14, [col-start] 1fr);\n  grid-gap: .75em;\n}\nThe CSS for the container remains unchanged.\n\nThis works, but we have added another div to our HTML. One of our requirements is to try and remove the potential for tag soup.\nThe faux subgrid subgrid\nI wanted to see if it would be possible to place the CSS for the 14 column grid within the CSS for the full-width grid. I replaced the CSS for the main grid and added the grid-column-gap to the .container.\n.container {\n  display: grid;\n  grid-gap: .75em;\n  grid-template-columns:\n    [full-start]\n      minmax(.75em, 1fr)\n        [main-start]\n          repeat(14, [col-start] 1fr)\n        [main-end]\n      minmax(.75em, 1fr)\n    [full-end];\n}\nWhat this gave me was a 16 column grid. I was unable to find a way to tell the main grid, the grid betwixt main-start and main-end to be a maximum of 1008px as required.\n\nI trawled the internet to find if it was possible to create our main requirement, a 14 column grid which also allows for full-width components. I found that we could not reverse minmax to minmax(1fr, 72px) as 1fr is not allowed as a minimum if there is a maximum. I tried working out if we could make the min larger than its max but in minmax it would be ignored.\nI was struggling, I was hoping for a cleaner version of the grid system we currently use but getting to the point where needing that extra <div> would be a necessity.\nAt 3 in the morning, when I was failing to get to sleep, my mind happened upon an question: \u201cCould you use calc?\u201d\nAt some point I drifted back to sleep so the next day I set upon seeing if this was possible. I knew that the maximum width of the central grid needed to be 1008px. The left and right columns needed to be however many pixels were left in the viewport divided by 2. In CSS it looked like I would need to use calc twice. The first time to takeaway 1008px from 100% of the viewport width and the second to divide that result by 2.\ncalc(calc(100% - 1008px) / 2)\nThe CSS above was part of the value that I would need to include in the declaration for the grid.\n.container {\n  display: grid;\n  grid-gap: .75em;\n  grid-template-columns:\n    [full-start]\n      minmax(calc(calc(100% - 1008px) / 2), 1fr)\n        [main-start]\n          repeat(14, [col-start] 1fr)\n        [main-end]\n      minmax(calc(calc(100% - 1008px) / 2), 1fr)\n    [full-end];\n}\nWe have created the grid required. A full-width grid, with a central 14 column grid, using fewer <div> elements.\n\nSee the Pen Design Systems and CSS Grid, 6 by Stuart Robson (@sturobson) on CodePen.\n\nSuccess!\nProgressive enhancement\nNow that we have created the grid system required we need to back-track a little.\nNot all browsers support Grid, over the last 9 months or so this has gotten a lot better. However there will still be browsers that visit that potentially won\u2019t have support. The effort required to make the grid system fall back for these browsers depends on your product or sites browser support.\n\nTo determine if we will be using Grid or not for a browser we will make use of  feature queries. This would mean that any version of Internet Explorer will not get Grid, as well as some mobile browsers and older versions of other browsers.\n@supports (display: grid) {\n /* Styles for browsers that support Grid */\n}\nIf a browser does not pass the requirements for @supports we will fallback to using flexbox where possible, and if that is not supported we are happy for the page to be laid out in one column.\nA website doesn\u2019t have to look the same in every browser after all.\nA responsive grid\nWe started with the big picture, how the grid would be at a large viewport and the grid system we have created gets a little silly when the viewport gets smaller.\nAt smaller viewports we have a single column layout where every item of content, every component stacks atop each other. We don\u2019t start to define a grid before we the viewport gets to 700px wide. At this point we have an 8 column grid and if the viewport gets to 1100px or wider  we have our 14 column grid.\n/*\n * to start with there is no 'grid' just a single column\n */\n.container {\n  padding: 0 .75em;\n}\n\n/*\n * when we get to 700px we create an 8 column grid with\n * a left and right area to breakout of the grid.\n */\n@media (min-width: 700px) {\n  .container {\n    display: grid;\n    grid-gap: .75em;\n    grid-template-columns:\n      [full-start]\n        minmax(calc(calc(100% - 1008px) / 2), 1fr)\n          [main-start]\n            repeat(8, [col-start] 1fr)\n          [main-end]\n        minmax(calc(calc(100% - 1008px) / 2), 1fr)\n      [full-end];\n    padding: 0;\n  }\n}\n\n/*\n * when we get to 1100px we create an 14 column grid with\n * a left and right area to breakout of the grid.\n */\n@media (min-width: 1100px) {\n  .container {\n    grid-template-columns:\n    [full-start]\n      minmax(calc(calc(100% - 1008px) / 2), 1fr)\n        [main-start]\n          repeat(14, [col-start] 1fr)\n        [main-end]\n      minmax(calc(calc(100% - 1008px) / 2), 1fr)\n    [full-end];\n  }\n}\nBeing explicit in creating this there is some repetition that we could avoid, we will define the number of columns for the inner grid by using a Sass variable or CSS custom properties (more commonly termed as CSS variables).\nLet\u2019s use CSS custom properties. We need to declare the variable first by adding it to our stylesheet.\n:root {\n  --inner-grid-columns: 8;\n}\nWe then need to edit a few more lines. First make use of the variable for this line.\nrepeat(8, [col-start] 1fr)\n/* replace with */\nrepeat(var(--inner-grid-columns), [col-start] 1fr)\nThen at the 1100px breakpoint we would only need to change the value of the \u2014inner-grid-columns value.\n@media (min-width: 1100px) {\n  .container {\n    grid-template-columns:\n    [full-start]\n      minmax(calc(calc(100% - 1008px) / 2), 1fr)\n        [main-start]\n          repeat(14, [col-start] 1fr)\n        [main-end]\n      minmax(calc(calc(100% - 1008px) / 2), 1fr)\n    [full-end];\n  }\n}\n/* replace with */\n@media (min-width: 1100px) {\n  .container {\n    --inner-grid-columns: 14;\n  }\n}\nSee the Pen Design Systems and CSS Grid, 8 by Stuart Robson (@sturobson) on CodePen.\n\nThe final grid system\nWe have finally created our new grid for the design system. It stays true to the existing grid in place, adds the ability to break-out of the grid, removes a <div> that could have been needed for the nested 14 column grid.\nWe can move on to the new component.\nCreating a new component\nBack to the new components we are needing to create.\n\nTo me there are two components one of which is a slight variant of the first. This component contains a title, subtitle, a paragraph (potentially paragraphs) of content, a list, and a call to action.\nTo start with we should write the HTML for the component, something like this:\n<article class=\"features\">\n  <h3 class=\"features__title\"></h3>\n  <p class=\"features__subtitle\"></p>\n  <div class=\"features__content\">\n    <p class=\"features__paragraph\"></p>\n  </div>\n  <ul class=\"features__list\">\n    <li></li>\n    <li></li>\n  </ul>\n  <a href=\"\" class=\"features__button\"></a>\n</article>\nTo place the component on the existing grid is fine, but as child elements are not affected by the container grid we need to define another grid for the features component.\nAs the grid doesn\u2019t get invoked until 700px it is possible to negate the need for a media query.\n.features {\n  grid-column: col-start 1 / span 6;\n}\n\n@supports (display: grid) {\n  @media (min-width: 1100px) {\n    .features {\n      grid-column-end: 9;\n    }\n  }\n}\nWe can also avoid duplication of declarations by making use of the grid-column shorthand and longhand. We need to write a little more CSS for the variant component, the one that will sit on the right side of the page too.\n.features:nth-of-type(even) {\n  grid-column-start: 4;\n  grid-row: 2;\n}\n\n@supports (display: grid) {\n  @media (min-width: 1100px) {\n    .features:nth-of-type(even) {\n      grid-column-start: 9;\n      grid-column-end: 16;\n    }\n  }\n}\nWe cannot place the items within features on the container grid as they are not direct children. To make this work we have to define a grid for the features component.\nWe can do this by defining the grid at the first breakpoint of 700px making use of CSS custom properties again to define how many columns there will need to be.\n.features {\n  grid-column: col-start 1 / span 6;\n  --features-grid-columns: 5;\n}\n\n@supports (display: grid) {\n  @media (min-width: 700px) {\n    .features {\n      display: grid;\n    grid-gap: .75em;\n      grid-template-columns: repeat(var(--features-grid-columns), [col-start] 1fr);\n    }\n  }\n}\n\n@supports (display: grid) {\n  @media (min-width: 1100px) {\n    .features {\n      grid-column-end: 9;\n      --features-grid-columns: 7;\n    }\n  }\n}\nSee the Pen Design Systems and CSS Grid, 10 by Stuart Robson (@sturobson) on CodePen.\n\nLaying out the parts\nLooking at the spec and reading several articles I feel there are two ways that I could layout the text of this component on the grid.\nWe could use the grid-column shorthand that incorporates grid-column-start and grid-column-end or we can make use of grid-template-areas.\ngrid-template-areas allow for a nice visual way of representing how the parts of the component would be laid out. We can take the the mock of the features on the grid and represent them in text in our CSS.\n\nWithin the .features  rule we can add the relevant grid-template-areas value to represent the above.\n.features {\n  display: grid;\n  grid-template-columns: repeat(var(--features-grid-columns), [col-start] 1fr);\n  grid-template-areas:\n   \". title     title     title     title     title    title\"\n   \". subtitle  subtitle  subtitle  subtitle  subtitle .    \"\n   \". content   content   content   content   .        .    \"\n   \". list      list      list      .         .        .    \"\n   \". .         .         .         link      link     link \";\n}\n\nIn order to make the variant of the component we would have to create the grid-template-areas for that component too.\nWe then need to tell each element of the component in what grid-area it should be placed within the grid.\n.features__title { grid-area: title; }\n.features__subtitle { grid-area: subtitle; }\n.features__content { grid-area: content; }\n.features__list { grid-area: list; }\n.features__link { grid-area: link; }\nSee the Pen Design Systems and CSS Grid, 12 by Stuart Robson (@sturobson) on CodePen.\n\nThe other way would be to use the grid-column shorthand and the grid-column-start and grid-column-end we have used previously.\n.features .features__title {\n  grid-column: col-start 2 / span 6;\n}\n.features .features__subtitle {\n  grid-column: col-start 2 / span 5;\n}\n.features .features__content {\n  grid-column: col-start 2 / span 4;\n}\n.features .features__list {\n  grid-column: col-start 2 / span 4;\n}\n.features .features__link {\n  grid-column: col-start 5 / span 3;\n}\nFor the variant of the component we can use the grid-column-start property as it will inherit the span defined in the grid-column shorthand.\n.features:nth-of-type(even) .features__title {\n  grid-column-start: col-start 1;\n}\n.features:nth-of-type(even) .features__subtitle {\n  grid-column-start: col-start 1;\n}\n.features:nth-of-type(even) .features__content {\n  grid-column-start: col-start 3;\n}\n.features:nth-of-type(even) .features__list {\n  grid-column-start: col-start 3;\n}\n.features:nth-of-type(even) .features__link {\n  grid-column-start: col-start 1;\n}\nSee the Pen Design Systems and CSS Grid, 14 by Stuart Robson (@sturobson) on CodePen.\n\nI think, for now, we will go with using grid-column properties rather than grid-template-areas. The repetition needed for creating the variant feels too much where we can change the grid-column-start instead, keeping the components elements layout properties tied a little closer to the elements rather than the grid.\nSome additional decisions\nThe current component library has existing styles for titles, subtitles, lists, paragraphs of text and calls to action. These are name-spaced so that they shouldn\u2019t clash with any other components. Looking forward there will be a chance that other products adopt the component library, but they may bring their own styles for titles, subtitles, etc.\nOne way that we could write our code now for that near future possibility is to make sure our classes are working hard. Using class-attribute selectors we can target part of the class attributes that we know the elements in the component will have using *=.\n.features [class*=\"title\"]  {\n  grid-column: col-start 2 / span 6;\n}\n.features [class*=\"subtitle\"] {\n  grid-column: col-start 2 / span 5;\n}\n.features [class*=\"content\"] {\n  grid-column: col-start 2 / span 4;\n}\n.features [class*=\"list\"] {\n  grid-column: col-start 2 / span 4;\n}\n.features [class*=\"link\"]  {\n  grid-column: col-start 5 / span 3;\n}\nSee the Pen Design Systems and CSS Grid, 15 by Stuart Robson (@sturobson) on CodePen.\n\nAlthough the component we have created have a title, subtitle, paragraphs, a list, and a call to action there may be a time where one ore more of these is not required or available. One thing I found out is that if the element doesn\u2019t exist then grid will not create space for it. This may be obvious, but it can be really helpful in making a nice malleable component.\nWe have only looked at columns, as existing components have their own spacing for the vertical rhythm of the page we don\u2019t really want to have them take up equal space in the component and just take up the space as needed. We can do this by adding grid-auto-rows: min-content; to our .features. This is useful if you also need your component to take up a height that is more than the component itself.\nThe grid of the future\nFrom prototyping this new grid and components in CSS Grid, I\u2019ve found it a fantastic way to reimagine how we can create a layout or grid system for our sites. It gives us options to create the same layouts in differing ways that could suit a project and its needs.\nIt allows us to carry on \u2013 if we choose to \u2013 using a <div>-based grid but swapping out floats for CSS Grid or to tie it to our components so they have specific places to go depending on what component is being used. Or we could have several \u2018grid components\u2019 in our design system that we could use to layout various components throughout a page.\nIf you find yourself tasked with creating some new components for your design system try it. If you are starting from scratch I believe you really should start with CSS Grid for your layout.\nIt really feels like the possibilities are endless in terms of layout for the web.\nResources\nHere are just a few resources I have pawed over these last few weeks whilst getting acquainted with CSS Grid.\n\nA collection of CodePens from this article\nGrid by Example from Rachel Andrew\nA Complete Guide to CSS Grid on Codrops from Hui Jing Chen\nRachel Andrew\u2019s Blog Archive tagged: cssgrid\nCSS Grid Layout Examples\nMDN\u2019s CSS Grid Layout\nA Complete Guide to Grid from CSS-Tricks\nCSS Grid Layout Module Level 1 Specification", "year": "2017", "author": "Stuart Robson", "author_slug": "stuartrobson", "published": "2017-12-12T00:00:00+00:00", "url": "https://24ways.org/2017/design-systems-and-css-grid/", "topic": "code"}
{"rowid": 201, "title": "Lint the Web Forward With Sonarwhal", "contents": "Years ago, when I was in a senior in college, much of my web development courses focused on two things: the basics like HTML and CSS (and boy, do I mean basic), and Adobe Flash. I spent many nights writing ActionScript 3.0 to build interactions for the websites that I would add to my portfolio. A few months after graduating, I built one website in Flash for a client, then never again. Flash was dying, and it became obsolete in my r\u00e9sum\u00e9 and portfolio. \nThat was my first lesson in the speed at which things change in technology, and what a daunting realization that was as a new graduate looking to enter the professional world. Now, seven years later, I work on the Microsoft Edge team where I help design and build a tool that would have lessened my early career anxieties: sonarwhal. \nSonarwhal is a linting tool, built by and for the web community. The code is open source and lives under the JS Foundation. It helps web developers and designers like me keep up with the constant change in technology while simultaneously teaching how to code better websites. \nIntroducing sonarwhal\u2019s mascot Nellie\nGood web development is hard. It is more than HTML, CSS, and JavaScript: developers are expected to have a grasp of accessibility, performance, security, emerging standards, and more, all while refreshing this knowledge every few months as the web evolves. It\u2019s a lot to keep track of.\n\u00a0\nWeb development is hard \nStaying up-to-date on all this knowledge is one of the driving forces for developing this scanning tool. Whether you are just starting out, are a student, or you have over a decade of experience, the sonarwhal team wants to help you build better websites for all browsers. \nCurrently sonarwhal checks for best practices in five categories: Accessibility, Interoperability, Performance, PWAs, and Security. Each check is called a \u201crule\u201d. You can configure them and even create your own rules if you need to follow some specific guidelines for your project (e.g. validate analytics attributes, title format of pages, etc.). \nYou can use sonarwhal in two ways:\n\nAn online version, that provides a quick and easy way to scan any public website.\nA command line tool, if you want more control over the configuration, or want to integrate it into your development flow.\n\nThe Online Scanner\nThe online version offers a streamlined way to scan a website; just enter a URL and you will get a web page of scan results with a permalink that you can share and revisit at any time.\nThe online version of sonarwal\nWhen my team works on a new rule, we spend the bulk of our time carefully researching each subject, finding sources, and documenting it rather than writing the rule\u2019s code. Not only is it important that we get you the right results, but we also want you to understand why something is failing. Next to each failing rule you\u2019ll find a link to its detailed documentation, explaining why you should care about it, what exactly we are testing, examples that pass and examples that don\u2019t, and useful links to even more in-depth documentation if you are interested in the subject.\nWe hope that between reading the documentation and continued use of sonarwhal, developers can stay on top of best practices. As devs continue to build sites and identify recurring issues that appear in their results, they will hopefully start to automatically include those missing elements or fix those pieces of code that are producing errors. This also isn\u2019t a one-way communication: the documentation is not only available on the sonarwhal site, but also on GitHub for editing so you can help us make it even better!\nA results report\nThe current configuration for the online scanner is very strict, so it might hurt your feelings (it did when I first tested it on my personal website). But you can configure sonarwhal to any level of strictness as well as customize the command line tool to your needs!  \nSonarwhal\u2019s CLI\u00a0\nThe CLI gives you full control of sonarwhal: what rules to use, tweaks to them, domains that are out of your control, and so on. You will need the latest node LTS (v8) or Stable (v9) and your favorite package manager, such as npm:\nnpm install -g sonarwhal\nYou can now run sonarwhal from anywhere via:\nsonarwhal https://example.com\nUsing the CLI\nThe configuration is done via a .sonarwhalrc file. When analyzing a site, if no file is available, you will be prompted to answer a series of questions:\n\nWhat connector do you want to use? Connectors are what sonarwhal uses to access a website and gather all the information about the requests, resources, HTML, etc. Currently it supports jsdom, Microsoft Edge, and Google Chrome.\nWhat formatter? This is how you want to see the results: summary, stylish, etc. Make sure to look at the full list. Some are concise for, perfect for a quick build assessment, while others are more verbose and informative.\nDo you want to use the recommended rules configuration? Rules are the things we are validating. Unless you\u2019ve read the documentation and know what you are doing, first timers should probably use the recommended configuration.\nWhat browsers are you targeting? One of the best features of sonarwhal is that rules can adapt their feedback depending on your targeted browsers, suggesting to add or remove things. For example, the rule \u201cHighest Document Mode\u201d will tell you to add the \u201cX-UA-Compatible\u201d header if IE10 or lower is targeted or remove if the opposite is true. \n\nsonarwhal configuration generator questions\nOnce you answer all these questions the scan will start and you will have a .sonarwhalrc file similar to the following:\n{\n    \"connector\": {\n        \"name\": \"jsdom\",\n        \"options\": {\n            \"waitFor\": 1000\n        }\n    },\n    \"formatters\": \"stylish\",\n    \"rulesTimeout\": 120000,\n    \"rules\": {\n        \"apple-touch-icons\": \"error\",\n        \"axe\": \"error\",\n        \"content-type\": \"error\",\n        \"disown-opener\": \"error\",\n        \"highest-available-document-mode\": \"error\",\n        \"validate-set-cookie-header\": \"warning\",\n        // ...\n    }\n}\nYou should see the scan initiate in the command line and within a few seconds the results should start to appear. Remember, the scan results will look different depending on which formatter you selected so try each one out to see which one you like best. \nsonarwhal results on my website and hurting my feelings \ud83d\udc94\nNow that you have a list of errors, you can get to work improving the site! Note though, that when you scan your website, it scans all the resources on that page and if you\u2019ve added something like analytics or fonts hosted elsewhere, you are unable to change those files. You can configure the CLI to ignore files from certain domains so that you are only getting results for files you are in control of.\nThe documentation should give enough guidance on how to fix the errors, but if it\u2019s insufficient, please help us and suggest edits or contribute back to it. This is a community effort and chances are someone else will have the same question as you.\nWhen I scanned both my websites, sonarwhal alerted me to not having an Apple Touch Icon. If I search on the web as opposed to using the sonarwhal documentation, the first top 3 results give me outdated information: I need to include many different icon sizes. I don\u2019t need to include all the different size icons that target different devices. Declaring one icon sized 180px x 180px will provide a large enough icon for devices and it will scale down as appropriate for people on older devices. \nThe information at the top of the search results isn\u2019t always the correct answer to an issue and we don\u2019t want you to have to search through outdated documentation. As sonarwhal\u2019s capabilities expand, the goal is for it to be the one stop shop for helping preflight your website. \nThe journey up until now and looking forward\n\nOn the Microsoft Edge team, we\u2019re passionate about empowering developers to build great websites. Every day we see so many sites come through our issue tracker. (Thanks for filing those bugs, they help us make Microsoft Edge better and better!) Some issues we see over and over are honest mistakes or outdated \u2018best practices\u2019 that could be avoided, so we built this tool to help everyone help make the web a better place.\nWhen we decided to create sonarwhal, we wanted to create a tool that would help developers write better and more up-to-date code for their websites. We want sonarwhal to be useful to anyone so, early on, we defined three guiding principles we\u2019ve used along the way:\n\nCommunity Driven. We build for the community\u2019s best interests. The web belongs to everyone and this project should too. Not only is it open source, we\u2019ve also donated it to the JS Foundation and have an inclusive governance model that welcomes the collaboration of anyone, individual or company.\nUser Centric. We want to put the user at the center, making sonarwhal configurable for your needs and easy to use no matter what your skill level is.\nCollaborative. We didn\u2019t want to reinvent the wheel, so we collaborated with existing tools and services that help developers build for the web. Some examples are aXe, snyk.io, Cloudinary, etc.\n\nThis is just the beginning and we still have lots to do. We\u2019re hard at work on a backlog of exciting features for future releases, such as:\n\nNew rules for a variety of areas like\u00a0performance,\u00a0accessibility,\u00a0security,\u00a0progressive web apps, and more.\nA plug-in for Visual Studio Code: we want sonarwhal to help you write better websites, and what better moment than when you are in your editor.\nConfiguration options for the online service: as we fine tune the infrastructure, the rule configuration for our scanner is locked, but we look forward to adding CLI customization options here in the near future.\n\nThis is a tool for the web community by the web community so if you are excited about sonarwhal, making a better web, and want to contribute, we have a\u00a0few issues where you might be able to help. Also, don\u2019t forget to check the rest of the\u00a0sonarwhal GitHub organization. PRs are always welcome and appreciated! \nLet us know what you think about the scanner at @NarwhalNellie on Twitter and we hope you\u2019ll help us lint the web forward!", "year": "2017", "author": "Stephanie Drescher", "author_slug": "stephaniedrescher", "published": "2017-12-02T00:00:00+00:00", "url": "https://24ways.org/2017/lint-the-web-forward-with-sonarwhal/", "topic": "code"}
{"rowid": 195, "title": "Levelling Up for Junior Developers", "contents": "If you are a junior developer starting out in the web industry, things can often seem a little daunting. There are so many things to learn, and as soon as you\u2019ve learnt one framework or tool, there seems to be something new out there.\nI am lucky enough to lead a team of developers building applications for the web. During a recent One to One meeting with one of our junior developers, he asked me about a learning path and the basic fundamentals that every developer should know. After a bit of digging around, I managed to come up with a (not so exhaustive) list of principles that was shared with him.\n\nIn this article, I will share the list with you, and hopefully help you level up from junior developer and become a better developer all round. This list doesn\u2019t focus on an particular programming language, but rather coding concepts as a whole. The idea behind this list is that whether you are a front-end developer, back-end developer, full stack developer or just a curious one, these principles apply to everyone that writes code. \nI have tried to be technology agnostic, so that you can use these tips to guide you, whatever your tech stack might be.\nWithout any further ado and in no particular order, let\u2019s get started.\nRefactoring code like a boss\nThe Boy Scouts have a rule that goes \u201calways leave the campground cleaner than you found it.\u201d This rule can be applied to code too and ensures that you leave code cleaner than you found it. As a junior developer, it\u2019s almost certain that you will either create or come across older code that could be improved. The resources below are a guide that will help point you in the right direction.\n\nMy favourite book on this subject has to be Clean Code by Robert C. Martin. It\u2019s a must read for anyone writing code as it helps you identify bad code and shows you techniques that you can use to improve existing code.\nIf you find that in your day to day work you deal with a lot of legacy code, Improving Existing Technology through Refactoring is another useful read.\nDesign Patterns are a general repeatable solution to a commonly occurring problem in software design. My friend and colleague Ranj Abass likes to refer to them as a \u201ccommon language\u201d that helps developers discuss the way that we write code as a pattern. My favourite book on this subject is Head First Design Patterns which goes right back to the basics. Another great read on this topic is Refactoring to Patterns.\nWorking Effectively With Legacy Code is another one that I found really valuable.\n\nImproving your debugging skills\nA solid understanding of how to debug code is a must for any developer. Whether you write code for the web or purely back-end code, the ability to debug will save you time and help you really understand what is going on under the hood.\n\nIf you write front-end code for the web, one of my favourite resources to help you understand how to debug code in Chrome can be found on the Chrome Dev Tools website. While some of the tips are specific to Chrome, these techniques apply to any modern browser of your choice.\nAt Settled, we use Node.js for much of our server side code. Without a doubt, our most trusted IDE has to be Visual Studio Code and the built-in debuggers are amazing. Regardless of whether you use Node.js or not, there are a number of plugins and debuggers that you can use in the IDE. I recommend reading the website of your favourite IDE for more information. \nAs a side note, it is worth mentioning that Chrome Developer Tools actually has functionality that allows you to debug Node.js code too. This makes it a seamless transition from front-end code to server-side code debugging.\nThe Debugging Mindset is an informative online article by Devon H. O\u2019Dell and discusses the the psychology of learning strategies that lead to effective problem-solving skills. \n\nA good understanding of relational databases and NoSQL databases\nAlmost all developers will need to persist data at some point in their career. Even if you don\u2019t write SQL queries in your day to day job, a solid understanding of how they work will help you become a better developer.\n\nIf you are a complete newbie when it comes to databases, I recommend checking out Code Academy. They offer a free online course that can help you get your head around how relational databases work. The course is quite basic, but is a useful hands-on approach to learning this topic.\nThis article provides a great explainer for the difference between the SQL and NoSQL databases, and this  Stackoverflow answer goes a little deeper into the subject of the two database types.\nIf you\u2019d like to learn more about NoSQL queries, I would recommend starting with this article on MongoDB queries. Unfortunately, there isn\u2019t one overall course as most NoSQL databases have their own syntax. \n\nYou may also have noticed that I haven\u2019t included other types of databases such as Graph or In-memory; it\u2019s worth focussing on the basics before going any deeper.\nPerformance on the web\nIf you build for the web today, it is important to understand how the browser receives and renders the content that you send it. I am pretty passionate about Web Performance, and hope that everyone can learn how to make websites faster and more efficient. It can be fun at the same time!\n\nSteve Souders High Performance Websites is the godfather of web performance books. While it was created a few years ago and many of the techniques might have changed slightly, it is the original book on the subject and set up many of the ground rules that we know about web performance today.\nA free online resource on this topic is the Google Developers website. The site is an up to date guide on the best web performance techniques for your site. It is definitely worth a read.\nThe network plays a key role in delivering data to your users, and it plays a big role in performance on the web. A fantastic book on this topic is Ilya Grigorik\u2019s High Performance Browser Networking. It is also available to read online at hpbn.co.\n\nUnderstand the end to end architecture of your software project\nI find that one of the best ways to improve my knowledge is to learn about the architecture of the software at the company I work at. It gives you a good understanding as to why things are designed the way they are, why certain decisions were made, and gives you an understanding of how you might do things differently with hindsight.\nTry and find someone more senior, such as a Technical Lead or Software Architect, at your company and ask them to explain the overall architecture and draw a few high-level diagrams for you. Not to mention that they will be impressed with your willingness to learn.\n\nI recommend reading Clean Architecture: A Craftsman\u2019s Guide to Software Structure and Design for more detail on this subject.\nFar too often, software projects can be over-engineered and over-architected, it is worth reading Just Enough Software Architecture. The book helps developers understand how the smallest of changes can affect the outcome of your software architecture.\n\nHow are things deployed\nA big part of creating software is actually shipping it! How is the software at your company released into the wild? Does your company do Continuous Integration? Continuous Deployment?\n\nEven if you answered no to any of these questions, it is worth finding someone with the knowledge in your company to explain these things to you. If it is not already documented, perhaps you could start a wiki to document everything you\u2019re learning about the system - this is a great way to level up and be appreciated and invaluable.\nA streamlined deployment process is a beautiful thing, and understanding how they work can help you grow your knowledge as a developer. \nContinuous Integration is a practical read on the ins and outs of implementing this deployment technique.\nDocker is another great tool to use when it comes to software deployment. It can be tricky at first to wrap your head around, but it is definitely worth learning about this great technology. The documentation on the website will teach and guide you on how to get started using Docker.\n\nWriting Tests\nTesting is an essential tool in the developer bag of skills. They help you to make big refactoring changes to your code, and feel a lot more confident knowing that your changes haven\u2019t broken anything. There are so many benefits to testing, which make it so important for developers at every level to become acquainted with it/them.\n\nThe book that started it all for me was Roy Osherove\u2019s The Art of Unit Testing. The code in the book is written in C#, but the principles apply to every language. It\u2019s a great, easy-to-understand read.\nAnother great read is How Google Tests Software and covers exactly what it says on the tin. It covers many different testing techniques such as exploratory, black box, white box, and acceptance testing and really helps you understand how large organisations test their code.\n\nSoft skills\nWhilst reading through this article, you\u2019ve probably noticed that a large chunk of it focusses on code and technical ability. Without a doubt, I\u2019d say that it is even more important to be a good teammate. If you look up the definition of soft skills in the dictionary, it is defined as \u201cpersonal attributes that enable someone to interact effectively and harmoniously with other people\u201d and I think that it sums this up perfectly. Working on your \u201csoft skills\u201d is something that can truly help you level up in your career. You may be the world\u2019s greatest coder, but if you colleagues can\u2019t get along with you, your coding skills won\u2019t matter!\nWhile you may not learn how to become the perfect co-worker overnight, I really try and live by the motto \u201cdon\u2019t be an arsehole\u201d. Think about how you like to be treated and then try and treat your co-workers with the same courtesy and respect. The next time you need to make a decision at work, ask yourself \u201cis this something an arsehole would do\u201d? If you answered yes to that question, you probably shouldn\u2019t do it!\nSummary\nLevelling up as a junior developer doesn\u2019t have to be scary. Focus on the fundamentals and they should hold you in good stead, regardless of the new things that come along. Software engineering is built on these great principles that have stood the test of time.\nWhilst researching for this article, I came across a useful Github repo that is worth mentioning. Things Every Programmer Should Know is packed with useful information. I have to admit, I didn\u2019t know everything on there!\nI hope that you have found this list helpful. Some of the topics I have mentioned might not be relevant for you at this stage in your career, but should give a nudge in the right direction. After all, knowledge is power!\nIf you are a junior developer reading this article, what would you add to it?", "year": "2017", "author": "Dean Hume", "author_slug": "deanhume", "published": "2017-12-05T00:00:00+00:00", "url": "https://24ways.org/2017/levelling-up-for-junior-developers/", "topic": "code"}
