[tt-rss.git] / lib / dojo / back.js

/*
	Copyright (c) 2004-2011, The Dojo Foundation All Rights Reserved.
	Available via Academic Free License >= 2.1 OR the modified BSD license.
	see: http://dojotoolkit.org/license for details
*/


if(!dojo._hasResource["dojo.back"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
dojo._hasResource["dojo.back"] = true;
dojo.provide("dojo.back");

dojo.getObject("back", true, dojo);

/*=====
dojo.back = {
	// summary: Browser history management resources
}
=====*/


(function(){
	var back = dojo.back,

	// everyone deals with encoding the hash slightly differently

	getHash= back.getHash= function(){
		var h = window.location.hash;
		if(h.charAt(0) == "#"){ h = h.substring(1); }
		return dojo.isMozilla ? h : decodeURIComponent(h);
	},
	
	setHash= back.setHash= function(h){
		if(!h){ h = ""; }
		window.location.hash = encodeURIComponent(h);
		historyCounter = history.length;
	};

	var initialHref = (typeof(window) !== "undefined") ? window.location.href : "";
	var initialHash = (typeof(window) !== "undefined") ? getHash() : "";
	var initialState = null;

	var locationTimer = null;
	var bookmarkAnchor = null;
	var historyIframe = null;
	var forwardStack = [];
	var historyStack = [];
	var moveForward = false;
	var changingUrl = false;
	var historyCounter;

	function handleBackButton(){
		//summary: private method. Do not call this directly.

		//The "current" page is always at the top of the history stack.
		var current = historyStack.pop();
		if(!current){ return; }
		var last = historyStack[historyStack.length-1];
		if(!last && historyStack.length == 0){
			last = initialState;
		}
		if(last){
			if(last.kwArgs["back"]){
				last.kwArgs["back"]();
			}else if(last.kwArgs["backButton"]){
				last.kwArgs["backButton"]();
			}else if(last.kwArgs["handle"]){
				last.kwArgs.handle("back");
			}
		}
		forwardStack.push(current);
	}

	back.goBack = handleBackButton;

	function handleForwardButton(){
		//summary: private method. Do not call this directly.
		var last = forwardStack.pop();
		if(!last){ return; }
		if(last.kwArgs["forward"]){
			last.kwArgs.forward();
		}else if(last.kwArgs["forwardButton"]){
			last.kwArgs.forwardButton();
		}else if(last.kwArgs["handle"]){
			last.kwArgs.handle("forward");
		}
		historyStack.push(last);
	}

	back.goForward = handleForwardButton;

	function createState(url, args, hash){
		//summary: private method. Do not call this directly.
		return {"url": url, "kwArgs": args, "urlHash": hash};	//Object
	}

	function getUrlQuery(url){
		//summary: private method. Do not call this directly.
		var segments = url.split("?");
		if(segments.length < 2){
			return null; //null
		}
		else{
			return segments[1]; //String
		}
	}
	
	function loadIframeHistory(){
		//summary: private method. Do not call this directly.
		var url = (dojo.config["dojoIframeHistoryUrl"] || dojo.moduleUrl("dojo", "resources/iframe_history.html")) + "?" + (new Date()).getTime();
		moveForward = true;
        if(historyIframe){
		    dojo.isWebKit ? historyIframe.location = url : window.frames[historyIframe.name].location = url;
        }else{
            //console.warn("dojo.back: Not initialised. You need to call dojo.back.init() from a <script> block that lives inside the <body> tag.");
        }
		return url; //String
	}

	function checkLocation(){
		if(!changingUrl){
			var hsl = historyStack.length;
			
			var hash = getHash();

			if((hash === initialHash||window.location.href == initialHref)&&(hsl == 1)){
				// FIXME: could this ever be a forward button?
				// we can't clear it because we still need to check for forwards. Ugg.
				// clearInterval(this.locationTimer);
				handleBackButton();
				return;
			}
			
			// first check to see if we could have gone forward. We always halt on
			// a no-hash item.
			if(forwardStack.length > 0){
				if(forwardStack[forwardStack.length-1].urlHash === hash){
					handleForwardButton();
					return;
				}
			}
	
