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": 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\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 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 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": 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 \n\n\n\nor Safari\u2019s slider control (think star movie ratings, for example):\n\n \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\n \n \n \n\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 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": 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": 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 , and 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 was introduced early and naturally to HTML, despite having some opponents at the time. Perhaps and 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 and 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 is simple and logical. Just as with , a src attribute specifies the file to load. Pretty straightforward \u2013 sounds easy, right?\n\n\n\t\n\tDownload mysong.ogg ;\n \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\n\t \n\t \n\t\n\tDownload mysong.ogg or mysong.mp3 \n \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 , 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 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 and may be slowed, since it is more complex than 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 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 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 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": 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 ; 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\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\n \n 1 \n 2 \n 3 \n 4 \n 5 \n 6 \n
\n \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\n
\n 1 \n 2 \n 3 \n 4 \n 5 \n 6 \n 7 \n 8 \n 9 \n
\n
\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": 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 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
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
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
and shook its content loose. Here\u2019s how it\u2019s done. \n\nfunction clickHandler(){\n\t$('#button').addClass('animate');\n\treturn false;\n}\n\nClicking the link adds a class of animate to our button. That class has the following CSS associated with it:\n\n\n\nIn our keyframe definition, we\u2019ve specified from and to states. This is great, because we can be explicit about how an object starts and finishes moving. \n\nWhat\u2019s also extra handy is that these CSS keyframes broadcast events that you can react to with JavaScript. In this example, we\u2019re listening to the webkitAnimationEnd event and opening the
only when the sequence is complete. Here\u2019s that code.\n\nfunction attachAnimationEventHandlers(){\n\tvar wrap = document.getElementById('wrap');\n\twrap.addEventListener('webkitAnimationEnd', function($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\n\nTake 4\n\nThe button animation is starting to feel much better, but the reaction of the
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
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 animations in 3-D animation tools or 2-D animation tools like Flash or After Effects\n\tUsing or SVG instead of \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": 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 \n\n(Credit to Thomas Maier)\n\nPrevent user scaling\n\nThis declaration, added into the , 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 \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 as follows: \n\n\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 \n \n \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 of your document\u2019s code to remove the address and status bars at the top and bottom of the screen. \n\n \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\nCall us \nText us \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 of your document:\n\n \n \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 \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": 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 url(\"faux-gradient-lol.png\") repeat-x ;\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": 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": 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 element with a class applied:\n\n& \n\nA CSS rule can then be written to select the 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 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": 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 rather than , 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\nView Basket \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\nView Basket \n\n\n\nWe could add others, in fact as many as we like.\n\nFavourites \nHistory \nLocation \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": 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 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
elements inside ): \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 $(this).toggleClass('active');\n});\n\nSimple enough, right? Sure, but the problem here is that we\u2019re still binding one hundred event listeners to our page, one to each individual table cell. A far better way to do things is to create one event listener on the table itself that listens for events inside it. Since the majority of events bubble up the DOM tree, we can bind a single event listener to one element (in this case, the ) and wait for events to bubble up from its children. The way to do this using the .on() method requires only one change from our code above:\n\n$('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 = ' ';\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 $(\"#imgList\") selection once for each iteration of our loop. The other problem here is that each time the loop iterates, it\u2019s adding a new to the DOM. Each of those insertions is going to be costly, and if our array is quite large then this could lead to a massive slowdown or even the dreaded \u2018A script is causing this page to run slowly\u2019 warning.\n\nvar arr = [reallyLongArrayOfImageURLs],\n tmp = ''; \n$.each(arr, function(count, item) {\n tmp += ' ';\n});\n$('#imgList').append(tmp);\n\nAll we\u2019ve done here is create a tmp variable that each 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 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": 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": 80, "title": "HTML5 Video Bumpers", "contents": "Video is a bigger part of the web experience than ever before. With native browser support for HTML5 video elements freeing us from the tyranny of plugins, and the availability of faster internet connections to the workplace, home and mobile networks, it\u2019s now pretty straightforward to publish video in a way that can be consumed in all sorts of ways on all sorts of different web devices.\n\nI recently worked on a project where the client had shot some dedicated video shorts to publish on their site. They also had some five-second motion graphics produced to top and tail the videos with context and branding. This pretty common requirement is a great idea on the web, where a user might land at your video having followed a link and be viewing a page without much context.