--- a/doc/extend.md +++ b/doc/extend.md @@ -1,1 +1,508 @@ - +[HTML5 Boilerplate homepage](http://html5boilerplate.com) | [Documentation +table of contents](README.md) + +# Extend and customise HTML5 Boilerplate + +Here is some useful advice for how you can make your project with HTML5 +Boilerplate even better. We don't want to include it all by default, as not +everything fits with everyone's needs. + + +## DNS prefetching + +In short, DNS Prefetching is a method of informing the browser of domain names +referenced on a site so that the client can resolve the DNS for those hosts, +cache them, and when it comes time to use them, have a faster turn around on +the request. + +### Implicit prefetches + +There is a lot of prefetching done for you automatically by the browser. When +the browser encounters an anchor in your html that does not share the same +domain name as the current location the browser requests, from the client OS, +the IP address for this new domain. The client first checks its cache and +then, lacking a cached copy, makes a request from a DNS server. These requests +happen in the background and are not meant to block the rendering of the +page. + +The goal of this is that when the foreign IP address is finally needed it will +already be in the client cache and will not block the loading of the foreign +content. Less requests result in faster page load times. The perception of this +is increased on a mobile platform where DNS latency can be greater. + +#### Disable implicit prefetching + +```html + +``` + +Even with X-DNS-Prefetch-Control meta tag (or http header) browsers will still +prefetch any explicit dns-prefetch links. + +**_WARNING:_** THIS MAY MAKE YOUR SITE SLOWER IF YOU RELY ON RESOURCES FROM +FOREIGN DOMAINS. + +### Explicit prefetches + +Typically the browser only scans the HTML for foreign domains. If you have +resources that are outside of your HTML (a javascript request to a remote +server or a CDN that hosts content that may not be present on every page of +your site, for example) then you can queue up a domain name to be prefetched. + +```html + + +``` + +You can use as many of these as you need, but it's best if they are all +immediately after the [Meta +Charset](https://developer.mozilla.org/en/HTML/Element/meta#attr-charset) +element (which should go right at the top of the `head`), so the browser can +act on them ASAP. + +#### Common Prefetch Links + +Amazon S3: + +```html + +``` + +Google APIs: + +```html + +``` + +Microsoft Ajax Content Delivery Network: + +```html + + +``` + +### Browser support for DNS prefetching + +Chrome, Firefox 3.5+, Safari 5+, Opera (Unknown), IE 9 (called "Pre-resolution" +on blogs.msdn.com) + +### Further reading about DNS prefetching + +* https://developer.mozilla.org/En/Controlling_DNS_prefetching +* http://dev.chromium.org/developers/design-documents/dns-prefetching +* http://www.apple.com/safari/whats-new.html +* http://blogs.msdn.com/b/ie/archive/2011/03/17/internet-explorer-9-network-performance-improvements.aspx +* http://dayofjs.com/videos/22158462/web-browsers_alex-russel + + +## Search + +### Direct search spiders to your sitemap + +[Learn how to make a sitemap](http://www.sitemaps.org/protocol.php) + +```html + +``` + +### Hide pages from search engines + +According to Heather Champ, former community manager at Flickr, you should not +allow search engines to index your "Contact Us" or "Complaints" page if you +value your sanity. This is an HTML-centric way of achieving that. + +```html + +``` + +**_WARNING:_** DO NOT INCLUDE ON PAGES THAT SHOULD APPEAR IN SEARCH ENGINES. + +### Firefox and IE Search Plugins + +Sites with in-site search functionality should be strongly considered for a +browser search plugin. A "search plugin" is an XML file which defines how your +plugin behaves in the browser. [How to make a browser search +plugin](http://www.google.com/search?ie=UTF-8&q=how+to+make+browser+search+plugin). + +```html + +``` + + +## Internet Explorer + +### Prompt users to switch to "Desktop Mode" in IE10 Metro + +IE10 does not support plugins, such as Flash, in Metro mode. If your site +requires plugins, you can let users know that via the X-UA-Compatible meta +element, which will prompt them to switch to Desktop Mode. + +```html + +``` + +Here's what it looks like alongside H5BP's default X-UA-Compatible values: + +```html + +``` + +You can find more information in [Microsoft's IEBlog post about prompting for +plugin use in IE10 Metro +Mode](http://blogs.msdn.com/b/ie/archive/2012/01/31/web-sites-and-a-plug-in-free-web.aspx). + +### IE Pinned Sites (IE9+) + +Enabling your application for pinning will allow IE9 users to add it to their +Windows Taskbar and Start Menu. This comes with a range of new tools that you +can easily configure with the elements below. See more [documentation on IE9 +Pinned Sites](http://msdn.microsoft.com/en-us/library/gg131029.aspx). + +### Name the Pinned Site for Windows + +Without this rule, Windows will use the page title as the