1// Backbone.js 1.6.0
2
3// (c) 2010-2024 Jeremy Ashkenas and DocumentCloud
4// Backbone may be freely distributed under the MIT license.
5// For all details and documentation:
6// http://backbonejs.org
7
8(function(factory) {
9
10 // Establish the root object, `window` (`self`) in the browser, or `global` on the server.
11 // We use `self` instead of `window` for `WebWorker` support.
12 var root = typeof self == 'object' && self.self === self && self ||
13 typeof global == 'object' && global.global === global && global;
14
15 // Set up Backbone appropriately for the environment. Start with AMD.
16 if (typeof define === 'function' && define.amd) {
17 define(['underscore', 'jquery', 'exports'], function(_, $, exports) {
18 // Export global even in AMD case in case this script is loaded with
19 // others that may still expect a global Backbone.
20 root.Backbone = factory(root, exports, _, $);
21 });
22
23 // Next for Node.js or CommonJS. jQuery may not be needed as a module.
24 } else if (typeof exports !== 'undefined') {
25 var _ = require('underscore'), $;
26 try { $ = require('jquery'); } catch (e) {}
27 factory(root, exports, _, $);
28
29 // Finally, as a browser global.
30 } else {
31 root.Backbone = factory(root, {}, root._, root.jQuery || root.Zepto || root.ender || root.$);
32 }
33
34})(function(root, Backbone, _, $) {
35
36 // Initial Setup
37 // -------------
38
39 // Save the previous value of the `Backbone` variable, so that it can be
40 // restored later on, if `noConflict` is used.
41 var previousBackbone = root.Backbone;
42
43 // Create a local reference to a common array method we'll want to use later.
44 var slice = Array.prototype.slice;
45
46 // Current version of the library. Keep in sync with `package.json`.
47 Backbone.VERSION = '1.6.0';
48
49 // For Backbone's purposes, jQuery, Zepto, Ender, or My Library (kidding) owns
50 // the `$` variable.
51 Backbone.$ = $;
52
53 // Runs Backbone.js in *noConflict* mode, returning the `Backbone` variable
54 // to its previous owner. Returns a reference to this Backbone object.
55 Backbone.noConflict = function() {
56 root.Backbone = previousBackbone;
57 return this;
58 };
59
60 // Turn on `emulateHTTP` to support legacy HTTP servers. Setting this option
61 // will fake `"PATCH"`, `"PUT"` and `"DELETE"` requests via the `_method` parameter and
62 // set a `X-Http-Method-Override` header.
63 Backbone.emulateHTTP = false;
64
65 // Turn on `emulateJSON` to support legacy servers that can't deal with direct
66 // `application/json` requests ... this will encode the body as
67 // `application/x-www-form-urlencoded` instead and will send the model in a
68 // form param named `model`.
69 Backbone.emulateJSON = false;
70
71 // Backbone.Events
72 // ---------------
73
74 // A module that can be mixed in to *any object* in order to provide it with
75 // a custom event channel. You may bind a callback to an event with `on` or
76 // remove with `off`; `trigger`-ing an event fires all callbacks in
77 // succession.
78 //
79 // var object = {};
80 // _.extend(object, Backbone.Events);
81 // object.on('expand', function(){ alert('expanded'); });
82 // object.trigger('expand');
83 //
84 var Events = Backbone.Events = {};
85
86 // Regular expression used to split event strings.
87 var eventSplitter = /\s+/;
88
89 // A private global variable to share between listeners and listenees.
90 var _listening;
91
92 // Iterates over the standard `event, callback` (as well as the fancy multiple
93 // space-separated events `"change blur", callback` and jQuery-style event
94 // maps `{event: callback}`).
95 var eventsApi = function(iteratee, events, name, callback, opts) {
96 var i = 0, names;
97 if (name && typeof name === 'object') {
98 // Handle event maps.
99 if (callback !== void 0 && 'context' in opts && opts.context === void 0) opts.context = callback;
100 for (names = _.keys(name); i < names.length ; i++) {
101 events = eventsApi(iteratee, events, names[i], name[names[i]], opts);
102 }
103 } else if (name && eventSplitter.test(name)) {
104 // Handle space-separated event names by delegating them individually.
105 for (names = name.split(eventSplitter); i < names.length; i++) {
106 events = iteratee(events, names[i], callback, opts);
107 }
108 } else {
109 // Finally, standard events.
110 events = iteratee(events, name, callback, opts);
111 }
112 return events;
113 };
114
115 // Bind an event to a `callback` function. Passing `"all"` will bind
116 // the callback to all events fired.
117 Events.on = function(name, callback, context) {
118 this._events = eventsApi(onApi, this._events || {}, name, callback, {
119 context: context,
120 ctx: this,
121 listening: _listening
122 });
123
124 if (_listening) {
125 var listeners = this._listeners || (this._listeners = {});
126 listeners[_listening.id] = _listening;
127 // Allow the listening to use a counter, instead of tracking
128 // callbacks for library interop
129 _listening.interop = false;
130 }
131
132 return this;
133 };
134
135 // Inversion-of-control versions of `on`. Tell *this* object to listen to
136 // an event in another object... keeping track of what it's listening to
137 // for easier unbinding later.
138 Events.listenTo = function(obj, name, callback) {
139 if (!obj) return this;
140 var id = obj._listenId || (obj._listenId = _.uniqueId('l'));
141 var listeningTo = this._listeningTo || (this._listeningTo = {});
142 var listening = _listening = listeningTo[id];
143
144 // This object is not listening to any other events on `obj` yet.
145 // Setup the necessary references to track the listening callbacks.
146 if (!listening) {
147 this._listenId || (this._listenId = _.uniqueId('l'));
148 listening = _listening = listeningTo[id] = new Listening(this, obj);
149 }
150
151 // Bind callbacks on obj.
152 var error = tryCatchOn(obj, name, callback, this);
153 _listening = void 0;
154
155 if (error) throw error;
156 // If the target obj is not Backbone.Events, track events manually.
157 if (listening.interop) listening.on(name, callback);
158
159 return this;
160 };
161
162 // The reducing API that adds a callback to the `events` object.
163 var onApi = function(events, name, callback, options) {
164 if (callback) {
165 var handlers = events[name] || (events[name] = []);
166 var context = options.context, ctx = options.ctx, listening = options.listening;
167 if (listening) listening.count++;
168
169 handlers.push({callback: callback, context: context, ctx: context || ctx, listening: listening});
170 }
171 return events;
172 };
173
174 // An try-catch guarded #on function, to prevent poisoning the global
175 // `_listening` variable.
176 var tryCatchOn = function(obj, name, callback, context) {
177 try {
178 obj.on(name, callback, context);
179 } catch (e) {
180 return e;
181 }
182 };
183
184 // Remove one or many callbacks. If `context` is null, removes all
185 // callbacks with that function. If `callback` is null, removes all
186 // callbacks for the event. If `name` is null, removes all bound
187 // callbacks for all events.
188 Events.off = function(name, callback, context) {
189 if (!this._events) return this;
190 this._events = eventsApi(offApi, this._events, name, callback, {
191 context: context,
192 listeners: this._listeners
193 });
194
195 return this;
196 };
197
198 // Tell this object to stop listening to either specific events ... or
199 // to every object it's currently listening to.
200 Events.stopListening = function(obj, name, callback) {
201 var listeningTo = this._listeningTo;
202 if (!listeningTo) return this;
203
204 var ids = obj ? [obj._listenId] : _.keys(listeningTo);
205 for (var i = 0; i < ids.length; i++) {
206 var listening = listeningTo[ids[i]];
207
208 // If listening doesn't exist, this object is not currently
209 // listening to obj. Break out early.
210 if (!listening) break;
211
212 listening.obj.off(name, callback, this);
213 if (listening.interop) listening.off(name, callback);
214 }
215 if (_.isEmpty(listeningTo)) this._listeningTo = void 0;
216
217 return this;
218 };
219
220 // The reducing API that removes a callback from the `events` object.
221 var offApi = function(events, name, callback, options) {
222 if (!events) return;
223
224 var context = options.context, listeners = options.listeners;
225 var i = 0, names;
226
227 // Delete all event listeners and "drop" events.
228 if (!name && !context && !callback) {
229 for (names = _.keys(listeners); i < names.length; i++) {
230 listeners[names[i]].cleanup();
231 }
232 return;
233 }
234
235 names = name ? [name] : _.keys(events);
236 for (; i < names.length; i++) {
237 name = names[i];
238 var handlers = events[name];
239
240 // Bail out if there are no events stored.
241 if (!handlers) break;
242
243 // Find any remaining events.
244 var remaining = [];
245 for (var j = 0; j < handlers.length; j++) {
246 var handler = handlers[j];
247 if (
248 callback && callback !== handler.callback &&
249 callback !== handler.callback._callback ||
250 context && context !== handler.context
251 ) {
252 remaining.push(handler);
253 } else {
254 var listening = handler.listening;
255 if (listening) listening.off(name, callback);
256 }
257 }
258
259 // Replace events if there are any remaining. Otherwise, clean up.
260 if (remaining.length) {
261 events[name] = remaining;
262 } else {
263 delete events[name];
264 }
265 }
266
267 return events;
268 };
269
270 // Bind an event to only be triggered a single time. After the first time
271 // the callback is invoked, its listener will be removed. If multiple events
272 // are passed in using the space-separated syntax, the handler will fire
273 // once for each event, not once for a combination of all events.
274 Events.once = function(name, callback, context) {
275 // Map the event into a `{event: once}` object.
276 var events = eventsApi(onceMap, {}, name, callback, this.off.bind(this));
277 if (typeof name === 'string' && context == null) callback = void 0;
278 return this.on(events, callback, context);
279 };
280
281 // Inversion-of-control versions of `once`.
282 Events.listenToOnce = function(obj, name, callback) {
283 // Map the event into a `{event: once}` object.