{"rowid": 193, "title": "Web Content Accessibility Guidelines\u2014for People Who Haven't Read Them", "contents": "I\u2019ve been a huge fan of the Web Content Accessibility Guidelines 2.0 since the World Wide Web Consortium (W3C) published them, nine years ago. I\u2019ve found them practical and future-proof, and I\u2019ve found that they can save a huge amount of time for designers and developers. You can apply them to anything that you can open in a browser. My favourite part is when I use the guidelines to make a website accessible, and then attend user-testing and see someone with a disability easily using that website.\nToday, the United Nations International Day of Persons with Disabilities, seems like a good time to re-read Laura Kalbag\u2019s explanation of why we should bother with accessibility. That should motivate you to devour this article.\nIf you haven\u2019t read the Web Content Accessibility Guidelines 2.0, you might find them a bit off-putting at first. The editors needed to create a single standard that countries around the world could refer to in legislation, and so some of the language in the guidelines reads like legalese. The editors also needed to future-proof the guidelines, and so some terminology\u2014such as \u201ctime-based media\u201d and \u201cprogrammatically determined\u201d\u2014can sound ambiguous. The guidelines can seem lengthy, too: printing the guidelines, the Understanding WCAG 2.0 document, and the Techniques for WCAG 2.0 document would take 1,200 printed pages.\nThis festive season, let\u2019s rip off that legalese and ambiguous terminology like wrapping paper, and see\u2014in a single article\u2014what gifts the Web Content Accessibility Guidelines 2.0 editors have bestowed upon us.\nCan your users perceive the information on your website?\nThe first guideline has criteria that help you prevent your users from asking \u201cWhat the **** is this thing here supposed to be?\u201d\n1.1.1 Text is the most accessible format for information. Screen readers\u2014such as the \u201cVoiceOver\u201d setting on your iPhone or the \u201cTalkBack\u201d app on your Android phone\u2014understand text better than any other format. The same applies for other assistive technology, such as translation apps and Braille displays. So, if you have anything on your webpage that\u2019s not text, you must add some text that gives your user the same information. You probably know how to do this already; for example:\n\nfor images in webpages, put some alternative text in an alt attribute to tell your user what the image conveys to the user;\nfor photos in tweets, add a description to make the images accessible;\nfor Instagram posts, write a caption that conveys the photo\u2019s information.\n\nThe alternative text should allow the user to get the same information as someone who can see the image. For websites that have too many images for someone to add alternative text to, consider how machine learning and Dynamically Generated Alt Text might\u2014might\u2014be appropriate.\nYou can probably think of a few exceptions where providing text to describe an image might not make sense. Remember I described these guidelines as \u201cpractical\u201d? They cover all those exceptions:\n\nUser interface controls such as buttons and text inputs must have names or labels to tell your user what they do.\nIf your webpage has video or audio (more about these later on!), you must\u2014at least\u2014have text to tell the user what they are.\nMaybe your webpage has a test where your user has to answer a question about an image or some audio, and alternative text would give away the answer. In that case, just describe the test in text so your users know what it is.\nIf your webpage features a work of art, tell your user the experience it evokes.\nIf you have to include a Captcha on your webpage\u2014and please avoid Captchas if at all possible, because some users cannot get past them\u2014you must include text to tell your user what it is, and make sure that it doesn\u2019t rely on only one sense, such as vision.\nIf you\u2019ve included something just as decoration, you must make sure that your user\u2019s assistive technology can ignore it. Again, you probably know how to do this. For example, you could use CSS instead of HTML to include decorative images, or you could add an empty alt attribute to the img element. (Please avoid that recent trend where developers add empty alt attributes to all images in a webpage just to make the HTML validate. You\u2019re better than that.)\n\n(Notice that the guidelines allow you to choose how to conform to them, with whatever technology you choose. To make your website conform to a guideline, you can either choose one of the techniques for WCAG 2.0 for that guideline or come up with your own. Choosing a tried-and-tested technique usually saves time!)\n1.2.1 If your website includes a podcast episode, speech, lecture, or any other recorded audio without video, you must include a transcription or some other text to give your user the same information. In a lot of cases, you might find this easier than you expect: professional transcription services can prove relatively inexpensive and fast, and sometimes a speaker or lecturer can provide the speech or lecture notes that they read out word-for-word. Just make sure that all your users can get the same information and the same results, whether they can hear the audio or not. For example, David Smith and Marco Arment always publish episode transcripts for their Under the Radar podcast. \nSimilarly, if your website includes recorded video without audio\u2014such as an animation or a promotional video\u2014you must either use text to detail what happens in the video or include an audio version. Again, this might work out easier then you perhaps fear: for example, you could check to see whether the animation started life as a list of instructions, or whether the promotional video conveys the same information as the \u201cAbout Us\u201d webpage. You want to make sure that all your users can get the same information and the same results, whether they can see that video or not.\n1.2.2 If your website includes recorded videos with audio, you must add captions to those videos for users who can\u2019t hear the audio. Professional transcription services can provide you with time-stamped text in caption formats that YouTube supports, such as .srt and .sbv. You can upload those to YouTube, so captions appear on your videos there. YouTube can auto-generate captions, but the quality varies from impressively accurate to comically inaccurate. If you have a text version of what the people in the video said\u2014such as the speech that a politician read or the bedtime story that an actor read\u2014you can create a transcript file in .txt format, without timestamps. YouTube then creates captions for your video by synchronising that text to the audio in the video. If you host your own videos, you can ask a professional transcription service to give you .vtt files that you can add to a video element\u2019s track element\u2014or you can handcraft your own. (A quick aside: if your website has more videos than you can caption in a reasonable amount of time, prioritise the most popular videos, the most important videos, and the videos most relevant to people with disabilities. Then make sure your users know how to ask you to caption other videos as they encounter them.)\n1.2.3 If your website has recorded videos that have audio, you must add an \u201caudio description\u201d narration to the video to describe important visual details, or add text to the webpage to detail what happens in the video for users who cannot see the videos. (I like to add audio files from videos to my Huffduffer account so that I can listen to them while commuting.) Maybe your home page has a video where someone says, \u201cI\u2019d like to explain our new TPS reports\u201d while \u201cBill Lumbergh, division Vice President of Initech\u201d appears on the bottom of the screen. In that case, you should add an audio description to the video that announces \u201cBill Lumbergh, division Vice President of Initech\u201d, just before Bill starts speaking. As always, you can make life easier for yourself by considering all of your users, before the event: in this example, you could ask the speaker to begin by saying, \u201cI\u2019m Bill Lumbergh, division Vice President of Initech, and I\u2019d like to explain our new TPS reports\u201d\u2014so you won\u2019t need to spend time adding an audio description afterwards. \n1.2.4 If your website has live videos that have some audio, you should get a stenographer to provide real-time captions that you can include with the video. I\u2019ll be honest: this can prove tricky nowadays. The Web Content Accessibility Guidelines 2.0 predate YouTube Live, Instagram live Stories, Periscope, and other such services. If your organisation creates a lot of live videos, you might not have enough resources to provide real-time captions for each one. In that case, if you know the contents of the audio beforehand, publish the contents during the live video\u2014or failing that, publish a transcription as soon as possible.\n1.2.5 Remember what I said about the recorded videos that have audio? If you can choose to either add an audio description or add text to the webpage to detail what happens in the video, you should go with the audio description.\n1.2.6 If your website has recorded videos that include audio information, you could provide a sign language version of the audio information; some people understand sign language better than written language. (You don\u2019t need to caption a video of a sign language version of audio information.)\n1.2.7 If your website has recorded videos that have audio, and you need to add an audio description, but the audio doesn\u2019t have enough pauses for you to add an \u201caudio description\u201d narration, you could provide a separate version of that video where you have added pauses to fit the audio description into.\n1.2.8 Let\u2019s go back to the recorded videos that have audio once more! You could add text to the webpage to detail what happens in the video, so that people who can neither read captions nor hear dialogue and audio description can use braille displays to understand your video.\n1.2.9 If your website has live audio, you could get a stenographer to provide real-time captions. Again, if you know the contents of the audio beforehand, publish the contents during the live audio or publish a transcription as soon as possible.\n(Congratulations on making it this far! I know that seems like a lot to remember, but keep in mind that we\u2019ve covered a complex area: helping your users to understand multimedia information that they can\u2019t see and/or hear. Grab a mince pie to celebrate, and let\u2019s keep going.)\n1.3.1 You must mark up your website\u2019s content so that your user\u2019s browser, and any assistive technology they use, can understand the hierarchy of the information and how each piece of information relates to the rest. Once again, you probably know how to do this: use the most appropriate HTML element for each piece of information. Mark up headings, lists, buttons, radio buttons, checkboxes, and links with the most appropriate HTML element. If you\u2019re looking for something to do to keep you busy this Christmas, scroll through the list of the elements of HTML. Do you notice any elements that you didn\u2019t know, or that you\u2019ve never used? Do you notice any elements that you could use on your current projects, to mark up the content more accurately? Also, revise HTML table advanced features and accessibility, how to structure an HTML form, and how to use the native form widgets\u2014you might be surprised at how much you can do with just HTML! Once you\u2019ve mastered those, you can make your website much more usable for your all of your users.\n1.3.2 If your webpage includes information that your user has to read in a certain order, you must make sure that their browser and assistive technology can present the information in that order. Don\u2019t rely on CSS or whitespace to create that order visually. Check that the order of the information makes sense when CSS and whitespace aren\u2019t formatting it. Also, try using the Tab key to move the focus through the links and form widgets on your webpage. Does the focus go where you expect it to? Keep this in mind when using order in CSS Grid or Flexbox.\n1.3.3 You must not presume that your users can identify sensory characteristics of things on your webpage. Some users can\u2019t tell what you\u2019ve positioned where on the screen. For example, instead of asking your users to \u201cChoose one of the options on the left\u201d, you could ask them to \u201cChoose one of our new products\u201d and link to that section of the webpage.\n1.4.1 You must not rely on colour as the only way to convey something to your users. Some of your users can\u2019t see, and some of your users can\u2019t distinguish between colours. For example, if your webpage uses green to highlight the products that your shop has in stock, you could add some text to identify those products, or you could group them under a sub-heading.\n1.4.2  If your webpage automatically plays a sound for more than 3 seconds, you must make sure your users can stop the sound or change its volume. Don\u2019t rely on your user turning down the volume on their computer; some users need to hear the screen reader on their computer, and some users just want to keep listening to whatever they were listening before your webpage interrupted them!\n1.4.3 You should make sure that your text contrasts enough with its background, so that your users can read it. Bookmark Lea Verou\u2019s Contrast Ratio calculator now. You can enter the text colour and background colour as named colours, or as RGB, RGBa, HSL, or HSLa values. You should make sure that:\n\nnormal text that set at 24px or larger has a ratio of at least 3:1;\nbold text that set at 18.75px or larger has a ratio of at least 3:1;\nall other text has a ratio of at least 4\u00bd:1.\n\nYou don\u2019t have to do this for disabled form controls, decorative stuff, or logos\u2014but you could!\n1.4.4 You should make sure your users can resize the text on your website up to 200% without using their assistive technology\u2014and still access all your content and functionality. You don\u2019t have to do this for subtitles or images of text.\n1.4.5 You should avoid using images of text and just use text instead. In 1998, Jeffrey Veen\u2019s first Hot Design Tip said, \u201cText is text. Graphics are graphics. Don\u2019t confuse them.\u201d Now that you can apply powerful CSS text-styling properties, use CSS Grid to precisely position text, and choose from thousands of web fonts (Jeffrey co-founded Typekit to help with this), you pretty much never need to use images of text. The guidelines say you can use images of text if you let your users specify the font, size, colour, and background of the text in the image of text\u2014but I\u2019ve never seen that on a real website. Also, this doesn\u2019t apply to logos.\n1.4.6 Let\u2019s go back to colour contrast for a second. You could make your text contrast even more with its background, so that even more of your users can read it. To do that, use Lea Verou\u2019s Contrast Ratio calculator to make sure that:\n\nnormal text that is 24px or larger has a ratio of at least 4\u00bd:1;\nbold text that 18.75px or larger has a ratio of at least 4\u00bd:1;\nall other text has a ratio of at least 7:1.\n\n1.4.7 If your website has recorded speech, you could make sure there are no background sounds, or that your users can turn off any background sounds. If that\u2019s not possible, you could make sure that any background sounds that last longer than a couple of seconds are at least four times quieter than the speech. This doesn\u2019t apply to audio Captchas, audio logos, singing, or rapping. (Yes, these guidelines mention rapping!)\n1.4.8 You could make sure that your users can reformat blocks of text on your website so they can read them better. To do this, make sure that your users can:\n\nspecify the colours of the text and the background, and\nmake the blocks of text less than 80-characters wide, and \nalign text to the left (or right for right-to-left languages), and \nset the line height to 150%, and \nset the vertical distance between paragraphs to 1\u00bd times the line height of the text, and \nresize the text (without using their assistive technology) up to 200% and still not have to scroll horizontally to read it.\n\nBy the way, when you specify a colour for text, always specify a colour for its background too. Don\u2019t rely on default background colours!\n1.4.9 Let\u2019s return to images of text for a second. You could make sure that you use them only for decoration and logos.\nCan users operate the controls and links on your website?\nThe second guideline has criteria that help you prevent your users from asking, \u201cHow the **** does this thing work?\u201d\n2.1.1 You must make sure that you users can carry out all of your website\u2019s activities with just their keyboard, without time limits for pressing keys. (This doesn\u2019t apply to drawing or anything else that requires a pointing device such as a mouse.) Again, if you use the most appropriate HTML element for each piece of information and for each form element, this should prove easy.\n2.1.2 You must make sure that when the user uses the keyboard to focus on some part of your website, they can then move the focus to some other part of your webpage without needing to use a mouse or touch the screen. If your website needs them to do something complex before they can move the focus elsewhere, explain that to your user. These \u201ckeyboard traps\u201d have become rare, but beware of forms that move focus from one text box to another as soon as they receive the correct number of characters.\n2.1.3 Let\u2019s revisit making sure that you users can carry out all of your website\u2019s activities with just their keyboard, without time limits for pressing keys. You could make sure that your user can do absolutely everything on your website with just the keyboard.\n2.2.1 Sometimes people need more time than you might expect to complete a task on your website. If any part of your website imposes a time limit on a task, you must do at least one of these: \n\nlet your users turn off the time limit before they encounter it; or\nlet your users increase the time limit to at least 10 times the default time limit before they encounter it; or\nwarn your users before the time limit expires and give them at least 20 seconds to extend it, and let them extend it at least 10 times.\n\nRemember: these guidelines are practical. They allow you to enforce time limits for real-time events such as auctions and ticket sales, where increasing or extending time limits wouldn\u2019t make sense. Also, the guidelines allow you to enforce a maximum time limit of 20 hours. The editors chose 20 hours because people need to go to sleep at some stage. See? Practical!\n2.2.2 In my experience, this criterion remains the least well-known\u2014even though some users can only use websites that conform to it. If your website presents content alongside other content that can distract users by automatically moving, blinking, scrolling, or updating, you must make sure that your users can:\n\npause, stop, or hide the other content if it\u2019s not essential and lasts more than 5 seconds; and\npause, stop, hide, or control the frequency of the other content if it automatically updates.\n\nIt\u2019s OK if your users miss live information such as stock price updates or football scores; you can\u2019t do anything about that! Also, this doesn\u2019t apply to animations such as progress bars that you put on a website to let all users know that the webpage isn\u2019t frozen.\n(If this one sounds complex, just add a pause button to anything that might distract your users.)\n2.2.3 Let\u2019s go back to time limits on tasks on your website. You could   make your website even easier to use by removing all time limits except those on real-time events such as auctions and ticket sales. That would mean your user wouldn\u2019t need to interact with a timer at all.\n2.2.4 You could let your users turn off all interruptions\u2014server updates, promotions, and so on\u2014apart from any emergency information.\n2.2.5 This is possibly my favourite of these criteria! After your website logs your user out, you could make sure that when they log in again, they can continue from where they were without having lost any information. Do that, and you\u2019ll be on everyone\u2019s Nice List this Christmas.\n2.3.1 You must make sure that nothing flashes more than three times a second on your website, unless you can make sure that the flashes remain below the acceptable general flash and red flash thresholds\u2026\n2.3.2 \u2026or you could just make sure that nothing flashes more than three times per second on your website. This is usually an easier goal.\n2.4.1 You must make sure that your users can jump past any blocks of content, such as navigation menus, that are repeated throughout your website. You know the drill here: using HTML\u2019s sectioning elements such as header, nav, main, aside, and footer allows users with assistive technology to go straight to the content they need, and adding \u201cSkip Navigation\u201d links allows everyone to get to your main content faster.\n2.4.2 You must add a proper title to describe each webpage\u2019s topic. Your webpage won\u2019t even validate without a title element, so make it a useful one.\n2.4.3 If your users can focus on links and native form widgets, you must make sure that they can focus on elements in an order that makes sense.\n2.4.4 You must make sure that your users can understand the purpose of a link when they read:\n\nthe text of the link; or\nthe text of the paragraph, list item, table cell, or table header for the cell that contains the link; or\nthe heading above the link.\n\nYou don\u2019t have to do that for games and quizzes.\n2.4.5 You should give your users multiple ways to find any webpage within a set of webpages. Add site-wide search and a site map and you\u2019re done!\nThis doesn\u2019t apply for a webpage that is part of a series of actions (like a shopping cart and checkout flow) or to a webpage that is a result of a series of actions (like a webpage confirming that the user has bought what was in the shopping cart).\n2.4.6 You should help your users to understand your content by providing:\n\nheadings that describe the topics of you content;\nlabels that describe the purpose of the native form widgets on the webpage.\n\n2.4.7 You should make sure that users can see which element they have focussed on. Next time you use your website, try hitting the Tab key repeatedly. Does it visually highlight each item as it moves focus to it? If it doesn\u2019t, search your CSS to see whether you\u2019ve applied outline: 0; to all elements\u2014that\u2019s usually the culprit. Use the :focus pseudo-element to define how elements should appear when they have focus.\n2.4.8 You could help your user to understand where the current webpage is located within your website. Add \u201cbreadcrumb navigation\u201d and/or a site map and you\u2019re done.\n2.4.9 You could make links even easier to understand, by making sure that your users can understand the purpose of a link when they read the text of the link. Again, you don\u2019t have to do that for games and quizzes.\n2.4.10 You could use headings to organise your content by topic. \nCan users understand your content?\nThe third guideline has criteria that help you prevent your users from asking, \u201cWhat the **** does this mean?\u201d\n3.1.1 Let\u2019s start this section with the criterion that possibly takes the least time to implement; you must make sure that the user\u2019s browser can identify the main language that your webpage\u2019s content is written in. For a webpage that has mainly English content, use <html lang=\"en\">. \n3.1.2 You  must specify when content in another language appears in your webpage, like so: <q>I wish you a <span lang=\"fr\">Joyeux No\u00ebl</span>.</q>. You don\u2019t have to do this for proper names, technical terms, or words that you can\u2019t identify a language for. You also don\u2019t have to do it for words from a different language that people consider part of the language around those words; for example, <q>Come to our Christmas rendezvous!</q> is OK.\n3.1.3 You could make sure that your users can find out the meaning of any unusual words or phrases, including idioms like \u201cstocking filler\u201d or \u201cBah! Humbug!\u201d and jargon such as \u201cVoiceOver\u201d and \u201cTalkBack\u201d. Provide a glossary or link to a dictionary.\n3.1.4 You could make sure that your users can find out the meaning of any    abbreviation. For example, VoiceOver pronounces \u201cXmas\u201d as \u201cSmas\u201d instead of \u201cChristmas\u201d. Using the abbr element and linking to a glossary can help. (Interestingly, VoiceOver pronounces \u201cabbr\u201d as \u201cabbreviation\u201d!)\n3.1.5 Do your users need to be able to read better than a typically educated nine-year-old, to read your content (apart from proper names and titles)? If so, you could provide a version that doesn\u2019t require that level of reading ability, or you could provide images, videos, or audio to explain your content. (You don\u2019t have to add captions or audio description to those videos.)\n3.1.6 You could make sure that your users can access the pronunciation of any word in your content if that word\u2019s meaning depends on its pronunciation. For example, the word \u201cclose\u201d could have one of two meanings, depending on pronunciation, in a phrase such as, \u201cReady for Christmas? Close now!\u201d\n3.2.1 Some users need to focus on elements to access information about them. You must make sure that focusing on an element doesn\u2019t trigger any major changes, such as opening a new window, focusing on another element, or submitting a form.\n3.2.2 Webpages are easier for users when the controls do what they\u2019re supposed to do. Unless you have warned your users about it, you must make sure that changing the value of a control such as a text box, checkbox, or drop-down list doesn\u2019t trigger any major changes, such as opening a new window, focusing on another element, or submitting a form.\n3.2.3 To help your users to find the content they want on each webpage, you should put your navigation elements in the same place on each webpage. (This doesn\u2019t apply when your user has changed their preferences or when they use assistive technology to change how your content appears.) \n3.2.4 When a set of webpages includes things that have the same functionality on different webpages, you should name those things consistently. For example, don\u2019t use the word \u201cSearch\u201d for the search box on one webpage and \u201cFind\u201d for the search box on another webpage within that set of webpages.\n3.2.5 Let\u2019s go back to major changes, such as a new window opening, another element taking focus, or a form being submitted. You could make sure that they only happen when users deliberately make them happen, or when you have warned users about them first. For example, you could give the user a button for updating some content instead of automatically updating that content. Also, if a link will open in a new window, you could add the words \u201copens in new window\u201d to the link text.\n3.3.1 Users make mistakes when filling in forms. Your website must identify each mistake to your user, and must describe the mistake to your users in text so that the user can fix it. One way to identify mistakes reliably to your users is to set the aria-invalid attribute to true in the element that has a mistake. That makes sure that users with assistive technology will be alerted about the mistake. Of course, you can then use the [aria-invalid=\"true\"] attribute selector in your CSS to visually highlight any such mistakes. Also, look into how certain attributes of the input element such as required, type, and list can help prevent and highlight mistakes.\n3.3.2 You must include labels or instructions (and possibly examples) in your website\u2019s forms, to help your users to avoid making mistakes. \n3.3.3 When your user makes a mistake when filling in a form, your webpage should suggest ways to fix that mistake, if possible. This doesn\u2019t apply in scenarios where those suggestions could affect the security of the content.\n3.3.4 Whenever your user submits information that:\n\nhas legal or financial consequences; or\naffects information that they have previously saved in your website; or\nis part of a test\n\n\u2026you should make sure that they can:\n\nundo it; or\ncorrect any mistakes, after your webpage checks their information; or\nreview, confirm, and correct the information before they finally submit it.\n\n3.3.5 You could help prevent your users from making mistakes by providing obvious, specific help, such as examples, animations, spell-checking, or extra instructions.\n3.3.6 Whenever your user submits any information, you could make sure that they can:\n\nundo it; or\ncorrect any mistakes, after your webpage checks their information; or\nreview, confirm, and correct the information before they finally submit it.\n\nHave you made your website robust enough to work on your users\u2019 browsers and assistive technologies?\nThe fourth and final guideline has criteria that help you prevent your users from asking, \u201cWhy the **** doesn\u2019t this work on my device?\u201d\n4.1.1 You must make sure that your website works as well as possible with current and future browsers and assistive technology. Prioritise  complying with web standards instead of relying on the capabilities of currently popular devices and browsers. Web developers didn\u2019t expect their users to be unwrapping the Wii U Browser five years ago\u2014who knows what browsers and assistive technologies our users will be unwrapping in five years\u2019 time? Avoid hacks, and use the W3C Markup Validation Service to make sure that your HTML has no errors.\n4.1.2 If you develop your own user interface components, you must make their name, role, state, properties, and values available to your user\u2019s browsers and assistive technologies. That should make them almost as accessible as standard HTML elements such as links, buttons, and checkboxes.\n\u201c\u2026and a partridge in a pear tree!\u201d\n\u2026as that very long Christmas song goes. We\u2019ve covered a lot in this article\u2014because your users have a lot of different levels of ability. Hopefully this has demystified the Web Content Accessibility Guidelines 2.0 for you. Hopefully you spotted a few situations that could arise for users on your website, and you now know how to tackle them. \nTo start applying what we\u2019ve covered, you might like to look at Sarah Horton and Whitney Quesenbery\u2019s personas for Accessible UX. Discuss the personas, get into their heads, and think about which aspects of your website might cause problems for them. See if you can apply what we\u2019ve covered today, to help users like them to do what they need to do on your website.\nHow to know when your website is perfectly accessible for everyone\nLOL! There will never be a time when your website becomes perfectly accessible for everyone. Don\u2019t aim for that. Instead, aim for regularly testing and making your website more accessible.\nWeb Content Accessibility Guidelines (WCAG) 2.1\nThe W3C hope to release the Web Content Accessibility Guidelines (WCAG) 2.1 as a \u201crecommendation\u201d (that\u2019s what the W3C call something that we should start using) by the middle of next year. Ten years may seem like a long time to move from version 2.0 to version 2.1, but consider the scale of the task: the editors have to update the guidelines to cover all the new ways that people interact with new technologies, while keeping the guidelines backwards-compatible. Keep an eye out for 2.1!\nYou\u2019ll go down in history\nOne last point: I\u2019ve met a surprising number of web designers and developers who do great work to make their websites more accessible without ever telling their users about it. Some of your potential customers have possibly tried and failed to use your website in the past. They probably won\u2019t try again unless you let them know that things have improved. A quick Twitter search for your website\u2019s name alongside phrases like \u201cassistive technology\u201d, \u201cdoesn\u2019t work\u201d, or \u201c#fail\u201d can let you find frustrated users\u2014so you can tell them about how you\u2019re making your website more accessible. Start making your websites work better for everyone\u2014and please, let everyone know.", "year": "2017", "author": "Alan Dalton", "author_slug": "alandalton", "published": "2017-12-03T00:00:00+00:00", "url": "https://24ways.org/2017/wcag-for-people-who-havent-read-them/", "topic": "code"}