name for your +application. + +```html + +``` + +### Give your Pinned Site a tooltip + +You know — a tooltip. A little textbox that appears when the user holds their +mouse over your Pinned Site's icon. + +```html + +``` + +### Set a default page for your Pinned Site + +If the site should go to a specific URL when it is pinned (such as the +homepage), enter it here. One idea is to send it to a special URL so you can +track the number of pinned users, like so: +`http://www.example.com/index.html?pinned=true` + +```html + +``` + +### Recolor IE's controls manually for a Pinned Site + +IE9+ will automatically use the overall color of your Pinned Site's favicon to +shade its browser buttons. UNLESS you give it another color here. Only use +named colors (`red`) or hex colors (`#ff0000`). + +```html + +``` + +### Manually set the window size of a Pinned Site + +If the site should open at a certain window size once pinned, you can specify +the dimensions here. It only supports static pixel dimensions. 800x600 +minimum. + +```html + +``` + +### Jump List "Tasks" for Pinned Sites + +Add Jump List Tasks that will appear when the Pinned Site's icon gets a +right-click. Each Task goes to the specified URL, and gets its own mini icon +(essentially a favicon, a 16x16 .ICO). You can add as many of these as you +need. + +```html + + +``` + +### (Windows 8) High quality visuals for Pinned Sites + +Windows 8 adds the ability for you to provide a PNG tile image and specify the +tile's background color. [Full details on the IE +blog](http://blogs.msdn.com/b/ie/archive/2012/06/08/high-quality-visuals-for-pinned-sites-in-windows-8.aspx). + +* Create a 144x144 image of your site icon, filling all of the canvas, and + using a transparent background. +* Save this image as a 32-bit PNG and optimize it without reducing + colour-depth. It can be named whatever you want (e.g. `metro-tile.png`). +* To reference the tile and its color, add the HTML `meta` elements described + in the IE Blog post. + +### (Windows 8) Badges for Pinned Sites + +IE10 will poll an XML document for badge information to display on your app's +tile in the Start screen. The user will be able to receive these badge updates +even when your app isn't actively running. The badge's value can be a number, +or one of a predefined list of glyphs. + +* [Tutorial on IEBlog with link to badge XML schema](http://blogs.msdn.com/b/ie/archive/2012/04/03/pinned-sites-in-windows-8.aspx) +* [Available badge values](http://msdn.microsoft.com/en-us/library/ie/br212849.aspx) + +```html + +``` + +### Suppress IE6 image toolbar + +Kill IE6's pop-up-on-mouseover toolbar for images that can interfere with +certain designs and be pretty distracting in general. + +```html + +``` + + +## Social Networks + +### Facebook Open Graph data + +You can control the information that Facebook and others display when users +share your site. Below are just the most basic data points you might need. For +specific content types (including "website"), see [Facebook's built-in Open +Graph content +templates](https://developers.facebook.com/docs/opengraph/objects/builtin/). +Take full advantage of Facebook's support for complex data and activity by +following the [Open Graph +tutorial](https://developers.facebook.com/docs/opengraph/tutorial/). + +```html + + + +``` + +### Twitter Cards + +Twitter provides a snippet specification that serves a similar purpose to Open +Graph. In fact, Twitter will use Open Graph when Cards is not available. Note +that, as of this writing, Twitter requires that app developers activate Cards +on a per-domain basis. You can read more about the various snippet formats +and application process in the [official Twitter Cards +documentation](https://dev.twitter.com/docs/cards). + +```html + + + + + + + +``` + + +## URLs + +### Canonical URL + +Signal to search engines and others "Use this URL for this page!" Useful when +parameters after a `#` or `?` is used to control the display state of a page. +`http://www.example.com/cart.html?shopping-cart-open=true` can be indexed as +the cleaner, more accurate `http://www.example.com/cart.html`. + +```html + +``` + +### Official shortlink + +Signal to the world "This is the shortened URL to use this page!" Poorly +supported at this time. Learn more by reading the [article about shortlinks on +the Microformats wiki](http://microformats.org/wiki/rel-shortlink). + +```html + +``` + + +## News Feeds + +### RSS + +Have an RSS feed? Link to it here. Want to [learn how to write an RSS feed from +scratch](http://www.rssboard.org/rss-specification)? + +```html + +``` + +### Atom + +Atom is similar to RSS, and you might prefer to use it instead of or in +addition to it. [See what Atom's all +about](http://www.atomenabled.org/developers/syndication/). + +```html + +``` + +### Pingbacks + +Your server may be notified when another site links to yours. The href +attribute should contain the location of your pingback service. + +```html + +``` + +* High-level explanation: http://codex.wordpress.org/Introduction_to_Blogging#Pingbacks +* Step-by-step example case: http://www.hixie.ch/specs/pingback/pingback-1.0#TOC5 +* PHP pingback service: http://blog.perplexedlabs.com/2009/07/15/xmlrpc-pingbacks-using-php/ + + +## App Stores + +### Install a Chrome Web Store app + +Users can install a Chrome app directly from your website, as long as the app +and site have been associated via Google's Webmaster Tools. Read more on +[Chrome Web Store's Inline Installation +docs](https://developers.google.com/chrome/web-store/docs/inline_installation). + +```html + +``` + +### Smart App Banners in iOS 6 Safari + +Stop bothering everyone with gross modals advertising your entry in the App Store. +This bit of code will unintrusively allow the user the option to download your iOS +app, or open it with some data about the user's current state on the website. + +```html + +``` + +## Google Analytics augments + +### More tracking settings + +The [optimized Google Analytics +snippet](http://mathiasbynens.be/notes/async-analytics-snippet) included with +HTML5 Boilerplate includes something like this: + +```js +var _gaq = [['_setAccount', 'UA-XXXXX-X'], ['_trackPageview']]; +``` + +In case you need more settings, just extend the array literal instead of +[`.push()`ing to the +array](http://mathiasbynens.be/notes/async-analytics-snippet#dont-push-it) +afterwards: + +```js +var _gaq = [['_setAccount', 'UA-XXXXX-X'], ['_trackPageview'], ['_setAllowAnchor', true]]; +``` + +### Anonymize IP addresses + +In some countries, no personal data may be transferred outside jurisdictions +that do not have similarly strict laws (i.e. from Germany to outside the EU). +Thus a webmaster using the Google Analytics script may have to ensure that no +personal (trackable) data is transferred to the US. You can do that with [the +`_gat.anonymizeIp` +option](http://code.google.com/apis/analytics/docs/gaJS/gaJSApi_gat.html#_gat._anonymizeIp). +In use it looks like this: + +```js +var _gaq = [['_setAccount', 'UA-XXXXX-X'], ['_gat._anonymizeIp'], ['_trackPageview']]; +``` + +### Track jQuery AJAX requests in Google Analytics + +An article by @JangoSteve explains how to [track jQuery AJAX requests in Google +Analytics](http://www.alfajango.com/blog/track-jquery-ajax-requests-in-google-analytics/). + +Add this to `plugins.js`: + +```js +/* + * Log all jQuery AJAX requests to Google Analytics + * See: http://www.alfajango.com/blog/track-jquery-ajax-requests-in-google-analytics/ + */ +if (typeof _gaq !== "undefined" && _gaq !== null) { + $(document).ajaxSend(function(event, xhr, settings){ + _gaq.push(['_trackPageview', settings.url]); + }); +} +``` + +### Track JavaScript errors in Google Analytics + +Add this function after `_gaq` is defined: + +```js +(function(window){ + var undefined, + link = function (href) { + var a = window.document.createElement('a'); + a.href = href; + return a; + }; + window.onerror = function (message, file, row) { + var host = link(file).hostname; + _gaq.push([ + '_trackEvent', + (host == window.location.hostname || host == undefined || host == '' ? '' : 'external ') + 'error', + message, file + ' LINE: ' + row, undefined, undefined, true + ]); + }; +}(window)); +``` + +### Track page scroll + +Add this function after `_gaq` is defined: + +```js +$(function(){ + var isDuplicateScrollEvent, + scrollTimeStart = new Date, + $window = $(window), + $document = $(document), + scrollPercent; + + $window.scroll(function() { + scrollPercent = Math.round(100 * ($window.height() + $window.scrollTop())/$document.height()); + if (scrollPercent > 90 && !isDuplicateScrollEvent) { //page scrolled to 90% + isDuplicateScrollEvent = 1; + _gaq.push(['_trackEvent', 'scroll', + 'Window: ' + $window.height() + 'px; Document: ' + $document.height() + 'px; Time: ' + Math.round((new Date - scrollTimeStart )/1000,1) + 's', + undefined, undefined, true + ]); + } + }); +}); +``` + + +## Miscellaneous + +* Use [HTML5 + polyfills](https://github.com/Modernizr/Modernizr/wiki/HTML5-Cross-browser-Polyfills). + +* Use [Microformats](http://microformats.org/wiki/Main_Page) (via + [microdata](http://microformats.org/wiki/microdata)) for optimum search + results + [visibility](http://googlewebmastercentral.blogspot.com/2009/05/introducing-rich-snippets.html). + +* If you're building a web app you may want [native style momentum scrolling in + iOS5](http://johanbrook.com/browsers/native-momentum-scrolling-ios-5/) using + `-webkit-overflow-scrolling: touch`. + +* Avoid development/stage websites "leaking" into SERPs (search engine results + page) by [implementing X-Robots-tag + headers](https://github.com/h5bp/html5-boilerplate/issues/804). + +* Screen readers currently have less-than-stellar support for HTML5 but the JS + script [accessifyhtml5.js](https://github.com/yatil/accessifyhtml5.js) can + help increase accessibility by adding ARIA roles to HTML5 elements. + + +*Many thanks to [Brian Blakely](https://github.com/brianblakely) for +contributing much of this information.* +