284 var events = eventsApi(onceMap, {}, name, callback, this.stopListening.bind(this, obj));
285 return this.listenTo(obj, events);
286 };
287
288 // Reduces the event callbacks into a map of `{event: onceWrapper}`.
289 // `offer` unbinds the `onceWrapper` after it has been called.
290 var onceMap = function(map, name, callback, offer) {
291 if (callback) {
292 var once = map[name] = _.once(function() {
293 offer(name, once);
294 callback.apply(this, arguments);
295 });
296 once._callback = callback;
297 }
298 return map;
299 };
300
301 // Trigger one or many events, firing all bound callbacks. Callbacks are
302 // passed the same arguments as `trigger` is, apart from the event name
303 // (unless you're listening on `"all"`, which will cause your callback to
304 // receive the true name of the event as the first argument).
305 Events.trigger = function(name) {
306 if (!this._events) return this;
307
308 var length = Math.max(0, arguments.length - 1);
309 var args = Array(length);
310 for (var i = 0; i < length; i++) args[i] = arguments[i + 1];
311
312 eventsApi(triggerApi, this._events, name, void 0, args);
313 return this;
314 };
315
316 // Handles triggering the appropriate event callbacks.
317 var triggerApi = function(objEvents, name, callback, args) {
318 if (objEvents) {
319 var events = objEvents[name];
320 var allEvents = objEvents.all;
321 if (events && allEvents) allEvents = allEvents.slice();
322 if (events) triggerEvents(events, args);
323 if (allEvents) triggerEvents(allEvents, [name].concat(args));
324 }
325 return objEvents;
326 };
327
328 // A difficult-to-believe, but optimized internal dispatch function for
329 // triggering events. Tries to keep the usual cases speedy (most internal
330 // Backbone events have 3 arguments).
331 var triggerEvents = function(events, args) {
332 var ev, i = -1, l = events.length, a1 = args[0], a2 = args[1], a3 = args[2];
333 switch (args.length) {
334 case 0: while (++i < l) (ev = events[i]).callback.call(ev.ctx); return;
335 case 1: while (++i < l) (ev = events[i]).callback.call(ev.ctx, a1); return;
336 case 2: while (++i < l) (ev = events[i]).callback.call(ev.ctx, a1, a2); return;
337 case 3: while (++i < l) (ev = events[i]).callback.call(ev.ctx, a1, a2, a3); return;
338 default: while (++i < l) (ev = events[i]).callback.apply(ev.ctx, args); return;
339 }
340 };
341
342 // A listening class that tracks and cleans up memory bindings
343 // when all callbacks have been offed.
344 var Listening = function(listener, obj) {
345 this.id = listener._listenId;
346 this.listener = listener;
347 this.obj = obj;
348 this.interop = true;
349 this.count = 0;
350 this._events = void 0;
351 };
352
353 Listening.prototype.on = Events.on;
354
355 // Offs a callback (or several).
356 // Uses an optimized counter if the listenee uses Backbone.Events.
357 // Otherwise, falls back to manual tracking to support events
358 // library interop.
359 Listening.prototype.off = function(name, callback) {
360 var cleanup;
361 if (this.interop) {
362 this._events = eventsApi(offApi, this._events, name, callback, {
363 context: void 0,
364 listeners: void 0
365 });
366 cleanup = !this._events;
367 } else {
368 this.count--;
369 cleanup = this.count === 0;
370 }
371 if (cleanup) this.cleanup();
372 };
373
374 // Cleans up memory bindings between the listener and the listenee.
375 Listening.prototype.cleanup = function() {
376 delete this.listener._listeningTo[this.obj._listenId];
377 if (!this.interop) delete this.obj._listeners[this.id];
378 };
379
380 // Aliases for backwards compatibility.
381 Events.bind = Events.on;
382 Events.unbind = Events.off;
383
384 // Allow the `Backbone` object to serve as a global event bus, for folks who
385 // want global "pubsub" in a convenient place.
386 _.extend(Backbone, Events);
387
388 // Backbone.Model
389 // --------------
390
391 // Backbone **Models** are the basic data object in the framework --
392 // frequently representing a row in a table in a database on your server.
393 // A discrete chunk of data and a bunch of useful, related methods for
394 // performing computations and transformations on that data.
395
396 // Create a new model with the specified attributes. A client id (`cid`)
397 // is automatically generated and assigned for you.
398 var Model = Backbone.Model = function(attributes, options) {
399 var attrs = attributes || {};
400 options || (options = {});
401 this.preinitialize.apply(this, arguments);
402 this.cid = _.uniqueId(this.cidPrefix);
403 this.attributes = {};
404 if (options.collection) this.collection = options.collection;
405 if (options.parse) attrs = this.parse(attrs, options) || {};
406 var defaults = _.result(this, 'defaults');
407
408 // Just _.defaults would work fine, but the additional _.extends
409 // is in there for historical reasons. See #3843.
410 attrs = _.defaults(_.extend({}, defaults, attrs), defaults);
411
412 this.set(attrs, options);
413 this.changed = {};
414 this.initialize.apply(this, arguments);
415 };
416
417 // Attach all inheritable methods to the Model prototype.
418 _.extend(Model.prototype, Events, {
419
420 // A hash of attributes whose current and previous value differ.
421 changed: null,
422
423 // The value returned during the last failed validation.
424 validationError: null,
425
426 // The default name for the JSON `id` attribute is `"id"`. MongoDB and
427 // CouchDB users may want to set this to `"_id"`.
428 idAttribute: 'id',
429
430 // The prefix is used to create the client id which is used to identify models locally.
431 // You may want to override this if you're experiencing name clashes with model ids.
432 cidPrefix: 'c',
433
434 // preinitialize is an empty function by default. You can override it with a function
435 // or object. preinitialize will run before any instantiation logic is run in the Model.
436 preinitialize: function(){},
437
438 // Initialize is an empty function by default. Override it with your own
439 // initialization logic.
440 initialize: function(){},
441
442 // Return a copy of the model's `attributes` object.
443 toJSON: function(options) {
444 return _.clone(this.attributes);
445 },
446
447 // Proxy `Backbone.sync` by default -- but override this if you need
448 // custom syncing semantics for *this* particular model.
449 sync: function() {
450 return Backbone.sync.apply(this, arguments);
451 },
452
453 // Get the value of an attribute.
454 get: function(attr) {
455 return this.attributes[attr];
456 },
457
458 // Get the HTML-escaped value of an attribute.
459 escape: function(attr) {
460 return _.escape(this.get(attr));
461 },
462
463 // Returns `true` if the attribute contains a value that is not null
464 // or undefined.
465 has: function(attr) {
466 return this.get(attr) != null;
467 },
468
469 // Special-cased proxy to underscore's `_.matches` method.
470 matches: function(attrs) {
471 return !!_.iteratee(attrs, this)(this.attributes);
472 },
473
474 // Set a hash of model attributes on the object, firing `"change"`. This is
475 // the core primitive operation of a model, updating the data and notifying
476 // anyone who needs to know about the change in state. The heart of the beast.
477 set: function(key, val, options) {
478 if (key == null) return this;
479
480 // Handle both `"key", value` and `{key: value}` -style arguments.
481 var attrs;
482 if (typeof key === 'object') {
483 attrs = key;
484 options = val;
485 } else {
486 (attrs = {})[key] = val;
487 }
488
489 options || (options = {});
490
491 // Run validation.
492 if (!this._validate(attrs, options)) return false;
493
494 // Extract attributes and options.
495 var unset = options.unset;
496 var silent = options.silent;
497 var changes = [];
498 var changing = this._changing;
499 this._changing = true;
500
501 if (!changing) {
502 this._previousAttributes = _.clone(this.attributes);
503 this.changed = {};
504 }
505
506 var current = this.attributes;
507 var changed = this.changed;
508 var prev = this._previousAttributes;
509
510 // For each `set` attribute, update or delete the current value.
511 for (var attr in attrs) {
512 val = attrs[attr];
513 if (!_.isEqual(current[attr], val)) changes.push(attr);
514 if (!_.isEqual(prev[attr], val)) {
515 changed[attr] = val;
516 } else {
517 delete changed[attr];
518 }
519 unset ? delete current[attr] : current[attr] = val;
520 }
521
522 // Update the `id`.
523 if (this.idAttribute in attrs) {
524 var prevId = this.id;
525 this.id = this.get(this.idAttribute);
526 this.trigger('changeId', this, prevId, options);
527 }
528
529 // Trigger all relevant attribute changes.
530 if (!silent) {
531 if (changes.length) this._pending = options;
532 for (var i = 0; i < changes.length; i++) {
533 this.trigger('change:' + changes[i], this, current[changes[i]], options);
534 }
535 }
536
537 // You might be wondering why there's a `while` loop here. Changes can
538 // be recursively nested within `"change"` events.
539 if (changing) return this;
540 if (!silent) {
541 while (this._pending) {
542 options = this._pending;
543 this._pending = false;
544 this.trigger('change', this, options);
545 }
546 }
547 this._pending = false;
548 this._changing = false;
549 return this;
550 },
551
552 // Remove an attribute from the model, firing `"change"`. `unset` is a noop
553 // if the attribute doesn't exist.
554 unset: function(attr, options) {
555 return this.set(attr, void 0, _.extend({}, options, {unset: true}));
556 },
557
558 // Clear all attributes on the model, firing `"change"`.
559 clear: function(options) {
560 var attrs = {};
561 for (var key in this.attributes) attrs[key] = void 0;
562 return this.set(attrs, _.extend({}, options, {unset: true}));
563 },
564
565 // Determine if the model has changed since the last `"change"` event.
566 // If you specify an attribute name, determine if that attribute has changed.
567 hasChanged: function(attr) {
568 if (attr == null) return !_.isEmpty(this.changed);
569 return _.has(this.changed, attr);
570 },
571
572 // Return an object containing all the attributes that have changed, or
573 // false if there are no changed attributes. Useful for determining what
574 // parts of a view need to be updated and/or what attributes need to be
575 // persisted to the server. Unset attributes will be set to undefined.
