jquery-mobile/js/jquery.mobile.navigation.pushstate.js

/*
* history.pushState support, layered on top of hashchange
*/

( function( $, window ) {
	// For now, let's Monkeypatch this onto the end of $.mobile._registerInternalEvents
	// Scope self to pushStateHandler so we can reference it sanely within the
	// methods handed off as event handlers
	var	pushStateHandler = {},
		self = pushStateHandler,
		$win = $( window ),
		url = $.mobile.path.parseUrl( location.href );

	$.extend( pushStateHandler, {
		// TODO move to a path helper, this is rather common functionality
		initialFilePath: (function() {
			return url.pathname + url.search;
		})(),

		initialHref: url.hrefNoHash,

		// Flag for tracking if a Hashchange naturally occurs after each popstate + replace
		hashchangeFired: false,

		state: function() {
			return {
				hash: location.hash || "#" + self.initialFilePath,
				title: document.title,

				// persist across refresh
				initialHref: self.initialHref
			};
		},

		resetUIKeys: function( url ) {
			var dialog = $.mobile.dialogHashKey,
				subkey = "&" + $.mobile.subPageUrlKey,
				dialogIndex = url.indexOf( dialog );

			if( dialogIndex > -1 ) {
				url = url.slice( 0, dialogIndex ) + "#" + url.slice( dialogIndex );
			} else if( url.indexOf( subkey ) > -1 ) {
				url = url.split( subkey ).join( "#" + subkey );
			}

			return url;
		},

		// TODO sort out a single barrier to hashchange functionality
		nextHashChangePrevented: function( value ) {
			$.mobile.urlHistory.ignoreNextHashChange = value;
			self.onHashChangeDisabled = value;
		},

		// on hash change we want to clean up the url
		// NOTE this takes place *after* the vanilla navigation hash change
		// handling has taken place and set the state of the DOM
		onHashChange: function( e ) {
			// disable this hash change
			if( self.onHashChangeDisabled ){
				return;
			}
			
			var href, state,
				hash = location.hash,
				isPath = $.mobile.path.isPath( hash ),
				resolutionUrl = isPath ? location.href : $.mobile.getDocumentUrl();
			hash = isPath ? hash.replace( "#", "" ) : hash;

			// propulate the hash when its not available
			state = self.state();

			// make the hash abolute with the current href
			href = $.mobile.path.makeUrlAbsolute( hash, resolutionUrl );

			if ( isPath ) {
				href = self.resetUIKeys( href );
			}

			// replace the current url with the new href and store the state
			// Note that in some cases we might be replacing an url with the
			// same url. We do this anyways because we need to make sure that
			// all of our history entries have a state object associated with
			// them. This allows us to work around the case where window.history.back()
			// is called to transition from an external page to an embedded page.
			// In that particular case, a hashchange event is *NOT* generated by the browser.
			// Ensuring each history entry has a state object means that onPopState()
			// will always trigger our hashchange callback even when a hashchange event
			// is not fired.
			history.replaceState( state, document.title, href );
		},

		// on popstate (ie back or forward) we need to replace the hash that was there previously
		// cleaned up by the additional hash handling
		onPopState: function( e ) {
			var poppedState = e.originalEvent.state, holdnexthashchange = false;

			// if there's no state its not a popstate we care about, ie chrome's initial popstate
			// or forward popstate
			if( poppedState ) {
				// disable any hashchange triggered by the browser
				self.nextHashChangePrevented( true );

				// defer our manual hashchange until after the browser fired
				// version has come and gone
				setTimeout(function() {
					// make sure that the manual hash handling takes place
					self.nextHashChangePrevented( false );

					// change the page based on the hash
					$.mobile._handleHashChange( poppedState.hash );
				}, 100);
			}
		},

		init: function() {
			$win.bind( "hashchange", self.onHashChange );

			// Handle popstate events the occur through history changes
			$win.bind( "popstate", self.onPopState );

			// if there's no hash, we need to replacestate for returning to home
			if ( location.hash === "" ) {
				history.replaceState( self.state(), document.title, location.href );
			}
		}
	});

	$( function() {
		if( $.mobile.pushStateEnabled && $.support.pushState ){
			pushStateHandler.init();
		}
	});
})( jQuery, this );