\n\nKnown as bumpers, these short introduction clips help brand a video and make it look a lot more professional.\n\n\n\nAdding bumpers to a video\n\nThe simplest way to add bumpers to a video would be to edit them on to the start and end of the video file itself. Cooking the bumpers into the video file is easy, but should you ever want to update them it can become a real headache. If the branding needs updating, for example, you\u2019d need to re-edit and re-encode all your videos. Not a fun task.\n\nWhat if the bumpers could be added dynamically? That would enable you to use the same bumper for multiple videos (decreasing download time for users who might watch more than one) and to update the bumpers whenever you wanted. You could change them seasonally, update them for special promotions, run different advertising slots, perform multivariate testing, or even target different bumpers to different users.\n\nThe trade-off, of course, is that if you dynamically add your bumpers, there\u2019s a chance that a user in a given circumstance might not see the bumper. For example, if the main video feature was uploaded to YouTube, you\u2019d have no way to control the playback. As always, you need to weigh up the pros and cons and make your choice.\n\nHTML5 bumpers\n\nIf you wanted to dynamically add bumpers to your HTML5 video, how would you go about it? That was the question I found myself needing to answer for this particular client project.\n\nMy initial thought was to treat it just like an image slideshow. If I were building a slideshow that moved between images, I\u2019d use CSS absolute positioning with z-index to stack the images up on top of each other in a pile, with the first image on top. To transition to the second image, I\u2019d use JavaScript to fade the top image out, revealing the second image beneath it.\n\n\n\nNow that video is just a native object in the DOM, just like an image, why not do the same? Stack the videos up with the opening bumper on top, listen for the video\u2019s onended event, and fade it out to reveal the main feature behind. Good idea, right?\n\nWrong\n\nRemember that this is the web. It\u2019s never going to be that easy. The problem here is that many non-desktop devices use native, dedicated video players. Think about watching a video on a mobile phone \u2013 when you play the video, the phone often goes full-screen in its native player, leaving the web page behind. There\u2019s no opportunity to fade or switch z-index, as the video isn\u2019t being viewed in the page. Your page is left powerless. Powerless!\n\n\n\nSo what can we do? What can we control?\n\nThose of us with particularly long memories might recall a time before CSS, when we\u2019d have to use JavaScript to perform image rollovers. As CSS background images weren\u2019t a practical reality, we would use lots of elements, and perform a rollover by modifying the src attribute of the image. \n\nTurns out, this old trick of modifying the source can help us out with video, too. In most cases, modifying the src attribute of a element, or perhaps more likely the src attribute of a source element, will swap from one video to another.\n\nSwappin\u2019 it\n\nLet\u2019s take a deliberately simple example of a super-basic video tag:\n\nno fallback coz i is lame, innit. \n\nWe could very simply write a script to find all video tags and give them a new src to show our bumper.\n\n\n\nView the example in a browser with WebM support. You\u2019ll see that the video is swapped out for the opening bumper. Great!\n\nBeefing it up\n\nOf course, we can\u2019t just publish video in one format. In practical use, you need a element with multiple elements containing your different source formats.\n\n\n \n \n \n \n\nThis time, our script needs to loop through the sources, not the videos. We\u2019ll use a regular expression replacement to swap out the file name while maintaining the correct file extension.\n\n\n\nThe difference this time is that when changing the src of a we need to call the .load() method on the video to get it to acknowledge the change.\n\nSee the code in action, this time in a wider range of browsers.\n\nBut, my video!\n\nI guess we should get the original video playing again. Keeping the same markup, we need to modify the script to do two things:\n\n\n\tStore the original src in a data- attribute so we can access it later\n\tAdd an event listener so we can detect the end of the bumper playing, and load the original video back in\n\n\nAs we need to loop through the videos this time to add the event listener, I\u2019ve moved the .load() call into that loop. It\u2019s a bit more efficient to call it only once after modifying all the video\u2019s sources.\n\n\n\nAgain, view the example to see the bumper play, followed by our spectacular main feature. (That\u2019s my cat, Widget. His interests include sleeping and internet marketing.)\n\nTidying things up\n\nThe final thing to do is add our closing bumper after the main video has played. This involves the following changes:\n\n\n\tWe need to keep track of whether the src has been changed, so we only play the video if it\u2019s changed. I\u2019ve added the modified variable to track this, and it stops us getting into a situation where the video just loops forever.\n\tAdd an else to the event listener, for when the orig is false (so the main feature has been playing) to load in the end bumper. We also check that we\u2019re not already playing the end bumper. Because looping.\n\n\n\n\nYo ho ho, that\u2019s a lot of JavaScript. See it in action \u2013 you should get a bumper, the cat video, and an end bumper.\n\nOf course, this code works fine for demonstrating the principle, but it\u2019s very procedural. Nothing wrong with that, but to do something similar in production, you\u2019d probably want to make the code more modular to ease maintainability. Besides, you may want to use a framework, rather than basic JavaScript. \n\nThe end credits\n\nOne really important principle here is that of progressive enhancement. If the browser doesn\u2019t support JavaScript, the user won\u2019t see your bumper, but they will get the main video. If the browser supports JavaScript but doesn\u2019t allow you to modify the src (as was the case with older versions of iOS), the user won\u2019t see your bumper, but they will get the main video.\n\nIf a search engine or social media bot grabs your page and looks for content, they won\u2019t see your bumper, but they will get the main video \u2013 which is absolutely what you want.\n\nThis means that if the bumper is absolutely crucial, you may still need to cook it into the video. However, for many applications, running it dynamically can work quite well.\n\nAs always, it comes down to three things:\n\n\n\tMeasure your audience: know how people access your site\n\tTest the solution: make sure it works for your audience\n\tPlan for failure: it\u2019s the web and that\u2019s how things work \u2018round these parts\n\n\nBut most of all play around with it, have fun and build something awesome.", "year": "2012", "author": "Drew McLellan", "author_slug": "drewmclellan", "published": "2012-12-01T00:00:00+00:00", "url": "https://24ways.org/2012/html5-video-bumpers/", "topic": "code"}
