This repository has been archived by the owner on Aug 1, 2024. It is now read-only.
-
Notifications
You must be signed in to change notification settings - Fork 0
/
back.js
397 lines (351 loc) · 13.7 KB
/
back.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
define(["./_base/config", "./_base/lang", "./sniff", "./dom", "./dom-construct", "./_base/window", "require"],
function(config, lang, has, dom, domConstruct, baseWindow, require){
// module:
// dojo/back
var back = {
// summary:
// Browser history management resources
};
has("extend-dojo") && lang.setObject("dojo.back", back);
// everyone deals with encoding the hash slightly differently
var getHash = back.getHash = function(){
var h = window.location.hash;
if(h.charAt(0) == "#"){ h = h.substring(1); }
return has("mozilla") ? 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 = (config["dojoIframeHistoryUrl"] || require.toUrl("./resources/iframe_history.html")) + "?" + (new Date()).getTime();
moveForward = true;
if(historyIframe){
has("webkit") ? historyIframe.location = url : window.frames[historyIframe.name].location = url;
}else{
//console.warn("dojo/back: Not initialised. You need to call 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();
}
}
}
}
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.
//
// 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.
// prevent reinit
if(dom.byId("dj_history")){ return; }
var src = config["dojoIframeHistoryUrl"] || require.toUrl("./resources/iframe_history.html");
if (config.afterOnLoad){
console.error("dojo/back::init() must be called before the DOM has loaded. "
+ "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.
//
// It is recommended that you call this method as part of an event
// listener that is registered via dojo/ready.
// 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.
/*=====
var __backArgs = {
// 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
// analogous 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(args){
// summary:
// adds a state object (args) to the history list.
// args: __backArgs
// The state object that will be added 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:
// | 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(config["useXDomain"] && !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 = domConstruct.create("a", {style: {display: "none"}}, baseWindow.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(has("ie")){
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(!has("ie")){
// 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();
}
};
return back;
});