			// ok, that didn't work, try someplace back in the history stack
			if((hsl >= 2)&&(historyStack[hsl-2])){
				if(historyStack[hsl-2].urlHash === hash){
					handleBackButton();
					return;
				}
			}
		}
	};
	
	back.init = function(){
		//summary: Initializes the undo stack. This must be called from a <script>
		//         block that lives inside the <body> tag to prevent bugs on IE.
		// description:
		// 		Only call this method before the page's DOM is finished loading. Otherwise
		// 		it will not work. Be careful with xdomain loading or djConfig.debugAtAllCosts scenarios,
		// 		in order for this method to work, dojo.back will need to be part of a build layer.
		if(dojo.byId("dj_history")){ return; } // prevent reinit
		var src = dojo.config["dojoIframeHistoryUrl"] || dojo.moduleUrl("dojo", "resources/iframe_history.html");
		if (dojo._postLoad) {
			console.error("dojo.back.init() must be called before the DOM has loaded. "
			            + "If using xdomain loading or djConfig.debugAtAllCosts, include dojo.back "
			            + "in a build layer.");
		} else {
			document.write('<iframe style="border:0;width:1px;height:1px;position:absolute;visibility:hidden;bottom:0;right:0;" name="dj_history" id="dj_history" src="' + src + '"></iframe>');
		}
	};

	back.setInitialState = function(/*Object*/args){
		//summary:
		//		Sets the state object and back callback for the very first page
		//		that is loaded.
		//description:
		//		It is recommended that you call this method as part of an event
		//		listener that is registered via dojo.addOnLoad().
		//args: Object
		//		See the addToHistory() function for the list of valid args properties.
		initialState = createState(initialHref, args, initialHash);
	};

	//FIXME: Make these doc comments not be awful. At least they're not wrong.
	//FIXME: Would like to support arbitrary back/forward jumps. Have to rework iframeLoaded among other things.
	//FIXME: is there a slight race condition in moz using change URL with the timer check and when
	//       the hash gets set? I think I have seen a back/forward call in quick succession, but not consistent.

	
	/*=====
	dojo.__backArgs = function(kwArgs){
		// back: Function?
		//		A function to be called when this state is reached via the user
		//		clicking the back button.
		//	forward: Function?
		//		Upon return to this state from the "back, forward" combination
		//		of navigation steps, this function will be called. Somewhat
		//		analgous to the semantic of an "onRedo" event handler.
		//	changeUrl: Boolean?|String?
		//		Boolean indicating whether or not to create a unique hash for
		//		this state. If a string is passed instead, it is used as the
		//		hash.
	}
	=====*/

	back.addToHistory = function(/*dojo.__backArgs*/ args){
		//	summary:
		//		adds a state object (args) to the history list.
		//	description:
		//		To support getting back button notifications, the object
		//		argument should implement a function called either "back",
		//		"backButton", or "handle". The string "back" will be passed as
		//		the first and only argument to this callback.
		//
		//		To support getting forward button notifications, the object
		//		argument should implement a function called either "forward",
		//		"forwardButton", or "handle". The string "forward" will be
		//		passed as the first and only argument to this callback.
		//
		//		If you want the browser location string to change, define "changeUrl" on the object. If the
		//		value of "changeUrl" is true, then a unique number will be appended to the URL as a fragment
		//		identifier (http://some.domain.com/path#uniquenumber). If it is any other value that does
		//		not evaluate to false, that value will be used as the fragment identifier. For example,
		//		if changeUrl: 'page1', then the URL will look like: http://some.domain.com/path#page1
		//
		//		There are problems with using dojo.back with semantically-named fragment identifiers
		//		("hash values" on an URL). In most browsers it will be hard for dojo.back to know
		//		distinguish a back from a forward event in those cases. For back/forward support to
		//		work best, the fragment ID should always be a unique value (something using new Date().getTime()
		//		for example). If you want to detect hash changes using semantic fragment IDs, then
		//		consider using dojo.hash instead (in Dojo 1.4+).
		//
	 	//	example:
		//		|	dojo.back.addToHistory({
		//		|		back: function(){ console.log('back pressed'); },
		//		|		forward: function(){ console.log('forward pressed'); },
		//		|		changeUrl: true
		//		|	});