{"rowid": 86, "title": "Flashless Animation", "contents": "Animation in a Flashless world\n\nWhen I splashed down in web design four years ago, the first thing I wanted to do was animate a cartoon in the browser. I\u2019d been drawing comics for years, and I\u2019ve wanted to see them come to life for nearly as long. Flash animation was still riding high, but I didn\u2019t want to learn Flash. I wanted to learn JavaScript!\n\nSadly, animating with JavaScript was limiting and resource-intensive. My initial foray into an infinitely looping background did more to burn a hole in my CPU than amaze my friends (although it still looks pretty cool). And there was still no simple way to incorporate audio. The browser technology just wasn\u2019t there.\n\nThings are different now. CSS3 transitions and animations can do most of the heavy lifting and HTML5 audio can serve up the music and audio clips. You can do a lot without leaning on JavaScript at all, and when you lean on JavaScript, you can do so much more!\n\nIn this project, I\u2019m going to show you how to animate a simple walk cycle with looping audio. I hope this will inspire you to do something really cool and impress your friends. I\u2019d love to see what you come up with, so please send your creations my way at rachelnabors.com!\n\nNote: Because every browser wants to use its own prefixes with CSS3 animations, and I have neither the time nor the space to write all of them out, I will use the W3C standard syntaxes; that is, going prefix-less. You can implement them out of the box with something like Prefixfree, or you can add prefixes on your own. If you take the latter route, I recommend using Sass and Compass so you can focus on your animations, not copying and pasting.\n\nThe walk cycle\n\nWalk cycles are the \u201cHello world\u201d of animation. One of the first projects of animation students is to spend hours drawing dozens of frames to complete a simple loopable animation of a character walking.\n\nMost animators don\u2019t have to draw every frame themselves, though. They draw a few key frames and send those on to production animators to work on the between frames (or tween frames). This is meticulous, grueling work requiring an eye for detail and natural movement. This is also why so much production animation gets shipped overseas where labor is cheaper.\n\nLuckily, we don\u2019t have to worry about our frame count because we can set our own frames-per-second rate on the fly in CSS3. Since we\u2019re trying to impress friends, not animation directors, the inconsistency shouldn\u2019t be a problem. (Unless your friend is an animation director.)\n\nThis is a simple walk cycle I made of my comic character Tuna for my CSS animation talk at CSS Dev Conference this year:\n\n\n\nThe magic lies here:\n\nanimation: walk-cycle 1s steps(12) infinite;\n\nBreaking those properties down:\n\nanimation: ;\n\nwalk-cycle is a simple @keyframes block that moves the background sprite on .tuna around:\n\n@keyframes walk-cycle { \n 0% {background-position: 0 0; }\n 100% {background-position: 0 -2391px;}\n}\n\nThe background sprite has exactly twelve images of Tuna that complete a full walk cycle. We\u2019re setting it to cycle through the entire sprite every second, infinitely. So why isn\u2019t the background image scrolling down the .tuna container? It\u2019s all down to the timing function steps(). Using steps() let us tell the CSS to make jumps instead of the smooth transitions you\u2019d get from something like linear. Chris Mills at dev.opera wrote in his excellent intro to CSS3 animation :\n\n\n\tInstead of giving a smooth animation throughout, [steps()] causes the animation to jump between a set number of steps placed equally along the duration. For example, steps(10) would make the animation jump along in ten equal steps. There\u2019s also an optional second parameter that takes a value of start or end. steps(10, start) would specify that the change in property value should happen at the start of each step, while steps(10, end) means the change would come at the end.\n\n\n(Seriously, go read his full article. I\u2019m not going to touch on half the stuff he does because I cannot improve on the basics any more than he already has.)\n\nThe background\n\nA cat walking in a void is hardly an impressive animation and certainly your buddy one cube over could do it if he chopped up some of those cat GIFs he keeps using in group chat. So let\u2019s add a parallax background! Yes, yes, all web designers signed a peace treaty to not abuse parallax anymore, but this is its true calling\u2014treaty be damned.\n\n\n\nAnd to think we used to need JavaScript to do this! It\u2019s still pretty CPU intensive but much less complicated. We start by splitting up the page into different layers, .foreground, .midground, and .background. We put .tuna in the .midground.\n\n.background has multiple background images, all set to repeat horizontally:\n\nbackground-image:\n url(background_mountain5.png),\n url(background_mountain4.png),\n url(background_mountain3.png),\n url(background_mountain2.png),\n url(background_mountain1.png);\nbackground-repeat: repeat-x;\n\nWith parallax, things in the foreground move faster than those in the background. Next time you\u2019re driving, notice how the things closer to you move out of your field of vision faster than something in the distance, like a mountain or a large building. We can imitate that here by making the background images on top (in the foreground, closer to us) wider than those on the bottom of the stack (in the distance).\n\nThe different lengths let us use one animation to move all the background images at different rates in the same interval of time: \n\nanimation: parallax_bg linear 40s infinite;\n\nThe shorter images have less distance to cover in the same amount of time as the longer images, so they move slower.\n\n\n\nLet\u2019s have a look at the background\u2019s animation:\n\n@keyframes parallax_bg { \n 0% {\n background-position: -2400px 100%, -2000px 100%, -1800px 100%, -1600px 100%, -1200px 100%;\n }\n 100% {\n background-position: 0 100%, 0 100%, 0 100%, 0 100%, 0 100%;\n }\n}\n\nAt 0%, all the background images are positioned at the negative value of their own widths. Then they start moving toward background-position: 0 100%. If we wanted to move them in the reverse direction, we\u2019d remove the negative values at 0% (so they would start at 2400px 100%, 2000px 100%, etc.). Try changing the values in the codepen above or changing background-repeat to none to see how the images play together.\n\n.foreground and .midground operate on the same principles, only they use single background images.\n\nThe music\n\nAfter finishing the first draft of my original walk cycle, I made a GIF with it and posted it on YTMND with some music from the movie Paprika, specifically the track \u201cThe Girl in Byakkoya.\u201d After showing it to some colleagues in my community, it became clear that this was a winning combination sure to drive away dresscode blues. So let\u2019s use HTML5 to get a clip of that music looping in there!\n\nWarning, there is sound. Please adjust your volume or apply headphones as needed.\n\n\n\nWe\u2019re using HTML5 audio\u2019s loop and autoplay abilities to automatically play and loop a sound file on page load:\n\n\n \n \n\nUnfortunately, you may notice there is a small pause between loops. HTML5 audio, thou art half-baked still. Let\u2019s hope one day the Web Audio API will be able to help us out, but until things improve, we\u2019ll have to hack our way around these shortcomings.