{"rowid": 192, "title": "Cleaner Code with CSS3 Selectors", "contents": "The parts of CSS3 that seem to grab the most column inches on blogs and in articles are the shiny bits. Rounded corners, text shadow and new ways to achieve CSS layouts are all exciting and bring with them all kinds of possibilities for web design. However what really gets me, as a developer, excited is a bit more mundane.  \n\nIn this article I\u2019m going to take a look at some of the ways our front and back-end code will be simplified by CSS3, by looking at the ways we achieve certain visual effects now in comparison to how we will achieve them in a glorious, CSS3-supported future. I\u2019m also going to demonstrate how we can use these selectors now with a little help from JavaScript \u2013 which can work out very useful if you find yourself in a situation where you can\u2019t change markup that is being output by some server-side code.\n\nThe wonder of nth-child\n\nSo why does nth-child get me so excited? Here is a really common situation, the designer would like the tables in the application to look like this:\n\n\n\nSetting every other table row to a different colour is a common way to enhance readability of long rows. The tried and tested way to implement this is by adding a class to every other row. If you are writing the markup for your table by hand this is a bit of a nuisance, and if you stick a row in the middle you have to change the rows the class is applied to. If your markup is generated by your content management system then you need to get the server-side code to add that class \u2013 if you have access to that code.\n\n<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Strict//EN\"\n\t  \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd\">\n<html xmlns=\"http://www.w3.org/1999/xhtml\">\n<head>\n<title>Striping every other row - using classes</title>\n<style type=\"text/css\">\n\tbody {\n\t\tpadding: 40px;\n\t\tmargin: 0;\n\t\tfont: 0.9em Arial, Helvetica, sans-serif;\n\t}\n\ttable {\n\t\tborder-collapse: collapse;\n\t\tborder: 1px solid #124412;\n\t\twidth: 600px;\n\t}\n\tth {\n\t\tborder: 1px solid #124412;\n\t\tbackground-color: #334f33;\n\t\tcolor: #fff;\n\t\tpadding: 0.4em;\n\t\ttext-align: left;\n\t}\n\ttd {\n\t\tpadding: 0.4em;\n\t}\n\ttr.odd td {\n\t\tbackground-color: #86B486;\n\t}\n</style>\n</head>\n<body>\n\t<table>\n\t\t<tr>\n\t\t\t<th>Name</th>\n\t\t\t<th>Cards sent</th>\n\t\t\t<th>Cards received</th>\n\t\t\t<th>Cards written but not sent</th>\n\t\t</tr>\n\t\t<tr>\n\t\t\t<td>Ann</td>\n\t\t\t<td>40</td>\n\t\t\t<td>28</td>\n\t\t\t<td>4</td>\n\t\t</tr>\n\t\t<tr class=\"odd\">\n\t\t\t<td>Joe</td>\n\t\t\t<td>2</td>\n\t\t\t<td>27</td>\n\t\t\t<td>29</td>\n\t\t</tr>\n\t\t<tr>\n\t\t\t<td>Paul</td>\n\t\t\t<td>5</td>\n\t\t\t<td>35</td>\n\t\t\t<td>2</td>\n\t\t</tr>\n\t\t<tr class=\"odd\">\n\t\t\t<td>Louise</td>\n\t\t\t<td>65</td>\n\t\t\t<td>65</td>\n\t\t\t<td>0</td>\n\t\t</tr>\n\t</table>\n</body>\n</html>\n\nView Example 1\n\nThis situation is something I deal with on almost every project, and apart from being an extra thing to do, it just isn\u2019t ideal having the server-side code squirt classes into the markup for purely presentational reasons. This is where the nth-child pseudo-class selector comes in. The server-side code creates a valid HTML table for the data, and the CSS then selects the odd rows with the following selector:\n\ntr:nth-child(odd) td {\n\tbackground-color: #86B486;\n}\n\nView Example 2\n\nThe odd and even keywords are very handy in this situation \u2013 however you can also use a multiplier here. 2n would be equivalent to the keyword \u2018odd\u2019 3n would select every third row and so on.\n\nBrowser support\n\nSadly, nth-child has pretty poor browser support. It is not supported in Internet Explorer 8 and has somewhat buggy support in some other browsers. Firefox 3.5 does have support. In some situations however, you might want to consider using JavaScript to add this support to browsers that don\u2019t have it. This can be very useful if you are dealing with a Content Management System where you have no ability to change the server-side code to add classes into the markup.\n\nI\u2019m going to use jQuery in these examples as it is very simple to use the same CSS selector used in the CSS to target elements with jQuery \u2013 however you could use any library or write your own function to do the same job. In the CSS I have added the original class selector to the nth-child selector:\n\ntr:nth-child(odd) td, tr.odd td {\n\tbackground-color: #86B486;\n}\n\nThen I am adding some jQuery to add a class to the markup once the document has loaded \u2013 using the very same nth-child selector that works for browsers that support it. \n\n<script src=\"http://code.jquery.com/jquery-latest.js\"></script> \n <script>\n  $(document).ready(function(){\n\t$(\"tr:nth-child(odd)\").addClass(\"odd\");\n  });\n </script>\n\nView Example 3\n\nWe could just add a background colour to the element using jQuery, however I prefer not to mix that information into the JavaScript as if we change the colour on our table rows I would need to remember to change it both in the CSS and in the JavaScript.\n\nDoing something different with the last element\n\nSo here\u2019s another thing that we often deal with. You have a list of items all floated left with a right hand margin on each element constrained within a fixed width layout. If each element has the right margin applied the margin on the final element will cause the set to become too wide forcing that last item down to the next row as shown in the below example where I have used a grey border to indicate the fixed width.\n\n\n\nCurrently we have two ways to deal with this. We can put a negative right margin on the list, the same width as the space between the elements. This means that the extra margin on the final element fills that space and the item doesn\u2019t drop down. \n\n<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Strict//EN\"\n\t  \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd\">\n<html xmlns=\"http://www.w3.org/1999/xhtml\">\n<head>\n<title>The last item is different</title>\n<style type=\"text/css\">\n\tbody {\n\t\tpadding: 40px;\n\t\tmargin: 0;\n\t\tfont: 0.9em Arial, Helvetica, sans-serif;\n\t}\n\tdiv#wrapper {\n\t\twidth: 740px;\n\t\tfloat: left;\n\t\tborder: 5px solid #ccc;\n\t}\n\tul.gallery {\n\t\tmargin: 0 -10px 0 0;\n\t\tpadding: 0;\n\t\tlist-style: none;\n\t}\n\tul.gallery li {\n\t\tfloat: left;\n\t\twidth: 240px;\n\t\tmargin: 0 10px 10px 0;\n\t}\n</style>\n</head>\n<body>\n\t<div id=\"wrapper\">\n\t\t<ul class=\"gallery\">\n\t\t\t<li><img src=\"xmas1.jpg\" alt=\"baubles\" /></li>\n\t\t\t<li><img src=\"xmas2.jpg\" alt=\"star\" /></li>\n\t\t\t<li><img src=\"xmas3.jpg\" alt=\"wreath\" /></li>\n\t\t</ul>\n\t</div>\n</body>\n</html>\n\nView Example 4\n\nThe other solution will be to put a class on the final element and in the CSS remove the margin for this class. \n\nul.gallery li.last {\n\tmargin-right: 0;\n}\n\nThis second solution may not be easy if the content is generated from server-side code that you don\u2019t have access to change.\n\nIt could all be so different. In CSS3 we have marvellously common-sense selectors such as last-child, meaning that we can simply add rules for the last list item. \n\nul.gallery li:last-child {\n\tmargin-right: 0;\n}\n\nView Example 5\n\nThis removed the margin on the li which is the last-child of the ul with a class of gallery. No messing about sticking classes on the last item, or pushing the width of the item out wit a negative margin.\n\nIf this list of items repeated ad infinitum then you could also use nth-child for this task. Creating a rule that makes every 3rd element margin-less.\n\nul.gallery li:nth-child(3n) {\n\tmargin-right: 0;\n}\n\nView Example 6\n\n\n\nA similar example is where the designer has added borders to the bottom of each element \u2013 but the last item does not have a border or is in some other way different. Again, only a class added to the last element will save you here if you cannot rely on using the last-child selector.\n\nBrowser support for last-child\n\nThe situation for last-child is similar to that of nth-child, in that there is no support in Internet Explorer 8. However, once again it is very simple to replicate the functionality using jQuery. Adding our .last class to the last list item.\n\n$(\"ul.gallery li:last-child\").addClass(\"last\");\n\nWe could also use the nth-child selector to add the .last class to every third list item.\n\n$(\"ul.gallery li:nth-child(3n)\").addClass(\"last\");\n\nView Example 7\n\nFun with forms\n\nStyling forms can be a bit of a trial, made difficult by the fact that any CSS applied to the input element will effect text fields, submit buttons, checkboxes and radio buttons. As developers we are left adding classes to our form fields to differentiate them. In most builds all of my text fields have a simple class of text whereas I wouldn\u2019t dream of adding a class of para to every paragraph element in a document.\n\n<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Strict//EN\"\n      \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd\">\n<html xmlns=\"http://www.w3.org/1999/xhtml\">\n<head>\n<title>Syling form fields</title>\n<style type=\"text/css\">\n\tbody {\n\t\tpadding: 40px;\n\t\tmargin: 0;\n\t\tfont: 0.9em Arial, Helvetica, sans-serif;\n\t}\n\tform div {\n\t\tclear: left;\n\t\tpadding: 0 0 0.8em 0;\n\t}\n\tform label {\n\t\tfloat: left;\n\t\twidth: 120px;\n\t}\n\tform .text, form textarea {\n\t\tborder:1px solid #333;\n\t\tpadding: 0.2em;\n\t\twidth: 400px;\n\t}\n\tform .button {\n\t\tborder: 1px solid #333;\n\t\tbackground-color: #eee;\n\t\tcolor: #000;\n\t\tpadding: 0.1em;\n\t} \n\t</style>\n</head>\n<body>\n\t<h1>Send your Christmas list to Santa</h1>\n\t<form method=\"post\" action=\"\" id=\"christmas-list\">\n\t\t<div><label for=\"fName\">Name</label>\n\t\t<input type=\"text\" name=\"fName\" id=\"fName\" class=\"text\" /></div>\n\t\t<div><label for=\"fEmail\">Email address</label>\n\t\t<input type=\"text\" name=\"fEmail\" id=\"fEmail\" class=\"text\" /></div>\n\t\t<div><label for=\"fList\">Your list</label>\n\t\t<textarea name=\"fList\" id=\"fList\" rows=\"10\" cols=\"30\"></textarea></div>\n\t\t<div><input type=\"submit\" name=\"btnSubmit\" id=\"btnSubmit\" value=\"Submit\" class=\"button\" ></div>\n\t</form>\n</body>\n</html>\n\nView Example 8\n\nAttribute selectors provide a way of targeting elements by looking at the attributes of those elements. Unlike the other examples in this article which are CSS3 selectors, the attribute selector is actually a CSS2.1 selector \u2013 it just doesn\u2019t get much use because of lack of support in Internet Explorer 6. Using attribute selectors we can write rules for text inputs and form buttons without needing to add any classes to the markup. For example after removing the text and button classes from my text and submit button input elements I can use the following rules to target them:\n\nform input[type=\"text\"] {\n    border: 1px solid #333;\n    padding: 0.2em;\n    width: 400px;\n}\nform input[type=\"submit\"]{\n    border: 1px solid #333;\n    background-color: #eee;\n    color: #000;\n    padding: 0.1em;\n} \n\nView Example 9\n\nAnother problem that I encounter with forms is where I am using CSS to position my labels and form elements by floating the labels. This works fine as long as I want all of my labels to be floated, however sometimes we get a set of radio buttons or a checkbox, and I don\u2019t want the label field to be floated. As you can see in the below example the label for the checkbox is squashed up into the space used for the other labels, yet it makes more sense for the checkbox to display after the text.\n\n\n\nI could use a class on this label element however CSS3 lets me to target the label attribute directly by looking at the value of the for attribute.\n\nlabel[for=\"fOptIn\"] {\n    float: none;\n    width: auto;\n}\n\n\n\nBeing able to precisely target attributes in this way is incredibly useful, and once IE6 is no longer an issue this will really help to clean up our markup and save us from having to create all kinds of special cases when generating this markup on the server-side.\n\nBrowser support\n\nThe news for attribute selectors is actually pretty good with Internet Explorer 7+, Firefox 2+ and all other modern browsers all having support. As I have already mentioned this is a CSS2.1 selector and so we really should expect to be able to use it as we head into 2010! Internet Explorer 7 has slightly buggy support and will fail on the label example shown above however I discovered a workaround in the Sitepoint CSS reference comments. Adding the selector label[htmlFor=\"fOptIn\"] to the correct selector will create a match for IE7.\n\nIE6 does not support these selector but, once again, you can use jQuery to plug the holes in IE6 support. The following jQuery will add the text and button classes to your fields and also add a checks class to the label for the checkbox, which you can use to remove the float and width for this element.\n\n$('form input[type=\"submit\"]').addClass(\"button\");\n$('form input[type=\"text\"]').addClass(\"text\");\n$('label[for=\"fOptIn\"]').addClass(\"checks\");\n\nView Example 10\n\nThe selectors I\u2019ve used in this article are easy to overlook as we do have ways to achieve these things currently. As developers \u2013 especially when we have frameworks and existing code that cope with these situations \u2013 it is easy to carry on as we always have done. \n\nI think that the time has come to start to clean up our front and backend code and replace our reliance on classes with these more advanced selectors. With the help of a little JavaScript almost all users will still get the full effect and, where we are dealing with purely visual effects, there is definitely a case to be made for not worrying about the very small percentage of people with old browsers and no JavaScript. They will still receive a readable website, it may just be missing some of the finesse offered to the modern browsing experience.", "year": "2009", "author": "Rachel Andrew", "author_slug": "rachelandrew", "published": "2009-12-20T00:00:00+00:00", "url": "https://24ways.org/2009/cleaner-code-with-css3-selectors/", "topic": "code"}
{"rowid": 191, "title": "CSS Animations", "contents": "Friend: You should learn how to write CSS!\nMe: \u2026\nFriend: CSS; Cascading Style Sheets. If you\u2019re serious about web design, that\u2019s the next thing you should learn.\nMe: What\u2019s wrong with <font> tags?\n\nThat was 8 years ago. Thanks to the hard work of Jeffrey, Andy, Andy, Cameron, Colly, Dan and many others, learning how to decently markup a website and write lightweight stylesheets was surprisingly easy. They made it so easy even a complete idiot (OH HAI) was able to quickly master it.\n\nAnd then\u2026 nothing. For a long time, it seemed like there wasn\u2019t happening anything in the land of CSS, time stood still. Once you knew the basics, there wasn\u2019t anything new to keep up with. It looked like a great band split, but people just kept re-releasing their music in various \u201cBest Of!\u201d or \u201cRemastered!\u201d albums.\n\nFast forward a couple of years to late 2006. On the official WebKit blog Surfin\u2019 Safari, there\u2019s an article about something called CSS animations. Great new stuff to play with, but only supported by nightly builds (read: very, very beta) of WebKit. In the following months, they release other goodies, like CSS gradients, CSS reflections, CSS masks, and even more CSS animation sexiness. Whoa, looks like the band got back together, found their second youth, and went into overdrive! The problem was that if you wanted to listen to their new albums, you had to own some kind of new high-tech player no one on earth (besides some early adopters) owned.\n\nBack in the time machine. It is now late 2009, close to Christmas. Things have changed. Browsers supporting these new toys are widely available left and right. Even non-techies are using these advanced browsers to surf the web on a daily basis!\n\nEpic win? Almost, but at least this gives us enough reason to start learning how we could use all this new CSS voodoo. On Monday, Natalie Downe showed you a good tutorial on Going Nuts with CSS Transitions. Today, I\u2019m taking it one step further\u2026\n\nHowto: A basic spinner\n\nNo matter how fast internet tubes or servers are, we\u2019ll always need spinners to indicate something\u2019s happening behind the scenes. Up until now, people would go to some site, pick one of the available templates, customize their foreground and background colors, and download a beautiful GIF image.\n\nThere are some downsides to this though:\n\n\n\tIt\u2019s only _semi_-transparent: If you change your mind and pick a slightly different background color, you need to go back to the site, set all the parameters again, and replace your current image. There isn\u2019t even a way to pick an image or gradient as background.\n\tLimited number of frames, probable to keep the file-size as small as possible (don\u2019t forget this thing needs to be loaded before whatever process is finished in the background), and you don\u2019t have that 24 frames per second smoothness.\n\tThis is just too fucking easy. As a front-end code geek, there must be a \u201ccooler\u201d way to do this!\n\n\nWhat do we need to make a spinner with CSS animations? One image, and one element on our webpage we can hook on to. Yes, that\u2019s it. I created a simple transparent PNG that looks it might be a spinner, and for the element on the page, I wrote this piece of genius HTML:\n\n<p id=\"spinner\">Please wait while we do what we do best.</p>\n\nLooks semantic enough to me! Here\u2019s the basic HTML I\u2019m using to position the element in the center of the screen, and make the text inside it disappear:\n\n#spinner {\n\tposition: absolute;\n\ttop: 50%;\n\tleft: 50%;\n\tmargin: -100px 0 0 -100px;\n\theight: 200px;\n\twidth: 200px;\n\ttext-indent: 250px;\n\twhite-space: nowrap;\n\toverflow: hidden;\n}\n\nCool, but now we don\u2019t see anything. Let\u2019s pull rabbit number one out of the hat: -webkit-mask-image (accompanied by the previously mentioned transparent PNG image):\n\n#spinner {\n\t...\n\t-webkit-mask-image: url(../img/spinner.png);\n}\n\nBy now you should be feeling like a magician already. Oh, wait, we still have a blank screen, looks like we left something in the hat (tip: not rabbit droppings):\n\n#spinner {\n\t...\n\t-webkit-mask-image: url(../img/spinner.png);\n\tbackground-color: #000;\n}\n\nNice! What we\u2019ve done right here is telling the element to clip onto the PNG. It\u2019s a lot like clipping layers in Photoshop. So, spinners, they move, right? Into the hat again, and look what we pull out this time: CSS animations!\n\n#spinner {\n\t...\n\t-webkit-mask-image: url(../img/spinner.png);\n\tbackground-color: #000;\n\t-webkit-animation-name: spinnerRotate;\n\t-webkit-animation-duration: 2s;\n\t-webkit-animation-iteration-count: infinite;\n\t-webkit-animation-timing-function: linear;\n}\n\nSome explanation:\n\n\n\t-webkit-animation-name: Name of the animation we\u2019ll be defining later.\n\t-webkit-animation-duration: The timespan of the animation.\n\t-webkit-animation-iteration-count: Repeat once, a defined number of times or infinitely?\n\t-webkit-animation-timing-function: Linear is the one you\u2019ll be using mostly. Other options are ease-in, ease-out, ease-in-out\u2026\n\n\nLet\u2019s define spinnerRotate:\n\n@-webkit-keyframes spinnerRotate {\n\tfrom {\n\t\t-webkit-transform:rotate(0deg);\n\t}\n\tto {\n\t\t-webkit-transform:rotate(360deg);\n\t}\n}\n\nEn Anglais: Rotate #spinner starting at 0 degrees, ending at 360 degrees, over a timespan of 2 seconds, at a constant speed, and keep repeating this animation forever.\n\nThat\u2019s it! See it in action on the demo page.\n\nNote: these examples only work when you\u2019re using a WebKit-based browser like Safari, Mobile Safari or Google Chrome. I\u2019m confident though that Mozilla and Opera will try their very best catching up with all this new CSS goodness soon.\n\nWhen looking at this example, you see the possibilities are endless. Another advantage is you can change the look of it entirely by only changing a couple of lines of CSS, instead of re-creating and re-downloading the image from some website smelling like web 2.0 gone bad. I made another demo that shows how great it is to be able to change background and foreground colors (even on the fly!).\n\nSo there you have it, a smoothly animated, fully transparent and completely customizable spinner. Cool? I think so. (Ladies?)\n\nBut you can do a lot more with CSS animations than just create pretty spinners. Since I was fooling around with it anyway, I decided to test how far you can push this, space is the final limit, right?\n\nConclusion\n\nCSS has never been more exciting than it is right now. I\u2019m even prepared to say CSS is \u201ccool\u201d again, both for the more experienced front-end developers as for the new designers discovering CSS every day now.\n\nBut\u2026\n\nRemember when Javascript became popular? Remember when Flash became popular? Every time we\u2019re been given new toys, some people aren\u2019t ashamed to use it in a way you can barely call constructive. I\u2019m thinking of Geocities websites, loaded with glowing blocks of text, moving images, bad color usage\u2026 In the wise words of Stan Lee: With great power there must also come great responsibility! A sprinkle of CSS animations is better than a bucket load. Apply with care.", "year": "2009", "author": "Tim Van Damme", "author_slug": "timvandamme", "published": "2009-12-15T00:00:00+00:00", "url": "https://24ways.org/2009/css-animations/", "topic": "code"}
{"rowid": 188, "title": "Don't Lose Your :focus", "contents": "For many web designers, accessibility conjures up images of blind users with screenreaders, and the difficulties in making sites accessible to this particular audience. Of course, accessibility covers a wide range of situations that go beyond the extreme example of screenreader users. And while it\u2019s true that making a complex site accessible can often be a daunting prospect, there are also many small things that don\u2019t take anything more than a bit of judicious planning, are very easy to test (without having to buy expensive assistive technology), and can make all the difference to certain user groups.\n\nIn this short article we\u2019ll focus on keyboard accessibility and how careless use of CSS can potentially make your sites completely unusable.\n\nKeyboard Access\n\nUsers who for whatever reason can\u2019t use a mouse will employ a keyboard (or keyboard-like custom interface) to navigate around web pages. By default, they will use TAB and SHIFT + TAB to move from one focusable element (links, form controls and area) of a page to the next.\n\nNote: in OS X, you\u2019ll first need to turn on full keyboard access under System Preferences > Keyboard and Mouse > Keyboard Shortcuts. Safari under Windows needs to have the option Press Tab to highlight each item on a webpage in Preferences > Advanced enabled. Opera is the odd one out, as it has a variety of keyboard navigation options \u2013 the most relevant here being spatial navigation via Shift+Down, Shift+Up, Shift+Left, and Shift+Right).\n\nBut I Don\u2019t Like Your Dotted Lines\u2026\n\nTo show users where they are within a page, browsers place an outline around the element that currently has focus. The \u201cproblem\u201d with these default outlines is that some browsers (Internet Explorer and Firefox) also display them when a user clicks on a focusable element with the mouse. Particularly on sites that make extensive use of image replacement on links with \u201coff left\u201d techniques this can create very unsightly outlines that stretch from the replaced element all the way to the left edge of the browser.\n\n Outline bleeding off to the left (image-replacement example from carsonified.com)\n\nThere is a trivial workaround to prevent outlines from \u201cspilling over\u201d by adding a simple overflow:hidden, which keeps the outline in check around the clickable portion of the image-replaced element itself.\n\n Outline tamed with overflow:hidden\n\nBut for many designers, even this is not enough. As a final solution, many actively suppress outlines altogether in their stylesheets. Controversially, even Eric Meyer\u2019s popular reset.css \u2013 an otherwise excellent set of styles that levels the playing field of varying browser defaults \u2013 suppresses outlines.\n\nhtml, body, div, span, applet, object, iframe ... {\n\t...\n\toutline: 0;\n\t...\n}\n/* remember to define focus styles! */\n:focus {\n\toutline: 0;\n}\n\nYes, in his explanation (and in the CSS itself) Eric does remind designers to define relevant styles for :focus\u2026 but judging by the number of sites that seem to ignore this (and often remove the related comment from the stylesheet altogether), the message doesn\u2019t seem to have sunk in.\n\nAnyway\u2026 hurrah! No more unsightly dotted lines on our lovely design. But what about keyboard users? Although technically they can still TAB from one element to the next, they now get no default cue as to where they are within the page (one notable exception here is Opera, where the outline is displayed regardless of stylesheets)\u2026 and if they\u2019re Safari users, they won\u2019t even get an indication of a link\u2019s target in the status bar, like they would if they hovered over it with the mouse.\n\nOnly Suppress outline For Mouse Users\n\nIs there a way to allow users navigating with the keyboard to retain the standard outline behaviour they\u2019ve come to expect from their browser, while also ensuring that it doesn\u2019t show display for mouse users?\n\n Testing some convoluted style combinations\n\nAfter playing with various approaches (see Better CSS outline suppression for more details), the most elegant solution also seemed to be the simplest: don\u2019t remove the outline on :focus, do it on :active instead \u2013 after all, :active is the dynamic pseudo-class that deals explicitly with the styles that should be applied when a focusable element is clicked or otherwise activated.\n\na:active { outline: none; }\n\nThe only minor issues with this method: if a user activates a link and then uses the browser\u2019s back button, the outline becomes visible. Oh, and old versions of Internet Explorer notoriously get confused by the exact meaning of :focus, :hover and :active, so this method fails in IE6 and below. Personally, I can live with both of these.\n\nNote: at the last minute before submitting this article, I discovered a fatal flaw in my test. It appears that outline still manages to appear in the time between activating a link and the link target loading (which in hindsight is logical \u2013 after activation, the link does indeed receive focus). As my test page only used in-page links, this issue never came up before. The slightly less elegant solution is to also suppress the outline on :hover.\n\na:hover, a:active { outline: none; }\n\nIn Conclusion\n\nOf course, many web designers may argue that they know what\u2019s best, even for their keyboard-using audience. Maybe they\u2019ve removed the default outline and are instead providing some carefully designed :focus styles. If they know for sure that these custom styles are indeed a reliable alternative for their users, more power to them\u2026 but, at the risk of sounding like Jakob \u201cblue underlined links\u201d Nielsen, I\u2019d still argue that sometimes the default browser behaviours are best left alone. Complemented, yes (and if you\u2019re already defining some fancy styles for :hover, by all means feel free to also make them display on :focus)\u2026 but not suppressed.", "year": "2009", "author": "Patrick Lauke", "author_slug": "patricklauke", "published": "2009-12-09T00:00:00+00:00", "url": "https://24ways.org/2009/dont-lose-your-focus/", "topic": "code"}
{"rowid": 186, "title": "The Web Is Your CMS", "contents": "It is amazing what you can do these days with the services offered on the web. Flickr stores terabytes of photos for us and converts them automatically to all kind of sizes, finds people in them and even allows us to edit them online. YouTube does almost the same complete job with videos, LinkedIn allows us to maintain our CV, Delicious our bookmarks and so on.\n\nWe don\u2019t have to do these tasks ourselves any more, as all of these systems also come with ways to use the data in the form of Application Programming Interfaces, or APIs for short. APIs give us raw data when we send requests telling the system what we want to get back.\n\nThe problem is that every API has a different idea of what is a simple way of accessing this data and in which format to give it back.\n\nMaking it easier to access APIs\n\nWhat we need is a way to abstract the pains of different data formats and authentication formats away from the developer \u2014 and this is the purpose of the Yahoo Query Language, or YQL for short. \n\nLibraries like jQuery and YUI make it easy and reliable to use JavaScript in browsers (yes, even IE6) and YQL allows us to access web services and even the data embedded in web documents in a simple fashion \u2013 SQL style.\n\nSelect * from the web and filter it the way I want\n\nYQL is a web service that takes a few inputs itself:\n\n\n\tA query that tells it what to get, update or access\n\tAn output format \u2013 XML, JSON, JSON-P or JSON-P-X\n\tA callback function (if you defined JSON-P or JSON-P-X)\n\n\nYou can try it out yourself \u2013 check out this link to get back Flickr photos for the search term \u2018santa\u2019*%20from%20flickr.photos.search%20where%20text%3D%22santa%22&format=xml in XML format. The YQL query for this is \n\nselect * from flickr.photos.search where text=\"santa\"\n\nThe easiest way to take your first steps with YQL is to look at the console. There you get sample queries, access to all the data sources available to you and you can easily put together complex queries. In this article, however, let\u2019s use PHP to put together a web page that pulls in Flickr photos, blog posts, Videos from YouTube and latest bookmarks from Delicious.\n\nCheck out the demo and get the source code on GitHub.\n\n<?php\n  /* YouTube RSS */\n  $query = 'select description from rss(5) where url=\"http://gdata.youtube.com/feeds/base/users/chrisheilmann/uploads?alt=rss&v=2&orderby=published&client=ytapi-youtube-profile\";';\n  /* Flickr search by user id */\n  $query .= 'select farm,id,owner,secret,server,title from flickr.photos.search where user_id=\"11414938@N00\";';\n  /* Delicious RSS */\n  $query .= 'select title,link from rss where url=\"http://feeds.delicious.com/v2/rss/codepo8?count=10\";';\n  /* Blog RSS */\n  $query .= 'select title,link from rss where url=\"http://feeds.feedburner.com/wait-till-i/gwZf\"';\n  /* The YQL web service root with JSON as the output */\n  $root = 'http://query.yahooapis.com/v1/public/yql?format=json&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys';\n  /* Assemble the query */\n  $query = \"select * from query.multi where queries='\".$query.\"'\";\n  $url = $root . '&q=' . urlencode($query);\n  /* Do the curl call (access the data just like a browser would) */\n  $ch = curl_init(); \n  curl_setopt($ch, CURLOPT_URL, $url); \n  curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); \n  curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);\n  curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);\n  $output = curl_exec($ch); \n  curl_close($ch);\n  $data = json_decode($output);\n  $results = $data->query->results->results;\n  /* YouTube output */\n  $youtube = '<ul id=\"youtube\">';\n  foreach($results[0]->item as $r){\n\t$cleanHTML = undoYouTubeMarkupCrimes($r->description);\n\t$youtube .= '<li>'.$cleanHTML.'</li>';\n  }\n  $youtube .= '</ul>';\n  /* Flickr output */\n  $flickr = '<ul id=\"flickr\">';\n  foreach($results[1]->photo as $r){\n\t$flickr .= '<li>'.\n\t\t\t   '<a href=\"http://www.flickr.com/photos/codepo8/'.$r->id.'/\">'.\n\t\t\t   '<img src=\"http://farm' .$r->farm . '.static.flickr.com/'.\n\t\t\t   $r->server . '/' . $r->id . '_' . $r->secret . \n\t\t\t   '_s.jpg\" alt=\"'.$r->title.'\"></a></li>';\n  }\n  $flickr .= '</ul>';\n  /* Delicious output */\n  $delicious = '<ul id=\"delicious\">';\n  foreach($results[2]->item as $r){\n\t$delicious .= '<li><a href=\"'.$r->link.'\">'.$r->title.'</a></li>';\n  }\n  $delicious .= '</ul>';\n  /* Blog output */\n  $blog = '<ul id=\"blog\">';\n  foreach($results[3]->item as $r){\n\t$blog .= '<li><a href=\"'.$r->link.'\">'.$r->title.'</a></li>';\n  }\n  $blog .= '</ul>';\n  function undoYouTubeMarkupCrimes($str){\n\t$cleaner = preg_replace('/555px/','100%',$str);\n\t$cleaner = preg_replace('/width=\"[^\"]+\"/','',$cleaner);\n\t$cleaner = preg_replace('/<tbody>/','<colgroup><col width=\"20%\"><col width=\"50%\"><col width=\"30%\"></colgroup><tbody>',$cleaner);\n\treturn $cleaner;\n  }\n?>\n\nWhat we are doing here is create a few different YQL statements and queue them together with the query.multi table. Each of these can be run inside YQL itself. Check out the YouTube, Flickr, Delicious and Blog example in the console if you don\u2019t believe me. The benefit of using this table is that we don\u2019t make individual requests for each query but we get all the data in one single request \u2013 which means a much better performing solution as the YQL server farm is faster on the web than our servers.\n\nWe point the query to the YQL web service end point and get the resulting data using cURL. All that we need to do then is to convert the returned data to HTML lists that can be printed out inside an HTML template.\n\nMixing, matching and using HTML as a data source\n\nThis was a simple example of what YQL can do for you. Where it gets really powerful however is by mixing and matching different APIs. YQL is also a good tool to get information from HTML documents. By using the html table you can load the content of an HTML document (which gets fixed automatically by HTMLTidy) and use XPATH to filter down results to what you need. Take the following example which takes headlines from the news.bbc.co.uk homepage and runs the results through Yahoo\u2019s Term Extractor API to give you a list of currently hot topics.\n\nselect * from search.termextract where context in (\n  select content from html where url=\"http://news.bbc.co.uk\" and xpath=\"//table[@width=800]//a\"\n)\n\nTry it out in the console or see the results here. In English, this means:\n\n\n\tGo to http://news.bbc.co.uk and get me the HTML\n\tRun it through HTML Tidy to clean it up.\n\tGet me only the links inside the table with an attribute of width and the value 800\n\tGet only the content of the link and for each of the links\n\t\n\t\tTake the content and send it as context to the Yahoo Term Extractor API\n\t\n\t\n\nIf we choose JSON-P as the output format we can use the outcome directly in JavaScript (see this demo or see its source):\n\n<ul id=\"hottopics\"></ul>\n<script type=\"text/javascript\">\nfunction hottopics(o){\n  var res = o.query.results.Result,\n\t  all = res.length,\n\t  topics = {},\n\t  out = [],\n\t  html = '',\n\t  i=0;\n  /* create hash from topics to prevent repetition */\t \n  for(i=0;i<all;i++){\n\ttopics[res[i]] = res[i];\n  };\n  for(i in topics){\n\tout.push(i);\n  };\n  html = '<li>' + out.join('</li><li>') + '</li>';\n  document.getElementById('hottopics').innerHTML = html;\n};\n</script>\n<script type=\"text/javascript\" src=\"http://query.yahooapis.com/v1/public/yql?q=select%20content%20from%20search.termextract%20where %20context%20in%20(select%20content%20from%20html%20where%20url%3D%22http%3A%2F%2Fnews.bbc.co.uk%22%20and%20xpath%3D%22%2F%2Ftable%5B%40width%3D800%5D%2F%2Fa%22)&format=json&callback=hottopics\"></script>\n\nUsing JSON, we can also use PHP which means the demo works for everybody \u2013 not only those with JavaScript enabled (see this demo or see its source):\n\n<ul id=\"hottopics\"><li>\n<?php\n$url = 'http://query.yahooapis.com/v1/public/yql?q=select%20content'.\n\t   '%20from%20search.termextract%20where%20context%20in'.\n\t   '%20(select%20content%20from%20html%20where%20url%3D%22'.\n\t   'http%3A%2F%2Fnews.bbc.co.uk%22%20and%20xpath%3D%22%2F%2F'.\n\t   'table%5B%40width%3D800%5D%2F%2Fa%22)&format=json';\n$ch = curl_init(); \ncurl_setopt($ch, CURLOPT_URL, $url); \ncurl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); \ncurl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);\ncurl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);\n$output = curl_exec($ch); \ncurl_close($ch);\n$data = json_decode($output);\n$topics = array_unique($data->query->results->Result);\necho join('</li><li>',$topics);\n?>\n</li></ul>\n\nSummary\n\nThis article could only scratch the surface of YQL. You have not only read access to the web but you can also write to web services. For example you can update Twitter, post to your WordPress blog or shorten a URL with bit.ly. Using Open Tables you can add any web service to the YQL interface and you can even run server-side JavaScript which is for example useful to return Flickr photos as HTML or get the HTML content from a document that needs POST data.\n\nThe web of data is already here, and using YQL you don\u2019t have to be a web services expert to use it and be part of it.", "year": "2009", "author": "Christian Heilmann", "author_slug": "chrisheilmann", "published": "2009-12-17T00:00:00+00:00", "url": "https://24ways.org/2009/the-web-is-your-cms/", "topic": "code"}
{"rowid": 184, "title": "Spruce It Up", "contents": "The landscape of web typography is changing quickly these days. We\u2019ve gone from the wild west days of sIFR to Cuf\u00f3n to finally seeing font embedding seeing wide spread adoption by browser developers (and soon web designers) with @font-face. For those who\u2019ve felt limited by the typographic possibilities before, this has been a good year.\n\nAs Mark Boulton has so eloquently elucidated, @font-face embedding doesn\u2019t come without its drawbacks. Font files can be quite large and FOUT\u2014that nasty flash of unstyled text\u2014can be a distraction for users.\n\nData URIs\n\nWe can battle FOUT by using Data URIs. A Data URI allows the font to be encoded right into the CSS file. When the font comes with the CSS, the flash of unstyled text is mitigated. No extra HTTP requests are required. \n\nDon\u2019t be a grinch, though. Sending hundreds of kilobytes down the pipe still isn\u2019t great. Sometimes, all we want to do is spruce up our site with a little typographic sugar. \n\nBe Selective\n\nDan Cederholm\u2019s SimpleBits is an attractive site. \n\n\n\nTake a look at the ampersand within the header of his site. It\u2019s the lovely (and free) Goudy Bookletter 1911 available from The League of Movable Type. The Opentype format is a respectable 28KB. Nothing too crazy but hold on here. Mr. Cederholm is only using the ampersand! Ouch. That\u2019s a lot of bandwidth just for one character.\n\nCan we optimize a font like we can an image? Yes. Image optimization essentially works by removing unnecessary image data such as colour data, hidden comments or using compression algorithms. How do you remove unnecessary information from a font? Subsetting. \n\nIf you\u2019re the adventurous type, grab a copy of FontForge, which is an open source font editing tool. You can open the font, view and edit any of the glyphs and then re-generate the font. The interface is a little clunky but you\u2019ll be able to select any character you don\u2019t want and then cut the glyphs. Re-generate your font and you\u2019ve now got a smaller file. \n\n\n\nThere are certainly more optimizations that can also be made such as removing hinting and kerning information. Keep in mind that removing this information may affect how well the type renders.\n\nAt this time of year, though, I\u2019m sure you\u2019re quite busy. Save yourself some time and head on over to the Font Squirrel Font Generator.\n\n\n\nThe Font Generator is extremely handy and allows for a number of optimizations and cross-platform options to be generated instantly. Select the font from your local system\u2014make sure that you are only using properly licensed fonts! \n\nIn this particular case, we only want the ampersand. Click on Subset Fonts which will open up a new menu. Unselect any preselected sets and enter the ampersand into the Single Characters text box. \n\nGenerate your font and what are you left with? 3KB. \n\n\n\nThe Font Generator even generates a base64 encoded data URI stylesheet to be imported easily into your project.\n\nCheck out the Demo page. (This demo won\u2019t work in Internet Explorer as we\u2019re only demonstrating the Data URI font embedding and not using the EOT file format that IE requires.) \n\nNo Unnecessary Additives\n\nIf you peeked under the hood of that demo, did you notice something interesting? There\u2019s no <span> around the ampersand. The great thing about this is that we can take advantage of the font stack\u2019s natural ability to switch to a fallback font when a character isn\u2019t available.\n\nJust like that, we\u2019ve managed to spruce up our page with a little typographic sugar without having to put on too much weight.", "year": "2009", "author": "Jonathan Snook", "author_slug": "jonathansnook", "published": "2009-12-19T00:00:00+00:00", "url": "https://24ways.org/2009/spruce-it-up/", "topic": "code"}