		//	BROWSER NOTES:
		//  Safari 1.2:
		//	back button "works" fine, however it's not possible to actually
		//	DETECT that you've moved backwards by inspecting window.location.
		//	Unless there is some other means of locating.
		//	FIXME: perhaps we can poll on history.length?
		//	Safari 2.0.3+ (and probably 1.3.2+):
		//	works fine, except when changeUrl is used. When changeUrl is used,
		//	Safari jumps all the way back to whatever page was shown before
		//	the page that uses dojo.undo.browser support.
		//	IE 5.5 SP2:
		//	back button behavior is macro. It does not move back to the
		//	previous hash value, but to the last full page load. This suggests
		//	that the iframe is the correct way to capture the back button in
		//	these cases.
		//	Don't test this page using local disk for MSIE. MSIE will not create
		//	a history list for iframe_history.html if served from a file: URL.
		//	The XML served back from the XHR tests will also not be properly
		//	created if served from local disk. Serve the test pages from a web
		//	server to test in that browser.
		//	IE 6.0:
		//	same behavior as IE 5.5 SP2
		//	Firefox 1.0+:
		//	the back button will return us to the previous hash on the same
		//	page, thereby not requiring an iframe hack, although we do then
		//	need to run a timer to detect inter-page movement.

		//If addToHistory is called, then that means we prune the
		//forward stack -- the user went back, then wanted to
		//start a new forward path.
		forwardStack = [];

		var hash = null;
		var url = null;
		if(!historyIframe){
			if(dojo.config["useXDomain"] && !dojo.config["dojoIframeHistoryUrl"]){
				console.warn("dojo.back: When using cross-domain Dojo builds,"
					+ " please save iframe_history.html to your domain and set djConfig.dojoIframeHistoryUrl"
					+ " to the path on your domain to iframe_history.html");
			}
			historyIframe = window.frames["dj_history"];
		}
		if(!bookmarkAnchor){
			bookmarkAnchor = dojo.create("a", {style: {display: "none"}}, dojo.body());
		}
		if(args["changeUrl"]){
			hash = ""+ ((args["changeUrl"]!==true) ? args["changeUrl"] : (new Date()).getTime());
			
			//If the current hash matches the new one, just replace the history object with
			//this new one. It doesn't make sense to track different state objects for the same
			//logical URL. This matches the browser behavior of only putting in one history
			//item no matter how many times you click on the same #hash link, at least in Firefox
			//and Safari, and there is no reliable way in those browsers to know if a #hash link
			//has been clicked on multiple times. So making this the standard behavior in all browsers
			//so that dojo.back's behavior is the same in all browsers.
			if(historyStack.length == 0 && initialState.urlHash == hash){
				initialState = createState(url, args, hash);
				return;
			}else if(historyStack.length > 0 && historyStack[historyStack.length - 1].urlHash == hash){
				historyStack[historyStack.length - 1] = createState(url, args, hash);
				return;
			}

			changingUrl = true;
			setTimeout(function() {
					setHash(hash);
					changingUrl = false;
				}, 1);
			bookmarkAnchor.href = hash;
			
			if(dojo.isIE){
				url = loadIframeHistory();

				var oldCB = args["back"]||args["backButton"]||args["handle"];

				//The function takes handleName as a parameter, in case the
				//callback we are overriding was "handle". In that case,
				//we will need to pass the handle name to handle.
				var tcb = function(handleName){
					if(getHash() != ""){
						setTimeout(function() { setHash(hash); }, 1);
					}
					//Use apply to set "this" to args, and to try to avoid memory leaks.
					oldCB.apply(this, [handleName]);
				};
		
				//Set interceptor function in the right place.
				if(args["back"]){
					args.back = tcb;
				}else if(args["backButton"]){
					args.backButton = tcb;
				}else if(args["handle"]){
					args.handle = tcb;
				}
		
				var oldFW = args["forward"]||args["forwardButton"]||args["handle"];
		
				//The function takes handleName as a parameter, in case the
				//callback we are overriding was "handle". In that case,
				//we will need to pass the handle name to handle.
				var tfw = function(handleName){
					if(getHash() != ""){
						setHash(hash);
					}
					if(oldFW){ // we might not actually have one
						//Use apply to set "this" to args, and to try to avoid memory leaks.
						oldFW.apply(this, [handleName]);
					}
				};

				//Set interceptor function in the right place.
				if(args["forward"]){
					args.forward = tfw;
				}else if(args["forwardButton"]){
					args.forwardButton = tfw;
				}else if(args["handle"]){
					args.handle = tfw;
				}

			}else if(!dojo.isIE){
				// start the timer
				if(!locationTimer){
					locationTimer = setInterval(checkLocation, 200);
				}
				