\n\nTurns out there\u2019s a handy little script called seamlessLoop.js which we can use to patch this. Mind you, if we were really getting crazy with the Cheese Whiz, we\u2019d want to get out big guns like sound.js. But that\u2019d be overkill for a mere loop (and explaining the Web Audio API might bore, rather than impress your friends)!\n\nInstalling seamlessLoop.js will get rid of the pause, and now our walk cycle is complete.\n\n(I\u2019ve done some very rough sniffing to see if the browser can play MP3 files. If not, we fall back to using .ogg formatted clips (Opera and Firefox users, you\u2019re welcome).)\n\nReally impress your friends by adding a run cycle\n\nSo we have music, we have a walk cycle, we have parallax. It will be a snap to bring them all together and have a simple, endless animation. But let\u2019s go one step further and knock the socks off our viewers by adding a run cycle.\n\nThe run cycle\n\nTacking a run cycle on to our walk cycle will require a third animation sequence: a transitional animation of Tuna switching from walking to running. I have added all these to the sprite:\n\n\n\nLet\u2019s work on getting that transition down. We\u2019re going to use multiple animations on the same .tuna div, but we\u2019re going to kick them off at different intervals using animation-delay\u2014no JavaScript required! Isn\u2019t that magical?\n\n\n\nIt requires a wee bit of math (not much, it doesn\u2019t hurt) to line them up. We want to:\n\n\n\tLoop the walk animation twice\n\tPlay the transitional cycle once (it has a finite beginning and end perfectly drawn to pick up between the last frame of the walk cycle and the first frame of the run cycle\u2014no looping this baby)\n\tRUN FOREVER.\n\n\nUsing the pattern animation: , here\u2019s what that looks like:\n\nanimation:\n walk-cycle 1s steps(12) 2,\n walk-to-run .75s steps(12) 2s 1,\n run-cycle .75s steps(13) 2.75s infinite;\n\nI played with the times to get make the movement more realistic. You may notice that the running animation looks smoother than the walking animation. That\u2019s because it has 13 keyframes running over .75 second instead of 12 running in one second. Remember, professional animation studios use super-high frame counts. This little animation isn\u2019t even up to PBS\u2019s standards!\n\nThe music: extended play with HTML5 audio sprites\n\nMy favorite part in the The Girl in Byakkoya is when the calm opening builds and transitions into a bouncy motif. I want to start with Tuna walking during the opening, and then loop the running and bounciness together for infinity.\n\n\n\tThe intro lasts for 24 seconds, so we set our 1 second walk cycle to run for 24 repetitions: \nwalk-cycle 1s steps(12) 24\n\tWe delay walk-to-run by 24 seconds so it runs for .75 seconds before\u2026\n\tWe play run-cycle at 24.75 seconds and loop it infinitely\n\n\nFor the music, we need to think of it as two parts: the intro and the bouncy loop. We can do this quite nicely with audio sprites: using one HTML5 audio element and using JavaScript to change the play head location, like skipping tracks with a CD player. Although this technique will result in a small gap in music shifts, I think it\u2019s worth using here to give you some ideas.\n\n// Get the audio element\nvar byakkoya = document.querySelector('audio');\n// create function to play and loop audio\nfunction song(a){\n //start playing at 0\n a.currentTime = 0;\n a.play();\n //when we hit 64 seconds...\n setTimeout(function(){\n // skip back to 24.5 seconds and keep playing...\n a.currentTime = 24.55;\n // then loop back when we hit 64 again, or every 59.5 seconds.\n setInterval(function(){\n a.currentTime = 24.55;\n },39450);\n },64000);\n}\n\nThe load screen\n\nI\u2019ve put it off as long as I can, but now that the music and the CSS are both running on their own separate clocks, it\u2019s imperative that both images and music be fully downloaded and ready to run when we kick this thing off. So we need a load screen (also, it\u2019s nice to give people a heads-up that you\u2019re about to blast them with music, no matter how wonderful that music may be).\n\nSince the two timers are so closely linked, we\u2019d best not run the animations until we run the music:\n\n* { animation-play-state: paused; }\n\nanimation-play-state can be set to paused or running, and it\u2019s the most useful thing you will learn today.\n\nFirst we use an event listener to see when the browser thinks we can play through from the beginning to end of the music without pause for buffering:\n\nbyakkoya.addEventListener(\"canplaythrough\", function () { });\n\n(More on HTML5 audio\u2019s media events at HTML5doctor.com)\n\nInside our event listener, I use a bit of jQuery to add class of .playable to the body when we\u2019re ready to enable the play button:\n\n$(\"body\").addClass(\"playable\");\n $(\"#play-me\").html(\"Play me.\").click(function(){\n song(byakkoya);\n $(\"body\").addClass(\"playing\");\n });\n\nThat .playing class is special because it turns on the animations at the same time we start playing the song:\n\n.playing * { animation-play-state: running; }\n\nThe background\n\nWe\u2019re almost done here! When we add the background, it needs to speed up at the same time that Tuna starts running. The music picks up speed around 24.75 seconds in, and so we\u2019re going to use animation-delay on those backgrounds, too.\n\nThis will require some math. If you try to simply shorten the animation\u2019s duration at the 24.75s mark, the backgrounds will, mid-scroll, jump back to their initial background positions to start the new animation! Argh! So let\u2019s make a new @keyframe and calculate where the background position would be just before we speed up the animation.\n\nHere\u2019s the formula:\n\nnew 0% value = delay \u00f7 old duration \u00d7 length of image\n\nnew 100% value = new 0% value + length of image\n\nHere\u2019s the formula put to work on a smaller scale:\n\n\n\nVoil\u00e0! The finished animation!\n\n\n\nI\u2019ve always wanted to bring my illustrations to life. Then I woke up one morning and realized that I had all the tools to do so in my browser and in my head. Now I have fallen in love with Flashless animation.\n\nI\u2019m sure there will be detractors who say HTML wasn\u2019t meant for this and it\u2019s a gross abuse of the DOM! But I say that these explorations help us expand what we expect from devices and software and challenge us in good ways as artists and programmers. The browser might not be the most appropriate place for animation, but is certainly a fun place to start.\n\nThere is so much you can do with the spec implemented today, and so much of the territory is still unexplored. I have not yet begun to show you everything. In eight months I expect this demo will represent the norm, not the bleeding edge. I look forward to seeing the wonderful things you create.\n\n(Also, someone, please, do something about that gappy HTML5 audio looping. It\u2019s a crying shame!)", "year": "2012", "author": "Rachel Nabors", "author_slug": "rachelnabors", "published": "2012-12-06T00:00:00+00:00", "url": "https://24ways.org/2012/flashless-animation/", "topic": "code"}