{"rowid": 182, "title": "Breaking Out The Edges of The Browser", "contents": "HTML5 contains more than just the new entities for a more meaningful document, it also contains an arsenal of JavaScript APIs.  So many in fact, that some APIs have outgrown the HTML5 spec\u2019s backyard and have been sent away to grow up all on their own and been given the prestigious honour of being specs in their own right.\n\nSo when I refer to (bendy finger quote) \u201cHTML5\u201d, I mean the HTML5 specification and a handful of other specifications that help us authors build web applications.\n\nExamples of those specs I would include in the umbrella term would be: geolocation, web storage, web databases, web sockets and web workers, to name a few.\n\nFor all you guys and gals, on this special 2009 series of 24 ways, I\u2019m just going to focus on data storage and offline applications: boldly taking your browser where no browser has gone before!\n\nWeb Storage\n\nThe Web Storage API is basically cookies on steroids, a unhealthy dosage of steroids.  Cookies are always a pain to work with.  First of all you have the problem of setting, changing and deleting them.  Typically solved by Googling and blindly relying on PPK\u2019s solution.  If that wasn\u2019t enough, there\u2019s the 4Kb limit that some of you have hit when you really don\u2019t want to.\n\nThe Web Storage API gets around all of the hoops you have to jump through with cookies.  Storage supports around 5Mb of data per domain (the spec\u2019s recommendation, but it\u2019s open to the browsers to implement anything they like) and splits in to two types of storage objects:\n\n\n\tsessionStorage \u2013 available to all pages on that domain while the window remains open\n\tlocalStorage \u2013 available on the domain until manually removed\n\n\nSupport\n\nIgnoring beta browsers for our support list, below is a list of the major browsers and their support for the Web Storage API:\n\n\n\tLatest: Internet Explorer, Firefox, Safari (desktop & mobile/iPhone)\n\tPartial: Google Chrome (only supports localStorage)\n\tNot supported: Opera (as of 10.10)\n\n\nUsage\n\nBoth sessionStorage and localStorage support the same interface for accessing their contents, so for these examples I\u2019ll use localStorage.\n\nThe storage interface includes the following methods:\n\n\n\tsetItem(key, value)\n\tgetItem(key)\n\tkey(index)\n\tremoveItem(key)\n\tclear()\n\n\nIn the simple example below, we\u2019ll use setItem and getItem to store and retrieve data:\n\nlocalStorage.setItem('name', 'Remy');\nalert( localStorage.getItem('name') );\n\nUsing alert boxes can be a pretty lame way of debugging.  Conveniently Safari (and Chrome) include database tab in their debugging tools (cmd+alt+i), so you can get a visual handle on the state of your data:\n\n Viewing localStorage\n\nAs far as I know only Safari has this view on stored data natively in the browser.  There may be a Firefox plugin (but I\u2019ve not found it yet!) and IE\u2026 well that\u2019s just IE.\n\nEven though we\u2019ve used setItem and getItem, there\u2019s also a few other ways you can set and access the data.\n\nIn the example below, we\u2019re accessing the stored value directly using an expando and equally, you can also set values this way:\n\nlocalStorage.name = \"Remy\";\nalert( localStorage.name ); // shows \"Remy\"\n\nThe Web Storage API also has a key method, which is zero based, and returns the key in which data has been stored. This should also be in the same order that you set the keys, for example:\n\nalert( localStorage.getItem(localStorage.key(0)) ); \n// shows \"Remy\"\n\nI mention the key() method because it\u2019s not an unlikely name for a stored value.  This can cause serious problems though.\n\nWhen selecting the names for your keys, you need to be sure you don\u2019t take one of the method names that are already on the storage object, like key, clear, etc. As there are no warnings when you try to overwrite the methods, it means when you come to access the key() method, the call breaks as key is a string value and not a function.\n\nYou can try this yourself by creating a new stored value using localStorage.key = \"foo\" and you\u2019ll see that the Safari debugger breaks because it relies on the key() method to enumerate each of the stored values.\n\nUsage Notes\n\nCurrently all browsers only support storing strings. This also means if you store a numeric, it will get converted to a string:\n\nlocalStorage.setItem('count', 31);\nalert(typeof localStorage.getItem('count')); \n// shows \"string\"\n\nThis also means you can\u2019t store more complicated objects natively with the storage objects.  To get around this, you can use Douglas Crockford\u2019s JSON parser (though Firefox 3.5 has JSON parsing support baked in to the browser \u2013 yay!) json2.js to convert the object to a stringified JSON object:\n\nvar person = {\n\tname: 'Remy',\n\theight: 'short',\n\tlocation: 'Brighton, UK'\n};\nlocalStorage.setItem('person', JSON.stringify(person));\nalert( JSON.parse(localStorage.getItem('person')).name ); \n// shows \"Remy\"\n\nAlternatives\n\nThere are a few solutions out there that provide storage solutions that detect the Web Storage API, and if it\u2019s not available, fall back to different technologies (for instance, using a flash object to store data).  One comprehensive version of this is Dojo\u2019s storage library.  I\u2019m personally more of a fan of libraries that plug missing functionality under the same namespace, just as Crockford\u2019s JSON parser does (above).\n\nFor those interested it what that might look like, I\u2019ve mocked together a simple implementation of sessionStorage.  Note that it\u2019s incomplete (because it\u2019s missing the key method), and it could be refactored to not using the JSON stringify (but you would need to ensure that the values were properly and safely encoded):\n\n// requires json2.js for all browsers other than Firefox 3.5\nif (!window.sessionStorage && JSON) {\n\twindow.sessionStorage = (function () {\n\t\t// window.top.name ensures top level, and supports around 2Mb\n\t\tvar data = window.top.name ? JSON.parse(window.top.name) : {};\n\t\treturn {    \n\t\t\tsetItem: function (key, value) {\n\t\t\t\tdata[key] = value+\"\"; // force to string\n\t\t\t\twindow.top.name = JSON.stringify(data);\n\t\t\t},\n\t\t\tremoveItem: function (key) {\n\t\t\t\tdelete data[key];\n\t\t\t\twindow.top.name = JSON.stringify(data);        \n\t\t\t},\n\t\t\tgetItem: function (key) {\n\t\t\t\treturn data[key] || null;\n\t\t\t},\n\t\t\tclear: function () {\n\t\t\t\tdata = {};\n\t\t\t\twindow.top.name = '';\n\t\t\t}\n\t\t};\n\t})();\n}\n\nNow that we\u2019ve cracked the cookie jar with our oversized Web Storage API, let\u2019s have a look at how we take our applications offline entirely.\n\nOffline Applications\n\nOffline applications is (still) part of the HTML5 specification.  It allows developers to build a web app and have it still function without an internet connection.  The app is access via the same URL as it would be if the user were online, but the contents (or what the developer specifies) is served up to the browser from a local cache. From there it\u2019s just an everyday stroll through open web technologies, i.e. you still have access to the Web Storage API and anything else you can do without a web connection.\n\nFor this section, I\u2019ll refer you to a prototype demo I wrote recently of a contrived Rubik\u2019s cube (contrived because it doesn\u2019t work and it only works in Safari because I\u2019m using 3D transforms).\n\n Offline Rubik\u2019s cube\n\nSupport\n\nSupport for offline applications is still fairly limited, but the possibilities of offline applications is pretty exciting, particularly as we\u2019re seeing mobile support and support in applications such as Fluid (and I would expect other render engine wrapping apps).\n\nSupport currently, is as follows:\n\n\n\tLatest: Safari (desktop & mobile/iPhone)\n\tSort of: Firefox\u2021\n\tNot supported: Internet Explorer, Opera, Google Chrome\n\n\n\u2021 Firefox 3.5 was released to include offline support, but in fact has bugs where it doesn\u2019t work properly (certainly on the Mac), Minefield (Firefox beta) has resolved the bug.\n\nUsage\n\nThe status of the application\u2019s cache can be tested from the window.applicationCache object.  However, we\u2019ll first look at how to enable your app for offline access.\n\nYou need to create a manifest file, which will tell the browser what to cache, and then we point our web page to that cache:\n\n<!DOCTYPE html>\n<html manifest=\"remy.manifest\">\n<!-- continues ... -->\n\nFor the manifest to be properly read by the browser, your server needs to serve the .manifest files as text/manifest by adding the following to your mime.types:\n\ntext/cache-manifest  manifest\n\nNext we need to populate our manifest file so the browser can read it:\n\nCACHE MANIFEST\n/demo/rubiks/index.html\n/demo/rubiks/style.css\n/demo/rubiks/jquery.min.js\n/demo/rubiks/rubiks.js\n# version 15\n\nThe first line of the manifest must read CACHE MANIFEST.  Then subsequent lines tell the browser what to cache.\n\nThe HTML5 spec recommends that you include the calling web page (in my case index.html), but it\u2019s not required.  If I didn\u2019t include index.html, the browser would cache it as part of the offline resources.\n\nThese resources are implicitly under the CACHE namespace (which you can specify any number of times if you want to).\n\nIn addition, there are two further namespaces: NETWORK and FALLBACK.\n\nNETWORK is a whitelist namespace that tells the browser not to cache this resource and always try to request it through the network.\n\nFALLBACK tells the browser that whilst in offline mode, if the resource isn\u2019t available, it should return the fallback resource.\n\nFinally, in my example I\u2019ve included a comment with a version number.  This is because once you include a manifest, the only way you can tell the browser to reload the resources is if the manifest contents changes. So I\u2019ve included a version number in the manifest which I can change forcing the browser to reload all of the assets.\n\nHow it works\n\nIf you\u2019re building an app that makes use of the offline cache, I would strongly recommend that you add the manifest last. The browser implementations are very new, so can sometimes get a bit tricky to debug since once the resources are cached, they really stick in the browser.\n\nThese are the steps that happen during a request for an app with a manifest:\n\n\n\tBrowser: sends request for your app.html\n\tServer: serves all associated resources with app.html \u2013 as normal\n\tBrowser: notices that app.html has a manifest, it re-request the assets in the manifest\n\tServer: serves the requested manifest assets (again)\n\tBrowser: window.applicationCache has a status of UPDATEREADY\n\tBrowser: reloads\n\tBrowser: only request manifest file (which doesn\u2019t show on the net requests panel)\n\tServer: responds with 304 Not Modified on the manifest file\n\tBrowser: serves all the cached resources locally\n\n\nWhat might also add confusion to this process, is that the way the browsers work (currently) is if there is a cache already in place, it will use this first over updated resources.  So if your manifest has changed, the browser will have already loaded the offline cache, so the user will only see the updated on the next reload.  \n\nThis may seem a bit convoluted, but you can also trigger some of this manually through the applicationCache methods which can ease some of this pain.\n\nIf you bind to the online event you can manually try to update the offline cache. If the cache has then updated, swap the updated resources in to the cache and the next time the app loads it will be up to date.  You could also prompt your user to reload the app (which is just a refresh) if there\u2019s an update available.\n\nFor example (though this is just pseudo code):\n\naddEvent(applicationCache, 'updateready', function () {\n\tapplicationCache.swapCache();\n\ttellUserToRefresh();\n});\naddEvent(window, 'online', function () {\n\tapplicationCache.update();\n});\n\nBreaking out of the Browser\n\nSo that\u2019s two different technologies that you can use to break out of the traditional browser/web page model and get your apps working in a more application-ny way.\n\nThere\u2019s loads more in the HTML5 and non-HTML5 APIs to play with, so take your Christmas break to check them out!", "year": "2009", "author": "Remy Sharp", "author_slug": "remysharp", "published": "2009-12-02T00:00:00+00:00", "url": "https://24ways.org/2009/breaking-out-the-edges-of-the-browser/", "topic": "code"}
{"rowid": 181, "title": "Working With RGBA Colour", "contents": "When Tim and I were discussing the redesign of this site last year, one of the clear goals was to have a graphical style without making the pages heavy with a lot of images. When we launched, a lot of people were surprised that the design wasn\u2019t built with PNGs. Instead we\u2019d used RGBA colour values, which is part of the CSS3 specification.\n\nWhat is RGBA Colour?\n\nWe\u2019re all familiar with specifying colours in CSS using by defining the mix of red, green and blue light required to achieve our tone. This is fine and dandy, but whatever values we specify have one thing in common \u2014 the colours are all solid, flat, and well, a bit boring.\n\n Flat RGB colours\n\nCSS3 introduces a couple of new ways to specify colours, and one of those is RGBA. The A stands for Alpha, which refers to the level of opacity of the colour, or to put it another way, the amount of transparency. This means that we can set not only the red, green and blue values, but also control how much of what\u2019s behind the colour shows through. Like with layers in Photoshop.\n\nDon\u2019t We Have Opacity Already?\n\nThe ability to set the opacity on a colour differs subtly from setting the opacity on an element using the CSS opacity property. Let\u2019s look at an example.\n\nHere we have an H1 with foreground and background colours set against a page with a patterned background.\n\n Heading with no transparency applied\n\nh1 {\n\tcolor: rgb(0, 0, 0);\n\tbackground-color: rgb(255, 255, 255);\n}\n\nBy setting the CSS opacity property, we can adjust the transparency of the entire element and its contents:\n\n Heading with 50% opacity on the element\n\nh1 {\n\tcolor: rgb(0, 0, 0);\n\tbackground-color: rgb(255, 255, 255);\n\topacity: 0.5;\n}\n\nRGBA colour gives us something different \u2013 the ability to control the opacity of the individual colours rather than the entire element. So we can set the opacity on just the background:\n\n 50% opacity on just the background colour\n\nh1 {\n\tcolor: rgb(0, 0, 0);\n\tbackground-color: rgba(255, 255, 255, 0.5);\n}\n\nOr leave the background solid and change the opacity on just the text:\n\n 50% opacity on just the foreground colour\n\nh1 {\n\tcolor: rgba(0, 0, 0, 0.5);\n\tbackground-color: rgb(255, 255, 255);\n}\n\nThe How-To\n\nYou\u2019ll notice that above I\u2019ve been using the rgb() syntax for specifying colours. This is a bit less common than the usual hex codes (like #FFF) but it makes sense when starting to use RGBA. As there\u2019s no way to specify opacity with hex codes, we use rgba() like so:\n\ncolor: rgba(255, 255, 255, 0.5);\n\nJust like rgb() the first three values are red, green and blue. You can specify these 0-255 or 0%-100%. The fourth value is the opacity level from 0 (completely transparent) to 1 (completely opaque).\n\nYou can use this anywhere you\u2019d normally set a colour in CSS \u2014 so it\u2019s good for foregrounds and background, borders, outlines and so on. All the transparency effects on this site\u2019s current design are achieved this way.\n\nSupporting All Browsers\n\nLike a lot of the features we\u2019ll be looking at in this year\u2019s 24 ways, RGBA colour is supported by a lot of the newest browsers, but not the rest. Firefox, Safari, Chrome and Opera browsers all support RGBA, but Internet Explorer does not.\n\nFortunately, due to the robust design of CSS as a language, we can specify RGBA colours for browsers that support it and an alternative for browsers that do not.\n\nFalling back to solid colour\n\nThe simplest technique is to allow the browser to fall back to using a solid colour when opacity isn\u2019t available. The CSS parsing rules specify that any unrecognised value should be ignored. We can make use of this because a browser without RGBA support will treat a colour value specified with rgba() as unrecognised and discard it.\n\nSo if we specify the colour first using rgb() for all browsers, we can then overwrite it with an rgba() colour for browsers that understand RGBA.\n\nh1 {\n\tcolor: rgb(127, 127, 127);\n\tcolor: rgba(0, 0, 0, 0.5);\n}\n\nFalling back to a PNG\n\nIn cases where you\u2019re using transparency on a background-color (although not on borders or text) it\u2019s possible to fall back to using a PNG with alpha channel to get the same effect. This is less flexible than using CSS as you\u2019ll need to create a new PNG for each level of transparency required, but it can be a useful solution.\n\nUsing the same principal as before, we can specify the background in a style that all browsers will understand, and then overwrite it in a way that browsers without RGBA support will ignore.\n\nh1 {\n\tbackground: transparent url(black50.png);\n\tbackground: rgba(0, 0, 0, 0.5) none;\n}\n\nIt\u2019s important to note that this works because we\u2019re using the background shorthand property, enabling us to set both the background colour and background image in a single declaration. It\u2019s this that enables us to rely on the browser ignoring the second declaration when it encounters the unknown rgba() value.\n\nNext Steps\n\nThe really great thing about RGBA colour is that it gives us the ability to create far more graphically rich designs without the need to use images. Not only does that make for faster and lighter pages, but sites which are easier and quicker to build and maintain. CSS values can also be changed in response to user interaction or even manipulated with JavaScript in a way that\u2019s just not so easy using images.\n\n Opacity can be changed on :hover or manipulated with JavaScript\n\ndiv {\n\tcolor: rgba(255, 255, 255, 0.8);\n\tbackground-color: rgba(142, 213, 87, 0.3);\n}\ndiv:hover {\n\tcolor: rgba(255, 255, 255, 1);\n\tbackground-color: rgba(142, 213, 87, 0.6);\n}\n\nClever use of transparency in border colours can help ease the transition between overlay items and the page behind.\n\n Borders can receive the RGBA treatment, too\n\ndiv {\n\tcolor: rgb(0, 0, 0);\n\tbackground-color: rgb(255, 255, 255);\n\tborder: 10px solid rgba(255, 255, 255, 0.3);\n}\n\nIn Conclusion\n\n\nThat\u2019s a brief insight into RGBA colour, what it\u2019s good for and how it can be used whilst providing support for older browsers. With the current lack of support in Internet Explorer, it\u2019s probably not a technique that commercial designs will want to heavily rely on right away \u2013 simply because of the overhead of needing to think about fallback all the time. \n\nIt is, however, a useful tool to have for those smaller, less critical touches that can really help to finesse a design. As browser support becomes more mainstream, you\u2019ll already be familiar and practised with RGBA and ready to go.", "year": "2009", "author": "Drew McLellan", "author_slug": "drewmclellan", "published": "2009-12-01T00:00:00+00:00", "url": "https://24ways.org/2009/working-with-rgba-colour/", "topic": "code"}
{"rowid": 180, "title": "Going Nuts with CSS Transitions", "contents": "I\u2019m going to show you how CSS 3 transforms and WebKit transitions can add zing to the way you present images on your site.\n\nLaying the foundations\n\nFirst we are going to make our images look like mini polaroids with captions. Here\u2019s the markup:\n\n<div class=\"polaroid pull-right\">\n\t<img src=\"../img/seal.jpg\" alt=\"\">\n\t<p class=\"caption\">Found this little cutie on a walk in New Zealand!</p>\n</div>\n\nYou\u2019ll notice we\u2019re using a somewhat presentational class of pull-right here. This means the logic is kept separate from the code that applies the polaroid effect. The polaroid class has no positioning, which allows it to be used generically anywhere that the effect is required. The pull classes set a float and add appropriate margins\u2014they can be used for things like blockquotes as well.\n\n.polaroid {\n\twidth: 150px;\n\tpadding: 10px 10px 20px 10px;\n\tborder: 1px solid #BFBFBF;\n\tbackground-color: white;\n\t-webkit-box-shadow: 2px 2px 3px rgba(135, 139, 144, 0.4);\n\t-moz-box-shadow: 2px 2px 3px rgba(135, 139, 144, 0.4);\n\tbox-shadow: 2px 2px 3px rgba(135, 139, 144, 0.4);\n}\n\nThe actual polaroid effect itself is simply applied using padding, a border and a background colour. We also apply a nice subtle box shadow, using a property that is supported by modern WebKit browsers and Firefox 3.5+. We include the box-shadow property last to ensure that future browsers that support the eventual CSS3 specified version natively will use that implementation over the legacy browser specific version.\n\nThe box-shadow property takes four values: three lengths and a colour. The first is the horizontal offset of the shadow\u2014positive values place the shadow on the right, while negative values place it to the left. The second is the vertical offset, positive meaning below. If both of these are set to 0, the shadow is positioned equally on all four sides. The last length value sets the blur radius\u2014the larger the number, the blurrier the shadow (therefore the darker you need to make the colour to have an effect).\n\nThe colour value can be given in any format recognised by CSS. Here, we\u2019re using rgba as explained by Drew behind the first door of this year\u2019s calendar.\n\nRotation\n\nFor browsers that understand it (currently our old favourites WebKit and FF3.5+) we can add some visual flair by rotating the image, using the transform CSS 3 property.\n\n-webkit-transform: rotate(9deg);\n-moz-transform: rotate(9deg);\ntransform: rotate(9deg);\n\nRotations can be specified in degrees, radians (rads) or grads. WebKit also supports turns unfortunately Firefox doesn\u2019t just yet.\n\nFor our example, we want any polaroid images on the left hand side to be rotated in the opposite direction, using a negative degree value:\n\n.pull-left.polaroid {\n\t-webkit-transform: rotate(-9deg);\n\t-moz-transform: rotate(-9deg);\n\ttransform: rotate(-9deg);\n}\n\nMultiple class selectors don\u2019t work in IE6 but as luck would have it, the transform property doesn\u2019t work in any current IE version either. The above code is a good example of progressive enrichment: browsers that don\u2019t support box-shadow or transform will still see the image and basic polaroid effect.\n\n\n\nAnimation\n\nWebKit is unique amongst browser rendering engines in that it allows animation to be specified in pure CSS. Although this may never actually make it in to the CSS 3 specification, it degrades nicely and more importantly is an awful lot of fun!\n\nLet\u2019s go nuts.\n\nIn the next demo, the image is contained within a link and mousing over that link causes the polaroid to animate from being angled to being straight.\n\nHere\u2019s our new markup:\n\n<a href=\"http://www.flickr.com/photos/nataliedowne/2340993237/\" class=\"polaroid\">\n\t<img src=\"../img/raft.jpg\" alt=\"\">\n\tWhite water rafting in Queenstown\n</a>\n\nAnd here are the relevant lines of CSS:\n\na.polaroid {\n\t/* ... */\n   -webkit-transform: rotate(10deg);\n   -webkit-transition: -webkit-transform 0.5s ease-in;\n}\na.polaroid:hover,\na.polaroid:focus,\na.polaroid:active {\n\t/* ... */\n\t-webkit-transform: rotate(0deg);\n}\n\nThe @-webkit-transition@ property is the magic wand that sets up the animation. It takes three values: the property to be animated, the duration of the animation and a \u2018timing function\u2019 (which affects the animation\u2019s acceleration, for a smoother effect).\n\n-webkit-transition only takes affect when the specified property changes. In pure CSS, this is done using dynamic pseudo-classes. You can also change the properties using JavaScript, but that\u2019s a story for another time.\n\nThrowing polaroids at a table\n\nImagine there are lots of differently sized polaroid photos scattered on a table. That\u2019s the effect we are aiming for with our next demo.\n\n\n\nAs an aside: we are using absolute positioning to arrange the images inside a flexible width container (with a minimum and maximum width specified in pixels). As some are positioned from the left and some from the right when you resize the browser they shuffle underneath each other. This is an effect used on the UX London site.\n\nThis demo uses a darker colour shadow with more transparency than before. The grey shadow in the previous example worked fine, but it was against a solid background. Since the images are now overlapping each other, the more opaque shadow looked fake.\n\n-webkit-box-shadow: 2px 2px 4px rgba(0,0, 0, 0.3);\n-moz-box-shadow: 2px 2px 4px rgba(0,0, 0, 0.3);\nbox-shadow: 2px 2px 4px rgba(0,0, 0, 0.3);\n\nOn hover, as well as our previous trick of animating the image rotation back to straight, we are also making the shadow darker and setting the z-index to be higher than the other images so that it appears on top.\n\nAnd Finally\u2026\n\nFinally, for a bit more fun, we\u2019re going to simulate the images coming towards you and lifting off the page. We\u2019ll achieve this by making them grow larger and by offsetting the shadow & making it longer.\n\n\n\n\nScreenshot 1 shows the default state, while 2 shows our previous hover effect. Screenshot 3 is the effect we are aiming for, illustrated by demo 4.\n\na.polaroid {\n\t/* ... */\n\tz-index: 2;\n\t-webkit-box-shadow: 2px 2px 4px rgba(0,0, 0, 0.3);\n\t-moz-box-shadow: 2px 2px 4px rgba(0,0, 0, 0.3);\n\tbox-shadow: 2px 2px 4px rgba(0,0, 0, 0.3);\n\t-webkit-transform: rotate(10deg);\n\t-moz-transform: rotate(10deg);\n\ttransform: rotate(10deg);\n\t-webkit-transition: all 0.5s ease-in;\n}\na.polaroid:hover,\na.polaroid:focus,\na.polaroid:active {\n\tz-index: 999;\n\tborder-color: #6A6A6A;\n\t-webkit-box-shadow: 15px 15px 20px rgba(0,0, 0, 0.4);\n\t-moz-box-shadow: 15px 15px 20px rgba(0,0, 0, 0.4);\n\tbox-shadow: 15px 15px 20px rgba(0,0, 0, 0.4);\n\t-webkit-transform: rotate(0deg) scale(1.05);\n\t-moz-transform: rotate(0deg) scale(1.05);\n\ttransform: rotate(0deg) scale(1.05);\n}\n\nYou\u2019ll notice we are now giving the transform property another transform function: scale, which takes increases the size by the specified factor. Other things you can do with transform include skewing, translating or you can go mad creating your own transforms with a matrix.\n\nThe box-shadow has both its offset and blur radius increased dramatically, and is darkened using the alpha channel of the rgba colour.\n\nAnd because we want the effects to all animate smoothly, we pass a value of all to the -webkit-transition property, ensuring that any changed property on that link will be animated.\n\nDemo 5 is the finished example, bringing everything nicely together.\n\nCSS transitions and transforms are a great example of progressive enrichment, which means improving the experience for a portion of the audience without negatively affecting other users. They are also a lot of fun to play with!\n\nFurther reading\n\n\n\t-moz-transform \u2013 the mozilla developer center has a comprehensive explanation of transform that also applies to -webkit-transform and transform.\n\tCSS: Animation Using CSS Transforms \u2013 this is a good, more indepth tutorial on animations.\n\tCSS Animation \u2013 the Safari blog explains the usage of -webkit-transform.\n\tDinky pocketbooks with transform \u2013 another use for transforms, create your own printable pocketbook.\n\tA while back, Simon wrote a little bookmarklet to spin the entire page\u2026 warning: this will spin the entire page.", "year": "2009", "author": "Natalie Downe", "author_slug": "nataliedowne", "published": "2009-12-14T00:00:00+00:00", "url": "https://24ways.org/2009/going-nuts-with-css-transitions/", "topic": "code"}
{"rowid": 179, "title": "Have a Field Day with HTML5 Forms", "contents": "Forms are usually seen as that obnoxious thing we have to markup and style. I respectfully disagree: forms (on a par with tables) are the most exciting thing we have to work with.\n\nHere we\u2019re going to take a look at how to style a beautiful HTML5 form using some advanced CSS and latest CSS3 techniques. I promise you will want to style your own forms after you\u2019ve read this article.\n\nHere\u2019s what we\u2019ll be creating:\n\n The form. (Icons from Chalkwork Payments)\n\nMeaningful markup\n\nWe\u2019re going to style a simple payment form. There are three main sections on this form:\n\n\n\tThe person\u2019s details\n\tThe address details\n\tThe credit card details\n\n\nWe are also going to use some of HTML5\u2019s new input types and attributes to create more meaningful fields and use less unnecessary classes and ids:\n\n\n\temail, for the email field\n\ttel, for the telephone field\n\tnumber, for the credit card number and security code\n\trequired, for required fields\n\tplaceholder, for the hints within some of the fields\n\tautofocus, to put focus on the first input field when the page loads\n\n\nThere are a million more new input types and form attributes on HTML5, and you should definitely take a look at what\u2019s new on the W3C website. Hopefully this will give you a good idea of how much more fun form markup can be.\n\nA good foundation\n\nEach section of the form will be contained within its own fieldset. In the case of the radio buttons for choosing the card type, we will enclose those options in another nested fieldset.\n\nWe will also be using an ordered list to group each label / input pair. This will provide us with a (kind of) semantic styling hook and it will also make the form easier to read when viewing with no CSS applied:\n\n The unstyled form\n\nSo here\u2019s the markup we are going to be working with:\n\n<form id=payment>\n\t<fieldset>\n\t\t<legend>Your details</legend>\n\t\t<ol>\n\t\t\t<li>\n\t\t\t\t<label for=name>Name</label>\n\t\t\t\t<input id=name name=name type=text placeholder=\"First and last name\" required autofocus>\n\t\t\t</li>\n\t\t\t<li>\n\t\t\t\t<label for=email>Email</label>\n\t\t\t\t<input id=email name=email type=email placeholder=\"example@domain.com\" required>\n\t\t\t</li>\n\t\t\t<li>\n\t\t\t\t<label for=phone>Phone</label>\n\t\t\t\t<input id=phone name=phone type=tel placeholder=\"Eg. +447500000000\" required>\n\t\t\t</li>\n\t\t</ol>\n\t</fieldset>\n\t<fieldset>\n\t\t<legend>Delivery address</legend>\n\t\t<ol>\n\t\t\t<li>\n\t\t\t\t<label for=address>Address</label>\n\t\t\t\t<textarea id=address name=address rows=5 required></textarea>\n\t\t\t</li>\n\t\t\t<li>\n\t\t\t\t<label for=postcode>Post code</label>\n\t\t\t\t<input id=postcode name=postcode type=text required>\n\t\t\t</li>\n\t\t\t<li>\n\t\t\t\t<label for=country>Country</label>\n\t\t\t\t<input id=country name=country type=text required>\n\t\t\t</li>\n\t\t</ol>\n\t</fieldset>\n\t<fieldset>\n\t\t<legend>Card details</legend>\n\t\t<ol>\t\t\n\t\t\t<li>\n\t\t\t\t<fieldset>\n\t\t\t\t\t<legend>Card type</legend>\n\t\t\t\t\t<ol>\n\t\t\t\t\t\t<li>\n\t\t\t\t\t\t\t<input id=visa name=cardtype type=radio>\n\t\t\t\t\t\t\t<label for=visa>VISA</label>\n\t\t\t\t\t\t</li>\n\t\t\t\t\t\t<li>\n\t\t\t\t\t\t\t<input id=amex name=cardtype type=radio>\n\t\t\t\t\t\t\t<label for=amex>AmEx</label>\n\t\t\t\t\t\t</li>\n\t\t\t\t\t\t<li>\n\t\t\t\t\t\t\t<input id=mastercard name=cardtype type=radio>\n\t\t\t\t\t\t\t<label for=mastercard>Mastercard</label>\n\t\t\t\t\t\t</li>\n\t\t\t\t\t</ol>\n\t\t\t\t</fieldset>\n\t\t\t</li>\n\t\t\t<li>\n\t\t\t\t<label for=cardnumber>Card number</label>\n\t\t\t\t<input id=cardnumber name=cardnumber type=number required>\n\t\t\t</li>\n\t\t\t<li>\n\t\t\t\t<label for=secure>Security code</label>\n\t\t\t\t<input id=secure name=secure type=number required>\n\t\t\t</li>\n\t\t\t<li>\n\t\t\t\t<label for=namecard>Name on card</label>\n\t\t\t\t<input id=namecard name=namecard type=text placeholder=\"Exact name as on the card\" required>\n\t\t\t</li>\n\t\t</ol>\n\t</fieldset>\n\t<fieldset>\n\t\t<button type=submit>Buy it!</button>\n\t</fieldset>\n</form>\n\nMaking things look nice\n\nFirst things first, so let\u2019s start by adding some defaults to our form by resetting the margins and paddings of the elements and adding a default font to the page:\n\nhtml, body, h1, form, fieldset, legend, ol, li {\n\tmargin: 0;\n\tpadding: 0;\n}\nbody {\n\tbackground: #ffffff;\n\tcolor: #111111;\n\tfont-family: Georgia, \"Times New Roman\", Times, serif;\n\tpadding: 20px;\n}\n\nNext we are going to style the form element that is wrapping our fields:\n\nform#payment {\n\tbackground: #9cbc2c;\n\t-moz-border-radius: 5px;\n\t-webkit-border-radius: 5px;\n\tborder-radius: 5px;\n\tpadding: 20px;\n\twidth: 400px;\n}\n\nWe will also remove the border from the fieldset and apply some bottom margin to it. Using the :last-of-type pseudo-class, we remove the bottom margin of the last fieldset \u2014 there is no need for it:\n\nform#payment fieldset {\n\tborder: none;\n\tmargin-bottom: 10px;\n}\nform#payment fieldset:last-of-type {\n\tmargin-bottom: 0;\n}\n\nNext we\u2019ll make the legends big and bold, and we will also apply a light-green text-shadow, to add that little extra special detail:\n\nform#payment legend {\n\tcolor: #384313;\n\tfont-size: 16px;\n\tfont-weight: bold;\n\tpadding-bottom: 10px;\n\ttext-shadow: 0 1px 1px #c0d576;\n}\n\nOur legends are looking great, but how about adding a clear indication of how many steps our form has? Instead of adding that manually to every legend, we can use automatically generated counters.\n\nTo add a counter to an element, we have to use either the :before or :after pseudo-elements to add content via CSS. We will follow these steps:\n\n\n\tcreate a counter using the counter-reset property on the form element\n\tcall the counter with the content property (using the same name we\u2019ve created before)\n\twith the counter-incremet property, indicate that for each element that matches our selector, that counter will be increased by 1\n\n\nform#payment > fieldset > legend:before {\n\tcontent: \"Step \" counter(fieldsets) \": \";\n\tcounter-increment: fieldsets;\n}\n\nFinally, we need to change the style of the legend that is part of the radio buttons group, to make it look like a label:\n\nform#payment fieldset fieldset legend {\n\tcolor: #111111;\n\tfont-size: 13px;\n\tfont-weight: normal;\n\tpadding-bottom: 0;\n}\n\nStyling the lists\n\nFor our list elements, we\u2019ll just add some nice rounded corners and semi-transparent border and background. Because we are using RGBa colors, we should provide a fallback for browsers that don\u2019t support them (that comes before the RBGa color). For the nested lists, we will remove these properties because they would be overlapping:\n\nform#payment ol li {\n\tbackground: #b9cf6a;\n\tbackground: rgba(255,255,255,.3);\n\tborder-color: #e3ebc3;\n\tborder-color: rgba(255,255,255,.6);\n\tborder-style: solid;\n\tborder-width: 2px;\n\t-moz-border-radius: 5px;\n\t-webkit-border-radius: 5px;\n\tborder-radius: 5px;\n\tline-height: 30px;\n\tlist-style: none;\n\tpadding: 5px 10px;\n\tmargin-bottom: 2px;\n}\nform#payment ol ol li {\n\tbackground: none;\n\tborder: none;\n\tfloat: left;\n}\n\nForm controls\n\nNow we only need to style our labels, inputs and the button element.\n\nAll our labels will look the same, with the exception of the one for the radio elements. We will float them to the left and give them a width.\n\nFor the credit card type labels, we will add an icon as the background, and override some of the properties that aren\u2019t necessary. We will be using the attribute selector to specify the background image for each label \u2014 in this case, we use the for attribute of each label.\n\nTo add an extra user-friendly detail, we\u2019ll add a cursor: pointer to the radio button labels on the :hover state, so the user knows that he can simply click them to select that option.\n\nform#payment label {\n\tfloat: left;\n\tfont-size: 13px;\n\twidth: 110px;\n}\nform#payment fieldset fieldset label {\n\tbackground:none no-repeat left 50%;\n\tline-height: 20px;\n\tpadding: 0 0 0 30px;\n\twidth: auto;\n}\nform#payment label[for=visa] {\n\tbackground-image: url(visa.gif);\n}\nform#payment label[for=amex] {\n\tbackground-image: url(amex.gif);\n}\nform#payment label[for=mastercard] {\n\tbackground-image: url(mastercard.gif);\n}\nform#payment fieldset fieldset label:hover {\n\tcursor: pointer;\n}\n\nAlmost there! Now onto the input elements. Here we want to match all inputs, except for the radio ones, and the textarea. For that we will use the negation pseudo-class (:not()). With it we can target all input elements except for the ones with type of radio.\n\nWe will also make sure to add some :focus styles and add the appropriate styling for the radio inputs:\n\nform#payment input:not([type=radio]),\nform#payment textarea {\n\tbackground: #ffffff;\n\tborder: none;\n\t-moz-border-radius: 3px;\n\t-webkit-border-radius: 3px;\n\t-khtml-border-radius: 3px;\n\tborder-radius: 3px;\n\tfont: italic 13px Georgia, \"Times New Roman\", Times, serif;\n\toutline: none;\n\tpadding: 5px;\n\twidth: 200px;\n}\nform#payment input:not([type=submit]):focus,\nform#payment textarea:focus {\n\tbackground: #eaeaea;\n}\nform#payment input[type=radio] {\n\tfloat: left;\n\tmargin-right: 5px;\n}\n\nAnd finally we come to our submit button. To it, we will just add some nice typography and text-shadow, align it to the center of the form and give it some background colors for its different states:\n\nform#payment button {\n\tbackground: #384313;\n\tborder: none;\n\t-moz-border-radius: 20px;\n\t-webkit-border-radius: 20px;\n\t-khtml-border-radius: 20px;\n\tborder-radius: 20px;\n\tcolor: #ffffff;\n\tdisplay: block;\n\tfont: 18px Georgia, \"Times New Roman\", Times, serif;\n\tletter-spacing: 1px;\n\tmargin: auto;\n\tpadding: 7px 25px;\n\ttext-shadow: 0 1px 1px #000000;\n\ttext-transform: uppercase;\n}\nform#payment button:hover {\n\tbackground: #1e2506;\n\tcursor: pointer;\n}\n\nAnd that\u2019s it! See the completed form.\n\nThis form will not look the same on every browser. Internet Explorer and Opera don\u2019t support border-radius (at least not for now); the new input types are rendered as just normal inputs on some browsers; and some of the most advanced CSS, like the counter, :last-of-type or text-shadow are not supported on some browsers. But that doesn\u2019t mean you can\u2019t use them right now, and simplify your development process. My gift to you!", "year": "2009", "author": "Inayaili de Le\u00f3n Persson", "author_slug": "inayailideleon", "published": "2009-12-03T00:00:00+00:00", "url": "https://24ways.org/2009/have-a-field-day-with-html5-forms/", "topic": "code"}