			}
		}else{
			url = loadIframeHistory();
		}

		historyStack.push(createState(url, args, hash));
	};

	back._iframeLoaded = function(evt, ifrLoc){
		//summary:
		//		private method. Do not call this directly.
		var query = getUrlQuery(ifrLoc.href);
		if(query == null){
			// alert("iframeLoaded");
			// we hit the end of the history, so we should go back
			if(historyStack.length == 1){
				handleBackButton();
			}
			return;
		}
		if(moveForward){
			// we were expecting it, so it's not either a forward or backward movement
			moveForward = false;
			return;
		}
	
		//Check the back stack first, since it is more likely.
		//Note that only one step back or forward is supported.
		if(historyStack.length >= 2 && query == getUrlQuery(historyStack[historyStack.length-2].url)){
			handleBackButton();
		}else if(forwardStack.length > 0 && query == getUrlQuery(forwardStack[forwardStack.length-1].url)){
			handleForwardButton();
		}
	};
 })();

}
Commit	Line	Data
2f01fe57	1	/*
81bea17a	2	Copyright (c) 2004-2011, The Dojo Foundation All Rights Reserved.
2f01fe57 AD	3	Available via Academic Free License >= 2.1 OR the modified BSD license.
	4	see: http://dojotoolkit.org/license for details
	5	*/
	6
	7
a089699c AD	8	if(!dojo._hasResource["dojo.back"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
a089699c AD	9	dojo._hasResource["dojo.back"] = true;
2f01fe57	10	dojo.provide("dojo.back");
a089699c	11
81bea17a AD	12	dojo.getObject("back", true, dojo);
81bea17a AD	13
a089699c AD	14	/*=====
	15	dojo.back = {
	16	// summary: Browser history management resources
2f01fe57	17	}
a089699c AD	18	=====*/
	19
	20
81bea17a AD	21	(function(){
81bea17a AD	22	var back = dojo.back,
a089699c AD	23
	24	// everyone deals with encoding the hash slightly differently
	25
81bea17a	26	getHash= back.getHash= function(){
a089699c AD	27	var h = window.location.hash;
a089699c AD	28	if(h.charAt(0) == "#"){ h = h.substring(1); }
81bea17a AD	29	return dojo.isMozilla ? h : decodeURIComponent(h);
81bea17a AD	30	},
a089699c	31
81bea17a	32	setHash= back.setHash= function(h){
a089699c AD	33	if(!h){ h = ""; }
	34	window.location.hash = encodeURIComponent(h);
	35	historyCounter = history.length;
81bea17a AD	36	};
81bea17a AD	37
a089699c AD	38	var initialHref = (typeof(window) !== "undefined") ? window.location.href : "";
	39	var initialHash = (typeof(window) !== "undefined") ? getHash() : "";
	40	var initialState = null;
	41
	42	var locationTimer = null;
	43	var bookmarkAnchor = null;
	44	var historyIframe = null;
	45	var forwardStack = [];
	46	var historyStack = [];
	47	var moveForward = false;
	48	var changingUrl = false;
	49	var historyCounter;
	50
	51	function handleBackButton(){
	52	//summary: private method. Do not call this directly.
	53
	54	//The "current" page is always at the top of the history stack.
	55	var current = historyStack.pop();
	56	if(!current){ return; }
	57	var last = historyStack[historyStack.length-1];
	58	if(!last && historyStack.length == 0){
	59	last = initialState;
	60	}
	61	if(last){
	62	if(last.kwArgs["back"]){
	63	last.kwArgs["back"]();
	64	}else if(last.kwArgs["backButton"]){
	65	last.kwArgs["backButton"]();
	66	}else if(last.kwArgs["handle"]){
	67	last.kwArgs.handle("back");
	68	}
	69	}
	70	forwardStack.push(current);
	71	}
	72
	73	back.goBack = handleBackButton;
	74
	75	function handleForwardButton(){
	76	//summary: private method. Do not call this directly.
	77	var last = forwardStack.pop();
	78	if(!last){ return; }
	79	if(last.kwArgs["forward"]){
	80	last.kwArgs.forward();
	81	}else if(last.kwArgs["forwardButton"]){
	82	last.kwArgs.forwardButton();
	83	}else if(last.kwArgs["handle"]){
	84	last.kwArgs.handle("forward");
	85	}
	86	historyStack.push(last);
	87	}
	88
	89	back.goForward = handleForwardButton;
	90
	91	function createState(url, args, hash){
	92	//summary: private method. Do not call this directly.
	93	return {"url": url, "kwArgs": args, "urlHash": hash}; //Object
	94	}
	95
	96	function getUrlQuery(url){
	97	//summary: private method. Do not call this directly.
	98	var segments = url.split("?");
	99	if(segments.length < 2){
	100	return null; //null
	101	}
102	else{