{"rowid": 76, "title": "Giving CSS Animations and Transitions Their Place", "contents": "CSS animations and transitions may not sit squarely in the realm of the behaviour layer, but they\u2019re stepping up into this area that used to be pure JavaScript territory. Heck, CSS might even perform better than its JavaScript equivalents in some cases. That\u2019s pretty serious! With CSS\u2019s new tricks blurring the lines between presentation and behaviour, it can start to feel bloated and messy in our CSS files. It\u2019s an uncomfortable feeling.\n\nHere are a pair of methods I\u2019ve found to be pretty helpful in keeping the potential bloat and wire-crossing under control when CSS has its hands in both presentation and behaviour.\n\nSame eggs, more baskets\n\nStructuring your CSS to have separate files for layout, typography, grids, and so on is a fairly common approach these days. But which one do you put your transitions and animations in? The initial answer, as always, is \u201cit depends\u201d.\n\nSmall effects here and there will likely sit just fine with your other styles. When you move into more involved effects that require multiple animations and some logic support from JavaScript, it\u2019s probably time to choose none of the above, and create a separate CSS file just for them.\n\nPutting all your animations in one file is a huge help for code organization. Even if you opt for a name less literal than animations.css, you\u2019ll know exactly where to go for anything CSS animation related. That saves time and effort when it comes to editing and maintenance. Keeping track of which animations are still currently used is easier when they\u2019re all grouped together as well. And as an added bonus, you won\u2019t have to look at all those horribly unattractive and repetitive prefixed @-keyframe rules unless you actually need to.\n\nAn animations.css file might look something like the snippet below. It defines each animation\u2019s keyframes and defines a class for each variation of that animation you\u2019ll be using. Depending on the situation, you may also want to include transitions here in a similar way. (I\u2019ve found defining transitions as their own class, or mixin, to be a huge help in past projects for me.)\n\n// defining the animation\n@keyframes catFall {\n from { background-position: center 0;}\n to {background-position: center 1000px;}\n}\n@-webkit-keyframes catFall {\n from { background-position: center 0;}\n to {background-position: center 1000px;}\n}\n@-moz-keyframes catFall {\n from { background-position: center 0;}\n to {background-position: center 1000px;}\n}\n@-ms-keyframes catFall {\n from { background-position: center 0;}\n to {background-position: center 1000px;}\n}\n\n\u2026\n\n// class that assigns the animation\n\n.catsBackground {\n height: 100%;\n background: transparent url(../endlessKittens.png) 0 0 repeat-y;\n animation: catFall 1s linear infinite;\n -webkit-animation: catFall 1s linear infinite;\n -moz-animation: catFall 1s linear infinite;\n -ms-animation: catFall 1s linear infinite;\n}\n\nIf we don\u2019t need it, why load it?\n\nHaving all those CSS animations and transitions in one file gives us the added flexibility to load them only when we want to. Loading a whole lot of things that will never be used might seem like a bit of a waste.\n\nWhile CSS has us impressed with its motion chops, it falls flat when it comes to the logic and fine-grained control. JavaScript, on the other hand, is pretty good at both those things. Chances are the content of your animations.css file isn\u2019t acting alone. You\u2019ll likely be adding and removing classes via JavaScript to manage your CSS animations at the very least. If your CSS animations are so entwined with JavaScript, why not let them hang out with the rest of the behaviour layer and only come out to play when JavaScript is supported?\n\nDynamically linking your animations.css file like this means it will be completely ignored if JavaScript is off or not supported. No JavaScript? No additional behaviour, not even the parts handled by CSS.\n\n\n\nThis technique comes up in progressive enhancement techniques as well, but it can help here to keep your presentation and behaviour nicely separated when more than one language is involved. The aim in both cases is to avoid loading files we won\u2019t be using.\n\nIf you happen to be doing something a bit fancier \u2013 like 3-D transforms or critical animations that require more nuanced fallbacks \u2013 you might need something like modernizr to step in to determine support more specifically. But the general idea is the same.\n\nSumming it all up\n\nUsing a couple of simple techniques like these, we get to pick where to best draw the line between behaviour and presentation based on the situation at hand, not just on what language we\u2019re using. The power of when to separate and how to reassemble the individual pieces can be even greater if you use preprocessors as part of your process. We\u2019ve got a lot of options! The important part is to make forward-thinking choices to save your future self, and even your current self, unnecessary headaches.", "year": "2012", "author": "Val Head", "author_slug": "valhead", "published": "2012-12-08T00:00:00+00:00", "url": "https://24ways.org/2012/giving-css-animations-and-transitions-their-place/", "topic": "code"}
{"rowid": 79, "title": "Responsive Images: What We Thought We Needed", "contents": "If you were to read a web designer\u2019s Christmas wish list, it would likely include a solution for displaying images responsively. For those concerned about users downloading unnecessary image data, or serving images that look blurry on high resolution displays, finding a solution has become a frustrating quest.\n\nHaving experimented with complex and sometimes devilish hacks, consensus is forming around defining new standards that could solve this problem. Two approaches have emerged.\n\nThe element markup pattern was proposed by Mat Marquis and is now being developed by the Responsive Images Community Group. By providing a means of declaring multiple sources, authors could use media queries to control which version of an image is displayed and under what conditions:\n\n\n \n \n \n \n Accessible text
\n \n\nA second proposal put forward by Apple, the srcset attribute, uses a more concise syntax intended for use with the element, although it could be compatible with the element too. This would allow authors to provide a set of images, but with the decision on which to use left to the browser:\n\n \n\nEnter Scrooge\n\n\n\tMen\u2019s courses will foreshadow certain ends, to which, if persevered in, they must lead.\nEbenezer Scrooge\n\n\nGiven the complexity of this issue, there\u2019s a heated debate about which is the best option. Yet code belies a certain truth. That both feature verbose and opaque syntax, I\u2019m not sure either should find its way into the browser \u2013 especially as alternative approaches have yet to be fully explored.\n\nSo, as if to dampen the festive cheer, here are five reasons why I believe both proposals are largely redundant.\n\n1. We need better formats, not more markup\n\nAs we move away from designs defined with fixed pixel values, bitmap images look increasingly unsuitable. While simple images and iconography can use scalable vector formats like SVG, for detailed photographic imagery, raster formats like GIF, PNG and JPEG remain the only suitable option.\n\nThere is scope within current formats to account for varying bandwidth but this requires cooperation from browser vendors. Newer formats like JPEG2000 and WebP generate higher quality images with smaller file sizes, but aren\u2019t widely supported.\n\nWhile it\u2019s tempting to try to solve this issue by inventing new markup, the crux of it remains at the file level.