576 // You can also pass an attributes object to diff against the model,
577 // determining if there *would be* a change.
578 changedAttributes: function(diff) {
579 if (!diff) return this.hasChanged() ? _.clone(this.changed) : false;
580 var old = this._changing ? this._previousAttributes : this.attributes;
581 var changed = {};
582 var hasChanged;
583 for (var attr in diff) {
584 var val = diff[attr];
585 if (_.isEqual(old[attr], val)) continue;
586 changed[attr] = val;
587 hasChanged = true;
588 }
589 return hasChanged ? changed : false;
590 },
591
592 // Get the previous value of an attribute, recorded at the time the last
593 // `"change"` event was fired.
594 previous: function(attr) {
595 if (attr == null || !this._previousAttributes) return null;
596 return this._previousAttributes[attr];
597 },
598
599 // Get all of the attributes of the model at the time of the previous
600 // `"change"` event.
601 previousAttributes: function() {
602 return _.clone(this._previousAttributes);
603 },
604
605 // Fetch the model from the server, merging the response with the model's
606 // local attributes. Any changed attributes will trigger a "change" event.
607 fetch: function(options) {
608 options = _.extend({parse: true}, options);
609 var model = this;
610 var success = options.success;
611 options.success = function(resp) {
612 var serverAttrs = options.parse ? model.parse(resp, options) : resp;
613 if (!model.set(serverAttrs, options)) return false;
614 if (success) success.call(options.context, model, resp, options);
615 model.trigger('sync', model, resp, options);
616 };
617 wrapError(this, options);
618 return this.sync('read', this, options);
619 },
620
621 // Set a hash of model attributes, and sync the model to the server.
622 // If the server returns an attributes hash that differs, the model's
623 // state will be `set` again.
624 save: function(key, val, options) {
625 // Handle both `"key", value` and `{key: value}` -style arguments.
626 var attrs;
627 if (key == null || typeof key === 'object') {
628 attrs = key;
629 options = val;
630 } else {
631 (attrs = {})[key] = val;
632 }
633
634 options = _.extend({validate: true, parse: true}, options);
635 var wait = options.wait;
636
637 // If we're not waiting and attributes exist, save acts as
638 // `set(attr).save(null, opts)` with validation. Otherwise, check if
639 // the model will be valid when the attributes, if any, are set.
640 if (attrs && !wait) {
641 if (!this.set(attrs, options)) return false;
642 } else if (!this._validate(attrs, options)) {
643 return false;
644 }
645
646 // After a successful server-side save, the client is (optionally)
647 // updated with the server-side state.
648 var model = this;
649 var success = options.success;
650 var attributes = this.attributes;
651 options.success = function(resp) {
652 // Ensure attributes are restored during synchronous saves.
653 model.attributes = attributes;
654 var serverAttrs = options.parse ? model.parse(resp, options) : resp;
655 if (wait) serverAttrs = _.extend({}, attrs, serverAttrs);
656 if (serverAttrs && !model.set(serverAttrs, options)) return false;
657 if (success) success.call(options.context, model, resp, options);
658 model.trigger('sync', model, resp, options);
659 };
660 wrapError(this, options);
661
662 // Set temporary attributes if `{wait: true}` to properly find new ids.
663 if (attrs && wait) this.attributes = _.extend({}, attributes, attrs);
664
665 var method = this.isNew() ? 'create' : options.patch ? 'patch' : 'update';
666 if (method === 'patch' && !options.attrs) options.attrs = attrs;
667 var xhr = this.sync(method, this, options);
668
669 // Restore attributes.
670 this.attributes = attributes;
671
672 return xhr;
673 },
674
675 // Destroy this model on the server if it was already persisted.
676 // Optimistically removes the model from its collection, if it has one.
677 // If `wait: true` is passed, waits for the server to respond before removal.
678 destroy: function(options) {
679 options = options ? _.clone(options) : {};
680 var model = this;
681 var success = options.success;
682 var wait = options.wait;
683
684 var destroy = function() {
685 model.stopListening();
686 model.trigger('destroy', model, model.collection, options);
687 };
688
689 options.success = function(resp) {
690 if (wait) destroy();
691 if (success) success.call(options.context, model, resp, options);
692 if (!model.isNew()) model.trigger('sync', model, resp, options);
693 };
694
695 var xhr = false;
696 if (this.isNew()) {
697 _.defer(options.success);
698 } else {
699 wrapError(this, options);
700 xhr = this.sync('delete', this, options);
701 }
702 if (!wait) destroy();
703 return xhr;
704 },
705
706 // Default URL for the model's representation on the server -- if you're
707 // using Backbone's restful methods, override this to change the endpoint
708 // that will be called.
709 url: function() {
710 var base =
711 _.result(this, 'urlRoot') ||
712 _.result(this.collection, 'url') ||
713 urlError();
714 if (this.isNew()) return base;
715 var id = this.get(this.idAttribute);
716 return base.replace(/[^\/]$/, '$&/') + encodeURIComponent(id);
717 },
718
719 // **parse** converts a response into the hash of attributes to be `set` on
720 // the model. The default implementation is just to pass the response along.
721 parse: function(resp, options) {
722 return resp;
723 },
724
725 // Create a new model with identical attributes to this one.
726 clone: function() {
727 return new this.constructor(this.attributes);
728 },
729
730 // A model is new if it has never been saved to the server, and lacks an id.
731 isNew: function() {
732 return !this.has(this.idAttribute);
733 },
734
735 // Check if the model is currently in a valid state.
736 isValid: function(options) {
737 return this._validate({}, _.extend({}, options, {validate: true}));
738 },
739
740 // Run validation against the next complete set of model attributes,
741 // returning `true` if all is well. Otherwise, fire an `"invalid"` event.
742 _validate: function(attrs, options) {
743 if (!options.validate || !this.validate) return true;
744 attrs = _.extend({}, this.attributes, attrs);
745 var error = this.validationError = this.validate(attrs, options) || null;
746 if (!error) return true;
747 this.trigger('invalid', this, error, _.extend(options, {validationError: error}));
748 return false;
749 }
750
751 });
752
753 // Backbone.Collection
754 // -------------------
755
756 // If models tend to represent a single row of data, a Backbone Collection is
757 // more analogous to a table full of data ... or a small slice or page of that
758 // table, or a collection of rows that belong together for a particular reason
759 // -- all of the messages in this particular folder, all of the documents
760 // belonging to this particular author, and so on. Collections maintain
761 // indexes of their models, both in order, and for lookup by `id`.
762
763 // Create a new **Collection**, perhaps to contain a specific type of `model`.
764 // If a `comparator` is specified, the Collection will maintain
765 // its models in sort order, as they're added and removed.
766 var Collection = Backbone.Collection = function(models, options) {
767 options || (options = {});
768 this.preinitialize.apply(this, arguments);
769 if (options.model) this.model = options.model;
770 if (options.comparator !== void 0) this.comparator = options.comparator;
771 this._reset();
772 this.initialize.apply(this, arguments);
773 if (models) this.reset(models, _.extend({silent: true}, options));
774 };
775
776 // Default options for `Collection#set`.
777 var setOptions = {add: true, remove: true, merge: true};
778 var addOptions = {add: true, remove: false};
779
780 // Splices `insert` into `array` at index `at`.
781 var splice = function(array, insert, at) {
782 at = Math.min(Math.max(at, 0), array.length);
783 var tail = Array(array.length - at);
784 var length = insert.length;
785 var i;
786 for (i = 0; i < tail.length; i++) tail[i] = array[i + at];
787 for (i = 0; i < length; i++) array[i + at] = insert[i];
788 for (i = 0; i < tail.length; i++) array[i + length + at] = tail[i];
789 };
790
791 // Define the Collection's inheritable methods.
792 _.extend(Collection.prototype, Events, {
793
794 // The default model for a collection is just a **Backbone.Model**.
795 // This should be overridden in most cases.
796 model: Model,
797
798
799 // preinitialize is an empty function by default. You can override it with a function
800 // or object. preinitialize will run before any instantiation logic is run in the Collection.
801 preinitialize: function(){},
802
803 // Initialize is an empty function by default. Override it with your own
804 // initialization logic.
805 initialize: function(){},
806
807 // The JSON representation of a Collection is an array of the
808 // models' attributes.
809 toJSON: function(options) {
810 return this.map(function(model) { return model.toJSON(options); });
811 },
812
813 // Proxy `Backbone.sync` by default.
814 sync: function() {
815 return Backbone.sync.apply(this, arguments);
816 },
817
818 // Add a model, or list of models to the set. `models` may be Backbone
819 // Models or raw JavaScript objects to be converted to Models, or any
820 // combination of the two.
821 add: function(models, options) {
822 return this.set(models, _.extend({merge: false}, options, addOptions));
823 },
824
825 // Remove a model, or a list of models from the set.
826 remove: function(models, options) {
827 options = _.extend({}, options);
828 var singular = !_.isArray(models);
829 models = singular ? [models] : models.slice();
830 var removed = this._removeModels(models, options);
831 if (!options.silent && removed.length) {
832 options.changes = {added: [], merged: [], removed: removed};
833 this.trigger('update', this, options);
834 }
835 return singular ? removed[0] : removed;
836 },
837
838 // Update a collection by `set`-ing a new list of models, adding new ones,
839 // removing models that are no longer present, and merging models that
840 // already exist in the collection, as necessary. Similar to **Model#set**,
841 // the core operation for updating the data contained by the collection.
