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

/*
* jQuery Mobile Framework : history.pushState support, layered on top of hashchange
* Copyright (c) jQuery Project
* Dual licensed under the MIT or GPL Version 2 licenses.
* http://jquery.org/license
*/
( 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
			};
		},

		isSubHashPage: function( page ) {
			var pageUrl = page.jqmData("url") || "";

			// if the page is a dialog, a subpage, or an embedded page
			// then the hash will have been maintained
			return page.is( "[role='dialog']" ) ||
				pageUrl.indexOf( $.mobile.subPageUrlKey ) >= 0 ||
				pageUrl === page.attr( "id" );
		},

		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;
		},

		// 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 ) {
			var href, state;

			self.hashchangeFired = true;

			// only replaceState when the hash doesn't represent an embeded page
			if( $.mobile.path.isPath(location.hash) ) {

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

				// make the hash abolute with the current href
				href = $.mobile.path.makeUrlAbsolute( state.hash.replace("#", ""), location.href );

				href = self.resetUIKeys( href );

				// replace the current url with the new href and store the state
				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 ) {
				// can't test the hash directly because the url has already been altered, possibly to
				// one without a hash, so we check if the page on display is one that would have
				// generated a hash. Generally speaking a crappy solution.
				if( self.isSubHashPage( $.mobile.activePage ) ){
					holdnexthashchange = true;
				}

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

				// disable the next hash change if the page we came from has a hash
				$.mobile.urlHistory.ignoreNextHashChange = holdnexthashchange;
			}
		},

		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 );