\n\nDaan Jobsis\u2019s experimentation with image compression strengthens this argument. He discovered that by increasing the dimensions of a JPEG image while simultaneously reducing its quality, a smaller files could be produced, with the resulting image looking just as good on both standard and high-resolution displays.\n\nThis may be a hack in lieu of a more permanent solution, but it\u2019s applied in the right place. Easy to accomplish with existing tools and without compatibility issues, it has few downsides. Further experimentation in this area should be encouraged, with standardisation efforts more helpful if focused on developing new image formats or, preferably, extending existing ones.\n\n2. Art direction doesn\u2019t belong in markup\n\nA desired benefit of the markup pattern is to allow for greater art direction. For example, rather than scaling down images on smaller displays to the point that their content is hard to discern, we could present closer crops instead:\n\n\n\nThis can be achieved with CSS of course, although with a download penalty for those parts of an image not shown. This point may be negligible, however, since in the context of adaptable layouts, these hidden areas may end up being revealed anyway.\n\nArt direction concerns design, not content. If we wish to maintain a separation of concerns, including presentation within our markup seems misguided.\n\n3. The size of a display has little relation to the size of an image\n\nBy using media queries, the element allows authors to choose which characteristics of the screen or viewport to query for different images to be displayed.\n\nIn developing sites at Clearleft, we have noticed that the viewport is essentially arbitrary, with the size of an image\u2019s containing element more important. For example, look at how this grid of images may adapt at different viewport widths:\n\n\n\nAs we build more modular systems, components need to be adaptable in and of themselves. There is a case to be made for developing more contextual methods of querying, rather than those based on attributes of the display.\n\n4. We haven\u2019t lived with the problem long enough\n\nA key strength of the web is that the underlying platform can be continually iterated. This can also be problematic if snap judgements are made about what constitutes an improvement.\n\nThe early history of the web is littered with such examples, be it the perceived need for blinking text or inline typographic styling. To build a platform for the future, additions to it should be carefully considered. And if we want more consistent support across browsers, burdening vendors with an ever increasing list of features seems counterproductive.\n\nOnly once the need for a new feature is sufficiently proven, should we look to standardise it. Before we could declare hover effects, rounded corners and typographic styling in CSS, we used JavaScript as a polyfill. Sure, doing so was painful, but use cases were fully explored, and the CSS specification better reflected the needs of authors.\n\n5. Images and the web aesthetic\n\nThe srcset proposal has emerged from a company that markets its phones as being able to browse the real \u2013 yet squashed down, tapped and zoomable \u2013 web. Perhaps Apple should make its own website responsive before suggesting how the rest of us should do so.\n\nConverserly, while the proposal has the backing of a few respected developers and designers, it was born out of the work Mat Marquis and Filament Group did for the Boston Globe. As the first large-scale responsive design, this was a landmark project that ignited the responsive web design movement and proved its worth. But it was the first.\n\nIts design shares a vernacular to that of contemporary newspaper websites, with a columnar, image-laden and densely packed layout. Compared to more recent examples \u2013 Quartz, The Next Web and the New York Times Skimmer \u2013 it feels out of step with the future direction of news sites. In seeking out a truer aesthetic for the web in which software interfaces have greater influence, we might discover that the need for responsive images isn\u2019t as great as originally thought.\n\n\n\nBuilding for the future\n\nWith responsive design, we\u2019ve accepted the idea that a fully fluid layout, rather than a set of fixed layouts, is best suited to the web\u2019s unpredictable nature. Current responsive image proposals are antithetical to this approach.\n\nWe need solutions that lack complexity, are device-agnostic and work within existing workflows. Any proposal that requires different versions of the same image to be created, is likely to have to acquiesce under the pressure of reality.\n\nWhile it\u2019s easy to get distracted about the size and quality of an image, and how we might choose to serve it, often the simplest solution is not to include it at all. After years of gluttonous design practice, in which fast connections and expansive display sizes were an accepted norm, we have got use to filling pages with needless images and countless items of page furniture.\n\nTo design more adaptable experiences, the presence of every element needs to be questioned, for its existence requires additional data to be downloaded or futher complexity within a design system. Conditional loading techniques mean that the inclusion of images is no longer a binary choice, but can instead appear in a progressively enhanced manner.\n\nSo here is my proposal. Instead of spending the next year worrying about responsive images, let\u2019s embrace the constraints of the medium, and seek out new solutions that can work within them.", "year": "2012", "author": "Paul Lloyd", "author_slug": "paulrobertlloyd", "published": "2012-12-11T00:00:00+00:00", "url": "https://24ways.org/2012/responsive-images-what-we-thought-we-needed/", "topic": "code"}
{"rowid": 92, "title": "Redesigning the Media Query", "contents": "Responsive web design is showing us that designing content is more important than designing containers. But if you\u2019ve given RWD a serious try, you know that shifting your focus from the container is surprisingly hard to do. There are many factors and\ninstincts working against you, and one culprit is a perpetrator you\u2019d least suspect.\n\nThe media query is the ringmaster of responsive design. It lets us establish the rules of the game and gives us what we need most: control. However, like some kind of evil double agent, the media query is actually working against you.\n\nIts very nature diverts your attention away from content and forces you to focus on the container.\n\nThe very act of choosing a media query value means choosing a screen size.\n\nLook at the history of the media query\u2014it\u2019s always been about the container. Values like screen, print, handheld and tv don\u2019t have anything to do with content. The modern media query lets us choose screen dimensions, which is great because it makes RWD possible. But it\u2019s still the act of choosing something that is completely unpredictable.\n\nContent should dictate our breakpoints, not the container. In order to get our focus back to the only thing that matters, we need a reengineered media query\u2014one that frees us from thinking about screen dimensions. A media query that works for your content, not the window. Fortunately, Sass 3.2 is ready and willing to take on this challenge.