{"rowid": 177, "title": "HTML5: Tool of Satan, or Yule of Santa?", "contents": "It would lead to unseasonal arguments to discuss the title of this piece here, and the arguments are as indigestible as the fourth turkey curry of the season, so we\u2019ll restrict our article to the practical rather than the philosophical: what HTML5 can you reasonably expect to be able to use reliably cross-browser in the early months of 2010?\n\nThe answer is that you can use more than you might think, due to the seasonal tinsel of feature-detection and using the sparkly pixie-dust of IE-only VML (but used in a way that won\u2019t damage your Elf).\n\nCanvas\n\ncanvas is a 2D drawing API that defines a blank area of the screen of arbitrary size, and allows you to draw on it using JavaScript. The pictures can be animated, such as in this canvas mashup of Wolfenstein 3D and Flickr. (The difference between canvas and SVG is that SVG uses vector graphics, so is infinitely scalable. It also keeps a DOM, whereas canvas is just pixels so you have to do all your own book-keeping yourself in JavaScript if you want to know where aliens are on screen, or do collision detection.)\n\nPreviously, you needed to do this using Adobe Flash or Java applets, requiring plugins and potentially compromising keyboard accessibility. Canvas drawing is supported now in Opera, Safari, Chrome and Firefox. The reindeer in the corner is, of course, Internet Explorer, which currently has zero support for canvas (or SVG, come to that).\n\nNow, don\u2019t pull a face like all you\u2019ve found in your Yuletide stocking is a mouldy satsuma and a couple of nuts\u2014that\u2019s not the end of the story. Canvas was originally an Apple proprietary technology, and Internet Explorer had a similar one called Vector Markup Language which was submitted to the W3C for standardisation in 1998 but which, unlike canvas, was not blessed with retrospective standardisation.\n\nWhat you need, then, is some way for Internet Explorer to translate canvas to VML on-the-fly, while leaving the other, more standards-compliant browsers to use the HTML5. And such a way exists\u2014it\u2019s a JavaScript library called excanvas. It\u2019s downloadable from http://code.google.com/p/explorercanvas/ and it\u2019s simple to include it via a conditional comment in the head for IE:\n\n<!--[if IE]>\n<script src=\"excanvas.js\"></script>\n<![endif]-->\n\nSimply include this, and your canvas will be natively supported in the modern browsers (and the library won\u2019t even be downloaded) whereas IE will suddenly render your canvas using its own VML engine. Be sure, however, to check it carefully, as the IE JavaScript engine isn\u2019t so fast and you\u2019ll need to be sure that performance isn\u2019t too degraded to use.\n\nForms\n\nSince the beginning of the Web, developers have been coding forms, and then writing JavaScript to check whether an input is a correctly formed email address, URL, credit card number or conforms to some other pattern. The cumulative labour of the world\u2019s developers over the last 15 years makes whizzing round in a sleigh and delivering presents seem like popping to the corner shop in comparison.\n\nWith HTML5, that\u2019s all about to change. As Yaili began to explore on Day 3, a host of new attributes to the input element provide built-in validation for email address formats (input type=email), URLs (input type=url), any pattern that can be expressed with a JavaScript-syntax regex (pattern=\"[0-9][A-Z]{3}\") and the like. New attributes such as required, autofocus, input type=number min=3 max=50 remove much of the tedious JavaScript from form validation.\n\nOther, really exciting input types are available (see all input types). The datalist is reminiscent of a select box, but allows the user to enter their own text if they don\u2019t want to choose one of the pre-defined options. input type=range is rendered as a slider, while input type=date pops up a date picker, all natively in the browser with no JavaScript required at all.\n\nCurrently, support is most complete in an experimental implementation in Opera and a number of the new attributes in Webkit-based browsers. But don\u2019t let that stop you! The clever thing about the specification of the new Web Forms is that all the new input types are attributes (rather than elements). input defaults to input type=text, so if a browser doesn\u2019t understand a new HTML5 type, it gracefully degrades to a plain text input.\n\nSo where does that leave validation in those browsers that don\u2019t support Web Forms? The answer is that you don\u2019t retire your pre-existing JavaScript validation just yet, but you leave it as a fallback after doing some feature detection. To detect whether (say) input type=email is supported, you make a new input type=email with JavaScript but don\u2019t add it to the page. Then, you interrogate your new element to find out what its type attribute is. If it\u2019s reported back as \u201cemail\u201d, then the browser supports the new feature, so let it do its work and don\u2019t bring in any JavaScript validation. If it\u2019s reported back as \u201ctext\u201d, it\u2019s fallen back to the default, indicating that it\u2019s not supported, so your code should branch to your old validation routines. Alternatively, use the small (7K) Modernizr library which will do this work for you and give you JavaScript booleans like Modernizr.inputtypes[email] set to true or false.\n\nSo what does this buy you? Well, first and foremost, you\u2019re future-proofing your code for that time when all browsers support these hugely useful additions to forms. Secondly, you buy a usability and accessibility win. Although it\u2019s tempting to style the stuffing out of your form fields (which can, incidentally, lead to madness), whatever your branding people say, it\u2019s better to leave forms as close to the browser defaults as possible. A browser\u2019s slider and date pickers will be the same across different sites, making it much more comprehensible to users. And, by using native controls rather than faking sliders and date pickers with JavaScript, your forms are much more likely to be accessible to users of assistive technology.\n\nHTML5 DOCTYPE\n\nYou can use the new DOCTYPE !doctype html now and \u2013 hey presto \u2013 you\u2019re writing HTML5, as it\u2019s pretty much a superset of HTML4. There are some useful advantages to doing this. The first is that the HTML5 validator (I use http://html5.validator.nu) also validates ARIA information, whereas the HTML4 validator doesn\u2019t, as ARIA is a new spec developed after HTML4. (Actually, it\u2019s more accurate to say that it doesn\u2019t validate your ARIA attributes, but it doesn\u2019t automatically report them as an error.)\n\nAnother advantage is that HTML5 allows tabindex as a global attribute (that is, on any element). Although originally designed as an accessibility bolt-on, I ordinarily advise you don\u2019t use it; a well-structured page should provide a logical tab order through links and form fields already.\n\nHowever, tabindex=\"-1\" is a legal value in HTML5 as it allows for the element to be programmatically focussable by JavaScript. It\u2019s also very useful for correcting a bug in Internet Explorer when used with a keyboard; in-page links go nowhere if the destination doesn\u2019t have a proprietary property called hasLayout set or a tabindex of -1.\n\nSo, whether it is the tool of Satan or yule of Santa, HTML5 is just around the corner. Some you can use now, and by the end of 2010 I predict you\u2019ll be able to use a whole lot more as new browser versions are released.", "year": "2009", "author": "Bruce Lawson", "author_slug": "brucelawson", "published": "2009-12-05T00:00:00+00:00", "url": "https://24ways.org/2009/html5-tool-of-satan-or-yule-of-santa/", "topic": "code"}
{"rowid": 175, "title": "Front-End Code Reusability with CSS and JavaScript", "contents": "Most web standards-based developers are more than familiar with creating their sites with semantic HTML with lots and lots of CSS. With each new page in a design, the CSS tends to grow and grow and more elements and styles are added. But CSS can be used to better effect.\n\nThe idea of object-oriented CSS isn\u2019t new. Nicole Sullivan has written a presentation on the subject and outlines two main concepts: separate structure and visual design; and separate container and content. Jeff Croft talks about Applying OOP Concepts to CSS:\n\n\n\tI can make a class of .box that defines some basic layout structure, and another class of .rounded that provides rounded corners, and classes of .wide and .narrow that define some widths, and then easily create boxes of varying widths and styles by assigning multiple classes to an element, without having to duplicate code in my CSS.\n\n\nThis concept helps reduce CSS file size, allows for great flexibility, rapid building of similar content areas and means greater consistency throughout the entire design. You can also take this concept one step further and apply it to site behaviour with JavaScript.\n\nBuild a versatile slideshow\n\nI will show you how to build multiple slideshows using jQuery, allowing varying levels of functionality which you may find on one site design. The code will be flexible enough to allow you to add previous/next links, image pagination and the ability to change the animation type. More importantly, it will allow you to apply any combination of these features.\n\nImage galleries are simply a list of images, so the obvious choice of marking the content up is to use a <ul>. Many designs, however, do not cater to non-JavaScript versions of the website, and thus don\u2019t take in to account large multiple images. You could also simply hide all the other images in the list, apart from the first image. This method can waste bandwidth because the other images might be downloaded when they are never going to be seen.\n\nTaking this second concept \u2014 only showing one image \u2014 the only code you need to start your slideshow is an <img> tag. The other images can be loaded dynamically via either a per-page JavaScript array or via AJAX.\n\nThe slideshow concept is built upon the very versatile Cycle jQuery Plugin and is structured in to another reusable jQuery plugin. Below is the HTML and JavaScript snippet needed to run every different type of slideshow I have mentioned above.\n\n<img src=\"path/to/image.jpg\" alt=\"About the image\" title=\"\" height=\"250\" width=\"400\" class=\"slideshow\">\n<script type=\"text/javascript\">\n\tjQuery().ready(function($) {\n\t\t$('img.slideshow').slideShow({\n\t\t\timages: ['1.jpg', '2.jpg', '3.jpg']\n\t\t});\n\t});\n</script>\n\nSlideshow plugin\n\nIf you\u2019re not familiar with jQuery or how to write and author your own plugin there are plenty of articles to help you out.\n\njQuery has a chainable interface and this is something your plugin must implement. This is easy to achieve, so your plugin simply returns the collection it is using:\n\nreturn this.each(\n\tfunction () {}\n};\n\nLocal Variables\n\nTo keep the JavaScript clean and avoid any conflicts, you must set up any variables which are local to the plugin and should be used on each collection item. Defining all your variables at the top under one statement makes adding more and finding which variables are used easier. For other tips, conventions and improvements check out JSLint, the \u201cJavaScript Code Quality Tool\u201d.\n\nvar $$, $div, $images, $arrows, $pager,\n\tid, selector, path, o, options,\n\theight, width,\n\tlist = [], li = 0,\n\tparts = [], pi = 0,\n\tarrows = ['Previous', 'Next'];\n\nCache jQuery Objects\n\nIt is good practice to cache any calls made to jQuery. This reduces wasted DOM calls, can improve the speed of your JavaScript code and makes code more reusable.\n\nThe following code snippet caches the current selected DOM element as a jQuery object using the variable name $$. Secondly, the plugin makes its settings available to the Metadata plugin\u2021 which is best practice within jQuery plugins.\n\nFor each slideshow the plugin generates a <div> with a class of slideshow and a unique id. This is used to wrap the slideshow images, pagination and controls.\n\nThe base path which is used for all the images in the slideshow is calculated based on the existing image which appears on the page. For example, if the path to the image on the page was /img/flowers/1.jpg the plugin would use the path /img/flowers/ to load the other images.\n\n$$ = $(this);\no = $.metadata ? $.extend({}, settings, $$.metadata()) : settings;\nid = 'slideshow-' + (i++ + 1);\n$div = $('<div />').addClass('slideshow').attr('id', id);\nselector = '#' + id + ' ';\npath = $$.attr('src').replace(/[0-9]\\.jpg/g, '');\noptions = {};\nheight = $$.height();\nwidth = $$.width();\n\nNote: the plugin uses conventions such as folder structure and numeric filenames. These conventions help with the reusable aspect of plugins and best practices.\n\nBuild the Images\n\nThe cycle plugin uses a list of images to create the slideshow. Because we chose to start with one image we must now build the list programmatically. This is a case of looping through the images which were added via the plugin options, building the appropriate HTML and appending the resulting <ul> to the DOM.\n\n$.each(o.images, function () {\n\tlist[li++] = '<li>';\n\tlist[li++] = '<img src=\"' + path + this + '\" height=\"' + height + '\" width=\"' + width + '\">';\n\tlist[li++] = '</li>';\n});\n$images = $('<ul />').addClass('cycle-images');\n$images.append(list.join('')).appendTo($div);\n\nAlthough jQuery provides the append method it is much faster to create one really long string and append it to the DOM at the end.\n\nUpdate the Options\n\nHere are some of the options we\u2019re making available by simply adding classes to the <img>. You can change the slideshow effect from the default fade to the sliding effect. By adding the class of stopped the slideshow will not auto-play and must be controlled via pagination or previous and next links.\n\n// different effect\nif ($$.is('.slide')) {\n\toptions.fx = 'scrollHorz';\n}\n// don't move by default\nif ($$.is('.stopped')) {\n\toptions.timeout = 0;\n}\n\nIf you are using the same set of images throughout a website you may wish to start on a different image on each page or section. This can be easily achieved by simply adding the appropriate starting class to the <img>.\n\n// based on the class name on the image\nif ($$.is('[class*=start-]')) {\n\toptions.startingSlide = parseInt($$.attr('class').replace(/.*start-([0-9]+).*/g, \"$1\"), 10) - 1;\n}\n\nFor example:\n\n<img src=\"/img/slideshow/3.jpg\" alt=\"About the image\" title=\"\" height=\"250\" width=\"400\" class=\"slideshow start-3\">\n\nBy default, and without JavaScript, the third image in this slideshow is shown. When the JavaScript is applied to the page the slideshow must know to start from the correct place, this is why the start class is required.\n\nYou could capture the default image name and parse it to get the position, but only the default image needs to be numeric to work with this plugin (and could easily be changed in future). Therefore, this extra specifically defined option means the plugin is more tolerant.\n\nPrevious/Next Links\n\nA common feature of slideshows is previous and next links enabling the user to manually progress the images. The Cycle plugin supports this functionality, but you must generate the markup yourself. Most people add these directly in the HTML but normally only support their behaviour when JavaScript is enabled. This goes against progressive enhancement. To keep with the best practice progress enhancement method the previous/next links should be generated with JavaScript.\n\nThe follow snippet checks whether the slideshow requires the previous/next links, via the arrows class. It restricts the Cycle plugin to the specific slideshow using the selector we created at the top of the plugin. This means multiple slideshows can run on one page without conflicting each other.\n\nThe code creates a <ul> using the arrows array we defined at the top of the plugin. It also adds a class to the slideshow container, meaning you can style different combinations of options in your CSS.\n\n// create the arrows\nif ($$.is('.arrows') && list.length > 1) {\n\toptions.next = selector + '.next';\n\toptions.prev = selector + '.previous';\n\t$arrows = $('<ul />').addClass('cycle-arrows');\n\t$.each(arrows, function (i, val) {\n\t\tparts[pi++] = '<li class=\"' + val.toLowerCase() + '\">';\n\t\tparts[pi++] = '<a href=\"#' + val.toLowerCase() + '\">';\n\t\tparts[pi++] = '<span>' + val + '</span>';\n\t\tparts[pi++] = '</a>';\n\t\tparts[pi++] = '</li>';\n\t});\n\t$arrows.append(parts.join('')).appendTo($div);\n\t$div.addClass('has-cycle-arrows');\n}\n\nThe arrow array could be placed inside the plugin settings to allow for localisation.\n\nPagination\n\nThe Cycle plugin creates its own HTML for the pagination of the slideshow. All our plugin needs to do is create the list and selector to use. This snippet creates the pagination container and appends it to our specific slideshow container. It sets the Cycle plugin pager option, restricting it to the specific slideshow using the selector we created at the top of the plugin. Like the previous/next links, a class is added to the slideshow container allowing you to style the slideshow itself differently.\n\n// create the clickable pagination\nif ($$.is('.pagination') && list.length > 1) {\n\toptions.pager = selector + '.cycle-pagination';\n\t$pager = $('<ul />').addClass('cycle-pagination');\n\t$pager.appendTo($div);\n\t$div.addClass('has-cycle-pagination');\n}\n\nNote: the Cycle plugin creates a <ul> with anchors listed directly inside without the surrounding <li>. Unfortunately this is invalid markup but the code still works.\n\nDemos\n\nWell, that describes all the ins-and-outs of the plugin, but demos make it easier to understand! Viewing the source on the demo page shows some of the combinations you can create with a simple <img>, a few classes and some thought-out JavaScript.\n\nView the demos \u2192\n\nDecide on defaults\n\nThe slideshow plugin uses the exact same settings as the Cycle plugin, but some are explicitly set within the slideshow plugin when using the classes you have set.\n\nWhen deciding on what functionality is going to be controlled via this class method, be careful to choose your defaults wisely. If all slideshows should auto-play, don\u2019t make this an option \u2014 make the option to stop the auto-play. Similarly, if every slideshow should have previous/next functionality make this the default and expose the ability to remove them with a class such as \u201cno-pagination\u201d.\n\nIn the examples presented on this article I have used a class on each <img>. You can easily change this to anything you want and simply apply the plugin based on the jQuery selector required.\n\nGrab your images\n\nIf you are using AJAX to load in your images, you can speed up development by deciding on and keeping to a folder structure and naming convention. There are two methods: basing the image path based on the current URL; or based on the src of the image. The first allows a different slideshow on each page, but in many instances a site will have a couple of sets of images and therefore the second method is probably preferred.\n\nMetadata \u2021\n\nA method which allows you to directly modify settings in certain plugins, which also uses the classes from your HTML already exists. This is a jQuery plugin called Metadata. This method allows for finer control over the plugin settings themselves. Some people, however, may dislike the syntax and prefer using normal classes, like above which when sprinkled with a bit more JavaScript allows you to control what you need to control.\n\nThe takeaway\n\nHopefully you have understood not only what goes in to a basic jQuery plugin but also learnt a new and powerful idea which you can apply to other areas of your website.\n\nThe idea can also be applied to other common interfaces such as lightboxes or mapping services such as Google Maps \u2014 for example creating markers based on a list of places, each with different pin icons based the anchor class.", "year": "2009", "author": "Trevor Morris", "author_slug": "trevormorris", "published": "2009-12-06T00:00:00+00:00", "url": "https://24ways.org/2009/front-end-code-reusability-with-css-and-javascript/", "topic": "code"}
{"rowid": 171, "title": "Rock Solid HTML Emails", "contents": "At some stage in your career, it\u2019s likely you\u2019ll be asked by a client to design a HTML email. Before you rush to explain that all the cool kids are using social media, keep in mind that when done correctly, email is still one of the best ways to promote you and your clients online. In fact, a recent survey showed that every dollar spent on email marketing this year generated more than $40 in return. That\u2019s more than any other marketing channel, including the cool ones.\n\nThere are a whole host of ingredients that contribute to a good email marketing campaign. Permission, relevance, timeliness and engaging content are all important. Even so, the biggest challenge for designers still remains building an email that renders well across all the popular email clients.\n\nSame same, but different\n\nBefore getting into the details, there are some uncomfortable facts that those new to HTML email should be aware of. Building an email is not like building for the web. While web browsers continue their onward march towards standards, many email clients have stubbornly stayed put. Some have even gone backwards. In 2007, Microsoft switched the Outlook rendering engine from Internet Explorer to Word. Yes, as in the word processor. Add to this the quirks of the major web-based email clients like Gmail and Hotmail, sprinkle in a little Lotus Notes and you\u2019ll soon realize how different the email game is.\n\nWhile it\u2019s not without its challenges, rest assured it can be done. In my experience the key is to focus on three things. First, you should keep it simple. The more complex your email design, the more likely is it to choke on one of the popular clients with poor standards support. Second, you need to take your coding skills back a good decade. That often means nesting tables, bringing CSS inline and following the coding guidelines I\u2019ll outline below. Finally, you need to test your designs regularly. Just because a template looks nice in Hotmail now, doesn\u2019t mean it will next week.\n\nSetting your lowest common denominator\n\nTo maintain your sanity, it\u2019s a good idea to decide exactly which email clients you plan on supporting when building a HTML email. While general research is helpful, the email clients your subscribers are using can vary significantly from list to list. If you have the time there are a number of tools that can tell you specifically which email clients your subscribers are using. Trust me, if the testing shows almost none of them are using a client like Lotus Notes, save yourself some frustration and ignore it altogether. \n\nKnowing which email clients you\u2019re targeting not only makes the building process easier, it can save you lots of time in the testing phase too. For the purpose of this article, I\u2019ll be sharing techniques that give the best results across all of the popular clients, including the notorious ones like Gmail, Lotus Notes 6 and Outlook 2007. Just remember that pixel perfection in all email clients is a pipe dream.\n\nLet\u2019s get started.\n\nUse tables for layout\n\nBecause clients like Gmail and Outlook 2007 have poor support for float, margin and padding, you\u2019ll need to use tables as the framework of your email. While nested tables are widely supported, consistent treatment of width, margin and padding within table cells is not. For the best results, keep the following in mind when coding your table structure.\n\nSet the width in each cell, not the table\n\nWhen you combine table widths, td widths, td padding and CSS padding into an email, the final result is different in almost every email client. The most reliable way to set the width of your table is to set a width for each cell, not for the table itself.\n\n<table cellspacing=\"0\" cellpadding=\"10\" border=\"0\">\n\t<tr>\n\t\t<td width=\"80\"></td>\n\t\t<td width=\"280\"></td>\n\t</tr>\n</table>\n\nNever assume that if you don\u2019t specify a cell width the email client will figure it out. It won\u2019t.  Also avoid using percentage based widths. Clients like Outlook 2007 don\u2019t respect them, especially for nested tables. Stick to pixels. If you want to add padding to each cell, use either the cellpadding attribute of the table or CSS padding for each cell, but never combine the two.\n\nErr toward nesting\n\nTable nesting is far more reliable than setting left and right margins or padding for table cells. If you can achieve the same effect by table nesting, that will always give you the best result across the buggier email clients.\n\nUse a container table for body background colors\n\nMany email clients ignore background colors specified in your CSS or the <body> tag. To work around this, wrap your entire email with a 100% width table and give that a background color.\n\n<table cellspacing=\"0\" cellpadding=\"0\" border=\"0\" width=\"100%\">\n\t<tr>\n\t\t<td bgcolor=\u201d#000000\u201d>\n\t\t\tYour email code goes here.\n\t\t</td>\n\t</tr>\n</table>\n\nYou can use the same approach for background images too. Just remember that some email clients don\u2019t support them, so always provide a fallback color.\n\nAvoid unnecessary whitespace in table cells\n\nWhere possible, avoid whitespace between your <td> tags. Some email clients (ahem, Yahoo! and Hotmail) can add additional padding above or below the cell contents in some scenarios, breaking your design for no apparent reason.\n\nCSS and general font formatting\n\nWhile some email designers do their best to avoid CSS altogether and rely on the dreaded <font> tag, the truth is many CSS properties are well supported by most email clients. See this comprehensive list of CSS support across the major clients for a good idea of the safe properties and those that should be avoided. \n\nAlways move your CSS inline\n\nGmail is the culprit for this one. By stripping the CSS from the <head> and <body> of any email, we\u2019re left with no choice but to move all CSS inline. The good news is this is something you can almost completely automate. Free services like Premailer will move all CSS inline with the click of a button. I recommend leaving this step to the end of your build process so you can utilize all the benefits of CSS.\n\nAvoid shorthand for fonts and hex notation\n\nA number of email clients reject CSS shorthand for the font property. For example, never set your font styles like this.\n\np {\n\tfont:bold 1em/1.2em georgia,times,serif;\n}\n\nInstead, declare the properties individually like this.\n\np {\n\tfont-weight: bold;\n\tfont-size: 1em;\n\tline-height: 1.2em;\n\tfont-family: georgia,times,serif;\n}\n\nWhile we\u2019re on the topic of fonts, I recently tested every conceivable variation of @font-face across the major email clients. The results were dismal, so unfortunately it\u2019s web-safe fonts in email for the foreseeable future.\n\nWhen declaring the color property in your CSS, some email clients don\u2019t support shorthand hexadecimal colors like color:#f60; instead of color:#ff6600;. Stick to the longhand approach for the best results.\n\nParagraphs\n\nJust like table cell spacing, paragraph spacing can be tricky to get a consistent result across the board. I\u2019ve seen many designers revert to using double <br /> or DIVs with inline CSS margins to work around these shortfalls, but recent testing showed that paragraph support is now reliable enough to use in most cases (there was a time when Yahoo! didn\u2019t support the paragraph tag at all).\n\nThe best approach is to set the margin inline via CSS for every paragraph in your email, like so:\n\np {\n\tmargin: 0 0 1.6em 0;\n}\n\nAgain, do this via CSS in the head when building your email, then use Premailer to bring it inline for each paragraph later.\n\nIf part of your design is height-sensitive and calls for pixel perfection, I recommend avoiding paragraphs altogether and setting the text formatting inline in the table cell. You might need to use table nesting or cellpadding / CSS to get the desired result. Here\u2019s an example:\n\n<td width=\"200\" style=\"font-weight:bold; font-size:1em; line-height:1.2em; font-family:georgia,'times',serif;\">your height sensitive text</td>\n\nLinks\n\nSome email clients will overwrite your link colors with their defaults, and you can avoid this by taking two steps. First, set a default color for each link inline like so:\n\n<a href=\"http://somesite.com/\" style=\"color:#ff00ff\">this is a link</a>\n\nNext, add a redundant span inside the a tag.\n\n<a href=\"http://somesite.com/\" style=\"color:#ff00ff\"><span style=\"color:#ff00ff\">this is a link</span></a>\n\nTo some this may be overkill, but if link color is important to your design then a superfluous span is the best way to achieve consistency.\n\nImages in HTML emails\n\nThe most important thing to remember about images in email is that they won\u2019t be visible by default for many subscribers. If you start your design with that assumption, it forces you to keep things simple and ensure no important content is suppressed by image blocking.\n\nWith this in mind, here are the essentials to remember when using images in HTML email:\n\nAvoid spacer images\n\nWhile the combination of spacer images and nested tables was popular on the web ten years ago, image blocking in many email clients has ruled it out as a reliable technique today. Most clients replace images with an empty placeholder in the same dimensions, others strip the image altogether. Given image blocking is on by default in most email clients, this can lead to a poor first impression for many of your subscribers. Stick to fixed cell widths to keep your formatting in place with or without images.\n\nAlways include the dimensions of your image\n\nIf you forget to set the dimensions for each image, a number of clients will invent their own sizes when images are blocked and break your layout. Also, ensure that any images are correctly sized before adding them to your email. Some email clients will ignore the dimensions specified in code and rely on the true dimensions of your image. \n\nAvoid PNGs\n\nLotus Notes 6 and 7 don\u2019t support 8-bit or 24-bit PNG images, so stick with the GIF or JPG formats for all images, even if it means some additional file size.\n\nProvide fallback colors for background images\n\nOutlook 2007 has no support for background images (aside from this hack to get full page background images working). If you want to use a background image in your design, always provide a background color the email client can fall back on. This solves both the image blocking and Outlook 2007 problem simultaneously.\n\nDon\u2019t forget alt text\n\nLack of standards support means email clients have long destroyed the chances of a semantic and accessible HTML email. Even still, providing alt text is important from an image blocking perspective. Even with images suppressed by default, many email clients will display the provided alt text instead. Just remember that some email clients like Outlook 2007, Hotmail and Apple Mail don\u2019t support alt text at all when images are blocked.\n\nUse the display hack for Hotmail\n\nFor some inexplicable reason, Windows Live Hotmail adds a few pixels of additional padding below images. A workaround is to set the display property like so.\n\nimg {display:block;}\n\nThis removes the padding in Hotmail and still gives you the predicable result in other email clients.\n\nDon\u2019t use floats\n\nBoth Outlook 2007 and earlier versions of Notes offer no support for the float property. Instead, use the align attribute of the img tag to float images in your email.\n\n<img src=\"image.jpg\" align=\"right\">\n\nIf you\u2019re seeing strange image behavior in Yahoo! Mail, adding align=\u201ctop\u201d to your images can often solve this problem.\n\nVideo in email\n\nWith no support for JavaScript or the object tag, video in email (if you can call it that) has long been limited to animated gifs. However, some recent research I did into the HTML5 video tag in email showed some promising results.\n\nTurns out HTML5 video does work in many email clients right now, including Apple Mail, Entourage 2008, MobileMe and the iPhone. The real benefit of this approach is that if the video isn\u2019t supported, you can provide reliable fallback content such as an animated GIF or a clickable image linking to the video in the browser.\n\nOf course, the question of whether you should add video to email is another issue altogether. If you lean toward the \u201cyes\u201d side check out the technique with code samples.\n\nWhat about mobile email?\n\nThe mobile email landscape was a huge mess until recently. With the advent of the iPhone, Android and big improvements from Palm and RIM, it\u2019s becoming less important to think of mobile as a different email platform altogether.\n\nThat said, there are a few key pointers to keep in mind when coding your emails to get a decent result for your more mobile subscribers.\n\nKeep the width less than 600 pixels\n\nBecause of email client preview panes, this rule was important long before mobile email clients came of age. In truth, the iPhone and Pre have a viewport of 320 pixels, the Droid 480 pixels and the Blackberry models hover around 360 pixels. Sticking to a maximum of 600 pixels wide ensures your design should still be readable when scaled down for each device. This width also gives good results in desktop and web-based preview panes.\n\nBe aware of automatic text resizing\n\nIn what is almost always a good feature, email clients using webkit (such as the iPhone, Pre and Android) can automatically adjust font sizes to increase readability. If testing shows this feature is doing more harm than good to your design, you can always disable it with the following CSS rule:\n\n-webkit-text-size-adjust: none;\n\nDon\u2019t forget to test\n\nWhile standards support in email clients hasn\u2019t made much progress in the last few years, there has been continual change (for better or worse) in some email clients. Web-based providers like Yahoo!, Hotmail and Gmail are notorious for this. On countless occasions I\u2019ve seen a proven design suddenly stop working without explanation.\n\nFor this reason alone it\u2019s important to retest your email designs on a regular basis. I find a quick test every month or so does the trick, especially in the web-based clients. The good news is that after designing and testing a few HTML email campaigns, you will find that order will emerge from the chaos. Many of these pitfalls will become quite predictable and your inbox-friendly designs will take shape with them in mind.\n\nLooking ahead\n\nDesigning HTML email can be a tough pill for new designers and standardistas to swallow, especially given the fickle and retrospective nature of email clients today. With HTML5 just around the corner we are entering a new, uncertain phase. Will email client developers take the opportunity to repent on past mistakes and bring email clients into the present? The aim of groups such as the Email Standards Project is to make much of the above advice as redundant as the long-forgotten <blink> and <marquee> tags, however, only time will tell if this is to become a reality.\n\nAlthough not the most compliant (or fashionable) medium, the results speak for themselves \u2013 email is, and will continue to be one of the most successful and targeted marketing channels available to you. As a designer with HTML email design skills in your arsenal, you have the opportunity to not only broaden your service offering, but gain a unique appreciation of how vital standards are.\n\nNext steps\n\nReady to get started? There are a number of HTML email design galleries to provide ideas and inspiration for your own designs. \n\n\n\thttp://www.campaignmonitor.com/gallery/\n\thttp://htmlemailgallery.com/\n\thttp://inboxaward.com/\n\n\nEnjoy!", "year": "2009", "author": "David Greiner", "author_slug": "davidgreiner", "published": "2009-12-13T00:00:00+00:00", "url": "https://24ways.org/2009/rock-solid-html-emails/", "topic": "code"}