842 set: function(models, options) {
843 if (models == null) return;
844
845 options = _.extend({}, setOptions, options);
846 if (options.parse && !this._isModel(models)) {
847 models = this.parse(models, options) || [];
848 }
849
850 var singular = !_.isArray(models);
851 models = singular ? [models] : models.slice();
852
853 var at = options.at;
854 if (at != null) at = +at;
855 if (at > this.length) at = this.length;
856 if (at < 0) at += this.length + 1;
857
858 var set = [];
859 var toAdd = [];
860 var toMerge = [];
861 var toRemove = [];
862 var modelMap = {};
863
864 var add = options.add;
865 var merge = options.merge;
866 var remove = options.remove;
867
868 var sort = false;
869 var sortable = this.comparator && at == null && options.sort !== false;
870 var sortAttr = _.isString(this.comparator) ? this.comparator : null;
871
872 // Turn bare objects into model references, and prevent invalid models
873 // from being added.
874 var model, i;
875 for (i = 0; i < models.length; i++) {
876 model = models[i];
877
878 // If a duplicate is found, prevent it from being added and
879 // optionally merge it into the existing model.
880 var existing = this.get(model);
881 if (existing) {
882 if (merge && model !== existing) {
883 var attrs = this._isModel(model) ? model.attributes : model;
884 if (options.parse) attrs = existing.parse(attrs, options);
885 existing.set(attrs, options);
886 toMerge.push(existing);
887 if (sortable && !sort) sort = existing.hasChanged(sortAttr);
888 }
889 if (!modelMap[existing.cid]) {
890 modelMap[existing.cid] = true;
891 set.push(existing);
892 }
893 models[i] = existing;
894
895 // If this is a new, valid model, push it to the `toAdd` list.
896 } else if (add) {
897 model = models[i] = this._prepareModel(model, options);
898 if (model) {
899 toAdd.push(model);
900 this._addReference(model, options);
901 modelMap[model.cid] = true;
902 set.push(model);
903 }
904 }
905 }
906
907 // Remove stale models.
908 if (remove) {
909 for (i = 0; i < this.length; i++) {
910 model = this.models[i];
911 if (!modelMap[model.cid]) toRemove.push(model);
912 }
913 if (toRemove.length) this._removeModels(toRemove, options);
914 }
915
916 // See if sorting is needed, update `length` and splice in new models.
917 var orderChanged = false;
918 var replace = !sortable && add && remove;
919 if (set.length && replace) {
920 orderChanged = this.length !== set.length || _.some(this.models, function(m, index) {
921 return m !== set[index];
922 });
923 this.models.length = 0;
924 splice(this.models, set, 0);
925 this.length = this.models.length;
926 } else if (toAdd.length) {
927 if (sortable) sort = true;
928 splice(this.models, toAdd, at == null ? this.length : at);
929 this.length = this.models.length;
930 }
931
932 // Silently sort the collection if appropriate.
933 if (sort) this.sort({silent: true});
934
935 // Unless silenced, it's time to fire all appropriate add/sort/update events.
936 if (!options.silent) {
937 for (i = 0; i < toAdd.length; i++) {
938 if (at != null) options.index = at + i;
939 model = toAdd[i];
940 model.trigger('add', model, this, options);
941 }
942 if (sort || orderChanged) this.trigger('sort', this, options);
943 if (toAdd.length || toRemove.length || toMerge.length) {
944 options.changes = {
945 added: toAdd,
946 removed: toRemove,
947 merged: toMerge
948 };
949 this.trigger('update', this, options);
950 }
951 }
952
953 // Return the added (or merged) model (or models).
954 return singular ? models[0] : models;
955 },
956
957 // When you have more items than you want to add or remove individually,
958 // you can reset the entire set with a new list of models, without firing
959 // any granular `add` or `remove` events. Fires `reset` when finished.
960 // Useful for bulk operations and optimizations.
961 reset: function(models, options) {
962 options = options ? _.clone(options) : {};
963 for (var i = 0; i < this.models.length; i++) {
964 this._removeReference(this.models[i], options);
965 }
966 options.previousModels = this.models;
967 this._reset();
968 models = this.add(models, _.extend({silent: true}, options));
969 if (!options.silent) this.trigger('reset', this, options);
970 return models;
971 },
972
973 // Add a model to the end of the collection.
974 push: function(model, options) {
975 return this.add(model, _.extend({at: this.length}, options));
976 },
977
978 // Remove a model from the end of the collection.
979 pop: function(options) {
980 var model = this.at(this.length - 1);
981 return this.remove(model, options);
982 },
983
984 // Add a model to the beginning of the collection.
985 unshift: function(model, options) {
986 return this.add(model, _.extend({at: 0}, options));
987 },
988
989 // Remove a model from the beginning of the collection.
990 shift: function(options) {
991 var model = this.at(0);
992 return this.remove(model, options);
993 },
994
995 // Slice out a sub-array of models from the collection.
996 slice: function() {
997 return slice.apply(this.models, arguments);
998 },
999
1000 // Get a model from the set by id, cid, model object with id or cid
1001 // properties, or an attributes object that is transformed through modelId.
1002 get: function(obj) {
1003 if (obj == null) return void 0;
1004 return this._byId[obj] ||
1005 this._byId[this.modelId(this._isModel(obj) ? obj.attributes : obj, obj.idAttribute)] ||
1006 obj.cid && this._byId[obj.cid];
1007 },
1008
1009 // Returns `true` if the model is in the collection.
1010 has: function(obj) {
1011 return this.get(obj) != null;
1012 },
1013
1014 // Get the model at the given index.
1015 at: function(index) {
1016 if (index < 0) index += this.length;
1017 return this.models[index];
1018 },
1019
1020 // Return models with matching attributes. Useful for simple cases of
1021 // `filter`.
1022 where: function(attrs, first) {
1023 return this[first ? 'find' : 'filter'](attrs);
1024 },
1025
1026 // Return the first model with matching attributes. Useful for simple cases
1027 // of `find`.
1028 findWhere: function(attrs) {
1029 return this.where(attrs, true);
1030 },
1031
1032 // Force the collection to re-sort itself. You don't need to call this under
1033 // normal circumstances, as the set will maintain sort order as each item
1034 // is added.
1035 sort: function(options) {
1036 var comparator = this.comparator;
1037 if (!comparator) throw new Error('Cannot sort a set without a comparator');
1038 options || (options = {});
1039
1040 var length = comparator.length;
1041 if (_.isFunction(comparator)) comparator = comparator.bind(this);
1042
1043 // Run sort based on type of `comparator`.
1044 if (length === 1 || _.isString(comparator)) {
1045 this.models = this.sortBy(comparator);
1046 } else {
1047 this.models.sort(comparator);
1048 }
1049 if (!options.silent) this.trigger('sort', this, options);
1050 return this;
1051 },
1052
1053 // Pluck an attribute from each model in the collection.
1054 pluck: function(attr) {
1055 return this.map(attr + '');
1056 },
1057
1058 // Fetch the default set of models for this collection, resetting the
1059 // collection when they arrive. If `reset: true` is passed, the response
1060 // data will be passed through the `reset` method instead of `set`.
1061 fetch: function(options) {
1062 options = _.extend({parse: true}, options);
1063 var success = options.success;
1064 var collection = this;
1065 options.success = function(resp) {
1066 var method = options.reset ? 'reset' : 'set';
1067 collection[method](resp, options);
1068 if (success) success.call(options.context, collection, resp, options);
1069 collection.trigger('sync', collection, resp, options);
1070 };
1071 wrapError(this, options);
1072 return this.sync('read', this, options);
1073 },
1074
1075 // Create a new instance of a model in this collection. Add the model to the
1076 // collection immediately, unless `wait: true` is passed, in which case we
1077 // wait for the server to agree.
1078 create: function(model, options) {
1079 options = options ? _.clone(options) : {};
1080 var wait = options.wait;
1081 model = this._prepareModel(model, options);
1082 if (!model) return false;
1083 if (!wait) this.add(model, options);
1084 var collection = this;
1085 var success = options.success;
1086 options.success = function(m, resp, callbackOpts) {
1087 if (wait) {
1088 m.off('error', collection._forwardPristineError, collection);
1089 collection.add(m, callbackOpts);
1090 }
1091 if (success) success.call(callbackOpts.context, m, resp, callbackOpts);
1092 };
1093 // In case of wait:true, our collection is not listening to any
1094 // of the model's events yet, so it will not forward the error
1095 // event. In this special case, we need to listen for it
1096 // separately and handle the event just once.
1097 // (The reason we don't need to do this for the sync event is
1098 // in the success handler above: we add the model first, which
1099 // causes the collection to listen, and then invoke the callback
1100 // that triggers the event.)
1101 if (wait) {
1102 model.once('error', this._forwardPristineError, this);
1103 }
1104 model.save(null, options);
1105 return model;
1106 },
1107
1108 // **parse** converts a response into a list of models to be added to the
1109 // collection. The default implementation is just to pass it through.
1110 parse: function(resp, options) {
1111 return resp;
1112 },
1113
1114 // Create a new collection with an identical list of models as this one.
1115 clone: function() {
1116 return new this.constructor(this.models, {
1117 model: this.model,
1118 comparator: this.comparator
1119 });
1120 },
1121
1122 // Define how to uniquely identify models in the collection.
1123 modelId: function(attrs, idAttribute) {
1124 return attrs[idAttribute || this.model.prototype.idAttribute || 'id'];
1125 },
1126
1127 // Get an iterator of all models in this collection.
1128 values: function() {
1129 return new CollectionIterator(this, ITERATOR_VALUES);
1130 },
1131
1132 // Get an iterator of all model IDs in this collection.
1133 keys: function() {
1134 return new CollectionIterator(this, ITERATOR_KEYS);
1135 },
1136
1137 // Get an iterator of all [ID, model] tuples in this collection.
1138 entries: function() {
1139 return new CollectionIterator(this, ITERATOR_KEYSVALUES);
1140 },
1141
1142 // Private method to reset all internal state. Called when the collection
1143 // is first initialized or reset.