\n\nThinking in Columns\n\nFluid grids never clicked for me. I feel so disoriented and confused by their squishiness. Responsive design demands their use though, right?\n\nI was ready to surrender until I found a grid that turned my world upright again. The Frameless Grid by Joni Korpi demonstrates that column and gutter sizes can stay fixed. As the screen size changes, you simply add or remove columns to accommodate. This made sense to me and armed with this concept I was able to give Sass the first component it needs to rewrite the media query: fixed column and gutter size variables.\n\n$grid-column: 60px;\n$grid-gutter: 20px;\n\nWe\u2019re going to want some resolution independence too, so let\u2019s create a function that converts those nasty pixel values into ems.\n\n@function em($px, $base: $base-font-size) {\n\t@return ($px / $base) * 1em;\n}\n\nWe now have the components needed to figure out the width of multiple columns in ems. Let\u2019s put them together in a function that will take any number of columns and return the fixed width value of their size.\n\n@function fixed($col) {\n\t@return $col * em($grid-column + $grid-gutter)\n}\n\nWith the math in place we can now write a mixin that takes a column count as a parameter, then generates the perfect media query necessary to fit that number of columns on the screen. We can also build in some left and right margin for our layout by adding an additional gutter value (remembering that we already have one gutter built into our fixed function).\n\n@mixin breakpoint($min) {\n\t@media (min-width: fixed($min) + em($grid-gutter)) {\n\t\t@content\n\t}\n}\n\nAnd, just like that, we\u2019ve rewritten the media query. Instead of picking a minimum screen size for our layout, we can simply determine the number of columns needed. Let\u2019s add a wrapper class so that we can center our content on the screen.\n\n@mixin breakpoint($min) {\n @media (min-width: fixed($min) + em($grid-gutter)) {\n\t.wrapper {\n\t\twidth: fixed($min) - em($grid-gutter);\n\t\tmargin-left: auto; margin-right: auto;\n\t}\n\t@content\n }\n}\n\nDesigning content with a column count gives us nice, easy, whole numbers to work with. Sizing content, sidebars or widgets is now as simple as specifying a single-digit number.\n\n@include breakpoint(8) {\n\t.main { width: fixed(5); }\n\t.sidebar { width: fixed(3); }\n}\n\nThose four lines of Sass just created a responsive layout for us. When the screen is big enough to fit eight columns, it will trigger a fixed width layout. And give widths to our main content and sidebar. The following is the outputted CSS\u2026\n\n@media (min-width: 41.25em) {\n .wrapper {\n width: 38.75em;\n margin-left: auto; margin-right: auto;\n }\n .main { width: 25em; }\n .sidebar { width: 15em; }\n}\n\nDemo\n\nI\u2019ve created a Codepen demo that demonstrates what we\u2019ve covered so far. I\u2019ve added to the demo some grid classes based on Griddle by Nicolas Gallagher to create a floatless layout. I\u2019ve also added a CSS gradient overlay to help you visualize columns. Try changing the column variable sizes or the breakpoint includes to see how the layout reacts to different screen sizes.\n\nResponsive Images\n\nResponsive images are a serious problem, but I\u2019m excited to see the community talk so passionately about a solution. Now, there are some excellent stopgaps while we wait for something official, but these solutions require you to mirror your breakpoints in JavaScript or HTML. This poses a serious problem for my Sass-generated media queries, because I have no idea what the real values of my breakpoints are anymore. For responsive images to work, JavaScript needs to recognize which media query is active so that proper images can be loaded for that layout.\n\nWhat I need is a way to label my breakpoints. Fortunately, people much smarter than I have figured this out. Jeremy Keith devised a labeling method by using CSS-generated content as the storage method for breakpoint labels. We can use this technique in our breakpoint mixin by passing a label as another argument.\n\n@include breakpoint(8, 'desktop') { /* styles */ }\n\nSass can take that label and use it when writing the corresponding media query. We just need to slightly modify our breakpoint mixin.\n\n@mixin breakpoint($min, $label) {\n @media (min-width: fixed($min) + em($grid-gutter)) {\n\n // label our mq with CSS generated content\n\tbody::before { content: $label; display: none; }\n\n\t.wrapper {\n\t\twidth: fixed($min) - em($grid-gutter);\n\t\tmargin-left: auto; margin-right: auto;\n\t}\n\t@content\n }\n}\n\nThis allows us to label our breakpoints with a user-friendly string. Now that our media queries are defined and labeled, we just need JavaScript to step in and read which label is active.\n\n// get css generated label for active media query\nvar label = getComputedStyle(document.body, '::before')['content'];\n\nJavaScript now knows which layout is active by reading the label in the current media query\u2014we just need to match that label to an image. I prefer to store references to different image sizes as data attributes on my image tag.\n\n \n \n\nThese data attributes have names that match the labels set in my CSS. So while there is some duplication going on, setting a keyword like \u2018tablet\u2019 in two places is much easier than hardcoding media query values. With matching labels in CSS and HTML our script can marry the two and load the right sized image for our layout.\n\n// get css generated label for active media query\nvar label = getComputedStyle(document.body, '::before')['content'];\n\n// select image\nvar $image = $('.responsive-image');\n\n// create source from data attribute\n$image.attr('src', $image.data(label));\n\nDemo\n\nWith some slight additions to our previous Codepen demo you can see this responsive image technique in action. While the above JavaScript will work it is not nearly robust enough for production so the demo uses a jQuery plugin that can accomodate multiple images, reloading on screen resize and fallbacks if something doesn\u2019t match up.\n\nCreating a Framework\n\nThis media query mixin and responsive image JavaScript are the center piece of a front end framework I use to develop websites. It\u2019s a fluid, mobile first foundation that uses the breakpoint mixin to structure fixed width layouts for tablet and desktop. Significant effort was focused on making this framework completely cross-browser. For example, one of the problems with using media queries is that essential desktop structure code ends up being hidden from legacy Internet Explorer. Respond.js is an excellent polyfill, but if you\u2019re comfortable serving a single desktop layout to older IE, we don\u2019t need JavaScript. We simply need to capture layout code outside of a media query and sandbox it under an IE only class name.\n\n// set IE fallback layout to 8 columns\n$ie-support = 8;\n\n// inside of our breakpoint mixin (but outside the media query)\n@if ($ie-support and $min <= $ie-support) {\n\t.lt-ie9 { @content; }\n}\n\nPerspective Regained\n\nThinking in columns means you are thinking about content layout. How big of a screen do you need for 12 columns? Who cares? Having Sass write media queries means you can use intuitive numbers for content layout. A fixed grid means more layout control and less edge cases to test than a fluid grid. Using CSS labels for activating responsive images means you don\u2019t have to duplicate breakpoints across separations of concern. \n\nIt\u2019s a harmonious blend of approaches that gives us something we need\u2014responsive design that feels intuitive. And design that, from the very outset, focuses on what matters most. Just like our kindergarten teachers taught us: It\u2019s what\u2019s inside that counts.", "year": "2012", "author": "Les James", "author_slug": "lesjames", "published": "2012-12-13T00:00:00+00:00", "url": "https://24ways.org/2012/redesigning-the-media-query/", "topic": "code"}