{"rowid": 169, "title": "Incite A Riot", "contents": "Given its relatively limited scope, HTML can be remarkably expressive. With a bit of lateral thinking, we can mark up content such as tag clouds and progress meters, even when we don\u2019t have explicit HTML elements for those patterns.\n\nSuppose we want to mark up a short conversation:\n\n \n  Alice: I think Eve is watching. \n\n  Bob: This isn\u2019t a cryptography tutorial \u2026we\u2019re in the wrong example!\n \n\n\nA note in the the HTML 4.01 spec says it\u2019s okay to use a definition list:\n\n\n\tAnother application of DL, for example, is for marking up dialogues, with each DT naming a speaker, and each DD containing his or her words.\n\n\nThat would give us:\n\n<dl>\n\t<dt>Alice</dt>: <dd>I think Eve is watching.</dd>\n\t<dt>Bob</dt>: <dd>This isn't a cryptography tutorial ...we're in the wrong example!</dd>\n</dl>\n\nThis usage of a definition list is proof that writing W3C specifications and smoking crack are not mutually exclusive activities. \u201cI think Eve is watching\u201d is not a definition of \u201cAlice.\u201d If you (ab)use a definition list in this way, Norm will hunt you down.\n\nThe conversation problem was revisited in HTML5. What if dt and dd didn\u2019t always mean \u201cdefinition title\u201d and \u201cdefinition description\u201d? A new element was forged: dialog. Now the the \u201cd\u201d in dt and dd doesn\u2019t stand for \u201cdefinition\u201d, it stands for \u201cdialog\u201d (or \u201cdialogue\u201d if you can spell):\n\n<dialog>\n\t<dt>Alice</dt>: <dd>I think Eve is watching.</dd>\n\t<dt>Bob</dt>: <dd>This isn't a cryptography tutorial ...we're in the wrong example!</dd>\n</dialog>\n\nProblem solved \u2026except that dialog is no longer in the HTML5 spec. Hixie further expanded the meaning of dt and dd so that they could be used inside details (which makes sense\u2014it starts with a \u201cd\u201d) and figure (\u2026um). At the same time as the content model of details and figure were being updated, the completely-unrelated dialog element was dropped.\n\nBack to the drawing board, or in this case, the HTML 4.01 specification. The spec defines the cite element thusly:\n\n\n\tContains a citation or a reference to other sources.\n\n\nPerfect! There\u2019s even an example showing how this can applied when attributing quotes to people:\n\nAs <CITE>Harry S. Truman</CITE> said,\n<Q lang=\"en-us\">The buck stops here.</Q>\n\nFor longer quotes, the blockquote element might be more appropriate. In a conversation, where the order matters, I think an ordered list would make a good containing element for this pattern:\n\n<ol>\n\t<li><cite>Alice</cite>: <q>I think Eve is watching.</q></li>\n\t<li><cite>Bob</cite>: <q>This isn't a cryptography tutorial ...we're in the wrong example!</q></li>\n</ol>\n\nProblem solved \u2026except that the cite element has been redefined in the HTML5 spec:\n\n\n\tThe cite element represents the title of a work \u2026 A person\u2019s name is not the title of a work \u2026 and the element must therefore not be used to mark up people\u2019s names.\n\n\nHTML5 is supposed to be backwards compatible with previous versions of HTML, yet here we have a semantic pattern already defined in HTML 4.01 that is now non-conforming in HTML5. The entire justification for the change boils down to this line of reasoning:\n\n\n\tGiven that: titles of works are often italicised and\n\tgiven that: people\u2019s names are not often italicised and\n\tgiven that: most browsers italicise the contents of the cite element,\n\ttherefore: the cite element should not be used to mark up people\u2019s names.\n\n\nIn other words, the default browser styling is now dictating semantic meaning. The tail is wagging the dog.\n\nNot to worry, the HTML5 spec tells us how we can mark up names in conversations without using the cite element:\n\n\n\tIn some cases, the b element might be appropriate for names\n\n\nI believe the colloquial response to this is a combination of the letters W, T and F, followed by a question mark.\n\nThe non-normative note continues:\n\n\n\tIn other cases, if an element is really needed, the span element can be used.\n\n\nThis is not a joke. We are seriously being told to use semantically meaningless elements to mark up content that is semantically meaningful.\n\nWe don\u2019t have to take it.\n\nFirstly, any conformance checker\u2014that\u2019s the new politically correct term for \u201cvalidator\u201d\u2014cannot possibly check every instance of the cite element to see if it\u2019s really the title of a work and not the name of a person. So we can disobey the specification without fear of invalidating our documents.\n\nSecondly, Hixie has repeatedly stated that browser makers have a powerful voice in deciding what goes into the HTML5 spec; if a browser maker refuses to implement a feature, then that feature should come out of the spec because otherwise, the spec is fiction. Well, one of the design principles of HTML5 is the Priority of Constituencies:\n\n\n\tIn case of conflict, consider users over authors over implementors over specifiers over theoretical purity.\n\n\nThat places us\u2014authors\u2014above browser makers. If we resolutely refuse to implement part of the HTML5 spec, then the spec becomes fiction.\n\nJoin me in a campaign of civil disobedience against the unnecessarily restrictive, backwards-incompatible change to the cite element. Start using HTML5 but start using it sensibly. Let\u2019s ensure that bad advice remains fictitious.\n\nTantek has set up a page on the WHATWG wiki to document usage of the cite element for conversations. Please contribute to it.", "year": "2009", "author": "Jeremy Keith", "author_slug": "jeremykeith", "published": "2009-12-11T00:00:00+00:00", "url": "https://24ways.org/2009/incite-a-riot/", "topic": "code"}
{"rowid": 168, "title": "Unobtrusively Mapping Microformats with jQuery", "contents": "Microformats are everywhere. You can\u2019t shake an electronic stick these days without accidentally poking a microformat-enabled site, and many developers use microformats as a matter of course. And why not? After all, why invent your own class names when you can re-use pre-defined ones that give your site extra functionality for free?\n\nNevertheless, while it\u2019s good to know that users of tools such as Tails and Operator will derive added value from your shiny semantics, it\u2019s nice to be able to reuse that effort in your own code.\n\nWe\u2019re going to build a map of some of my favourite restaurants in Brighton. Fitting with the principles of unobtrusive JavaScript, we\u2019ll start with a semantically marked up list of restaurants, then use JavaScript to add the map, look up the restaurant locations and plot them as markers.\n\nWe\u2019ll be using a couple of powerful tools. The first is jQuery, a JavaScript library that is ideally suited for unobtrusive scripting. jQuery allows us to manipulate elements on the page based on their CSS selector, which makes it easy to extract information from microformats.\n\nThe second is Mapstraction, introduced here by Andrew Turner a few days ago. We\u2019ll be using Google Maps in the background, but Mapstraction makes it easy to change to a different provider if we want to later.\n\nGetting Started\n\nWe\u2019ll start off with a simple collection of microformatted restaurant details, representing my seven favourite restaurants in Brighton. The full, unstyled list can be seen in restaurants-plain.html. Each restaurant listing looks like this:\n\n<li class=\"vcard\">\n\t<h3><a class=\"fn org url\" href=\"http://www.riddleandfinns.co.uk/\">Riddle & Finns</a></h3>\n\t<div class=\"adr\">\n\t\t<p class=\"street-address\">12b Meeting House Lane</p>\n\t\t<p><span class=\"locality\">Brighton</span>, <abbr class=\"country-name\" title=\"United Kingdom\">UK</abbr></p>\n\t\t<p class=\"postal-code\">BN1 1HB</p>\n\t</div>\n\t<p>Telephone: <span class=\"tel\">+44 (0)1273 323 008</span></p>\n\t<p>E-mail: <a href=\"mailto:info@riddleandfinns.co.uk\" class=\"email\">info@riddleandfinns.co.uk</a></p>\n</li>\n\nSince we\u2019re dealing with a list of restaurants, each hCard is marked up inside a list item. Each restaurant is an organisation; we signify this by placing the classes fn and org on the element surrounding the restaurant\u2019s name (according to the hCard spec, setting both fn and org to the same value signifies that the hCard represents an organisation rather than a person).\n\nThe address information itself is contained within a div of class adr. Note that the HTML <address> element is not suitable here for two reasons: firstly, it is intended to mark up contact details for the current document rather than generic addresses; secondly, address is an inline element and as such cannot contain the paragraphs elements used here for the address information.\n\nA nice thing about microformats is that they provide us with automatic hooks for our styling. For the moment we\u2019ll just tidy up the whitespace a bit; for more advanced style tips consult John Allsop\u2019s guide from 24 ways 2006.\n\n.vcard p {\n\tmargin: 0;\n}\n.adr {\n\tmargin-bottom: 0.5em;\n}\n\nTo plot the restaurants on a map we\u2019ll need latitude and longitude for each one. We can find this out from their address using geocoding. Most mapping APIs include support for geocoding, which means we can pass the API an address and get back a latitude/longitude point. Mapstraction provides an abstraction layer around these APIs which can be included using the following script tag:\n\n<script type=\"text/javascript\" src=\"http://mapstraction.com/src/mapstraction-geocode.js\"></script>\n\nWhile we\u2019re at it, let\u2019s pull in the other external scripts we\u2019ll be using:\n\n<script type=\"text/javascript\" src=\"jquery-1.2.1.js\"></script>\n<script src=\"http://maps.google.com/maps?file=api&v=2&key=YOUR_KEY\" type=\"text/javascript\"></script>\n<script type=\"text/javascript\" src=\"http://mapstraction.com/src/mapstraction.js\"></script>\n<script type=\"text/javascript\" src=\"http://mapstraction.com/src/mapstraction-geocode.js\"></script>\n\nThat\u2019s everything set up: let\u2019s write some JavaScript!\n\nIn jQuery, almost every operation starts with a call to the jQuery function. The function simulates method overloading to behave in different ways depending on the arguments passed to it. When writing unobtrusive JavaScript it\u2019s important to set up code to execute when the page has loaded to the point that the DOM is available to be manipulated. To do this with jQuery, pass a callback function to the jQuery function itself:\n\njQuery(function() {\n\t// This code will be executed when the DOM is ready\n});\n\nInitialising the map\n\nThe first thing we need to do is initialise our map. Mapstraction needs a div with an explicit width, height and ID to show it where to put the map. Our document doesn\u2019t currently include this markup, but we can insert it with a single line of jQuery code:\n\njQuery(function() {\n\t// First create a div to host the map\n\tvar themap = jQuery('<div id=\"themap\"></div>').css({\n\t\t'width': '90%',\n\t\t'height': '400px'\n\t}).insertBefore('ul.restaurants');\n});\n\nWhile this is technically just a single line of JavaScript (with line-breaks added for readability) it\u2019s actually doing quite a lot of work. Let\u2019s break it down in to steps:\n\nvar themap = jQuery('<div id=\"themap\"></div>')\n\nHere\u2019s jQuery\u2019s method overloading in action: if you pass it a string that starts with a < it assumes that you wish to create a new HTML element. This provides us with a handy shortcut for the more verbose DOM equivalent:\n\nvar themap = document.createElement('div');\nthemap.id = 'themap';\n\nNext we want to apply some CSS rules to the element. jQuery supports chaining, which means we can continue to call methods on the object returned by jQuery or any of its methods:\n\nvar themap = jQuery('<div id=\"themap\"></div>').css({\n\t'width': '90%',\n\t'height': '400px'\n})\n\nFinally, we need to insert our new HTML element in to the page. jQuery provides a number of methods for element insertion, but in this case we want to position it directly before the <ul> we are using to contain our restaurants. jQuery\u2019s insertBefore() method takes a CSS selector indicating an element already on the page and places the current jQuery selection directly before that element in the DOM.\n\nvar themap = jQuery('<div id=\"themap\"></div>').css({\n\t'width': '90%',\n\t'height': '400px'\n}).insertBefore('ul.restaurants');\n\nFinally, we need to initialise the map itself using Mapstraction. The Mapstraction constructor takes two arguments: the first is the ID of the element used to position the map; the second is the mapping provider to use (in this case google ):\n\n// Initialise the map\nvar mapstraction = new Mapstraction('themap','google');\n\nWe want the map to appear centred on Brighton, so we\u2019ll need to know the correct co-ordinates. We can use www.getlatlon.com to find both the co-ordinates and the initial map zoom level.\n\n// Show map centred on Brighton\nmapstraction.setCenterAndZoom(\n\tnew LatLonPoint(50.82423734980143, -0.14007568359375),\n\t15 // Zoom level appropriate for Brighton city centre\n);\n\nWe also want controls on the map to allow the user to zoom in and out and toggle between map and satellite view.\n\nmapstraction.addControls({\n\tzoom: 'large',\n\tmap_type: true\n});\n\nAdding the markers\n\nIt\u2019s finally time to parse some microformats. Since we\u2019re using hCard, the information we want is wrapped in elements with the class vcard. We can use jQuery\u2019s CSS selector support to find them:\n\nvar vcards = jQuery('.vcard');\n\nNow that we\u2019ve found them, we need to create a marker for each one in turn. Rather than using a regular JavaScript for loop, we can instead use jQuery\u2019s each() method to execute a function against each of the hCards.\n\njQuery('.vcard').each(function() {\n\t// Do something with the hCard\n});\n\nWithin the callback function, this is set to the current DOM element (in our case, the list item). If we want to call the magic jQuery methods on it we\u2019ll need to wrap it in another call to jQuery:\n\njQuery('.vcard').each(function() {\n\tvar hcard = jQuery(this);\n});\n\nThe Google maps geocoder seems to work best if you pass it the street address and a postcode. We can extract these using CSS selectors: this time, we\u2019ll use jQuery\u2019s find() method which searches within the current jQuery selection:\n\nvar streetaddress = hcard.find('.street-address').text();\nvar postcode = hcard.find('.postal-code').text();\n\nThe text() method extracts the text contents of the selected node, minus any HTML markup.\n\nWe\u2019ve got the address; now we need to geocode it. Mapstraction\u2019s geocoding API requires us to first construct a MapstractionGeocoder, then use the geocode() method to pass it an address. Here\u2019s the code outline:\n\nvar geocoder = new MapstractionGeocoder(onComplete, 'google');\ngeocoder.geocode({'address': 'the address goes here');\n\nThe onComplete function is executed when the geocoding operation has been completed, and will be passed an object with the resulting point on the map. We just want to create a marker for the point:\n\nvar geocoder = new MapstractionGeocoder(function(result) {\n\tvar marker = new Marker(result.point);\n\tmapstraction.addMarker(marker);\n}, 'google');   \n\nFor our purposes, joining the street address and postcode with a comma to create the address should suffice:\n\ngeocoder.geocode({'address': streetaddress + ', ' + postcode});   \n\nThere\u2019s one last step: when the marker is clicked, we want to display details of the restaurant. We can do this with an info bubble, which can be configured by passing in a string of HTML. We\u2019ll construct that HTML using jQuery\u2019s html() method on our hcard object, which extracts the HTML contained within that DOM node as a string.\n\nvar marker = new Marker(result.point);\nmarker.setInfoBubble(\n\t'<div class=\"bubble\">' + hcard.html() + '</div>'\n);\nmapstraction.addMarker(marker);\n\nWe\u2019ve wrapped the bubble in a div with class bubble to make it easier to style. Google Maps can behave strangely if you don\u2019t provide an explicit width for your info bubbles, so we\u2019ll add that to our CSS now:\n\n.bubble {\n\twidth: 300px;\n}\n\nThat\u2019s everything we need: let\u2019s combine our code together:\n\njQuery(function() {\n\t// First create a div to host the map\n\tvar themap = jQuery('<div id=\"themap\"></div>').css({\n\t\t'width': '90%',\n\t\t'height': '400px'\n\t}).insertBefore('ul.restaurants');\n\t// Now initialise the map\n\tvar mapstraction = new Mapstraction('themap','google');\n\tmapstraction.addControls({\n\t\tzoom: 'large',\n\t\tmap_type: true\n\t});\n\t// Show map centred on Brighton\n\tmapstraction.setCenterAndZoom(\n\t\tnew LatLonPoint(50.82423734980143, -0.14007568359375),\n\t\t15 // Zoom level appropriate for Brighton city centre\n\t);\n\t// Geocode each hcard and add a marker\n\tjQuery('.vcard').each(function() {\n\t\tvar hcard = jQuery(this);\n\t\tvar streetaddress = hcard.find('.street-address').text();\n\t\tvar postcode = hcard.find('.postal-code').text();\n\t\tvar geocoder = new MapstractionGeocoder(function(result) {\n\t\t\tvar marker = new Marker(result.point);\n\t\t\tmarker.setInfoBubble(\n\t\t\t\t'<div class=\"bubble\">' + hcard.html() + '</div>'\n\t\t\t);\n\t\t\tmapstraction.addMarker(marker);\n\t\t}, 'google');\t \n\t\tgeocoder.geocode({'address': streetaddress + ', ' + postcode});\n\t});\n});\n\nHere\u2019s the finished code.\n\nThere\u2019s one last shortcut we can add: jQuery provides the $ symbol as an alias for jQuery. We could just go through our code and replace every call to jQuery() with a call to $(), but this would cause incompatibilities if we ever attempted to use our script on a page that also includes the Prototype library. A more robust approach is to start our code with the following:\n\njQuery(function($) {\n\t// Within this function, $ now refers to jQuery\n\t// ...\n});\n\njQuery cleverly passes itself as the first argument to any function registered to the DOM ready event, which means we can assign a local $ variable shortcut without affecting the $ symbol in the global scope. This makes it easy to use jQuery with other libraries.\n\nLimitations of Geocoding\n\nYou may have noticed a discrepancy creep in to the last example: whereas my original list included seven restaurants, the geocoding example only shows five. This is because the Google Maps geocoder incorporates a rate limit: more than five lookups in a second and it starts returning error messages instead of regular results.\n\nIn addition to this problem, geocoding itself is an inexact science: while UK postcodes generally get you down to the correct street, figuring out the exact point on the street from the provided address usually isn\u2019t too accurate (although Google do a pretty good job).\n\nFinally, there\u2019s the performance overhead. We\u2019re making five geocoding requests to Google for every page served, even though the restaurants themselves aren\u2019t likely to change location any time soon. Surely there\u2019s a better way of doing this?\n\nMicroformats to the rescue (again)! The geo microformat suggests simple classes for including latitude and longitude information in a page. We can add specific points for each restaurant using the following markup:\n\n<li class=\"vcard\">\n\t<h3 class=\"fn org\">E-Kagen</h3>\n\t<div class=\"adr\">\n\t\t<p class=\"street-address\">22-23 Sydney Street</p>\n\t\t<p><span class=\"locality\">Brighton</span>, <abbr class=\"country-name\" title=\"United Kingdom\">UK</abbr></p>\n\t\t<p class=\"postal-code\">BN1 4EN</p>\n\t</div>\n\t<p>Telephone: <span class=\"tel\">+44 (0)1273 687 068</span></p>\n\t<p class=\"geo\">Lat/Lon: \n\t\t<span class=\"latitude\">50.827917</span>, \n\t\t<span class=\"longitude\">-0.137764</span>\n\t</p>\n</li>\n\nAs before, I used www.getlatlon.com to find the exact locations \u2013 I find satellite view is particularly useful for locating individual buildings.\n\nLatitudes and longitudes are great for machines but not so useful for human beings. We could hide them entirely with display: none, but I prefer to merely de-emphasise them (someone might want them for their GPS unit):\n\n.vcard .geo {\n\tmargin-top: 0.5em;\n\tfont-size: 0.85em;\n\tcolor: #ccc;\n}\n\nIt\u2019s probably a good idea to hide them completely when they\u2019re displayed inside an info bubble:\n\n.bubble .geo {\n\tdisplay: none;\n}\n\nWe can extract the co-ordinates in the same way we extracted the address. Since we\u2019re no longer geocoding anything our code becomes a lot simpler:\n\n$('.vcard').each(function() {\n\tvar hcard = $(this);\n\tvar latitude = hcard.find('.geo .latitude').text();\n\tvar longitude = hcard.find('.geo .longitude').text();\n\tvar marker = new Marker(new LatLonPoint(latitude, longitude));\n\tmarker.setInfoBubble(\n\t\t'<div class=\"bubble\">' + hcard.html() + '</div>'\n\t);\n\tmapstraction.addMarker(marker);\n});\n\nAnd here\u2019s the finished geo example.\n\nFurther reading\n\nWe\u2019ve only scratched the surface of what\u2019s possible with microformats, jQuery (or just regular JavaScript) and a bit of imagination. If this example has piqued your interest, the following links should give you some more food for thought.\n\n\n\tThe hCard specification\n\tNotes on parsing hCards\n\tjQuery for JavaScript programmers \u2013 my extended tutorial on jQuery.\n\tDann Webb\u2019s Sumo \u2013 a full JavaScript library for parsing microformats, based around some clever metaprogramming techniques.\n\tJeremy Keith\u2019s Adactio Austin \u2013 the first place I saw using microformats to unobtrusively plot locations on a map. Makes clever use of hEvent as well.", "year": "2007", "author": "Simon Willison", "author_slug": "simonwillison", "published": "2007-12-12T00:00:00+00:00", "url": "https://24ways.org/2007/unobtrusively-mapping-microformats-with-jquery/", "topic": "code"}
{"rowid": 165, "title": "Transparent PNGs in Internet Explorer 6", "contents": "Newer breeds of browser such as Firefox and Safari have offered support for PNG images with full alpha channel transparency for a few years. With the use of hacks, support has been available in Internet Explorer 5.5 and 6, but the hacks are non-ideal and have been tricky to use. With IE7 winning masses of users from earlier versions over the last year, full PNG alpha-channel transparency is becoming more of a reality for day-to-day use.\n\nHowever, there are still numbers of IE6 users out there who we can\u2019t leave out in the cold this Christmas, so in this article I\u2019m going to look what we can do to support IE6 users whilst taking full advantage of transparency for the majority of a site\u2019s visitors.\n\nSo what\u2019s alpha channel transparency?\n\nCast your minds back to the Ghost of Christmas Past, the humble GIF. Images in GIF format offer transparency, but that transparency is either on or off for any given pixel. Each pixel\u2019s either fully transparent, or a solid colour. In GIF, transparency is effectively just a special colour you can chose for a pixel.\n\nThe PNG format tackles the problem rather differently. As well as having any colour you chose, each pixel also carries a separate channel of information detailing how transparent it is. This alpha channel enables a pixel to be fully transparent, fully opaque, or critically, any step in between.\n\nThis enables designers to produce images that can have, for example, soft edges without any of the \u2018halo effect\u2019 traditionally associated with GIF transparency. If you\u2019ve ever worked on a site that has different colour schemes and therefore requires multiple versions of each graphic against a different colour, you\u2019ll immediately see the benefit. \n\nWhat\u2019s perhaps more interesting than that, however, is the extra creative freedom this gives designers in creating beautiful sites that can remain web-like in their ability to adjust, scale and reflow.\n\nThe Internet Explorer problem\n\nUp until IE7, there has been no fully native support for PNG alpha channel transparency in Internet Explorer. However, since IE5.5 there has been some support in the form of proprietary filter called the AlphaImageLoader. Internet Explorer filters can be applied directly in your CSS (for both inline and background images), or by setting the same CSS property with JavaScript. \n\nCSS:\n\nimg {\n\tfilter: progid:DXImageTransform.Microsoft.AlphaImageLoader(...);\n}\n\nJavaScript:\n\nimg.style.filter = \"progid:DXImageTransform.Microsoft.AlphaImageLoader(...)\";\n\nThat may sound like a problem solved, but all is not as it may appear. Firstly, as you may realise, there\u2019s no CSS property called filter in the W3C CSS spec. It\u2019s a proprietary extension added by Microsoft that could potentially cause other browsers to reject your entire CSS rule. \n\nSecondly, AlphaImageLoader does not magically add full PNG transparency support so that a PNG in the page will just start working. Instead, when applied to an element in the page, it draws a new rendering surface in the same space that element occupies and loads a PNG into it. If that sounds weird, it\u2019s because that\u2019s precisely what it is. However, by and large the result is that PNGs with an alpha channel can be accommodated.\n\nThe pitfalls\n\nSo, whilst support for PNG transparency in IE5.5 and 6 is possible, it\u2019s not without its problems.\n\nBackground images cannot be positioned or repeated\n\nThe AlphaImageLoader does work for background images, but only for the simplest of cases. If your design requires the image to be tiled (background-repeat) or positioned (background-position) you\u2019re out of luck. The AlphaImageLoader allows you to set a sizingMethod to either crop the image (if necessary) or to scale it to fit. Not massively useful, but something at least.\n\nDelayed loading and resource use\n\nThe AlphaImageLoader can be quite slow to load, and appears to consume more resources than a standard image when applied. Typically, you\u2019d need to add thousands of GIFs or JPEGs to a page before you saw any noticeable impact on the browser, but with the AlphaImageLoader filter applied Internet Explorer can become sluggish after just a handful of alpha channel PNGs.\n\nThe other noticeable effect is that as more instances of the AlphaImageLoader are applied, the longer it takes to render the PNGs with their transparency. The user sees the PNG load in its original non-supported state (with black or grey areas where transparency should be) before one by one the filter kicks in and makes them properly transparent.\n\nBoth the issue of sluggish behaviour and delayed load only really manifest themselves with volume and size of image. Use just a couple of instances and it\u2019s fine, but be careful adding more than five or six. As ever, test, test, test.\n\nLinks become unclickable, forms unfocusable \n\nThis is a big one. There\u2019s a bug/weirdness with AlphaImageLoader that sometimes prevents interaction with links and forms when a PNG background image is used. This is sometimes reported as a z-index issue, but I don\u2019t believe it is. Rather, it\u2019s an artefact of that weird way the filter gets applied to the document almost outside of the normal render process. \n\nOften this can be solved by giving the links or form elements hasLayout using position: relative; where possible. However, this doesn\u2019t always work and the non-interaction problem cannot always be solved. You may find yourself having to go back to the drawing board.\n\nSidestepping the danger zones\n\nFrankly, it\u2019s pretty bad news if you design a site, have that design signed off by your client, build it and then find out only at the end (because you don\u2019t know what might trigger a problem) that your search field can\u2019t be focused in IE6. That\u2019s an absolute nightmare, and whilst it\u2019s not likely to happen, it\u2019s possible that it might. It\u2019s happened to me. So what can you do?\n\nThe best approach I\u2019ve found to this scenario is\n\n\n\tIsolate the PNG or PNGs that are causing the problem. Step through the PNGs in your page, commenting them out one by one and retesting. Typically it\u2019ll be the nearest PNG to the problem, so try there first. Keep going until you can click your links or focus your form fields.\n\tThis is where you really need luck on your side, because you\u2019re going to have to fake it. This will depend on the design of the site, but some way or other create a replacement GIF or JPEG image that will give you an acceptable result. Then use conditional comments to serve that image to only users of IE older than version 7.\n\n\nA hack, you say? Well, you started it chum.\n\nApplying AlphaImageLoader\n\nBecause the filter property is invalid CSS, the safest pragmatic approach is to apply it selectively with JavaScript for only Internet Explorer versions 5.5 and 6. This helps ensure that by default you\u2019re serving standard CSS to browsers that support both the CSS and PNG standards correct, and then selectively patching up only the browsers that need it. \n\nSeveral years ago, Aaron Boodman wrote and released a script called sleight for doing just that. However, sleight dealt only with images in the page, and not background images applied with CSS. Building on top of Aaron\u2019s work, I hacked sleight and came up with bgsleight for applying the filter to background images instead. That was in 2003, and over the years I\u2019ve made a couple of improvements here and there to keep it ticking over and to resolve conflicts between sleight and bgsleight when used together. However, with alpha channel PNGs becoming much more widespread, it\u2019s time for a new version.\n\nIntroducing SuperSleight\n\nSuperSleight adds a number of new and useful features that have come from the day-to-day needs of working with PNGs.\n\n\n\tWorks with both inline and background images, replacing the need for both sleight and bgsleight\n\tWill automatically apply position: relative to links and form fields if they don\u2019t already have position set. (Can be disabled.)\n\tCan be run on the entire document, or just a selected part where you know the PNGs are. This is better for performance.\n\tDetects background images set to no-repeat and sets the scaleMode to crop rather than scale.\n\tCan be re-applied by any other JavaScript in the page \u2013 useful if new content has been loaded by an Ajax request.\n\n\n  Download SuperSleight \n\nImplementation\n\nGetting SuperSleight running on a page is quite straightforward, you just need to link the supplied JavaScript file (or the minified version if you prefer) into your document inside conditional comments so that it is delivered to only Internet Explorer 6 or older.\n\n<!--[if lte IE 6]>\n\t<script type=\"text/javascript\" src=\"supersleight-min.js\"></script>\n<![endif]-->\n\nSupplied with the JavaScript is a simple transparent GIF file. The script replaces the existing PNG with this before re-layering the PNG over the top using AlphaImageLoaded. You can change the name or path of the image in the top of the JavaScript file, where you\u2019ll also find the option to turn off the adding of position: relative to links and fields if you don\u2019t want that.\n\nThe script is kicked off with a call to supersleight.init() at the bottom. The scope of the script can be limited to just one part of the page by passing an ID of an element to supersleight.limitTo(). And that\u2019s all there is to it.\n\nUpdate March 2008: a version of this script as a jQuery plugin is also now available.", "year": "2007", "author": "Drew McLellan", "author_slug": "drewmclellan", "published": "2007-12-01T00:00:00+00:00", "url": "https://24ways.org/2007/supersleight-transparent-png-in-ie6/", "topic": "code"}
{"rowid": 164, "title": "My Other Christmas Present Is a Definition List", "contents": "A note from the editors:  readers should note that the HTML5 redefinition of definition lists has come to pass and is now \u00e0 la mode.\n                \n                \n                      \n                Last year, I looked at how the markup for tag clouds was generally terrible. I thought this year I would look not at a method of marking up a common module, but instead just at a simple part of HTML and how it generally gets abused.\n\nNo, not tables. Definition lists. Ah, definition lists. Often used but rarely understood.\n\nExamining the definition of definitions\n\nTo start with, let\u2019s see what the HTML spec has to say about them.\n\n\n\tDefinition lists vary only slightly from other types of lists in that list items consist of two parts: a term and a description.\n\n\nThe canonical example of a definition list is a dictionary. Words can have multiple descriptions (even the word definition has at least five). Also, many terms can share a single definition (for example, the word colour can also be spelt color, but they have the same definition).\n\nExcellent, we can all grasp that. But it very quickly starts to fall apart. Even in the HTML specification the definition list is mis-used.\n\n\n\tAnother application of DL, for example, is for marking up dialogues, with each DT naming a speaker, and each DD containing his or her words.\n\n\nWrong. Completely and utterly wrong. This is the biggest flaw in the HTML spec, along with dropping support for the start attribute on ordered lists. \u201cWhy?\u201d, you may ask. Let me give you an example from Romeo and Juliet, act 2, scene 2.\n\n<dt>Juliet</dt>\n\t<dd>Romeo!</dd>\n<dt>Romeo</dt>\n\t<dd>My niesse?</dd>\n<dt>Juliet</dt>\n\t<dd>At what o'clock tomorrow shall I send to thee?</dd>\n<dt>Romeo</dt>\n\t<dd>At the hour of nine.</dd>\n\nNow, the problem here is that a given definition can have multiple descriptions (the DD). Really the dialog \u201cdescriptions\u201d should be rolled up under the terms, like so:\n\n<dt>Juliet</dt>\n\t<dd>Romeo!</dd>\n\t<dd>At what o'clock tomorrow shall I send to thee?</dd>\n<dt>Romeo</dt>\n\t<dd>My niesse?</dd>\n\t<dd>At the hour of nine.</dd>\n\nSuddenly the play won\u2019t make anywhere near as much sense. (If it\u2019s anything, the correct markup for a play is an ordered list of CITE and BLOCKQUOTE elements.)\n\nThis is the first part of the problem. That simple example has turned definition lists in everyone\u2019s mind from pure definitions to more along the lines of a list with pre-configured heading(s) and text(s).\n\nScreen reader, enter stage left.\n\nIn many screen readers, a simple definition list would be read out as \u201cdefinition term equals definition description\u201d. So in our play excerpt, Juliet equals Romeo! That\u2019s not right, either. But this also leads a lot of people astray with definition lists to believing that they are useful for key/value pairs.\n\nBehaviour and convention\n\nThe WHAT-WG have noticed the common mis-use of the DL, and have codified it into the new spec. In the HTML5 draft, a definition list is no longer a definition list.\n\n\n\tThe dl element introduces an unordered association list consisting of zero or more name-value groups (a description list). Each group must consist of one or more names (dt elements) followed by one or more values (dd elements).\n\n\nThey also note that the \u201cdl element is inappropriate for marking up dialogue, since dialogue is ordered\u201d. So for that example they have created a DIALOG (sic) element.\n\nStrange, then, that they keep DL as-is but instead refer to it an \u201cassociation list\u201d. They have not created a new AL element, and kept DL for the original purpose. They have chosen not to correct the usage or to create a new opportunity for increased specificity in our HTML, but to \u201cpave the cowpath\u201d of convention.\n\nHow to use a definition list\n\nGiven that everyone else is using a DL incorrectly, should we? Well, if they all jumped off a bridge, would you too? No, of course you wouldn\u2019t. We don\u2019t have HTML5 yet, so we\u2019re stuck with the existing semantics of HTML4 and XHTML1. Which means that:\n\n\n\tListing dialogue is not defining anything.\n\tListing the attributes of a piece of hardware (resolution = 1600\u00d71200) is illustrating sample values, not defining anything (however, stating what \u2018resolution\u2019 actually means in this context would be a definition).\n\tListing the cast and crew of a given movie is not defining the people involved in making movies. (Stuart Gordon may have been the director of Space Truckers, but that by no means makes him the true definition of a director.)\n\tA menu of navigation items is simply a nested ordered or unordered list of links, not a definition list.\n\tApplying styling handles to form labels and elements is not a good use for a definition list.\n\n\nAnd so on.\n\nLiving by the specification, a definition list should be used for term definitions \u2013 glossaries, lexicons and dictionaries \u2013 only.\n\nAnything else is a crime against markup.", "year": "2007", "author": "Mark Norman Francis", "author_slug": "marknormanfrancis", "published": "2007-12-05T00:00:00+00:00", "url": "https://24ways.org/2007/my-other-christmas-present-is-a-definition-list/", "topic": "code"}
