Ajaxify a Website with the HTML5 History API using History.js, jQuery and ScrollTo

readme.md

This gist will ajaxify your website with the HTML5 History API using History.js and ScrollTo.

Installation

<!-- jQuery --> 
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.6.2/jquery.min.js"></script> 
 
<!-- jQuery ScrollTo Plugin -->
<script defer src="http://balupton.github.com/jquery-scrollto/scripts/jquery.scrollto.min.js"></script>

<!-- History.js --> 
<script defer src="http://balupton.github.com/history.js/scripts/bundled/html4+html5/jquery.history.js"></script> 

Explanation

What do the installation instructions do?

1. Load in jQuery
2. Load in the jQuery ScrollTo Plugin allowing our ajaxify gist to scroll nicely and smoothly to the new loaded in content
3. Load in History.js with support for jQuery, HTML4 and HTML5
4. Load in this gist :-)

What does this gist do?

1. Check if History.js is enabled for our current browser, if it isn't then skip this gist.

2. Create a way to detect our page's root url, so we can compare our links against it.

3. Create a way to convert the ajax repsonse into a format jQuery will understand - as jQuery is only made to handle elements which go inside the body element, not elements made for the head element.

4. Define our content and menu selectors, these are using when we load in new pages. We use our content selector to find our new content within the response, and replace the existing content on our current page. We use our menu selector to update the active navigation link in our menu when the page changes.

5. Discover our internal links on our website, and upgrade them so when they are clicked it instead of changing the page to the new page, it will change our page's state to the new page. Links with the class no-ajaxy will not be upgraded.

6. When a page state change occurs, we will:

   1. Determine the absolute and relative urls from the new url

   2. Use our content selector to find our current page's content and fade it out

   3. Send off an ajax request to the absolute url

   4. Convert the response into one we can undertand

   5. Extract the response's title and set document.title and the title element to it

   6. Use our menu selector to find our page's menu, then scan for new page's url in the menu, and make that the active menu item and mark other menu items inactive

   7. Finish the current content's fadeout animation

   8. Use our menu selector to find the new page's content, and replace the current content with the new page's content

   9. Fade the new content in

   10. Scroll to the new current content so the user is directed to the right place - rather than them ending up looking at the footer or something instead of your page's content due to the height shift with the content change

   11. Inform Google Analytics and other tracking software about the page change

Using this Gist?

Post your website in the showcase here!

Further Reading

• The History.js Readme: Your guide to History.js
• Intelligent State Handling: The evolution from hashes, to hashbangs to the HTML5 History API
• The state of the HTML5 History API, why it isn't good enough and why we need History.js

ajaxify-html5.js

// https://gist.github.com/854622
(function(window,undefined){
	
	// Prepare our Variables
	var
		History = window.History,
		$ = window.jQuery,
		document = window.document;

	// Check to see if History.js is enabled for our Browser
	if ( !History.enabled ) {
		return false;
	}

	// Wait for Document
	$(function(){
		// Prepare Variables
		var
			/* Application Specific Variables */
			contentSelector = '#content,article:first,.article:first,.post:first',
			$content = $(contentSelector).filter(':first'),
			contentNode = $content.get(0),
			$menu = $('#menu,#nav,nav:first,.nav:first').filter(':first'),
			activeClass = 'active selected current youarehere',
			activeSelector = '.active,.selected,.current,.youarehere',
			menuChildrenSelector = '> li,> ul > li',
			/* Application Generic Variables */
			$body = $(document.body),
			rootUrl = History.getRootUrl(),
			scrollOptions = {
				duration: 800,
				easing:'swing'
			};
		
		// Ensure Content
		if ( $content.length === 0 ) {
			$content = $body;
		}
		
		// Internal Helper
		$.expr[':'].internal = function(obj, index, meta, stack){
			// Prepare
			var
				$this = $(obj),
				url = $this.attr('href')||'',
				isInternalLink;
			
			// Check link
			isInternalLink = url.substring(0,rootUrl.length) === rootUrl || url.indexOf(':') === -1;
			
			// Ignore or Keep
			return isInternalLink;
		};
		