1144 _reset: function() {
1145 this.length = 0;
1146 this.models = [];
1147 this._byId = {};
1148 },
1149
1150 // Prepare a hash of attributes (or other model) to be added to this
1151 // collection.
1152 _prepareModel: function(attrs, options) {
1153 if (this._isModel(attrs)) {
1154 if (!attrs.collection) attrs.collection = this;
1155 return attrs;
1156 }
1157 options = options ? _.clone(options) : {};
1158 options.collection = this;
1159
1160 var model;
1161 if (this.model.prototype) {
1162 model = new this.model(attrs, options);
1163 } else {
1164 // ES class methods didn't have prototype
1165 model = this.model(attrs, options);
1166 }
1167
1168 if (!model.validationError) return model;
1169 this.trigger('invalid', this, model.validationError, options);
1170 return false;
1171 },
1172
1173 // Internal method called by both remove and set.
1174 _removeModels: function(models, options) {
1175 var removed = [];
1176 for (var i = 0; i < models.length; i++) {
1177 var model = this.get(models[i]);
1178 if (!model) continue;
1179
1180 var index = this.indexOf(model);
1181 this.models.splice(index, 1);
1182 this.length--;
1183
1184 // Remove references before triggering 'remove' event to prevent an
1185 // infinite loop. #3693
1186 delete this._byId[model.cid];
1187 var id = this.modelId(model.attributes, model.idAttribute);
1188 if (id != null) delete this._byId[id];
1189
1190 if (!options.silent) {
1191 options.index = index;
1192 model.trigger('remove', model, this, options);
1193 }
1194
1195 removed.push(model);
1196 this._removeReference(model, options);
1197 }
1198 if (models.length > 0 && !options.silent) delete options.index;
1199 return removed;
1200 },
1201
1202 // Method for checking whether an object should be considered a model for
1203 // the purposes of adding to the collection.
1204 _isModel: function(model) {
1205 return model instanceof Model;
1206 },
1207
1208 // Internal method to create a model's ties to a collection.
1209 _addReference: function(model, options) {
1210 this._byId[model.cid] = model;
1211 var id = this.modelId(model.attributes, model.idAttribute);
1212 if (id != null) this._byId[id] = model;
1213 model.on('all', this._onModelEvent, this);
1214 },
1215
1216 // Internal method to sever a model's ties to a collection.
1217 _removeReference: function(model, options) {
1218 delete this._byId[model.cid];
1219 var id = this.modelId(model.attributes, model.idAttribute);
1220 if (id != null) delete this._byId[id];
1221 if (this === model.collection) delete model.collection;
1222 model.off('all', this._onModelEvent, this);
1223 },
1224
1225 // Internal method called every time a model in the set fires an event.
1226 // Sets need to update their indexes when models change ids. All other
1227 // events simply proxy through. "add" and "remove" events that originate
1228 // in other collections are ignored.
1229 _onModelEvent: function(event, model, collection, options) {
1230 if (model) {
1231 if ((event === 'add' || event === 'remove') && collection !== this) return;
1232 if (event === 'destroy') this.remove(model, options);
1233 if (event === 'changeId') {
1234 var prevId = this.modelId(model.previousAttributes(), model.idAttribute);
1235 var id = this.modelId(model.attributes, model.idAttribute);
1236 if (prevId != null) delete this._byId[prevId];
1237 if (id != null) this._byId[id] = model;
1238 }
1239 }
1240 this.trigger.apply(this, arguments);
1241 },
1242
1243 // Internal callback method used in `create`. It serves as a
1244 // stand-in for the `_onModelEvent` method, which is not yet bound
1245 // during the `wait` period of the `create` call. We still want to
1246 // forward any `'error'` event at the end of the `wait` period,
1247 // hence a customized callback.
1248 _forwardPristineError: function(model, collection, options) {
1249 // Prevent double forward if the model was already in the
1250 // collection before the call to `create`.
1251 if (this.has(model)) return;
1252 this._onModelEvent('error', model, collection, options);
1253 }
1254 });
1255
1256 // Defining an @@iterator method implements JavaScript's Iterable protocol.
1257 // In modern ES2015 browsers, this value is found at Symbol.iterator.
1258 /* global Symbol */
1259 var $$iterator = typeof Symbol === 'function' && Symbol.iterator;
1260 if ($$iterator) {
1261 Collection.prototype[$$iterator] = Collection.prototype.values;
1262 }
1263
1264 // CollectionIterator
1265 // ------------------
1266
1267 // A CollectionIterator implements JavaScript's Iterator protocol, allowing the
1268 // use of `for of` loops in modern browsers and interoperation between
1269 // Backbone.Collection and other JavaScript functions and third-party libraries
1270 // which can operate on Iterables.
1271 var CollectionIterator = function(collection, kind) {
1272 this._collection = collection;
1273 this._kind = kind;
1274 this._index = 0;
1275 };
1276
1277 // This "enum" defines the three possible kinds of values which can be emitted
1278 // by a CollectionIterator that correspond to the values(), keys() and entries()
1279 // methods on Collection, respectively.
1280 var ITERATOR_VALUES = 1;
1281 var ITERATOR_KEYS = 2;
1282 var ITERATOR_KEYSVALUES = 3;
1283
1284 // All Iterators should themselves be Iterable.
1285 if ($$iterator) {
1286 CollectionIterator.prototype[$$iterator] = function() {
1287 return this;
1288 };
1289 }
1290
1291 CollectionIterator.prototype.next = function() {
1292 if (this._collection) {
1293
1294 // Only continue iterating if the iterated collection is long enough.
1295 if (this._index < this._collection.length) {
1296 var model = this._collection.at(this._index);
1297 this._index++;
1298
1299 // Construct a value depending on what kind of values should be iterated.
1300 var value;
1301 if (this._kind === ITERATOR_VALUES) {
1302 value = model;
1303 } else {
1304 var id = this._collection.modelId(model.attributes, model.idAttribute);
1305 if (this._kind === ITERATOR_KEYS) {
1306 value = id;
1307 } else { // ITERATOR_KEYSVALUES
1308 value = [id, model];
1309 }
1310 }
1311 return {value: value, done: false};
1312 }
1313
1314 // Once exhausted, remove the reference to the collection so future
1315 // calls to the next method always return done.
1316 this._collection = void 0;
1317 }
1318
1319 return {value: void 0, done: true};
1320 };
1321
1322 // Backbone.View
1323 // -------------
1324
1325 // Backbone Views are almost more convention than they are actual code. A View
1326 // is simply a JavaScript object that represents a logical chunk of UI in the
1327 // DOM. This might be a single item, an entire list, a sidebar or panel, or
1328 // even the surrounding frame which wraps your whole app. Defining a chunk of
1329 // UI as a **View** allows you to define your DOM events declaratively, without
1330 // having to worry about render order ... and makes it easy for the view to
1331 // react to specific changes in the state of your models.
1332
1333 // Creating a Backbone.View creates its initial element outside of the DOM,
1334 // if an existing element is not provided...
1335 var View = Backbone.View = function(options) {
1336 this.cid = _.uniqueId('view');
1337 this.preinitialize.apply(this, arguments);
1338 _.extend(this, _.pick(options, viewOptions));
1339 this._ensureElement();
1340 this.initialize.apply(this, arguments);
1341 };
1342
1343 // Cached regex to split keys for `delegate`.
1344 var delegateEventSplitter = /^(\S+)\s*(.*)$/;
1345
1346 // List of view options to be set as properties.
1347 var viewOptions = ['model', 'collection', 'el', 'id', 'attributes', 'className', 'tagName', 'events'];
1348
1349 // Set up all inheritable **Backbone.View** properties and methods.
1350 _.extend(View.prototype, Events, {
1351
1352 // The default `tagName` of a View's element is `"div"`.
1353 tagName: 'div',
1354
1355 // jQuery delegate for element lookup, scoped to DOM elements within the
1356 // current view. This should be preferred to global lookups where possible.
1357 $: function(selector) {
1358 return this.$el.find(selector);
1359 },
1360
1361 // preinitialize is an empty function by default. You can override it with a function
1362 // or object. preinitialize will run before any instantiation logic is run in the View
1363 preinitialize: function(){},
1364
1365 // Initialize is an empty function by default. Override it with your own
1366 // initialization logic.
1367 initialize: function(){},
1368
1369 // **render** is the core function that your view should override, in order
1370 // to populate its element (`this.el`), with the appropriate HTML. The
1371 // convention is for **render** to always return `this`.
1372 render: function() {
1373 return this;
1374 },
1375
1376 // Remove this view by taking the element out of the DOM, and removing any
1377 // applicable Backbone.Events listeners.
1378 remove: function() {
1379 this._removeElement();
1380 this.stopListening();
1381 return this;
1382 },
1383
1384 // Remove this view's element from the document and all event listeners
1385 // attached to it. Exposed for subclasses using an alternative DOM
1386 // manipulation API.
1387 _removeElement: function() {
1388 this.$el.remove();
1389 },
1390
1391 // Change the view's element (`this.el` property) and re-delegate the
1392 // view's events on the new element.
1393 setElement: function(element) {
1394 this.undelegateEvents();
1395 this._setElement(element);
1396 this.delegateEvents();
1397 return this;
1398 },
1399
1400 // Creates the `this.el` and `this.$el` references for this view using the
1401 // given `el`. `el` can be a CSS selector or an HTML string, a jQuery
1402 // context or an element. Subclasses can override this to utilize an
1403 // alternative DOM manipulation API and are only required to set the
1404 // `this.el` property.
1405 _setElement: function(el) {
1406 this.$el = el instanceof Backbone.$ ? el : Backbone.$(el);
1407 this.el = this.$el[0];
1408 },
1409
1410 // Set callbacks, where `this.events` is a hash of
1411 //
1412 // *{"event selector": "callback"}*
1413 //
1414 // {
1415 // 'mousedown .title': 'edit',
1416 // 'click .button': 'save',
1417 // 'click .open': function(e) { ... }
1418 // }
1419 //
1420 // pairs. Callbacks will be bound to the view, with `this` set properly.