103	return segments[1]; //String
104	}
105	}
106
107	function loadIframeHistory(){
108	//summary: private method. Do not call this directly.
109	var url = (dojo.config["dojoIframeHistoryUrl"] \|\| dojo.moduleUrl("dojo", "resources/iframe_history.html")) + "?" + (new Date()).getTime();
110	moveForward = true;
111	if(historyIframe){
112	dojo.isWebKit ? historyIframe.location = url : window.frames[historyIframe.name].location = url;
113	}else{
114	//console.warn("dojo.back: Not initialised. You need to call dojo.back.init() from a <script> block that lives inside the <body> tag.");
115	}
116	return url; //String
117	}
118
119	function checkLocation(){
120	if(!changingUrl){
121	var hsl = historyStack.length;
122
123	var hash = getHash();
124
125	if((hash === initialHash\|\|window.location.href == initialHref)&&(hsl == 1)){
126	// FIXME: could this ever be a forward button?
127	// we can't clear it because we still need to check for forwards. Ugg.
128	// clearInterval(this.locationTimer);
129	handleBackButton();
130	return;
131	}
132
133	// first check to see if we could have gone forward. We always halt on
134	// a no-hash item.
135	if(forwardStack.length > 0){
136	if(forwardStack[forwardStack.length-1].urlHash === hash){
137	handleForwardButton();
138	return;
139	}
140	}
141
142	// ok, that didn't work, try someplace back in the history stack
143	if((hsl >= 2)&&(historyStack[hsl-2])){
144	if(historyStack[hsl-2].urlHash === hash){
145	handleBackButton();
146	return;
147	}
148	}
a089699c AD	149	}
	150	};
	151
	152	back.init = function(){
81bea17a	153	//summary: Initializes the undo stack. This must be called from a <script>
a089699c AD	154	// block that lives inside the <body> tag to prevent bugs on IE.
	155	// description:
	156	// Only call this method before the page's DOM is finished loading. Otherwise
	157	// it will not work. Be careful with xdomain loading or djConfig.debugAtAllCosts scenarios,
	158	// in order for this method to work, dojo.back will need to be part of a build layer.
	159	if(dojo.byId("dj_history")){ return; } // prevent reinit
	160	var src = dojo.config["dojoIframeHistoryUrl"] \|\| dojo.moduleUrl("dojo", "resources/iframe_history.html");
	161	if (dojo._postLoad) {
	162	console.error("dojo.back.init() must be called before the DOM has loaded. "
	163	+ "If using xdomain loading or djConfig.debugAtAllCosts, include dojo.back "
	164	+ "in a build layer.");
	165	} else {
	166	document.write('<iframe style="border:0;width:1px;height:1px;position:absolute;visibility:hidden;bottom:0;right:0;" name="dj_history" id="dj_history" src="' + src + '"></iframe>');
	167	}
	168	};
	169
	170	back.setInitialState = function(/Object/args){
81bea17a	171	//summary:
a089699c AD	172	// Sets the state object and back callback for the very first page
	173	// that is loaded.
	174	//description:
	175	// It is recommended that you call this method as part of an event
	176	// listener that is registered via dojo.addOnLoad().
	177	//args: Object
	178	// See the addToHistory() function for the list of valid args properties.
	179	initialState = createState(initialHref, args, initialHash);
	180	};
	181
	182	//FIXME: Make these doc comments not be awful. At least they're not wrong.
	183	//FIXME: Would like to support arbitrary back/forward jumps. Have to rework iframeLoaded among other things.
	184	//FIXME: is there a slight race condition in moz using change URL with the timer check and when
	185	// the hash gets set? I think I have seen a back/forward call in quick succession, but not consistent.
	186
	187
	188	/*=====
	189	dojo.__backArgs = function(kwArgs){
	190	// back: Function?
	191	// A function to be called when this state is reached via the user
	192	// clicking the back button.
	193	// forward: Function?
	194	// Upon return to this state from the "back, forward" combination
	195	// of navigation steps, this function will be called. Somewhat
	196	// analgous to the semantic of an "onRedo" event handler.
	197	// changeUrl: Boolean?\|String?
	198	// Boolean indicating whether or not to create a unique hash for
	199	// this state. If a string is passed instead, it is used as the
