3 // (c) 2010-2016 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
4 // Backbone may be freely distributed under the MIT license.
5 // For all details and documentation:
6 // http://backbonejs.org
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);
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, _, $);
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, _, $);
29 // Finally, as a browser global.
31 root.Backbone = factory(root, {}, root._, (root.jQuery || root.Zepto || root.ender || root.$));
34 })(function(root, Backbone, _, $) {
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;
43 // Create a local reference to a common array method we'll want to use later.
44 var slice = Array.prototype.slice;
46 // Current version of the library. Keep in sync with `package.json`.
47 Backbone.VERSION = '1.2.3';
49 // For Backbone's purposes, jQuery, Zepto, Ender, or My Library (kidding) owns
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;
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;
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;
71 // Proxy Backbone class methods to Underscore functions, wrapping the model's
72 // `attributes` object or collection's `models` array behind the scenes.
74 // collection.filter(function(model) { return model.get('age') > 10 });
75 // collection.each(this.addView);
77 // `Function#apply` can be slow so we use the method's arg count, if we know it.
78 var addMethod = function(length, method, attribute) {
80 case 1: return function() {
81 return _[method](this[attribute]);
83 case 2: return function(value) {
84 return _[method](this[attribute], value);
86 case 3: return function(iteratee, context) {
87 return _[method](this[attribute], cb(iteratee, this), context);
89 case 4: return function(iteratee, defaultVal, context) {
90 return _[method](this[attribute], cb(iteratee, this), defaultVal, context);
92 default: return function() {
93 var args = slice.call(arguments);
94 args.unshift(this[attribute]);
95 return _[method].apply(_, args);
99 var addUnderscoreMethods = function(Class, methods, attribute) {
100 _.each(methods, function(length, method) {
101 if (_[method]) Class.prototype[method] = addMethod(length, method, attribute);
105 // Support `collection.sortBy('attr')` and `collection.findWhere({id: 1})`.
106 var cb = function(iteratee, instance) {
107 if (_.isFunction(iteratee)) return iteratee;
108 if (_.isObject(iteratee) && !instance._isModel(iteratee)) return modelMatcher(iteratee);
109 if (_.isString(iteratee)) return function(model) { return model.get(iteratee); };
112 var modelMatcher = function(attrs) {
113 var matcher = _.matches(attrs);
114 return function(model) {
115 return matcher(model.attributes);
122 // A module that can be mixed in to *any object* in order to provide it with
123 // a custom event channel. You may bind a callback to an event with `on` or
124 // remove with `off`; `trigger`-ing an event fires all callbacks in
128 // _.extend(object, Backbone.Events);
129 // object.on('expand', function(){ alert('expanded'); });
130 // object.trigger('expand');
132 var Events = Backbone.Events = {};
134 // Regular expression used to split event strings.
135 var eventSplitter = /\s+/;
137 // Iterates over the standard `event, callback` (as well as the fancy multiple
138 // space-separated events `"change blur", callback` and jQuery-style event
139 // maps `{event: callback}`).
140 var eventsApi = function(iteratee, events, name, callback, opts) {
142 if (name && typeof name === 'object') {
143 // Handle event maps.
144 if (callback !== void 0 && 'context' in opts && opts.context === void 0) opts.context = callback;
145 for (names = _.keys(name); i < names.length ; i++) {
146 events = eventsApi(iteratee, events, names[i], name[names[i]], opts);
148 } else if (name && eventSplitter.test(name)) {
149 // Handle space-separated event names by delegating them individually.
150 for (names = name.split(eventSplitter); i < names.length; i++) {
151 events = iteratee(events, names[i], callback, opts);
154 // Finally, standard events.
155 events = iteratee(events, name, callback, opts);
160 // Bind an event to a `callback` function. Passing `"all"` will bind
161 // the callback to all events fired.
162 Events.on = function(name, callback, context) {
163 return internalOn(this, name, callback, context);
166 // Guard the `listening` argument from the public API.
167 var internalOn = function(obj, name, callback, context, listening) {
168 obj._events = eventsApi(onApi, obj._events || {}, name, callback, {
175 var listeners = obj._listeners || (obj._listeners = {});
176 listeners[listening.id] = listening;
182 // Inversion-of-control versions of `on`. Tell *this* object to listen to
183 // an event in another object... keeping track of what it's listening to
184 // for easier unbinding later.