1421 // Uses event delegation for efficiency.
1422 // Omitting the selector binds the event to `this.el`.
1423 delegateEvents: function(events) {
1424 events || (events = _.result(this, 'events'));
1425 if (!events) return this;
1426 this.undelegateEvents();
1427 for (var key in events) {
1428 var method = events[key];
1429 if (!_.isFunction(method)) method = this[method];
1430 if (!method) continue;
1431 var match = key.match(delegateEventSplitter);
1432 this.delegate(match[1], match[2], method.bind(this));
1433 }
1434 return this;
1435 },
1436
1437 // Add a single event listener to the view's element (or a child element
1438 // using `selector`). This only works for delegate-able events: not `focus`,
1439 // `blur`, and not `change`, `submit`, and `reset` in Internet Explorer.
1440 delegate: function(eventName, selector, listener) {
1441 this.$el.on(eventName + '.delegateEvents' + this.cid, selector, listener);
1442 return this;
1443 },
1444
1445 // Clears all callbacks previously bound to the view by `delegateEvents`.
1446 // You usually don't need to use this, but may wish to if you have multiple
1447 // Backbone views attached to the same DOM element.
1448 undelegateEvents: function() {
1449 if (this.$el) this.$el.off('.delegateEvents' + this.cid);
1450 return this;
1451 },
1452
1453 // A finer-grained `undelegateEvents` for removing a single delegated event.
1454 // `selector` and `listener` are both optional.
1455 undelegate: function(eventName, selector, listener) {
1456 this.$el.off(eventName + '.delegateEvents' + this.cid, selector, listener);
1457 return this;
1458 },
1459
1460 // Produces a DOM element to be assigned to your view. Exposed for
1461 // subclasses using an alternative DOM manipulation API.
1462 _createElement: function(tagName) {
1463 return document.createElement(tagName);
1464 },
1465
1466 // Ensure that the View has a DOM element to render into.
1467 // If `this.el` is a string, pass it through `$()`, take the first
1468 // matching element, and re-assign it to `el`. Otherwise, create
1469 // an element from the `id`, `className` and `tagName` properties.
1470 _ensureElement: function() {
1471 if (!this.el) {
1472 var attrs = _.extend({}, _.result(this, 'attributes'));
1473 if (this.id) attrs.id = _.result(this, 'id');
1474 if (this.className) attrs['class'] = _.result(this, 'className');
1475 this.setElement(this._createElement(_.result(this, 'tagName')));
1476 this._setAttributes(attrs);
1477 } else {
1478 this.setElement(_.result(this, 'el'));
1479 }
1480 },
1481
1482 // Set attributes from a hash on this view's element. Exposed for
1483 // subclasses using an alternative DOM manipulation API.
1484 _setAttributes: function(attributes) {
1485 this.$el.attr(attributes);
1486 }
1487
1488 });
1489
1490 // Proxy Backbone class methods to Underscore functions, wrapping the model's
1491 // `attributes` object or collection's `models` array behind the scenes.
1492 //
1493 // collection.filter(function(model) { return model.get('age') > 10 });
1494 // collection.each(this.addView);
1495 //
1496 // `Function#apply` can be slow so we use the method's arg count, if we know it.
1497 var addMethod = function(base, length, method, attribute) {
1498 switch (length) {
1499 case 1: return function() {
1500 return base[method](this[attribute]);
1501 };
1502 case 2: return function(value) {
1503 return base[method](this[attribute], value);
1504 };
1505 case 3: return function(iteratee, context) {
1506 return base[method](this[attribute], cb(iteratee, this), context);
1507 };
1508 case 4: return function(iteratee, defaultVal, context) {
1509 return base[method](this[attribute], cb(iteratee, this), defaultVal, context);
1510 };
1511 default: return function() {
1512 var args = slice.call(arguments);
1513 args.unshift(this[attribute]);
1514 return base[method].apply(base, args);
1515 };
1516 }
1517 };
1518
1519 var addUnderscoreMethods = function(Class, base, methods, attribute) {
1520 _.each(methods, function(length, method) {
1521 if (base[method]) Class.prototype[method] = addMethod(base, length, method, attribute);
1522 });
1523 };
1524
1525 // Support `collection.sortBy('attr')` and `collection.findWhere({id: 1})`.
1526 var cb = function(iteratee, instance) {
1527 if (_.isFunction(iteratee)) return iteratee;
1528 if (_.isObject(iteratee) && !instance._isModel(iteratee)) return modelMatcher(iteratee);
1529 if (_.isString(iteratee)) return function(model) { return model.get(iteratee); };
1530 return iteratee;
1531 };
1532 var modelMatcher = function(attrs) {
1533 var matcher = _.matches(attrs);
1534 return function(model) {
1535 return matcher(model.attributes);
1536 };
1537 };
1538
1539 // Underscore methods that we want to implement on the Collection.
1540 // 90% of the core usefulness of Backbone Collections is actually implemented
1541 // right here:
1542 var collectionMethods = {forEach: 3, each: 3, map: 3, collect: 3, reduce: 0,
1543 foldl: 0, inject: 0, reduceRight: 0, foldr: 0, find: 3, detect: 3, filter: 3,
1544 select: 3, reject: 3, every: 3, all: 3, some: 3, any: 3, include: 3, includes: 3,
1545 contains: 3, invoke: 0, max: 3, min: 3, toArray: 1, size: 1, first: 3,
1546 head: 3, take: 3, initial: 3, rest: 3, tail: 3, drop: 3, last: 3,
1547 without: 0, difference: 0, indexOf: 3, shuffle: 1, lastIndexOf: 3,
1548 isEmpty: 1, chain: 1, sample: 3, partition: 3, groupBy: 3, countBy: 3,
1549 sortBy: 3, indexBy: 3, findIndex: 3, findLastIndex: 3};
1550
1551
1552 // Underscore methods that we want to implement on the Model, mapped to the
1553 // number of arguments they take.
1554 var modelMethods = {keys: 1, values: 1, pairs: 1, invert: 1, pick: 0,
1555 omit: 0, chain: 1, isEmpty: 1};
1556
1557 // Mix in each Underscore method as a proxy to `Collection#models`.
1558
1559 _.each([
1560 [Collection, collectionMethods, 'models'],
1561 [Model, modelMethods, 'attributes']
1562 ], function(config) {
1563 var Base = config[0],
1564 methods = config[1],
1565 attribute = config[2];
1566
1567 Base.mixin = function(obj) {
1568 var mappings = _.reduce(_.functions(obj), function(memo, name) {
1569 memo[name] = 0;
1570 return memo;
1571 }, {});
1572 addUnderscoreMethods(Base, obj, mappings, attribute);
1573 };
1574
1575 addUnderscoreMethods(Base, _, methods, attribute);
1576 });
1577
1578 // Backbone.sync
1579 // -------------
1580
1581 // Override this function to change the manner in which Backbone persists
1582 // models to the server. You will be passed the type of request, and the
1583 // model in question. By default, makes a RESTful Ajax request
1584 // to the model's `url()`. Some possible customizations could be:
1585 //
1586 // * Use `setTimeout` to batch rapid-fire updates into a single request.
1587 // * Send up the models as XML instead of JSON.
1588 // * Persist models via WebSockets instead of Ajax.
1589 //
1590 // Turn on `Backbone.emulateHTTP` in order to send `PUT` and `DELETE` requests
1591 // as `POST`, with a `_method` parameter containing the true HTTP method,
1592 // as well as all requests with the body as `application/x-www-form-urlencoded`
1593 // instead of `application/json` with the model in a param named `model`.
1594 // Useful when interfacing with server-side languages like **PHP** that make
1595 // it difficult to read the body of `PUT` requests.
1596 Backbone.sync = function(method, model, options) {
1597 var type = methodMap[method];
1598
1599 // Default options, unless specified.
1600 _.defaults(options || (options = {}), {
1601 emulateHTTP: Backbone.emulateHTTP,
1602 emulateJSON: Backbone.emulateJSON
1603 });
1604
1605 // Default JSON-request options.
1606 var params = {type: type, dataType: 'json'};
1607
1608 // Ensure that we have a URL.
1609 if (!options.url) {
1610 params.url = _.result(model, 'url') || urlError();
1611 }
1612
1613 // Ensure that we have the appropriate request data.
1614 if (options.data == null && model && (method === 'create' || method === 'update' || method === 'patch')) {
1615 params.contentType = 'application/json';
1616 params.data = JSON.stringify(options.attrs || model.toJSON(options));
1617 }
1618
1619 // For older servers, emulate JSON by encoding the request into an HTML-form.
1620 if (options.emulateJSON) {
1621 params.contentType = 'application/x-www-form-urlencoded';
1622 params.data = params.data ? {model: params.data} : {};
1623 }
1624
1625 // For older servers, emulate HTTP by mimicking the HTTP method with `_method`
1626 // And an `X-HTTP-Method-Override` header.
1627 if (options.emulateHTTP && (type === 'PUT' || type === 'DELETE' || type === 'PATCH')) {
1628 params.type = 'POST';
1629 if (options.emulateJSON) params.data._method = type;
1630 var beforeSend = options.beforeSend;
1631 options.beforeSend = function(xhr) {
1632 xhr.setRequestHeader('X-HTTP-Method-Override', type);
1633 if (beforeSend) return beforeSend.apply(this, arguments);
1634 };
1635 }
1636
1637 // Don't process data on a non-GET request.
1638 if (params.type !== 'GET' && !options.emulateJSON) {
1639 params.processData = false;
1640 }
1641
1642 // Pass along `textStatus` and `errorThrown` from jQuery.