	200	// hash.
	201	}
	202	=====*/
	203
	204	back.addToHistory = function(/dojo.__backArgs/ args){
81bea17a AD	205	// summary:
81bea17a AD	206	// adds a state object (args) to the history list.
a089699c AD	207	// description:
	208	// To support getting back button notifications, the object
	209	// argument should implement a function called either "back",
	210	// "backButton", or "handle". The string "back" will be passed as
	211	// the first and only argument to this callback.
81bea17a	212	//
a089699c AD	213	// To support getting forward button notifications, the object
	214	// argument should implement a function called either "forward",
	215	// "forwardButton", or "handle". The string "forward" will be
	216	// passed as the first and only argument to this callback.
	217	//
	218	// If you want the browser location string to change, define "changeUrl" on the object. If the
	219	// value of "changeUrl" is true, then a unique number will be appended to the URL as a fragment
	220	// identifier (http://some.domain.com/path#uniquenumber). If it is any other value that does
	221	// not evaluate to false, that value will be used as the fragment identifier. For example,
	222	// if changeUrl: 'page1', then the URL will look like: http://some.domain.com/path#page1
	223	//
	224	// There are problems with using dojo.back with semantically-named fragment identifiers
	225	// ("hash values" on an URL). In most browsers it will be hard for dojo.back to know
	226	// distinguish a back from a forward event in those cases. For back/forward support to
	227	// work best, the fragment ID should always be a unique value (something using new Date().getTime()
	228	// for example). If you want to detect hash changes using semantic fragment IDs, then
	229	// consider using dojo.hash instead (in Dojo 1.4+).
	230	//
	231	// example:
	232	// \| dojo.back.addToHistory({
	233	// \| back: function(){ console.log('back pressed'); },
	234	// \| forward: function(){ console.log('forward pressed'); },
	235	// \| changeUrl: true
	236	// \| });
	237
	238	// BROWSER NOTES:
81bea17a	239	// Safari 1.2:
a089699c AD	240	// back button "works" fine, however it's not possible to actually
	241	// DETECT that you've moved backwards by inspecting window.location.
	242	// Unless there is some other means of locating.
	243	// FIXME: perhaps we can poll on history.length?
	244	// Safari 2.0.3+ (and probably 1.3.2+):
	245	// works fine, except when changeUrl is used. When changeUrl is used,
	246	// Safari jumps all the way back to whatever page was shown before
	247	// the page that uses dojo.undo.browser support.
	248	// IE 5.5 SP2:
	249	// back button behavior is macro. It does not move back to the
	250	// previous hash value, but to the last full page load. This suggests
	251	// that the iframe is the correct way to capture the back button in
	252	// these cases.
81bea17a AD	253	// Don't test this page using local disk for MSIE. MSIE will not create
	254	// a history list for iframe_history.html if served from a file: URL.
	255	// The XML served back from the XHR tests will also not be properly
	256	// created if served from local disk. Serve the test pages from a web
a089699c AD	257	// server to test in that browser.
	258	// IE 6.0:
	259	// same behavior as IE 5.5 SP2
	260	// Firefox 1.0+:
	261	// the back button will return us to the previous hash on the same
	262	// page, thereby not requiring an iframe hack, although we do then
	263	// need to run a timer to detect inter-page movement.
	264
	265	//If addToHistory is called, then that means we prune the
	266	//forward stack -- the user went back, then wanted to
	267	//start a new forward path.
81bea17a	268	forwardStack = [];
a089699c AD	269
	270	var hash = null;
	271	var url = null;
	272	if(!historyIframe){
	273	if(dojo.config["useXDomain"] && !dojo.config["dojoIframeHistoryUrl"]){
	274	console.warn("dojo.back: When using cross-domain Dojo builds,"
	275	+ " please save iframe_history.html to your domain and set djConfig.dojoIframeHistoryUrl"
	276	+ " to the path on your domain to iframe_history.html");
	277	}
	278	historyIframe = window.frames["dj_history"];
	279	}