{"rowid": 75, "title": "A Harder-Working Class", "contents": "Class is only becoming more important. Focusing on its original definition as an attribute for grouping (or classifying) as well as linking HTML to CSS, recent front-end development practices are emphasizing class as a vessel for structured, modularized style packages. These patterns reduce the need for repetitive declarations that can seriously bloat file sizes, and instil human-readable understanding of how the interface, layout, and aesthetics are constructed.\n\nIn the next handful of paragraphs, we will look at how these emerging practices \u2013 such as object-oriented CSS and SMACSS \u2013 are pushing the relevance of class. We will also explore how HTML and CSS architecture can be further simplified, performance can be boosted, and CSS utility sharpened by combining class with the attribute selector.\n\nA primer on attribute selectors\n\nWhile attribute selectors were introduced in the CSS 2 spec, they are still considered rather exotic. These well-established and well-supported features give us vastly improved flexibility in targeting elements in CSS, and offer us opportunities for smarter markup. With an attribute selector, you can directly style an element based on any of its unique \u2013 or uniquely shared \u2013 attributes, without the need for an ID or extra classes. Unlike pseudo-classes, pseudo-elements, and other exciting features of CSS3, attribute selectors do not require any browser-specific syntax or prefix, and are even supported in Internet Explorer 7. \n\nFor example, say we want to target all anchor tags on a page that link to our homepage. Where otherwise we might need to manually identify and add classes to the HTML for these specific links, we could simply write:\n\n[href=index.html] { }\n\nThis selector reads: target every element that has an href attribute of \u201cindex.html\u201d. \n\nAttribute selectors are more faceted, though, as they also give us some very simple regular expression-like logic that helps further narrow (or widen) a selector\u2019s scope. In our previous example, what if we wanted to also give indicative styles to any anchor tag linking to an external site? With no way to know what the exact href value would be for every external link, we need to use an expression to match a common aspect of those links. In this case, we know that all external links need to start with \u201chttp\u201d, so we can use that as a hook:\n\n[href^=http] { }\n\nThe selector here reads: target every element that has an href attribute that begins with \u201chttp\u201d (which will also include \u201chttps\u201d). The ^= means \u201cstarts with\u201d. There are a few other simple expressions that give us a lot of flexibility in targeting elements, and I have found that a deep understanding of these and other selector types to be very useful.\n\nThe class-attribute selector\n\nBy matching classes with the attribute selector, CSS can be pushed to accomplish some exciting new feats. What I call a class-attribute selector combines the advantages of classes with attribute selectors by targeting the class attribute, rather than a specific class. Instead of selecting .urgent, you could select [class*=urgent]. The latter may seem like a more verbose way of accomplishing the former, but each would actually match two subtly different groups of elements.\n\nEric Meyer first explored the possibility of using classes with attribute selectors over a decade ago. While his interest in this technique mostly explored the different facets of the syntax, I have found that using class-attribute selectors can have distinct advantages over either using an attribute selector or a straightforward class selector.\n\nFirst, let\u2019s explore some of the subtleties of why we would target class before other attributes:\n\n\n\tClasses are ubiquitous. They have been supported since the HTML 4 spec was released in 1999. Newer attributes, such as the custom data attribute, have only recently begun to be adopted by browsers.\n\tClasses have multiple ways of being targeted. You can use the class selector or attribute selector (.classname or [class=classname]), allowing more flexible specificity than resorting to an ID or !important.\n\tClasses are already widely used, so adding more classes will usually require less markup than adding more attributes.\n\tClasses were designed to abstractly group and specify elements, making them the most appropriate attribute for styling using object-oriented methods (as we will learn in a moment).\n\n\nAlso, as Meyer pointed out, we can use the class-attribute selector to be more strict about class declarations. Of these two elements:\n\n\n\n\n\n\u2026only the second h2 would be selected by [class=urgent], while .urgent would select both. The use of = matches any element with the exact class value of \u201curgent\u201d. Eric explores these nuances further in his series on attribute selectors, but perhaps more dramatic is the added power that class-attribute selectors can bring to our CSS.\n\nMore object-oriented, more scalable and modular\n\nNicole Sullivan has been pushing abstracted, object-oriented thinking in CSS development for years now. She has shared stacks of knowledge on how behemoth sites have seen impressive gains in maintenance overhead and CSS file sizes by leaning heavier on classes derived from common patterns. Jonathan Snook also speaks, writes and is genuinely passionate about improving our markup by using more stratified and modular class name conventions. With SMACSS, he shows this to be highly useful across sites \u2013 both complex and simple \u2013 that exhibit repeated design patterns. Sullivan and Snook both push the use of class for styling over other attributes, and many front-end developers are fast advocating such thinking as best practice.\n\nWith class-attribute selectors, we can further abstract our CSS, pushing its scalability. In his chapter on modules, Snook gives the example of a .pod class that might represent a certain set of styles. A .pod style set might be used in varying contexts, leading to CSS that might normally look like this:\n\n.pod { }\nform .pod { }\naside .pod { }\n\nAccording to Snook, we can make these styles more portable by targeting more verbose classes, rather than context:\n\n.pod { }\n.pod-form { }\n.pod-sidebar { }\n\n\u2026resulting in the following HTML:\n\n\n
\n
\n\nThis divorces the
\u2019s styles from its context, making it applicable to any situation in which it is needed. The markup is clean and portable, and the classes are imbued with meaning as to what module they belong to. \n\nUsing class-attribute selectors, we can simplify this further:\n\n[class*=pod] { }\n.pod-form { }\n.pod-sidebar { }\n\nThe *= tells the browser to look for any element with a class attribute containing \u201cpod\u201d, so it matches \u201cpod\u201d, \u201cpod-form\u201d, \u201cpod-sidebar\u201d, etc. This allows only one class per element, resulting in simpler HTML:\n\n