{"rowid": 163, "title": "Get To Grips with Slippy Maps", "contents": "Online mapping has definitely hit mainstream. Google Maps made \u2018slippy maps\u2019 popular and made it easy for any developer to quickly add a dynamic map to his or her website. You can now find maps for store locations, friends nearby, upcoming events, and embedded in blogs. \n\nIn this tutorial we\u2019ll show you how to easily add a map to your site using the Mapstraction mapping library. There are many map providers available to choose from, each with slightly different functionality, design, and terms of service. Mapstraction makes deciding which provider to use easy by allowing you to write your mapping code once, and then easily switch providers.\n\nAssemble the pieces\n\nUtilizing any of the mapping library typically consists of similar overall steps:\n\n\n\tCreate an HTML div to hold the map\n\tInclude the Javascript libraries\n\tCreate the Javascript Map element\n\tSet the initial map center and zoom level\n\tAdd markers, lines, overlays and more\n\n\nCreate the Map Div\n\nThe HTML div is where the map will actually show up on your page. It needs to have a unique id, because we\u2019ll refer to that later to actually put the map here. This also lets you have multiple maps on a page, by creating individual divs and Javascript map elements. The size of the div also sets the height and width of the map. You set the size using CSS, either inline with the element, or via a CSS reference to the element id or class. For this example, we\u2019ll use inline styling.\n\n<div id=\"map\" style=\"width: 400px; height: 400px;\"></div>\n\nInclude Javascript libraries\n\nA mapping library is like any Javascript library. You need to include the library in your page before you use the methods of that library. For our tutorial, we\u2019ll need to include at least two libraries: Mapstraction, and the mapping API(s) we want to display. Our first example we\u2019ll use the ubiquitous Google Maps library. However, you can just as easily include Yahoo, MapQuest, or any of the other supported libraries.\n\nAnother important aspect of the mapping libraries is that many of them require an API key. You will need to agree to the terms of service, and get an API key these.\n\n<script src=\"http://maps.google.com/maps?file=api&v=2&key=YOUR_KEY\" type=\"text/javascript\"></script>\n<script type=\"text/javascript\" src=\"http://mapstraction.com/src/mapstraction.js\"></script>\n\nCreate the Map\n\nGreat, we\u2019ve now put in all the pieces we need to start actually creating our map. This is as simple as creating a new Mapstraction object with the id of the HTML div we created earlier, and the name of the mapping provider we want to use for this map. \n\nWith several of the mapping libraries you will need to set the map center and zoom level before the map will appear. The map centering actually triggers the initialization of the map. \n\nvar mapstraction = new Mapstraction('map','google');\nvar myPoint = new LatLonPoint(37.404,-122.008);\nmapstraction.setCenterAndZoom(myPoint, 10);\n\nA note about zoom levels. The setCenterAndZoom function takes two parameters, the center as a LatLonPoint, and a zoom level that has been defined by mapping libraries. The current usage is for zoom level 1 to be \u201czoomed out\u201d, or view the entire earth \u2013 and increasing the zoom level as you zoom in. Typically 17 is the maximum zoom, which is about the size of a house. \n\nDifferent mapping providers have different quality of zoomed in maps over different parts of the world. This is a perfect reason why using a library like Mapstraction is very useful, because you can quickly change mapping providers to accommodate users in areas that have bad coverage with some maps. \n\nTo switch providers, you just need to include the Javascript library, and then change the second parameter in the Mapstraction creation. Or, you can call the switch method to dynamically switch the provider.\n\nSo for Yahoo Maps  (demo):\n\nvar mapstraction = new Mapstraction('map','yahoo');\n\nor Microsoft Maps (demo):\n\nvar mapstraction = new Mapstraction('map','microsoft');\n\nwant a 3D globe in your browser? try FreeEarth (demo):\n\nvar mapstraction = new Mapstraction('map','freeearth');\n\nor even OpenStreetMap (free your data!)  (demo):\n\nvar mapstraction = new Mapstraction('map','openstreetmap');\n\nVisit the Mapstraction multiple map demo page for an example of how easy it is to have many maps on your page, each with a different provider. \n\nAdding Markers\n\nWhile adding your first map is fun, and you can probably spend hours just sliding around, the point of adding a map to your site is usually to show the location of something. So now you want to add some markers. There are a couple of ways to add to your map.\n\nThe simplest is directly creating markers. You could either hard code this into a rather static page, or dynamically generate these using whatever tools your site is built on.\n\nvar marker = new Marker( new LatLonPoint(37.404,-122.008) );\nmarker.setInfoBubble(\"It's easy to add maps to your site\");\nmapstraction.addMarker( marker );\n\nThere is a lot more you can do with markers, including changing the icon, adding timestamps, automatically opening the bubble, or making them draggable. \n\nWhile it is straight-forward to create markers one by one, there is a much easier way to create a large set of markers. And chances are, you can make it very easy by extending some data you already are sharing: RSS. \n\nSpecifically, using GeoRSS you can easily add a large set of markers directly to a map. GeoRSS is a community built standard (like Microformats) that added geographic markup to RSS and Atom entries. It\u2019s as simple as adding <georss:point>42 -83</georss:point> to your feeds to share items via GeoRSS. Once you\u2019ve done that, you can add that feed as an \u2018overlay\u2019 to your map using the function:\n\nmapstraction.addOverlay(\"http://api.flickr.com/services/feeds/groups_pool.gne?id=322338@N20&format=rss_200&georss=1\");\n\nMapstraction also supports KML for many of the mapping providers. So it\u2019s easy to add various data sources together with your own data. Check out Mapufacture for a growing index of available GeoRSS feeds and KML documents. \n\nPlay with your new toys\n\nMapstraction offers a lot more functionality you can utilize for demonstrating a lot of geographic data on your website. It also includes geocoding and routing abstraction layers for making sure your users know where to go. You can see more on the Mapstraction website: http://mapstraction.com.", "year": "2007", "author": "Andrew Turner", "author_slug": "andrewturner", "published": "2007-12-02T00:00:00+00:00", "url": "https://24ways.org/2007/get-to-grips-with-slippy-maps/", "topic": "code"}
{"rowid": 162, "title": "Conditional Love", "contents": "\u201cBrowser.\u201d The four-letter word of web design.\n\nI mean, let\u2019s face it: on the good days, when things just work in your target browsers, it\u2019s marvelous. The air smells sweeter, birds\u2019 songs sound more melodious, and both your design and your code are looking sharp.\n\nBut on the less-than-good days (which is, frankly, most of them), you\u2019re compelled to tie up all your browsers in a sack, heave them into the nearest river, and start designing all-imagemap websites. We all play favorites, after all: some will swear by Firefox, Opera fans are allegedly legion, and others still will frown upon anything less than the latest WebKit nightly.\n\nThankfully, we do have an out for those little inconsistencies that crop up when dealing with cross-browser testing: CSS patches.\n\nSpare the Rod, Hack the Browser\n\nBefore committing browsercide over some rendering bug, a designer will typically reach for a snippet of CSS fix the faulty browser. Historically referred to as \u201chacks,\u201d I prefer Dan Cederholm\u2019s more client-friendly alternative, \u201cpatches\u201d.\n\nBut whatever you call them, CSS patches all work along the same principle: supply the proper property value to the good browsers, while giving higher maintenance other browsers an incorrect value that their frustrating idiosyncratic rendering engine can understand.\n\nTraditionally, this has been done either by exploiting incomplete CSS support:\n\n#content {\n\theight: 1%;\t // Let's force hasLayout for old versions of IE.\n\tline-height: 1.6;\n\tpadding: 1em;\n}\nhtml>body #content {\n\theight: auto; // Modern browsers get a proper height value.\n}\n\nor by exploiting bugs in their rendering engine to deliver alternate style rules:\n\n#content p {\n\tfont-size: .8em;\n\t/* Hide from Mac IE5 \\*/\n\tfont-size: .9em;\n\t/* End hiding from Mac IE5 */\n}\n\nWe\u2019ve even used these exploits to serve up whole stylesheets altogether:\n\n@import url(\"core.css\");\n@media tty {\n\ti{content:\"\\\";/*\" \"*/}} @import 'windows-ie5.css'; /*\";}\n}/* */\n\nThe list goes on, and on, and on. For every browser, for every bug, there\u2019s a patch available to fix some rendering bug.\n\nBut after some time working with standards-based layouts, I\u2019ve found that CSS patches, as we\u2019ve traditionally used them, become increasingly difficult to maintain. As stylesheets are modified over the course of a site\u2019s lifetime, inline fixes we\u2019ve written may become obsolete, making them difficult to find, update, or prune out of our CSS. A good patch requires a constant gardener to ensure that it adds more than just bloat to a stylesheet, and inline patches can be very hard to weed out of a decently sized CSS file.\n\nGiving the Kids Separate Rooms\n\nSince I joined Airbag Industries earlier this year, every project we\u2019ve worked on has this in the head of its templates:\n\n<link rel=\"stylesheet\" href=\"-/css/screen/main.css\" type=\"text/css\" media=\"screen, projection\" />\n<!--[if lt IE 7]>\n<link rel=\"stylesheet\" href=\"-/css/screen/patches/win-ie-old.css\" type=\"text/css\" media=\"screen, projection\" />\n<![endif]-->\n<!--[if gte IE 7]>\n<link rel=\"stylesheet\" href=\"-/css/screen/patches/win-ie7-up.css\" type=\"text/css\" media=\"screen, projection\" />\n<![endif]-->\n\nThe first element is, simply enough, a link element that points to the project\u2019s main CSS file. No patches, no hacks: just pure, modern browser-friendly style rules. Which, nine times out of ten, will net you a design that looks like spilled eggnog in various versions of Internet Explorer.\n\nBut don\u2019t reach for the mulled wine quite yet. Immediately after, we\u2019ve got a brace of conditional comments wrapped around two other link elements. These odd-looking comments allow us to selectively serve up additional stylesheets just to the version of IE that needs them. We\u2019ve got one for IE 6 and below:\n\n<!--[if lt IE 7]>\n<link rel=\"stylesheet\" href=\"-/css/screen/patches/win-ie-old.css\" type=\"text/css\" media=\"screen, projection\" />\n<![endif]-->\n\nAnd another for IE7 and above:\n\n<!--[if gte IE 7]>\n<link rel=\"stylesheet\" href=\"-/css/screen/patches/win-ie7-up.css\" type=\"text/css\" media=\"screen, projection\" />\n<![endif]-->\n\nMicrosoft\u2019s conditional comments aren\u2019t exactly new, but they can be a valuable alternative to cooking CSS patches directly into a master stylesheet. And though they\u2019re not a W3C-approved markup structure, I think they\u2019re just brilliant because they innovate within the spec: non-IE devices will assume that the comments are just that, and ignore the markup altogether.\n\nThis does, of course, mean that there\u2019s a little extra markup in the head of our documents. But this approach can seriously cut down on the unnecessary patches served up to the browsers that don\u2019t need them. Namely, we no longer have to write rules like this in our main stylesheet:\n\n#content {\n\theight: 1%;\t// Let's force hasLayout for old versions of IE.\n\tline-height: 1.6;\n\tpadding: 1em;\n}\nhtml>body #content {\n\theight: auto;\t// Modern browsers get a proper height value.\n}\n\nRather, we can simply write an un-patched rule in our core stylesheet:\n\n#content {\n\tline-height: 1.6;\n\tpadding: 1em;\n}\n\nAnd now, our patch for older versions of IE goes in\u2014you guessed it\u2014the stylesheet for older versions of IE:\n\n#content {\n\theight: 1%;\n}\n\nThe hasLayout patch is applied, our design\u2019s repaired, and\u2014most importantly\u2014the patch is only seen by the browser that needs it. The \u201cgood\u201d browsers don\u2019t have to incur any added stylesheet weight from our IE patches, and Internet Explorer gets the conditional love it deserves.\n\nMost importantly, this \u201ccompartmentalized\u201d approach to CSS patching makes it much easier for me to patch and maintain the fixes applied to a particular browser. If I need to track down a bug for IE7, I don\u2019t need to scroll through dozens or hundreds of rules in my core stylesheet: instead, I just open the considerably slimmer IE7-specific patch file, make my edits, and move right along.\n\nEven Good Children Misbehave\n\nWhile IE may occupy the bulk of our debugging time, there\u2019s no denying that other popular, modern browsers will occasionally disagree on how certain bits of CSS should be rendered. But without something as, well, pimp as conditional comments at our disposal, how do we bring the so-called \u201cgood browsers\u201d back in line with our design?\n\nAssuming you\u2019re loving the \u201cone patch file per browser\u201d model as much as I do, there\u2019s just one alternative: JavaScript.\n\nfunction isSaf() {\n\tvar isSaf = (document.childNodes && !document.all && !navigator.taintEnabled && !navigator.accentColorName) ? true : false;\n\treturn isSaf;\n}\nfunction isOp() {\n\tvar isOp = (window.opera) ? true : false;\n\treturn isOp;\n}\n\nInstead of relying on dotcom-era tactics of parsing the browser\u2019s user-agent string, we\u2019re testing here for support for various DOM objects, whose presence or absence we can use to reasonably infer the browser we\u2019re looking at. So running the isOp() function, for example, will test for Opera\u2019s proprietary window.opera object, and thereby accurately tell you if your user\u2019s running Norway\u2019s finest browser.\n\nWith scripts such as isOp() and isSaf() in place, you can then reasonably test which browser\u2019s viewing your content, and insert additional link elements as needed.\n\nfunction loadPatches(dir) {\n\tif (document.getElementsByTagName() && document.createElement()) {\n\t\tvar head = document.getElementsByTagName(\"head\")[0];\n\t\tif (head) {\n\t\t\tvar css = new Array();\n\t\t\tif (isSaf()) {\n\t\t\t\tcss.push(\"saf.css\");\n\t\t\t} else if (isOp()) {\n\t\t\t\tcss.push(\"opera.css\");\n\t\t\t}\n\t\t\tif (css.length) {\n\t\t\t\tvar link = document.createElement(\"link\");\n\t\t\t\tlink.setAttribute(\"rel\", \"stylesheet\");\n\t\t\t\tlink.setAttribute(\"type\", \"text/css\");\n\t\t\t\tlink.setAttribute(\"media\", \"screen, projection\");\n\t\t\t\tfor (var i = 0; i < css.length; i++) {\n\t\t\t\t\tvar tag = link.cloneNode(true);\n\t\t\t\t\ttag.setAttribute(\"href\", dir + css[0]);\n\t\t\t\t\thead.appendChild(tag);\n\t\t\t\t}\n\t\t\t}\n\t\t}\n\t}\n}\n\nHere, we\u2019re testing the results of isSaf() and isOp(), one after the other. For each function that returns true, then the name of a new stylesheet is added to the oh-so-cleverly named css array. Then, for each entry in css, we create a new link element, point it at our patch file, and insert it into the head of our template.\n\nFire it up using your favorite onload or DOMContentLoaded function, and you\u2019re good to go.\n\nScripteat Emptor\n\nAt this point, some of the audience\u2019s more conscientious \u2018scripters may be preparing to lob figgy pudding at this author\u2019s head. And that\u2019s perfectly understandable; relying on JavaScript to patch CSS chafes a bit against the normally clean separation we have between our pages\u2019 content, presentation, and behavior layers.\n\nAnd beyond the philosophical concerns, this approach comes with a few technical caveats attached:\n\nBrowser detection? So un-133t.\n\nBrowser detection is not something I\u2019d typically recommend. Whenever possible, a proper DOM script should check for the support of a given object or method, rather than the device with which your users view your content.\n\nIt\u2019s JavaScript, so don\u2019t count on it being available.\n\nAccording to one site, roughly four percent of Internet users don\u2019t have JavaScript enabled. Your site\u2019s stats might be higher or lower than this number, but still: don\u2019t expect that every member of your audience will see these additional stylesheets, and ensure that your content\u2019s still accessible with JS turned off.\n\nBe a constant gardener.\n\nThe sample isSaf() and isOp() functions I\u2019ve written will tell you if the user\u2019s browser is Safari or Opera. As a result, stylesheets written to patch issues in an old browser may break when later releases repair the relevant CSS bugs.\n\nYou can, of course, add logic to these simple little scripts to serve up version-specific stylesheets, but that way madness may lie. In any event, test your work vigorously, and keep testing it when new versions of the targeted browsers come out. Make sure that a patch written today doesn\u2019t become a bug tomorrow.\n\nPatching Firefox, Opera, and Safari isn\u2019t something I\u2019ve had to do frequently: still, there have been occasions where the above script\u2019s come in handy. Between conditional comments, careful CSS auditing, and some judicious JavaScript, browser-based bugs can be handled with near-surgical precision.\n\nSo pass the \u2018nog. It\u2019s patchin\u2019 time.", "year": "2007", "author": "Ethan Marcotte", "author_slug": "ethanmarcotte", "published": "2007-12-15T00:00:00+00:00", "url": "https://24ways.org/2007/conditional-love/", "topic": "code"}
{"rowid": 161, "title": "Keeping JavaScript Dependencies At Bay", "contents": "As we are writing more and more complex JavaScript applications we run into issues that have hitherto (god I love that word) not been an issue. The first decision we have to make is what to do when planning our app: one big massive JS file or a lot of smaller, specialised files separated by task. \n\nPersonally, I tend to favour the latter, mainly because it allows you to work on components in parallel with other developers without lots of clashes in your version control. It also means that your application will be more lightweight as you only include components on demand.\n\nStarting with a global object\n\nThis is why it is a good plan to start your app with one single object that also becomes the namespace for the whole application, say for example myAwesomeApp:\n\nvar myAwesomeApp = {};\n\nYou can nest any necessary components into this one and also make sure that you check for dependencies like DOM support right up front.\n\nAdding the components\n\nThe other thing to add to this main object is a components object, which defines all the components that are there and their file names.\n\nvar myAwesomeApp = {\n\tcomponents :{\n\t\tformcheck:{\n\t\t\turl:'formcheck.js',\n\t\t\tloaded:false\n\t\t},\n\t\tdynamicnav:{\n\t\t\turl:'dynamicnav.js',\n\t\t\tloaded:false\n\t\t},\n\t\tgallery:{\n\t\t\turl:'gallery.js',\n\t\t\tloaded:false\n\t\t},\n\t\tlightbox:{\n\t\t\turl:'lightbox.js',\n\t\t\tloaded:false\n\t\t}\n\t}\n};\n\nTechnically you can also omit the loaded properties, but it is cleaner this way. The next thing to add is an addComponent function that can load your components on demand by adding new SCRIPT elements to the head of the documents when they are needed.\n\nvar myAwesomeApp = {\n\tcomponents :{\n\t\tformcheck:{\n\t\t\turl:'formcheck.js',\n\t\t\tloaded:false\n\t\t},\n\t\tdynamicnav:{\n\t\t\turl:'dynamicnav.js',\n\t\t\tloaded:false\n\t\t},\n\t\tgallery:{\n\t\t\turl:'gallery.js',\n\t\t\tloaded:false\n\t\t},\n\t\tlightbox:{\n\t\t\turl:'lightbox.js',\n\t\t\tloaded:false\n\t\t}\n\t},\n\taddComponent:function(component){\n\t\tvar c = this.components[component];\n\t\tif(c && c.loaded === false){\n\t\t\tvar s = document.createElement('script');\n\t\t\ts.setAttribute('type', 'text/javascript');\n\t\t\ts.setAttribute('src',c.url);\n\t\t\tdocument.getElementsByTagName('head')[0].appendChild(s);\n\t\t}\n\t}\n};\n\nThis allows you to add new components on the fly when they are not defined:\n\nif(!myAwesomeApp.components.gallery.loaded){\n\tmyAwesomeApp.addComponent('gallery');\n};\n\nVerifying that components have been loaded\n\nHowever, this is not safe as the file might not be available. To make the dynamic adding of components safer each of the components should have a callback at the end of them that notifies the main object that they indeed have been loaded:\n\nvar myAwesomeApp = {\n\tcomponents :{\n\t\tformcheck:{\n\t\t\turl:'formcheck.js',\n\t\t\tloaded:false\n\t\t},\n\t\tdynamicnav:{\n\t\t\turl:'dynamicnav.js',\n\t\t\tloaded:false\n\t\t},\n\t\tgallery:{\n\t\t\turl:'gallery.js',\n\t\t\tloaded:false\n\t\t},\n\t\tlightbox:{\n\t\t\turl:'lightbox.js',\n\t\t\tloaded:false\n\t\t}\n\t},\n\taddComponent:function(component){\n\t\tvar c = this.components[component];\n\t\tif(c && c.loaded === false){\n\t\t\tvar s = document.createElement('script');\n\t\t\ts.setAttribute('type', 'text/javascript');\n\t\t\ts.setAttribute('src',c.url);\n\t\t\tdocument.getElementsByTagName('head')[0].appendChild(s);\n\t\t}\n\t},\n\tcomponentAvailable:function(component){\n\t\tthis.components[component].loaded = true;\n\t}\n}\n\nFor example the gallery.js file should call this notification as a last line:\n\nmyAwesomeApp.gallery = function(){\n\t// [... other code ...]\n}();\nmyAwesomeApp.componentAvailable('gallery');\n\nTelling the implementers when components are available\n\nThe last thing to add (actually as a courtesy measure for debugging and implementers) is to offer a listener function that gets notified when the component has been loaded:\n\nvar myAwesomeApp = {\n\tcomponents :{\n\t\tformcheck:{\n\t\t\turl:'formcheck.js',\n\t\t\tloaded:false\n\t\t},\n\t\tdynamicnav:{\n\t\t\turl:'dynamicnav.js',\n\t\t\tloaded:false\n\t\t},\n\t\tgallery:{\n\t\t\turl:'gallery.js',\n\t\t\tloaded:false\n\t\t},\n\t\tlightbox:{\n\t\t\turl:'lightbox.js',\n\t\t\tloaded:false\n\t\t}\n\t},\n\taddComponent:function(component){\n\t\tvar c = this.components[component];\n\t\tif(c && c.loaded === false){\n\t\t\tvar s = document.createElement('script');\n\t\t\ts.setAttribute('type', 'text/javascript');\n\t\t\ts.setAttribute('src',c.url);\n\t\t\tdocument.getElementsByTagName('head')[0].appendChild(s);\n\t\t}\n\t},\n\tcomponentAvailable:function(component){\n\t\tthis.components[component].loaded = true;\n\t\tif(this.listener){\n\t\t\tthis.listener(component);\n\t\t};\n\t}\n};\n\nThis allows you to write a main listener function that acts when certain components have been loaded, for example:\n\nmyAwesomeApp.listener = function(component){\n\tif(component === 'gallery'){\n\t   showGallery();\n\t}\n};\n\nExtending with other components\n\nAs the main object is public, other developers can extend the components object with own components and use the listener function to load dependent components. Say you have a bespoke component with data and labels in extra files:\n\nmyAwesomeApp.listener = function(component){\n\tif(component === 'bespokecomponent'){\n\t\tmyAwesomeApp.addComponent('bespokelabels');\n\t};\n\tif(component === 'bespokelabels'){\n\t\tmyAwesomeApp.addComponent('bespokedata');\n\t};\n\tif(component === 'bespokedata'){\n\t\tmyAwesomeApp,bespokecomponent.init();\n\t};\n};\nmyAwesomeApp.components.bespokecomponent = {\n\turl:'bespoke.js',\n\tloaded:false\n};\nmyAwesomeApp.components.bespokelabels = {\n\turl:'bespokelabels.js',\n\tloaded:false\n};\nmyAwesomeApp.components.bespokedata = {\n\turl:'bespokedata.js',\n\tloaded:false\n};\nmyAwesomeApp.addComponent('bespokecomponent');\n\nFollowing this practice you can write pretty complex apps and still have full control over what is available when. You can also extend this to allow for CSS files to be added on demand.\n\nInfluences\n\nIf you like this idea and wondered if someone already uses it, take a look at the Yahoo! User Interface library, and especially at the YAHOO_config option of the global YAHOO.js object.", "year": "2007", "author": "Christian Heilmann", "author_slug": "chrisheilmann", "published": "2007-12-18T00:00:00+00:00", "url": "https://24ways.org/2007/keeping-javascript-dependencies-at-bay/", "topic": "code"}
{"rowid": 157, "title": "Capturing Caps Lock", "contents": "One of the more annoying aspects of having to remember passwords (along with having to remember loads of them) is that if you\u2019ve got Caps Lock turned on accidentally when you type one in, it won\u2019t work, and you won\u2019t know why. Most desktop computers alert you in some way if you\u2019re trying to enter your password to log on and you\u2019ve enabled Caps Lock; there\u2019s no reason why the web can\u2019t do the same. What we want is a warning \u2013 maybe the user wants Caps Lock on, because maybe their password is in capitals \u2013 rather than something that interrupts what they\u2019re doing. Something subtle.\n\nBut that doesn\u2019t answer the question of how to do it. Sadly, there\u2019s no way of actually detecting whether Caps Lock is on directly. However, there\u2019s a simple work-around; if the user presses a key, and it\u2019s a capital letter, and they don\u2019t have the Shift key depressed, why then they must have Caps Lock on! Simple. \n\nDOM scripting allows your code to be notified when a key is pressed in an element; when the key is pressed, you get the ASCII code for that key. Capital letters, A to Z, have ASCII codes 65 to 90. So, the code would look something like:\n\non a key press\n\tif the ASCII code for the key is between 65 and 90 *and* if shift is pressed\n\t\twarn the user that they have Caps Lock on, but let them carry on\n\tend if\nend keypress\n\nThe actual JavaScript for this is more complicated, because both event handling and keypress information differ across browsers. Your event handling functions are passed an event object, except in Internet Explorer where you use the global event object; the event object has a which parameter containing the ASCII code for the key pressed, except in Internet Explorer where the event object has a keyCode parameter; some browsers store whether the shift key is pressed in a shiftKey parameter and some in a modifiers parameter. All this boils down to code that looks something like this:\n\nkeypress: function(e) {\n\tvar ev = e ? e : window.event;\n\tif (!ev) {\n\t\treturn;\n\t}\n\tvar targ = ev.target ? ev.target : ev.srcElement;\n\t// get key pressed\n\tvar which = -1;\n\tif (ev.which) {\n\t\twhich = ev.which;\n\t} else if (ev.keyCode) {\n\t\twhich = ev.keyCode;\n\t}\n\t// get shift status\n\tvar shift_status = false;\n\tif (ev.shiftKey) {\n\t\tshift_status = ev.shiftKey;\n\t} else if (ev.modifiers) {\n\t\tshift_status = !!(ev.modifiers & 4);\n\t}\n\n\t// At this point, you have the ASCII code in \u201cwhich\u201d, \n\t// and shift_status is true if the shift key is pressed\n}\n\nThen it\u2019s just a check to see if the ASCII code is between 65 and 90 and the shift key is pressed. (You also need to do the same work if the ASCII code is between 97 (a) and 122 (z) and the shift key is not pressed, because shifted letters are lower-case if Caps Lock is on.)\n\nif (((which >= 65 && which <= 90) && !shift_status) || \n\t((which >= 97 && which <= 122) && shift_status)) {\n\t// uppercase, no shift key\n\t/* SHOW THE WARNING HERE */\n} else {\n\t/* HIDE THE WARNING HERE */\n}\n\nThe warning can be implemented in many different ways: highlight the password field that the user is typing into, show a tooltip, display text next to the field. For simplicity, this code shows the warning as a previously created image, with appropriate alt text. Showing the warning means creating a new <img> tag with DOM scripting, dropping it into the page, and positioning it so that it\u2019s next to the appropriate field. The image looks like this:\n\n\n\nYou know the position of the field the user is typing into (from its offsetTop and offsetLeft properties) and how wide it is (from its offsetWidth properties), so use createElement to make the new img element, and then absolutely position it with style properties so that it appears in the appropriate place (near to the text field). \n\nThe image is a transparent PNG with an alpha channel, so that the drop shadow appears nicely over whatever else is on the page. Because Internet Explorer version 6 and below doesn\u2019t handle transparent PNGs correctly, you need to use the AlphaImageLoader technique to make the image appear correctly.\n\nnewimage = document.createElement('img');\nnewimage.src = \"http://farm3.static.flickr.com/2145/2067574980_3ddd405905_o_d.png\";\nnewimage.style.position = \"absolute\";\nnewimage.style.top = (targ.offsetTop - 73) + \"px\";\nnewimage.style.left = (targ.offsetLeft + targ.offsetWidth - 5) + \"px\";\nnewimage.style.zIndex = \"999\";\nnewimage.setAttribute(\"alt\", \"Warning: Caps Lock is on\");\nif (newimage.runtimeStyle) {\n\t// PNG transparency for IE\n\tnewimage.runtimeStyle.filter += \"progid:DXImageTransform.Microsoft.AlphaImageLoader(src='http://farm3.static.flickr.com/2145/2067574980_3ddd405905_o_d.png',sizingMethod='scale')\";\n}\ndocument.body.appendChild(newimage);\n\nNote that the alt text on the image is also correctly set. Next, all these parts need to be pulled together. On page load, identify all the password fields on the page, and attach a keypress handler to each. (This only needs to be done for password fields because the user can see if Caps Lock is on in ordinary text fields.)\n\nvar inps = document.getElementsByTagName(\"input\");\nfor (var i=0, l=inps.length; i\n\nThe \u201ccreate an image\u201d code from above should only be run if the image is not already showing, so instead of creating a newimage object, create the image and attach it to the password field so that it can be checked for later (and not shown if it\u2019s already showing). For safety, all the code should be wrapped up in its own object, so that its functions don\u2019t collide with anyone else\u2019s functions. So, create a single object called capslock and make all the functions be named methods of the object:\n\nvar capslock = {\n\t... \n\tkeypress: function(e) {\n\t}\n\t...\n}\n\nAlso, the \u201ccreate an image\u201d code is saved into its own named function, show_warning(), and the converse \u201cremove the image\u201d code into hide_warning(). This has the advantage that developers can include the JavaScript library that has been written here, but override what actually happens with their own code, using something like:\n\n<script src=\"jscapslock.js\" type=\"text/javascript\"></script>\n<script type=\"text/javascript\">\n\tcapslock.show_warning(target) {\n\t\t// do something different here to warn the user\n\t}\n\tcapslock.hide_warning(target) {\n\t\t// hide the warning that we created in show_warning() above\n\t}\n</script>\n\nAnd that\u2019s all. Simply include the JavaScript library in your pages, override what happens on a warning if that\u2019s more appropriate for what you\u2019re doing, and that\u2019s all you need.\n\n See the script in action.", "year": "2007", "author": "Stuart Langridge", "author_slug": "stuartlangridge", "published": "2007-12-04T00:00:00+00:00", "url": "https://24ways.org/2007/capturing-caps-lock/", "topic": "code"}
{"rowid": 153, "title": "JavaScript Internationalisation", "contents": "or:  Why Rudolph Is More Than Just a Shiny Nose\n\nDunder sat, glumly staring at the computer screen.\n\n\u201cWhat\u2019s up, Dunder?\u201d asked Rudolph, entering the stable and shaking off the snow from his antlers.\n\n\u201cWell,\u201d Dunder replied, \u201cI\u2019ve just finished coding the new reindeer intranet Santa Claus asked me to do. You know how he likes to appear to be at the cutting edge, talking incessantly about Web 2.0, AJAX, rounded corners; he even spooked Comet recently by talking about him as if he were some pushy web server.\n\n\u201cI\u2019ve managed to keep him happy, whilst also keeping it usable, accessible, and gleaming \u2014 and I\u2019m still on the back row of the sleigh! But anyway, given the elves will be the ones using the site, and they come from all over the world, the site is in multiple languages. Which is great, except when it comes to the preview JavaScript I\u2019ve written for the reindeer order form. Here, have a look\u2026\u201d\n\nAs he said that, he brought up the textileRef:8234272265470b85d91702:linkStartMarker:\u201corder\n    form in French\u201d:/examples/javascript-internationalisation/initial.fr.html on the screen. (Same in English).\n\n\u201cLooks good,\u201d said Rudolph.\n\n\u201cBut if I add some items,\u201d said Dunder, \u201cthe preview appears in English, as it\u2019s hard-coded in the JavaScript. I don\u2019t want separate code for each language, as that\u2019s just silly \u2014 I thought about just having if statements, but that doesn\u2019t scale at all\u2026\u201d\n\n\u201cAnd there\u2019s more, you aren\u2019t displaying large numbers in French properly, either,\u201d added Rudolph, who had been playing and looking at part of the source code:\n\nfunction update_text() {\n\tvar hay = getValue('hay');\n\tvar carrots = getValue('carrots');\n\tvar bells = getValue('bells');\n\tvar total = 50 * bells + 30 * hay + 10 * carrots;\n\tvar out = 'You are ordering '\n\t\t+ pretty_num(hay) + ' bushel' + pluralise(hay) + ' of hay, '\n\t\t+ pretty_num(carrots) + ' carrot' + pluralise(carrots)\n\t\t+ ', and ' + pretty_num(bells) + ' shiny bell' + pluralise(bells)\n\t\t+ ', at a total cost of <strong>' + pretty_num(total)\n\t\t+ '</strong> gold pieces. Thank you.';\n\tdocument.getElementById('preview').innerHTML = out;\n}\nfunction pretty_num(n) {\n\tn += '';\n\tvar o = '';\n\tfor (i=n.length; i>3; i-=3) {\n\t\to = ',' + n.slice(i-3, i) + o;\n\t}\n\to = n.slice(0, i) + o;\n\treturn o;\n}\nfunction pluralise(n) {\n\tif (n!=1) return 's';\n\treturn '';\n}\n\n\u201cOh, botheration!\u201d cried Dunder. \u201cThis is just so complicated.\u201d\n\n\u201cIt doesn\u2019t have to be,\u201d said Rudolph, \u201cyou just have to think about things in a slightly different way from what you\u2019re used to. As we\u2019re only a simple example, we won\u2019t be able to cover all possibilities, but for starters, we need some way of providing different information to the script dependent on the language. We\u2019ll create a global i18n object, say, and fill it with the correct language information. The first variable we\u2019ll need will be a thousands separator, and then we can change the pretty_num function to use that instead:\n\nfunction pretty_num(n) {\n\tn += '';\n\tvar o = '';\n\tfor (i=n.length; i>3; i-=3) {\n\t\to = i18n.thousands_sep + n.slice(i-3, i) + o;\n\t}\n\to = n.slice(0, i) + o;\n\treturn o;\n}\n\n\u201cThe i18n object will also contain our translations, which we will access through a function called _() \u2014 that\u2019s just an underscore. Other languages have a function of the same name doing the same thing. It\u2019s very simple:\n\nfunction _(s) {\n\tif (typeof(i18n)!='undefined' && i18n[s]) {\n\t\treturn i18n[s];\n\t}\n\treturn s;\n}\n\n\u201cSo if a translation is available and provided, we\u2019ll use that; otherwise we\u2019ll default to the string provided \u2014 which is helpful if the translation begins to lag behind the site\u2019s text at all, as at least something will be output.\u201d\n\n\u201cGot it,\u201d said Dunder. \u201c _('Hello Dunder') will print the translation of that string, if one exists, \u2018Hello Dunder\u2019 if not.\u201d\n\n\u201cExactly. Moving on, your plural function breaks even in English if we have a word where the plural doesn\u2019t add an s \u2014 like \u2018children\u2019.\u201d\n\n\u201cYou\u2019re right,\u201d said Dunder. \u201cHow did I miss that?\u201d\n\n\u201cNo harm done. Better to provide both singular and plural words to the function and let it decide which to use, performing any translation as well:\n\nfunction pluralise(s, p, n) {\n\tif (n != 1) return _(p);\n\treturn _(s);\n}\n\n\u201cWe\u2019d have to provide different functions for different languages as we employed more elves and got more complicated \u2014 for example, in Polish, the word \u2018file\u2019 pluralises like this: 1 plik, 2-4 pliki, 5-21 plik\u00f3w, 22-24 pliki, 25-31 plik\u00f3w, and so on.\u201d (More information on plural forms)\n\n\u201cGosh!\u201d\n\n\u201cNext, as different languages have different word orders, we must stop using concatenation to construct sentences, as it would be impossible for other languages to fit in; we have to keep coherent strings together. Let\u2019s rewrite your update function, and then go through it:\n\nfunction update_text() {\n\tvar hay = getValue('hay');\n\tvar carrots = getValue('carrots');\n\tvar bells = getValue('bells');\n\tvar total = 50 * bells + 30 * hay + 10 * carrots;\n\thay = sprintf(pluralise('%s bushel of hay', '%s bushels of hay', hay), pretty_num(hay));\n\tcarrots = sprintf(pluralise('%s carrot', '%s carrots', carrots), pretty_num(carrots));\n\tbells = sprintf(pluralise('%s shiny bell', '%s shiny bells', bells), pretty_num(bells));\n\tvar list = sprintf(_('%s, %s, and %s'), hay, carrots, bells);\n\tvar out = sprintf(_('You are ordering %s, at a total cost of <strong>%s</strong> gold pieces.'),\n\t\tlist, pretty_num(total));\n\tout += ' ';\n\tout += _('Thank you.');\n\tdocument.getElementById('preview').innerHTML = out;\n}\n\n\u201c sprintf is a function in many other languages that, given a format string and some variables, slots the variables into place within the string. JavaScript doesn\u2019t have such a function, so we\u2019ll write our own. Again, keep it simple for now, only integers and strings; I\u2019m sure more complete ones can be found on the internet.\n\nfunction sprintf(s) {\n\tvar bits = s.split('%');\n\tvar out = bits[0];\n\tvar re = /^([ds])(.*)$/;\n\tfor (var i=1; i<bits.length; i++) {\n\t\tp = re.exec(bits[i]);\n\t\tif (!p || arguments[i]==null) continue;\n\t\tif (p[1] == 'd') {\n\t\t\tout += parseInt(arguments[i], 10);\n\t\t} else if (p[1] == 's') {\n\t\t\tout += arguments[i];\n\t\t}\n\t\tout += p[2];\n\t}\n\treturn out;\n}\n\n\u201cLastly, we need to create one file for each language, containing our i18n object, and then include that from the relevant HTML. Here\u2019s what a blank translation file would look like for your order form:\n\nvar i18n = {\n\tthousands_sep: ',',\n\t\"%s bushel of hay\": '',\n\t\"%s bushels of hay\": '',\n\t\"%s carrot\": '',\n\t\"%s carrots\": '',\n\t\"%s shiny bell\": '',\n\t\"%s shiny bells\": '',\n\t\"%s, %s, and %s\": '',\n\t\"You are ordering %s, at a total cost of <strong>%s</strong> gold pieces.\": '',\n\t\"Thank you.\": ''\n};\n\n\u201cIf you implement this across the intranet, you\u2019ll want to investigate the xgettext program, which can automatically extract all strings that need translating from all sorts of code files into a standard .po file (I think Python mode works best for JavaScript). You can then use a different program to take the translated .po file and automatically create the language-specific JavaScript files for us.\u201d (e.g. German .po file for PledgeBank, mySociety\u2019s .po-.js script, example output)\n\nWith a flourish, Rudolph finished editing. \u201cAnd there we go, localised JavaScript in English, French, or German, all using the same main code.\u201d\n\n\u201cThanks so much, Rudolph!\u201d said Dunder.\n\n\u201cI\u2019m not just a pretty nose!\u201d Rudolph quipped. \u201cOh, and one last thing \u2014 please comment liberally explaining the context of strings you use. Your translator will thank you, probably at the same time as they point out the four hundred places you\u2019ve done something in code that only works in your language and no-one else\u2019s\u2026\u201d\n\nThanks to Tim Morley and Edmund Grimley Evans for the French and German translations respectively.", "year": "2007", "author": "Matthew Somerville", "author_slug": "matthewsomerville", "published": "2007-12-08T00:00:00+00:00", "url": "https://24ways.org/2007/javascript-internationalisation/", "topic": "code"}