	280	if(!bookmarkAnchor){
	281	bookmarkAnchor = dojo.create("a", {style: {display: "none"}}, dojo.body());
	282	}
	283	if(args["changeUrl"]){
	284	hash = ""+ ((args["changeUrl"]!==true) ? args["changeUrl"] : (new Date()).getTime());
	285
	286	//If the current hash matches the new one, just replace the history object with
	287	//this new one. It doesn't make sense to track different state objects for the same
	288	//logical URL. This matches the browser behavior of only putting in one history
	289	//item no matter how many times you click on the same #hash link, at least in Firefox
	290	//and Safari, and there is no reliable way in those browsers to know if a #hash link
	291	//has been clicked on multiple times. So making this the standard behavior in all browsers
	292	//so that dojo.back's behavior is the same in all browsers.
	293	if(historyStack.length == 0 && initialState.urlHash == hash){
	294	initialState = createState(url, args, hash);
	295	return;
	296	}else if(historyStack.length > 0 && historyStack[historyStack.length - 1].urlHash == hash){
	297	historyStack[historyStack.length - 1] = createState(url, args, hash);
	298	return;
	299	}
	300
	301	changingUrl = true;
81bea17a AD	302	setTimeout(function() {
	303	setHash(hash);
	304	changingUrl = false;
a089699c AD	305	}, 1);
	306	bookmarkAnchor.href = hash;
	307
	308	if(dojo.isIE){
	309	url = loadIframeHistory();
	310
	311	var oldCB = args["back"]\|\|args["backButton"]\|\|args["handle"];
	312
	313	//The function takes handleName as a parameter, in case the
	314	//callback we are overriding was "handle". In that case,
	315	//we will need to pass the handle name to handle.
	316	var tcb = function(handleName){
	317	if(getHash() != ""){
	318	setTimeout(function() { setHash(hash); }, 1);
	319	}
	320	//Use apply to set "this" to args, and to try to avoid memory leaks.
	321	oldCB.apply(this, [handleName]);
	322	};
	323
	324	//Set interceptor function in the right place.
	325	if(args["back"]){
	326	args.back = tcb;
	327	}else if(args["backButton"]){
	328	args.backButton = tcb;
	329	}else if(args["handle"]){
	330	args.handle = tcb;
	331	}
	332
	333	var oldFW = args["forward"]\|\|args["forwardButton"]\|\|args["handle"];
	334
	335	//The function takes handleName as a parameter, in case the
	336	//callback we are overriding was "handle". In that case,
	337	//we will need to pass the handle name to handle.
	338	var tfw = function(handleName){
	339	if(getHash() != ""){
	340	setHash(hash);
	341	}
	342	if(oldFW){ // we might not actually have one
	343	//Use apply to set "this" to args, and to try to avoid memory leaks.
	344	oldFW.apply(this, [handleName]);
	345	}
	346	};
	347
	348	//Set interceptor function in the right place.
	349	if(args["forward"]){
	350	args.forward = tfw;
	351	}else if(args["forwardButton"]){
	352	args.forwardButton = tfw;
	353	}else if(args["handle"]){
	354	args.handle = tfw;
	355	}
	356
	357	}else if(!dojo.isIE){
	358	// start the timer
	359	if(!locationTimer){
	360	locationTimer = setInterval(checkLocation, 200);
	361	}
	362
	363	}
	364	}else{
	365	url = loadIframeHistory();
	366	}
	367
	368	historyStack.push(createState(url, args, hash));
369	};
370
371	back._iframeLoaded = function(evt, ifrLoc){
81bea17a	372	//summary:
a089699c AD	373	// private method. Do not call this directly.
a089699c AD	374	var query = getUrlQuery(ifrLoc.href);
81bea17a	375	if(query == null){
a089699c AD	376	// alert("iframeLoaded");
	377	// we hit the end of the history, so we should go back
	378	if(historyStack.length == 1){
	379	handleBackButton();
	380	}
	381	return;
	382	}
	383	if(moveForward){
	384	// we were expecting it, so it's not either a forward or backward movement
	385	moveForward = false;
	386	return;
	387	}
	388
	389	//Check the back stack first, since it is more likely.
	390	//Note that only one step back or forward is supported.
	391	if(historyStack.length >= 2 && query == getUrlQuery(historyStack[historyStack.length-2].url)){
	392	handleBackButton();
	393	}else if(forwardStack.length > 0 && query == getUrlQuery(forwardStack[forwardStack.length-1].url)){
	394	handleForwardButton();
	395	}
	396	};
	397	})();
	398
2f01fe57	399	}