1643 var error = options.error;
1644 options.error = function(xhr, textStatus, errorThrown) {
1645 options.textStatus = textStatus;
1646 options.errorThrown = errorThrown;
1647 if (error) error.call(options.context, xhr, textStatus, errorThrown);
1648 };
1649
1650 // Make the request, allowing the user to override any Ajax options.
1651 var xhr = options.xhr = Backbone.ajax(_.extend(params, options));
1652 model.trigger('request', model, xhr, options);
1653 return xhr;
1654 };
1655
1656 // Map from CRUD to HTTP for our default `Backbone.sync` implementation.
1657 var methodMap = {
1658 'create': 'POST',
1659 'update': 'PUT',
1660 'patch': 'PATCH',
1661 'delete': 'DELETE',
1662 'read': 'GET'
1663 };
1664
1665 // Set the default implementation of `Backbone.ajax` to proxy through to `$`.
1666 // Override this if you'd like to use a different library.
1667 Backbone.ajax = function() {
1668 return Backbone.$.ajax.apply(Backbone.$, arguments);
1669 };
1670
1671 // Backbone.Router
1672 // ---------------
1673
1674 // Routers map faux-URLs to actions, and fire events when routes are
1675 // matched. Creating a new one sets its `routes` hash, if not set statically.
1676 var Router = Backbone.Router = function(options) {
1677 options || (options = {});
1678 this.preinitialize.apply(this, arguments);
1679 if (options.routes) this.routes = options.routes;
1680 this._bindRoutes();
1681 this.initialize.apply(this, arguments);
1682 };
1683
1684 // Cached regular expressions for matching named param parts and splatted
1685 // parts of route strings.
1686 var optionalParam = /\((.*?)\)/g;
1687 var namedParam = /(\(\?)?:\w+/g;
1688 var splatParam = /\*\w+/g;
1689 var escapeRegExp = /[\-{}\[\]+?.,\\\^$|#\s]/g;
1690
1691 // Set up all inheritable **Backbone.Router** properties and methods.
1692 _.extend(Router.prototype, Events, {
1693
1694 // preinitialize is an empty function by default. You can override it with a function
1695 // or object. preinitialize will run before any instantiation logic is run in the Router.
1696 preinitialize: function(){},
1697
1698 // Initialize is an empty function by default. Override it with your own
1699 // initialization logic.
1700 initialize: function(){},
1701
1702 // Manually bind a single named route to a callback. For example:
1703 //
1704 // this.route('search/:query/p:num', 'search', function(query, num) {
1705 // ...
1706 // });
1707 //
1708 route: function(route, name, callback) {
1709 if (!_.isRegExp(route)) route = this._routeToRegExp(route);
1710 if (_.isFunction(name)) {
1711 callback = name;
1712 name = '';
1713 }
1714 if (!callback) callback = this[name];
1715 var router = this;
1716 Backbone.history.route(route, function(fragment) {
1717 var args = router._extractParameters(route, fragment);
1718 if (router.execute(callback, args, name) !== false) {
1719 router.trigger.apply(router, ['route:' + name].concat(args));
1720 router.trigger('route', name, args);
1721 Backbone.history.trigger('route', router, name, args);
1722 }
1723 });
1724 return this;
1725 },
1726
1727 // Execute a route handler with the provided parameters. This is an
1728 // excellent place to do pre-route setup or post-route cleanup.
1729 execute: function(callback, args, name) {
1730 if (callback) callback.apply(this, args);
1731 },
1732
1733 // Simple proxy to `Backbone.history` to save a fragment into the history.
1734 navigate: function(fragment, options) {
1735 Backbone.history.navigate(fragment, options);
1736 return this;
1737 },
1738
1739 // Bind all defined routes to `Backbone.history`. We have to reverse the
1740 // order of the routes here to support behavior where the most general
1741 // routes can be defined at the bottom of the route map.
1742 _bindRoutes: function() {
1743 if (!this.routes) return;
1744 this.routes = _.result(this, 'routes');
1745 var route, routes = _.keys(this.routes);
1746 while ((route = routes.pop()) != null) {
1747 this.route(route, this.routes[route]);
1748 }
1749 },
1750
1751 // Convert a route string into a regular expression, suitable for matching
1752 // against the current location hash.
1753 _routeToRegExp: function(route) {
1754 route = route.replace(escapeRegExp, '\\$&')
1755 .replace(optionalParam, '(?:$1)?')
1756 .replace(namedParam, function(match, optional) {
1757 return optional ? match : '([^/?]+)';
1758 })
1759 .replace(splatParam, '([^?]*?)');
1760 return new RegExp('^' + route + '(?:\\?([\\s\\S]*))?$');
1761 },
1762
1763 // Given a route, and a URL fragment that it matches, return the array of
1764 // extracted decoded parameters. Empty or unmatched parameters will be
1765 // treated as `null` to normalize cross-browser behavior.
1766 _extractParameters: function(route, fragment) {
1767 var params = route.exec(fragment).slice(1);
1768 return _.map(params, function(param, i) {
1769 // Don't decode the search params.
1770 if (i === params.length - 1) return param || null;
1771 return param ? decodeURIComponent(param) : null;
1772 });
1773 }
1774
1775 });
1776
1777 // Backbone.History
1778 // ----------------
1779
1780 // Handles cross-browser history management, based on either
1781 // [pushState](http://diveintohtml5.info/history.html) and real URLs, or
1782 // [onhashchange](https://developer.mozilla.org/en-US/docs/DOM/window.onhashchange)
1783 // and URL fragments. If the browser supports neither (old IE, natch),
1784 // falls back to polling.
1785 var History = Backbone.History = function() {
1786 this.handlers = [];
1787 this.checkUrl = this.checkUrl.bind(this);
1788
1789 // Ensure that `History` can be used outside of the browser.
1790 if (typeof window !== 'undefined') {
1791 this.location = window.location;
1792 this.history = window.history;
1793 }
1794 };
1795
1796 // Cached regex for stripping a leading hash/slash and trailing space.
1797 var routeStripper = /^[#\/]|\s+$/g;
1798
1799 // Cached regex for stripping leading and trailing slashes.
1800 var rootStripper = /^\/+|\/+$/g;
1801
1802 // Cached regex for stripping urls of hash.
1803 var pathStripper = /#.*$/;
1804
1805 // Has the history handling already been started?
1806 History.started = false;
1807
1808 // Set up all inheritable **Backbone.History** properties and methods.
1809 _.extend(History.prototype, Events, {
1810
1811 // The default interval to poll for hash changes, if necessary, is
1812 // twenty times a second.
1813 interval: 50,
1814
1815 // Are we at the app root?
1816 atRoot: function() {
1817 var path = this.location.pathname.replace(/[^\/]$/, '$&/');
1818 return path === this.root && !this.getSearch();
1819 },
1820
1821 // Does the pathname match the root?
1822 matchRoot: function() {
1823 var path = this.decodeFragment(this.location.pathname);
1824 var rootPath = path.slice(0, this.root.length - 1) + '/';
1825 return rootPath === this.root;
1826 },
1827
1828 // Unicode characters in `location.pathname` are percent encoded so they're
1829 // decoded for comparison. `%25` should not be decoded since it may be part
1830 // of an encoded parameter.
1831 decodeFragment: function(fragment) {
1832 return decodeURI(fragment.replace(/%25/g, '%2525'));
1833 },
1834
1835 // In IE6, the hash fragment and search params are incorrect if the
1836 // fragment contains `?`.
1837 getSearch: function() {
1838 var match = this.location.href.replace(/#.*/, '').match(/\?.+/);
1839 return match ? match[0] : '';
1840 },
1841
1842 // Gets the true hash value. Cannot use location.hash directly due to bug
1843 // in Firefox where location.hash will always be decoded.
1844 getHash: function(window) {
1845 var match = (window || this).location.href.match(/#(.*)$/);
1846 return match ? match[1] : '';
1847 },
1848
1849 // Get the pathname and search params, without the root.
1850 getPath: function() {
1851 var path = this.decodeFragment(
1852 this.location.pathname + this.getSearch()
1853 ).slice(this.root.length - 1);
1854 return path.charAt(0) === '/' ? path.slice(1) : path;
1855 },
1856
1857 // Get the cross-browser normalized URL fragment from the path or hash.
1858 getFragment: function(fragment) {
1859 if (fragment == null) {
1860 if (this._usePushState || !this._wantsHashChange) {
1861 fragment = this.getPath();
1862 } else {
1863 fragment = this.getHash();
1864 }
1865 }
1866 return fragment.replace(routeStripper, '');
1867 },
1868
1869 // Start the hash change handling, returning `true` if the current URL matches
1870 // an existing route, and `false` otherwise.
1871 start: function(options) {
1872 if (History.started) throw new Error('Backbone.history has already been started');
1873 History.started = true;
1874
1875 // Figure out the initial configuration. Do we need an iframe?
1876 // Is pushState desired ... is it available?
1877 this.options = _.extend({root: '/'}, this.options, options);
1878 this.root = this.options.root;
1879 this._trailingSlash = this.options.trailingSlash;
1880 this._wantsHashChange = this.options.hashChange !== false;
1881 this._hasHashChange = 'onhashchange' in window && (document.documentMode === void 0 || document.documentMode > 7);
1882 this._useHashChange = this._wantsHashChange && this._hasHashChange;
1883 this._wantsPushState = !!this.options.pushState;
1884 this._hasPushState = !!(this.history && this.history.pushState);
1885 this._usePushState = this._wantsPushState && this._hasPushState;
1886 this.fragment = this.getFragment();
1887
1888 // Normalize root to always include a leading and trailing slash.
1889 this.root = ('/' + this.root + '/').replace(rootStripper, '/');
1890
1891 // Transition from hashChange to pushState or vice versa if both are
1892 // requested.
1893 if (this._wantsHashChange && this._wantsPushState) {
1894
1895 // If we've started off with a route from a `pushState`-enabled
1896 // browser, but we're currently in a browser that doesn't support it...