{"rowid": 147, "title": "Christmas Is In The AIR", "contents": "That\u2019s right, Christmas is coming up fast and there\u2019s plenty of things to do. Get the tree and lights up, get the turkey, buy presents and who know what else. And what about Santa? He\u2019s got a list. I\u2019m pretty sure he\u2019s checking it twice.\n\nSure, we could use an existing list making web site or even a desktop widget. But we\u2019re geeks! What\u2019s the fun in that? Let\u2019s build our own to-do list application and do it with Adobe AIR!\n\nWhat\u2019s Adobe AIR?\n\nAdobe AIR, formerly codenamed Apollo, is a runtime environment that runs on both Windows and OSX (with Linux support to follow). This runtime environment lets you build desktop applications using Adobe technologies like Flash and Flex. Oh, and HTML. That\u2019s right, you web standards lovin\u2019 maniac. You can build desktop applications that can run cross-platform using the trio of technologies, HTML, CSS and JavaScript.\n\nIf you\u2019ve tried developing with AIR before, you\u2019ll need to get re-familiarized with the latest beta release as many things have changed since the last one (such as the API and restrictions within the sandbox.)\n\nTo get started\n\nTo get started in building an AIR application, you\u2019ll need two basic things:\n\n\n\tThe AIR runtime. The runtime is needed to run any AIR-based application.\n\tThe SDK. The software development kit gives you all the pieces to test your application. Unzip the SDK into any folder you wish.\n\n\nYou\u2019ll also want to get your hands on the JavaScript API documentation which you\u2019ll no doubt find yourself getting into before too long. (You can download it, too.)\n\nAlso of interest, some development environments have support for AIR built right in. Aptana doesn\u2019t have support for beta 3 yet but I suspect it\u2019ll be available shortly.\n\nWithin the SDK, there are two main tools that we\u2019ll use: one to test the application (ADL) and another to build a distributable package of our application (ADT). I\u2019ll get into this some more when we get to that stage of development.\n\nBuilding our To-do list application\n\nThe first step to building an application within AIR is to create an XML file that defines our default application settings. I call mine application.xml, mostly because Aptana does that by default when creating a new AIR project. It makes sense though and I\u2019ve stuck with it. Included in the templates folder of the SDK is an example XML file that you can use.\n\nThe first key part to this after specifying things like the application ID, version, and filename, is to specify what the default content should be within the content tags. Enter in the name of the HTML file you wish to load. Within this HTML file will be our application.\n\n<content>ui.html</content>\n\nCreate a new HTML document and name it ui.html and place it in the same directory as the application.xml file. The first thing you\u2019ll want to do is copy over the AIRAliases.js file from the frameworks folder of the SDK and add a link to it within your HTML document.\n\n<script type=\"text/javascript\" src=\"AIRAliases.js\"></script>\n\nThe aliases create shorthand links to all of the Flash-based APIs.\n\nNow is probably a good time to explain how to debug your application.\n\nDebugging our application\n\nSo, with our XML file created and HTML file started, let\u2019s try testing our \u2018application\u2019. We\u2019ll need the ADL application located in BIN folder of the SDK and tell it to run the application.xml file.\n\n/path/to/adl /path/to/application.xml\n\nYou can also just drag the XML file onto ADL and it\u2019ll accomplish the same thing. If you just did that and noticed that your blank application didn\u2019t load, you\u2019d be correct. It\u2019s running but isn\u2019t visible. Which at this point means you\u2019ll have to shut down the ADL process. Sorry about that!\n\nChanging the visibility\n\nYou have two ways to make your application visible. You can do it automatically by setting the placing true in the visible tag within the application.xml file.\n\n<visible>true</visible>\n\nThe other way is to do it programmatically from within your application. You\u2019d want to do it this way if you had other startup tasks to perform before showing the interface. To turn the UI on programmatically, simple set the visible property of nativeWindow to true.\n\n<script type=\"text/javascript\">\n\tnativeWindow.visible = true;\n</script>\n\nSandbox Security\n\nNow that we have an application that we can see when we start it, it\u2019s time to build the to-do list application. In doing so, you\u2019d probably think that using a JavaScript library is a really good idea \u2014 and it can be but there are some limitations within AIR that have to be considered.\n\nAn HTML document, by default, runs within the application sandbox. You have full access to the AIR APIs but once the onload event of the window has fired, you\u2019ll have a limited ability to make use of eval and other dynamic script injection approaches. This limits the ability of external sources from gaining access to everything the AIR API offers, such as database and local file system access. You\u2019ll still be able to make use of eval for evaluating JSON responses, which is probably the most important if you wish to consume JSON-based services.\n\nIf you wish to create a greater wall of security between AIR and your HTML document loading in external resources, you can create a child sandbox. We won\u2019t need to worry about it for our application so I won\u2019t go any further into it but definitely keep this in mind.\n\nFinally, our application\n\nGetting tired of all this preamble? Let\u2019s actually build our to-do list application. I\u2019ll use jQuery because it\u2019s small and should suit our needs nicely. Let\u2019s begin with some structure:\n\n<body>\n\t<input type=\"text\" id=\"text\" value=\"\">\n\t<input type=\"button\" id=\"add\" value=\"Add\">\n\t<ul id=\"list\"></ul>\n</body>\n\nNow we need to wire up that button to actually add a new item to our to-do list.\n\n<script type=\"text/javascript\">\n$(document).ready(function(){\n\t// make sure the application is visible\n\tnativeWindow.visible = true;\n\t$('#add').click(function(){\n\t\tvar t = $('#text').val();\n\t\tif(t)\n\t\t{\n\t\t\t// use DOM methods to create the new list item\n\t\t\tvar li = document.createElement('li');\n\t\t\t// the extra space at the end creates a buffer between the text\n\t\t\t// and the delete link we're about to add\n\t\t\tli.appendChild(document.createTextNode(t + ' '));\n\t\t\t// create the delete link\n\t\t\tvar del = document.createElement('a');\n\t\t\t// this makes it a true link. I feel dirty doing this.\n\t\t\tdel.setAttribute('href', '#');\n\t\t\tdel.addEventListener('click', function(evt){\n\t\t\t\tthis.parentNode.parentNode.removeChild(this.parentNode);\n\t\t\t});\n\t\t\tdel.appendChild(document.createTextNode('[del]'));\n\t\t\tli.appendChild(del);\n\t\t\t// append everything to the list\n\t\t\t$('#list').append(li);\n\t\t\t//reset the text box\n\t\t\t$('#text').val('');\n\t\t}\n\t})\n});\n</script>\n\nAnd just like that, we\u2019ve got a to-do list! That\u2019s it! Just never close your application and you\u2019ll remember everything. Okay, that\u2019s not very practical. You need to have some way of storing your to-do items until the next time you open up the application.\n\nStoring Data\n\nYou\u2019ve essentially got 4 different ways that you can store data:\n\n\n\tUsing the local database. AIR comes with SQLLite built in. That means you can create tables and insert, update and select data from that database just like on a web server.\n\tUsing the file system. You can also create files on the local machine. You have access to a few folders on the local system such as the documents folder and the desktop.\n\tUsing EcryptedLocalStore. I like using the EcryptedLocalStore because it allows you to easily save key/value pairs and have that information encrypted. All this within just a couple lines of code.\n\tSending the data to a remote API. Our to-do list could sync up with Remember the Milk, for example.\n\n\nTo demonstrate some persistence, we\u2019ll use the file system to store our files. In addition, we\u2019ll let the user specify where the file should be saved. This way, we can create multiple to-do lists, keeping them separate and organized.\n\nThe application is now broken down into 4 basic tasks:\n\n\n\tLoad data from the file system.\n\tPerform any interface bindings.\n\tManage creating and deleting items from the list.\n\tSave any changes to the list back to the file system.\n\n\nLoading in data from the file system\n\nWhen the application starts up, we\u2019ll prompt the user to select a file or specify a new to-do list. Within AIR, there are 3 main file objects: File, FileMode, and FileStream. File handles file and path names, FileMode is used as a parameter for the FileStream to specify whether the file should be read-only or for write access. The FileStream object handles all the read/write activity.\n\nThe File object has a number of shortcuts to default paths like the documents folder, the desktop, or even the application store. In this case, we\u2019ll specify the documents folder as the default location and then use the browseForSave method to prompt the user to specify a new or existing file. If the user specifies an existing file, they\u2019ll be asked whether they want to overwrite it.\n\nvar store = air.File.documentsDirectory;\nvar fileStream = new air.FileStream();\nstore.browseForSave(\"Choose To-do List\");\n\nThen we add an event listener for when the user has selected a file. When the file is selected, we check to see if the file exists and if it does, read in the contents, splitting the file on new lines and creating our list items within the interface.\n\nstore.addEventListener(air.Event.SELECT, fileSelected);\nfunction fileSelected()\n{\n\tair.trace(store.nativePath);\n\t// load in any stored data\n\tvar byteData = new air.ByteArray();\n\tif(store.exists)\n\t{\n\t\tfileStream.open(store, air.FileMode.READ);\n\t\tfileStream.readBytes(byteData, 0, store.size);\n\t\tfileStream.close();\n\n\t\tif(byteData.length > 0)\n\t\t{\n\t\t\tvar s = byteData.readUTFBytes(byteData.length);\n\t\t\toldlist = s.split(\u201c\\r\\n\u201d);\n\n\t\t\t// create todolist items\n\t\t\tfor(var i=0; i < oldlist.length; i++)\n\t\t\t{\n\t\t\t\tcreateItem(oldlist[i], (new Date()).getTime() + i );\n\t\t\t}\n\t\t}\n\t}\n}\n\nPerform Interface Bindings\n\nThis is similar to before where we set the click event on the Add button but we\u2019ve moved the code to save the list into a separate function.\n\n$('#add').click(function(){\n\t\tvar t = $('#text').val();\n\t\tif(t){\n\t\t\t// create an ID using the time\n\t\t\tcreateItem(t, (new Date()).getTime() );\n\t\t}\n})\n\nManage creating and deleting items from the list\n\nThe list management is now in its own function, similar to before but with some extra information to identify list items and with calls to save our list after each change.\n\nfunction createItem(t, id)\n{\n\tif(t.length == 0) return;\n\t// add it to the todo list\n\ttodolist[id] = t;\n\t// use DOM methods to create the new list item\n\tvar li = document.createElement('li');\n\t// the extra space at the end creates a buffer between the text\n\t// and the delete link we're about to add\n\tli.appendChild(document.createTextNode(t + ' '));\n\t// create the delete link\n\tvar del = document.createElement('a');\n\t// this makes it a true link. I feel dirty doing this.\n\tdel.setAttribute('href', '#');\n\tdel.addEventListener('click', function(evt){\n\t\tvar id = this.id.substr(1);\n\t\tdelete todolist[id]; // remove the item from the list\n\t\tthis.parentNode.parentNode.removeChild(this.parentNode);\n\t\tsaveList();\n\t});\n\tdel.appendChild(document.createTextNode('[del]'));\n\tdel.id = 'd' + id;\n\tli.appendChild(del);\n\t// append everything to the list\n\t$('#list').append(li);\n\t//reset the text box\n\t$('#text').val('');\n\tsaveList();\n}\n\nSave changes to the file system\n\nAny time a change is made to the list, we update the file. The file will always reflect the current state of the list and we\u2019ll never have to click a save button. It just iterates through the list, adding a new line to each one.\n\nfunction saveList(){\n\tif(store.isDirectory) return;\n\tvar packet = '';\n\tfor(var i in todolist)\n\t{\n\t\tpacket += todolist[i] + '\\r\\n';\n\t}\n\tvar bytes = new air.ByteArray();\n\tbytes.writeUTFBytes(packet);\n\tfileStream.open(store, air.FileMode.WRITE);\n\tfileStream.writeBytes(bytes, 0, bytes.length);\n\tfileStream.close();\n}\n\nOne important thing to mention here is that we check if the store is a directory first. The reason we do this goes back to our browseForSave call. If the user cancels the dialog without selecting a file first, then the store points to the documentsDirectory that we set it to initially. Since we haven\u2019t specified a file, there\u2019s no place to save the list.\n\nHopefully by this point, you\u2019ve been thinking of some cool ways to pimp out your list. Now we need to package this up so that we can let other people use it, too.\n\nCreating a Package\n\nNow that we\u2019ve created our application, we need to package it up so that we can distribute it. This is a two step process. The first step is to create a code signing certificate (or you can pay for one from Thawte which will help authenticate you as an AIR application developer).\n\nTo create a self-signed certificate, run the following command. This will create a PFX file that you\u2019ll use to sign your application.\n\nadt -certificate -cn todo24ways 1024-RSA todo24ways.pfx mypassword\n\nAfter you\u2019ve done that, you\u2019ll need to create the package with the certificate\n\nadt -package -storetype pkcs12 -keystore todo24ways.pfx todo24ways.air application.xml .\n\nThe important part to mention here is the period at the end of the command. We\u2019re telling it to package up all files in the current directory.\n\nAfter that, just run the AIR file, which will install your application and run it.\n\nImportant things to remember about AIR\n\nWhen developing an HTML application, the rendering engine is Webkit. You\u2019ll thank your lucky stars that you aren\u2019t struggling with cross-browser issues. (My personal favourites are multiple backgrounds and border radius!)\n\nBe mindful of memory leaks. Things like Ajax calls and event binding can cause applications to slowly leak memory over time. Web pages are normally short lived but desktop applications are often open for hours, if not days, and you may find your little desktop application taking up more memory than anything else on your machine!\n\nThe WebKit runtime itself can also be a memory hog, usually taking about 15MB just for itself. If you create multiple HTML windows, it\u2019ll add another 15MB to your memory footprint. Our little to-do list application shouldn\u2019t be much of a concern, though.\n\nThe other important thing to remember is that you\u2019re still essentially running within a Flash environment. While you probably won\u2019t notice this working in small applications, the moment you need to move to multiple windows or need to accomplish stuff beyond what HTML and JavaScript can give you, the need to understand some of the Flash-based elements will become more important.\n\nLastly, the other thing to remember is that HTML links will load within the AIR application. If you want a link to open in the users web browser, you\u2019ll need to capture that event and handle it on your own. The following code takes the HREF from a clicked link and opens it in the default web browser.\n\nair.navigateToURL(new air.URLRequest(this.href));\n\nOnly the beginning\n\nOf course, this is only the beginning of what you can do with Adobe AIR. You don\u2019t have the same level of control as building a native desktop application, such as being able to launch other applications, but you do have more control than what you could have within a web application. Check out the Adobe AIR Developer Center for HTML and Ajax for tutorials and other resources.\n\nNow, go forth and create your desktop applications and hopefully you finish all your shopping before Christmas!\n\nDownload the example files.", "year": "2007", "author": "Jonathan Snook", "author_slug": "jonathansnook", "published": "2007-12-19T00:00:00+00:00", "url": "https://24ways.org/2007/christmas-is-in-the-air/", "topic": "code"}
{"rowid": 145, "title": "The Neverending (Background Image) Story", "contents": "Everyone likes candy for Christmas, and there\u2019s none better than eye candy. Well, that, and just more of the stuff. Today we\u2019re going to combine both of those good points and look at how to create a beautiful background image that goes on and on\u2026 forever!\n\nOf course, each background image is different, so instead of agonising over each and every pixel, I\u2019m going to concentrate on five key steps that you can apply to any of your own repeating background images. In this example, we\u2019ll look at the Miami Beach background image used on the new FOWA site, which I\u2019m afraid is about as un-festive as you can get.\n\n1. Choose your image wisely\n\nI find there are three main criteria when judging photos you\u2019re considering for repetition manipulation (or \u2018repetulation\u2019, as I like to say)\u2026\n\n\n\tsimplicity (beware of complex patterns)\n\tangle and perspective (watch out for shadows and obvious vanishing points)\n\tconsistent elements (for easy cloning)\n\n\nYou might want to check out this annotated version of the image, where I\u2019ve highlighted elements of the photo that led me to choose it as the right one.\n\nThe original image purchased from iStockPhoto.\n\nThe Photoshopped version used on the FOWA site.\n\n2. The power of horizontal lines\n\nWith the image chosen and your cursor poised for some Photoshop magic, the most useful thing you can do is drag out the edge pixels from one side of the image to create a kind of rough colour \u2018template\u2019 on which to work over. It doesn\u2019t matter which side you choose, although you might find it beneficial to use the one with the simplest spread of colour and complex elements.\n\nClick and hold on the marquee tool in the toolbar and select the \u2018single column marquee tool\u2019, which will span the full height of your document but will only be one pixel wide. Make the selection right at the edge of your document, press ctrl-c / cmd-c to copy the selection you made, create a new layer, and hit ctrl-v / cmd-v to paste the selection onto your new layer. using free transform (ctrl-t / cmd-t), drag out your selection so that it becomes as wide as your entire canvas. \n\nA one-pixel-wide selection stretched out to the entire width of the canvas.\n\n3. Cloning\n\nIt goes without saying that the trusty clone tool is one of the most important in the process of creating a seamlessly repeating background image, but I think it\u2019s important to be fairly loose with it. Always clone on to a new layer so that you\u2019ve got the freedom to move it around, but above all else, use the eraser tool to tweak your cloned areas: let that handle the precision stuff and you won\u2019t have to worry about getting your clones right first time.\n\nIn the example below, you can see how I overcame the problem of the far-left tree shadow being chopped off by cloning the shadow from the tree on its right. \n\nThe edge of the shadow is cut off and needs to be \u2018made\u2019 from a pre-existing element.\n\nThe successful clone completes the missing shadow.\n\nThe two elements are obviously very similar but it doesn\u2019t look like a clone because the majority of the shape is \u2018genuine\u2019 and only a small part is a duplicate. Also, after cloning I transformed the duplicate, erased parts of it, used gradients, and \u2014 ooh, did someone mention gradients?\n\n4. Never underestimate a gradient\n\nFor this image, I used gradients in a similar way to a brush: covering large parts of the canvas with a colour that faded out to a desired point, before erasing certain parts for accuracy.\n\nSeveral of the gradients and brushes that make up the \u2018customised\u2019 part of the image, visible when the main photograph layer is hidden.\n\nThe full composite.\n\nGradients are also a bit of an easy fix: you can use a gradient on one side of the image, flip it horizontally, and then use it again on the opposite side to make a more seamless join.\n\nSpeaking of which\u2026\n\n5. Sewing the seams\n\nNo matter what kind of magic Photoshop dust you sprinkle over your image, there will still always be the area where the two edges meet: that scary \u2018loop\u2019 point. Fret ye not, however, for there\u2019s help at hand in the form of a nice little cheat. Even though the loop point might still be apparent, we can help hide it by doing something to throw viewers off the scent.\n\nThe seam is usually easy to spot because it\u2019s a blank area with not much detail or colour variation, so in order to disguise it, go against the rule: put something across it!\n\nThis isn\u2019t quite as challenging as it may sound, because if we intentionally make our own \u2018object\u2019 to span the join, we can accurately measure the exact halfway point where we need to split it across the two sides of the image. This is exactly what I did with the FOWA background image: I made some clouds!\n\nA sky with no clouds in an unhappy one.\n\nA simple soft white brush creates a cloud-like formation in the sky.\n\nAfter taking the cloud\u2019s opacity down to 20%, I used free transform to highlight the boundaries of the layer. I then moved it over to the right, so that the middle of the layer perfectly aligned with the right side of the canvas.\n\nFinally, I duplicated the layer and did the same in reverse: dragging the layer over to the left and making sure that the middle of the duplicate layer perfectly aligned with the left side of the canvas.\n\nAnd there you have it! Boom! Ta-da! Et Voila! To see the repeating background image in action, visit futureofwebapps.com on a large widescreen monitor or see a simulation of the effect.\n\nThanks for reading, folks. Have a great Christmas!", "year": "2007", "author": "Elliot Jay Stocks", "author_slug": "elliotjaystocks", "published": "2007-12-03T00:00:00+00:00", "url": "https://24ways.org/2007/the-neverending-background-image-story/", "topic": "code"}
{"rowid": 143, "title": "Marking Up a Tag Cloud", "contents": "Everyone\u2019s doing it. \n\nThe problem is, everyone\u2019s doing it wrong. \n\nHarsh words, you might think. But the crimes against decent markup are legion in this area. You see, I\u2019m something of a markup and semantics junkie. So I\u2019m going to analyse some of the more well-known tag clouds on the internet, explain what\u2019s wrong, and then show you one way to do it better. \n\ndel.icio.us \n\nI think the first ever tag cloud I saw was on del.icio.us. Here\u2019s how they mark it up. \n\n<div class=\"alphacloud\">\n\t<a href=\"/tag/.net\" class=\"lb s2\">.net</a>\n\t<a href=\"/tag/advertising\" class=\" s3\">advertising</a>\n\t<a href=\"/tag/ajax\" class=\" s5\">ajax</a>\n\t...\n</div>\n\nUnfortunately, that is one of the worst examples of tag cloud markup I have ever seen. The page states that a tag cloud is a list of tags where size reflects popularity. However, despite describing it in this way to the human readers, the page\u2019s author hasn\u2019t described it that way in the markup. It isn\u2019t a list of tags, just a bunch of anchors in a <div>. This is also inaccessible because a screenreader will not pause between adjacent links, and in some configurations will not announce the individual links, but rather all of the tags will be read as just one link containing a whole bunch of words. Markup crime number one. \n\nFlickr \n\nAh, Flickr. The darling photo sharing site of the internet, and the biggest blind spot in every standardista\u2019s vision. Forgive it for having atrocious markup and sometimes confusing UI because it\u2019s just so much damn fun to use. Let\u2019s see what they do. \n\n<p id=\"TagCloud\">\n\t\u00a0<a href=\"/photos/tags/06/\" style=\"font-size: 14px;\">06</a>\u00a0\n\t\u00a0<a href=\"/photos/tags/africa/\" style=\"font-size: 12px;\">africa</a>\u00a0\n\t\u00a0<a href=\"/photos/tags/amsterdam/\" style=\"font-size: 14px;\">amsterdam</a>\u00a0\n\t...\n</p>\n\nAgain we have a simple collection of anchors like del.icio.us, only this time in a paragraph. But rather than using a class to represent the size of the tag they use an inline style. An inline style using a pixel-based font size. That\u2019s so far away from the goal of separating style from content, they might as well use a <font> tag. You could theoretically parse that to extract the information, but you have more work to guess what the pixel sizes represent. Markup crime number two (and extra jail time for using non-breaking spaces purely for visual spacing purposes.)\n\nTechnorati \n\nAh, now. Here, you\u2019d expect something decent. After all, the Overlord of microformats and King of Semantics Tantek \u00c7elik works there. Surely we\u2019ll see something decent here? \n\n<ol class=\"heatmap\">\n\t<li><em><em><em><em><a href=\"/tag/Britney+Spears\">Britney Spears</a></em></em></em></em></li>\n\t<li><em><em><em><em><em><em><em><em><em><a href=\"/tag/Bush\">Bush</a></em></em></em></em></em></em></em></em></em></li>\n\t<li><em><em><em><em><em><em><em><em><em><em><em><em><em><a href=\"/tag/Christmas\">Christmas</a></em></em></em></em></em></em></em></em></em></em></em></em></em></li>\n\t...\n\t<li><em><em><em><em><em><em><a href=\"/tag/SEO\">SEO</a></em></em></em></em></em></em></li>\n\t<li><em><em><em><em><em><em><em><em><em><em><em><em><em><em><em><a href=\"/tag/Shopping\">Shopping</a></em></em></em></em></em></em></em></em></em></em></em></em></em></em></em></li>\n\t...\n</ol>\n\nUnfortunately it turns out not to be that decent, and stop calling me Shirley. It\u2019s not exactly terrible code. It does recognise that a tag cloud is a list of links. And, since they\u2019re in alphabetical order, that it\u2019s an ordered list of links. That\u2019s nice. However \u2026 fifteen nested <em> tags? FIFTEEN? That\u2019s emphasis for you. Yes, it is parse-able, but it\u2019s also something of a strange way of looking at emphasis. The HTML spec states that <em> is emphasis, and <strong> is for stronger emphasis. Nesting <em> tags seems counter to the idea that different tags are used for different levels of emphasis. Plus, if you had a screen reader that stressed the voice for emphasis, what would it do? Shout at you? Markup crime number three. \n\nSo what should it be? \n\nAs del.icio.us tells us, a tag cloud is a list of tags where the size that they are rendered at contains extra information. However, by hiding the extra context purely within the CSS or the HTML tags used, you are denying that context to some users. The basic assumption being made is that all users will be able to see the difference between font sizes, and this is demonstrably false. \n\nA better way to code a tag cloud is to put the context of the cloud within the content, not the markup or CSS alone. As an example, I\u2019m going to take some of my favourite flickr tags and put them into a cloud which communicates the relative frequency of each tag. \n\nTo start with a tag cloud in its most basic form is just a list of links. I am going to present them in alphabetical order, so I\u2019ll use an ordered list. Into each list item I add the number of photos I have with that particular tag. The tag itself is linked to the page on flickr which contains those photos. So we end up with this first example. To display this as a traditional tag cloud, we need to alter it in a few ways: \n\n\n\tThe items need to be displayed next to each other, rather than one-per-line\n\tThe context information should be hidden from display (but not from screen readers)\n\tThe tag should link to the page of items with that tag\n\n\nDisplaying the items next to each other simply means setting the display of the list elements to inline. The context can be hidden by wrapping it in a <span> and then using the off-left method to hide it. And the link just means adding an anchor (with rel=\"tag\" for some extra microformats bonus points). So, now we have a simple collection of links in our second example. \n\nThe last stage is to add the sizes. Since we already have context in our content, the size is purely for visual rendering, so we can just use classes to define the different sizes. For my example, I\u2019ll use a range of class names from not-popular through ultra-popular, in order of smallest to largest, and then use CSS to define different font sizes. If you preferred, you could always use less verbose class names such as  size1 through size6. Anyway, adding some classes and CSS gives us our final example, a semantic and more accessible tag cloud.", "year": "2006", "author": "Mark Norman Francis", "author_slug": "marknormanfrancis", "published": "2006-12-09T00:00:00+00:00", "url": "https://24ways.org/2006/marking-up-a-tag-cloud/", "topic": "code"}
{"rowid": 139, "title": "Flickr Photos On Demand with getFlickr", "contents": "In case you don\u2019t know it yet, Flickr is great. It is a lot of fun to upload, tag and caption photos and it is really handy to get a vast network of contacts through it. \n\nUsing Flickr photos outside of it is a bit of a problem though. There is a Flickr API, and you can get almost every page as an RSS feed, but in general it is a bit tricky to use Flickr photos inside your blog posts or web sites. You might not want to get into the whole API game or use a server side proxy script as you cannot retrieve RSS with Ajax because of the cross-domain security settings.\n\nHowever, Flickr also provides an undocumented JSON  output, that can be used to hack your own solutions in JavaScript without having to use a server side script.\n\n\n\tIf you enter the URL http://flickr.com/photos/tags/panda you get to the flickr page with photos tagged \u201cpanda\u201d.\n\tIf you enter the URL http://api.flickr.com/services/feeds/photos_public.gne?tags=panda&format=rss_200 you get the same page as an RSS feed.\n\tIf you enter the URL http://api.flickr.com/services/feeds/photos_public.gne?tags=panda&format=json you get a JavaScript function called jsonFlickrFeed with a parameter that contains the same data in JSON format\n\n\nYou can use this to easily hack together your own output by just providing a function with the same name. I wanted to make it easier for you, which is why I created the helper getFlickr for you to download and use.\n\ngetFlickr for Non-Scripters\n\nSimply include the javascript file getflickr.js and the style getflickr.css in the head of your document:\n\n<script type=\"text/javascript\" src=\"getflickr.js\"></script>\n<link rel=\"stylesheet\" href=\"getflickr.css\" type=\"text/css\">\n\nOnce this is done you can add links to Flickr pages anywhere in your document, and when you give them the CSS class getflickrphotos they get turned into gallery links. When a visitor clicks these links they turn into loading messages and show a \u201cpopup\u201d gallery with the connected photos once they were loaded. As the JSON returned is very small it won\u2019t take long. You can close the gallery, or click any of the thumbnails to view a photo. Clicking the photo makes it disappear and go back to the thumbnails.\n\nCheck out the example page and click the different gallery links to see the results.\n\nNotice that getFlickr works with Unobtrusive JavaScript as when scripting is disabled the links still get to the photos on Flickr.\n\ngetFlickr for JavaScript Hackers\n\nIf you want to use getFlickr with your own JavaScripts you can use its main method leech():\n\ngetFlickr.leech(sTag, sCallback);\n\n \n\tsTag\n\tthe tag you are looking for\n\tsCallback\n\tan optional function to call when the data was retrieved.\n \n\nAfter you called the leech() method you have two strings to use:\n\n \n\tgetFlickr.html[sTag]\n\tcontains an HTML list (without the outer UL element) of all the images linked to the correct pages at flickr. The images are the medium size, you can easily change that by replacing _m.jpg with _s.jpg for thumbnails.\n\tgetFlickr.tags[sTag]\n\tcontains a string of all the other tags flickr users added with the tag you searched for(space separated)\n \n\nYou can call getFlickr.leech() several times when the page has loaded to cache several result feeds before the page gets loaded. This\u2019ll make the photos quicker for the end user to show up. If you want to offer a form for people to search for flickr photos and display them immediately you can use the following HTML:\n\n<form onsubmit=\"getFlickr.leech(document.getElementById('tag').value, 'populate');return false\">\n  <label for=\"tag\">Enter Tag</label>\n  <input type=\"text\" id=\"tag\" name=\"tag\" />\n  <input type=\"submit\" value=\"energize\" />\n  <h3>Tags:</h3><div id=\"tags\"></div>\n  <h3>Photos:</h3><ul id=\"photos\"></ul>\n</form>\n\nAll the JavaScript you\u2019ll need (for a basic display) is this:\n\nfunction populate(){\n  var tag = document.getElementById('tag').value;\n  document.getElementById('photos').innerHTML = getFlickr.html[tag].replace(/_m\\.jpg/g,'_s.jpg');\n  document.getElementById('tags').innerHTML = getFlickr.tags[tag];\n  return false;\n}\n\nEasy as pie, enjoy!\n\nCheck out the example page and try the form to see the results.", "year": "2006", "author": "Christian Heilmann", "author_slug": "chrisheilmann", "published": "2006-12-03T00:00:00+00:00", "url": "https://24ways.org/2006/flickr-photos-on-demand/", "topic": "code"}