		// HTML Helper
		var documentHtml = function(html){
			// Prepare
			var result = String(html)
				.replace(/<\!DOCTYPE[^>]*>/i, '')
				.replace(/<(html|head|body|title|meta|script)([\s\>])/gi,'<div class="document-$1"$2')
				.replace(/<\/(html|head|body|title|meta|script)\>/gi,'</div>')
			;
			
			// Return
			return result;
		};
		
		// Ajaxify Helper
		$.fn.ajaxify = function(){
			// Prepare
			var $this = $(this);
			
			// Ajaxify
			$this.find('a:internal:not(.no-ajaxy)').click(function(event){
				// Prepare
				var
					$this = $(this),
					url = $this.attr('href'),
					title = $this.attr('title')||null;
				
				// Continue as normal for cmd clicks etc
				if ( event.which == 2 || event.metaKey ) { return true; }
				
				// Ajaxify this link
				History.pushState(null,title,url);
				event.preventDefault();
				return false;
			});
			
			// Chain
			return $this;
		};
		
		// Ajaxify our Internal Links
		$body.ajaxify();
		
		// Hook into State Changes
		$(window).bind('statechange',function(){
			// Prepare Variables
			var
				State = History.getState(),
				url = State.url,
				relativeUrl = url.replace(rootUrl,'');

			// Set Loading
			$body.addClass('loading');

			// Start Fade Out
			// Animating to opacity to 0 still keeps the element's height intact
			// Which prevents that annoying pop bang issue when loading in new content
			$content.animate({opacity:0},800);
			
			// Ajax Request the Traditional Page
			$.ajax({
				url: url,
				success: function(data, textStatus, jqXHR){
					// Prepare
					var
						$data = $(documentHtml(data)),
						$dataBody = $data.find('.document-body:first'),
						$dataContent = $dataBody.find(contentSelector).filter(':first'),
						$menuChildren, contentHtml, $scripts;
					
					// Fetch the scripts
					$scripts = $dataContent.find('.document-script');
					if ( $scripts.length ) {
						$scripts.detach();
					}

					// Fetch the content
					contentHtml = $dataContent.html()||$data.html();
					if ( !contentHtml ) {
						document.location.href = url;
						return false;
					}
					
					// Update the menu
					$menuChildren = $menu.find(menuChildrenSelector);
					$menuChildren.filter(activeSelector).removeClass(activeClass);
					$menuChildren = $menuChildren.has('a[href^="'+relativeUrl+'"],a[href^="/'+relativeUrl+'"],a[href^="'+url+'"]');
					if ( $menuChildren.length === 1 ) { $menuChildren.addClass(activeClass); }

					// Update the content
					$content.stop(true,true);
					$content.html(contentHtml).ajaxify().css('opacity',100).show(); /* you could fade in here if you'd like */

					// Update the title
					document.title = $data.find('.document-title:first').text();
					try {
						document.getElementsByTagName('title')[0].innerHTML = document.title.replace('<','&lt;').replace('>','&gt;').replace(' & ',' &amp; ');
					}
					catch ( Exception ) { }
					
					// Add the scripts
					$scripts.each(function(){
						var $script = $(this), scriptText = $script.text(), scriptNode = document.createElement('script');
						scriptNode.appendChild(document.createTextNode(scriptText));
						contentNode.appendChild(scriptNode);
					});

					// Complete the change
					if ( $body.ScrollTo||false ) { $body.ScrollTo(scrollOptions); } /* http://balupton.com/projects/jquery-scrollto */
					$body.removeClass('loading');
	
					// Inform Google Analytics of the change
					if ( typeof window.pageTracker !== 'undefined' ) {
						window.pageTracker._trackPageview(relativeUrl);
					}

					// Inform ReInvigorate of a state change
					if ( typeof window.reinvigorate !== 'undefined' && typeof window.reinvigorate.ajax_track !== 'undefined' ) {
						reinvigorate.ajax_track(url);
						// ^ we use the full url here as that is what reinvigorate supports
					}
				},
				error: function(jqXHR, textStatus, errorThrown){
					document.location.href = url;
					return false;
				}
			}); // end ajax

		}); // end onStateChange

	}); // end onDomLoad

})(window); // end closure