1897 if (!this._hasPushState && !this.atRoot()) {
1898 var rootPath = this.root.slice(0, -1) || '/';
1899 this.location.replace(rootPath + '#' + this.getPath());
1900 // Return immediately as browser will do redirect to new url
1901 return true;
1902
1903 // Or if we've started out with a hash-based route, but we're currently
1904 // in a browser where it could be `pushState`-based instead...
1905 } else if (this._hasPushState && this.atRoot()) {
1906 this.navigate(this.getHash(), {replace: true});
1907 }
1908
1909 }
1910
1911 // Proxy an iframe to handle location events if the browser doesn't
1912 // support the `hashchange` event, HTML5 history, or the user wants
1913 // `hashChange` but not `pushState`.
1914 if (!this._hasHashChange && this._wantsHashChange && !this._usePushState) {
1915 this.iframe = document.createElement('iframe');
1916 this.iframe.src = 'javascript:0';
1917 this.iframe.style.display = 'none';
1918 this.iframe.tabIndex = -1;
1919 var body = document.body;
1920 // Using `appendChild` will throw on IE < 9 if the document is not ready.
1921 var iWindow = body.insertBefore(this.iframe, body.firstChild).contentWindow;
1922 iWindow.document.open();
1923 iWindow.document.close();
1924 iWindow.location.hash = '#' + this.fragment;
1925 }
1926
1927 // Add a cross-platform `addEventListener` shim for older browsers.
1928 var addEventListener = window.addEventListener || function(eventName, listener) {
1929 return attachEvent('on' + eventName, listener);
1930 };
1931
1932 // Depending on whether we're using pushState or hashes, and whether
1933 // 'onhashchange' is supported, determine how we check the URL state.
1934 if (this._usePushState) {
1935 addEventListener('popstate', this.checkUrl, false);
1936 } else if (this._useHashChange && !this.iframe) {
1937 addEventListener('hashchange', this.checkUrl, false);
1938 } else if (this._wantsHashChange) {
1939 this._checkUrlInterval = setInterval(this.checkUrl, this.interval);
1940 }
1941
1942 if (!this.options.silent) return this.loadUrl();
1943 },
1944
1945 // Disable Backbone.history, perhaps temporarily. Not useful in a real app,
1946 // but possibly useful for unit testing Routers.
1947 stop: function() {
1948 // Add a cross-platform `removeEventListener` shim for older browsers.
1949 var removeEventListener = window.removeEventListener || function(eventName, listener) {
1950 return detachEvent('on' + eventName, listener);
1951 };
1952
1953 // Remove window listeners.
1954 if (this._usePushState) {
1955 removeEventListener('popstate', this.checkUrl, false);
1956 } else if (this._useHashChange && !this.iframe) {
1957 removeEventListener('hashchange', this.checkUrl, false);
1958 }
1959
1960 // Clean up the iframe if necessary.
1961 if (this.iframe) {
1962 document.body.removeChild(this.iframe);
1963 this.iframe = null;
1964 }
1965
1966 // Some environments will throw when clearing an undefined interval.
1967 if (this._checkUrlInterval) clearInterval(this._checkUrlInterval);
1968 History.started = false;
1969 },
1970
1971 // Add a route to be tested when the fragment changes. Routes added later
1972 // may override previous routes.
1973 route: function(route, callback) {
1974 this.handlers.unshift({route: route, callback: callback});
1975 },
1976
1977 // Checks the current URL to see if it has changed, and if it has,
1978 // calls `loadUrl`, normalizing across the hidden iframe.
1979 checkUrl: function(e) {
1980 var current = this.getFragment();
1981
1982 // If the user pressed the back button, the iframe's hash will have
1983 // changed and we should use that for comparison.
1984 if (current === this.fragment && this.iframe) {
1985 current = this.getHash(this.iframe.contentWindow);
1986 }
1987
1988 if (current === this.fragment) {
1989 if (!this.matchRoot()) return this.notfound();
1990 return false;
1991 }
1992 if (this.iframe) this.navigate(current);
1993 this.loadUrl();
1994 },
1995
1996 // Attempt to load the current URL fragment. If a route succeeds with a
1997 // match, returns `true`. If no defined routes matches the fragment,
1998 // returns `false`.
1999 loadUrl: function(fragment) {
2000 // If the root doesn't match, no routes can match either.
2001 if (!this.matchRoot()) return this.notfound();
2002 fragment = this.fragment = this.getFragment(fragment);
2003 return _.some(this.handlers, function(handler) {
2004 if (handler.route.test(fragment)) {
2005 handler.callback(fragment);
2006 return true;
2007 }
2008 }) || this.notfound();
2009 },
2010
2011 // When no route could be matched, this method is called internally to
2012 // trigger the `'notfound'` event. It returns `false` so that it can be used
2013 // in tail position.
2014 notfound: function() {
2015 this.trigger('notfound');
2016 return false;
2017 },
2018
2019 // Save a fragment into the hash history, or replace the URL state if the
2020 // 'replace' option is passed. You are responsible for properly URL-encoding
2021 // the fragment in advance.
2022 //
2023 // The options object can contain `trigger: true` if you wish to have the
2024 // route callback be fired (not usually desirable), or `replace: true`, if
2025 // you wish to modify the current URL without adding an entry to the history.
2026 navigate: function(fragment, options) {
2027 if (!History.started) return false;
2028 if (!options || options === true) options = {trigger: !!options};
2029
2030 // Normalize the fragment.
2031 fragment = this.getFragment(fragment || '');
2032
2033 // Strip trailing slash on the root unless _trailingSlash is true
2034 var rootPath = this.root;
2035 if (!this._trailingSlash && (fragment === '' || fragment.charAt(0) === '?')) {
2036 rootPath = rootPath.slice(0, -1) || '/';
2037 }
2038 var url = rootPath + fragment;
2039
2040 // Strip the fragment of the query and hash for matching.
2041 fragment = fragment.replace(pathStripper, '');
2042
2043 // Decode for matching.
2044 var decodedFragment = this.decodeFragment(fragment);
2045
2046 if (this.fragment === decodedFragment) return;
2047 this.fragment = decodedFragment;
2048
2049 // If pushState is available, we use it to set the fragment as a real URL.
2050 if (this._usePushState) {
2051 this.history[options.replace ? 'replaceState' : 'pushState']({}, document.title, url);
2052
2053 // If hash changes haven't been explicitly disabled, update the hash
2054 // fragment to store history.
2055 } else if (this._wantsHashChange) {
2056 this._updateHash(this.location, fragment, options.replace);
2057 if (this.iframe && fragment !== this.getHash(this.iframe.contentWindow)) {
2058 var iWindow = this.iframe.contentWindow;
2059
2060 // Opening and closing the iframe tricks IE7 and earlier to push a
2061 // history entry on hash-tag change. When replace is true, we don't
2062 // want this.
2063 if (!options.replace) {
2064 iWindow.document.open();
2065 iWindow.document.close();
2066 }
2067
2068 this._updateHash(iWindow.location, fragment, options.replace);
2069 }
2070
2071 // If you've told us that you explicitly don't want fallback hashchange-
2072 // based history, then `navigate` becomes a page refresh.
2073 } else {
2074 return this.location.assign(url);
2075 }
2076 if (options.trigger) return this.loadUrl(fragment);
2077 },
2078
2079 // Update the hash location, either replacing the current entry, or adding
2080 // a new one to the browser history.
2081 _updateHash: function(location, fragment, replace) {
2082 if (replace) {
2083 var href = location.href.replace(/(javascript:|#).*$/, '');
2084 location.replace(href + '#' + fragment);
2085 } else {
2086 // Some browsers require that `hash` contains a leading #.
2087 location.hash = '#' + fragment;
2088 }
2089 }
2090
2091 });
2092
2093 // Create the default Backbone.history.
2094 Backbone.history = new History;
2095
2096 // Helpers
2097 // -------
2098
2099 // Helper function to correctly set up the prototype chain for subclasses.
2100 // Similar to `goog.inherits`, but uses a hash of prototype properties and
2101 // class properties to be extended.
2102 var extend = function(protoProps, staticProps) {
2103 var parent = this;
2104 var child;
2105
2106 // The constructor function for the new subclass is either defined by you
2107 // (the "constructor" property in your `extend` definition), or defaulted
2108 // by us to simply call the parent constructor.
2109 if (protoProps && _.has(protoProps, 'constructor')) {
2110 child = protoProps.constructor;
2111 } else {
2112 child = function(){ return parent.apply(this, arguments); };
2113 }
2114
2115 // Add static properties to the constructor function, if supplied.
2116 _.extend(child, parent, staticProps);
2117
2118 // Set the prototype chain to inherit from `parent`, without calling
2119 // `parent`'s constructor function and add the prototype properties.
2120 child.prototype = _.create(parent.prototype, protoProps);
2121 child.prototype.constructor = child;
2122
2123 // Set a convenience property in case the parent's prototype is needed
2124 // later.
2125 child.__super__ = parent.prototype;
2126
2127 return child;
2128 };
2129
2130 // Set up inheritance for the model, collection, router, view and history.
2131 Model.extend = Collection.extend = Router.extend = View.extend = History.extend = extend;
2132
2133 // Throw an error when a URL is needed, and none is supplied.
2134 var urlError = function() {
2135 throw new Error('A "url" property or function must be specified');
2136 };
2137
2138 // Wrap an optional error callback with a fallback error event.
2139 var wrapError = function(model, options) {
2140 var error = options.error;
2141 options.error = function(resp) {
2142 if (error) error.call(options.context, model, resp, options);
2143 model.trigger('error', model, resp, options);
2144 };
2145 };
2146
2147 // Provide useful information when things go wrong. This method is not meant
2148 // to be used directly; it merely provides the necessary introspection for the
2149 // external `debugInfo` function.
2150 Backbone._debug = function() {
2151 return {root: root, _: _};
2152 };
2153
2154 return Backbone;
2155});
2156