185 Events.listenTo = function(obj, name, callback) {
186 if (!obj) return this;
187 var id = obj._listenId || (obj._listenId = _.uniqueId('l'));
188 var listeningTo = this._listeningTo || (this._listeningTo = {});
189 var listening = listeningTo[id];
191 // This object is not listening to any other events on `obj` yet.
192 // Setup the necessary references to track the listening callbacks.
194 var thisId = this._listenId || (this._listenId = _.uniqueId('l'));
195 listening = listeningTo[id] = {obj: obj, objId: id, id: thisId, listeningTo: listeningTo, count: 0};
198 // Bind callbacks on obj, and keep track of them on listening.
199 internalOn(obj, name, callback, this, listening);
203 // The reducing API that adds a callback to the `events` object.
204 var onApi = function(events, name, callback, options) {
206 var handlers = events[name] || (events[name] = []);
207 var context = options.context, ctx = options.ctx, listening = options.listening;
208 if (listening) listening.count++;
210 handlers.push({callback: callback, context: context, ctx: context || ctx, listening: listening});
215 // Remove one or many callbacks. If `context` is null, removes all
216 // callbacks with that function. If `callback` is null, removes all
217 // callbacks for the event. If `name` is null, removes all bound
218 // callbacks for all events.
219 Events.off = function(name, callback, context) {
220 if (!this._events) return this;
221 this._events = eventsApi(offApi, this._events, name, callback, {
223 listeners: this._listeners
228 // Tell this object to stop listening to either specific events ... or
229 // to every object it's currently listening to.
230 Events.stopListening = function(obj, name, callback) {
231 var listeningTo = this._listeningTo;
232 if (!listeningTo) return this;
234 var ids = obj ? [obj._listenId] : _.keys(listeningTo);
236 for (var i = 0; i < ids.length; i++) {
237 var listening = listeningTo[ids[i]];
239 // If listening doesn't exist, this object is not currently
240 // listening to obj. Break out early.
241 if (!listening) break;
243 listening.obj.off(name, callback, this);
245 if (_.isEmpty(listeningTo)) this._listeningTo = void 0;
250 // The reducing API that removes a callback from the `events` object.
251 var offApi = function(events, name, callback, options) {
254 var i = 0, listening;
255 var context = options.context, listeners = options.listeners;
257 // Delete all events listeners and "drop" events.
258 if (!name && !callback && !context) {
259 var ids = _.keys(listeners);
260 for (; i < ids.length; i++) {
261 listening = listeners[ids[i]];
262 delete listeners[listening.id];
263 delete listening.listeningTo[listening.objId];
268 var names = name ? [name] : _.keys(events);
269 for (; i < names.length; i++) {
271 var handlers = events[name];
273 // Bail out if there are no events stored.
274 if (!handlers) break;
276 // Replace events if there are any remaining. Otherwise, clean up.
278 for (var j = 0; j < handlers.length; j++) {
279 var handler = handlers[j];
281 callback && callback !== handler.callback &&
282 callback !== handler.callback._callback ||
283 context && context !== handler.context
285 remaining.push(handler);
287 listening = handler.listening;
288 if (listening && --listening.count === 0) {
289 delete listeners[listening.id];
290 delete listening.listeningTo[listening.objId];
295 // Update tail event if the list has any events. Otherwise, clean up.
296 if (remaining.length) {
297 events[name] = remaining;
302 if (_.size(events)) return events;
305 // Bind an event to only be triggered a single time. After the first time
306 // the callback is invoked, its listener will be removed. If multiple events
307 // are passed in using the space-separated syntax, the handler will fire
308 // once for each event, not once for a combination of all events.
309 Events.once = function(name, callback, context) {
310 // Map the event into a `{event: once}` object.
311 var events = eventsApi(onceMap, {}, name, callback, _.bind(this.off, this));
312 return this.on(events, void 0, context);
315 // Inversion-of-control versions of `once`.
316 Events.listenToOnce = function(obj, name, callback) {
317 // Map the event into a `{event: once}` object.
318 var events = eventsApi(onceMap, {}, name, callback, _.bind(this.stopListening, this, obj));
319 return this.listenTo(obj, events);
322 // Reduces the event callbacks into a map of `{event: onceWrapper}`.
323 // `offer` unbinds the `onceWrapper` after it has been called.
324 var onceMap = function(map, name, callback, offer) {
326 var once = map[name] = _.once(function() {
328 callback.apply(this, arguments);
330 once._callback = callback;
335 // Trigger one or many events, firing all bound callbacks. Callbacks are
336 // passed the same arguments as `trigger` is, apart from the event name
337 // (unless you're listening on `"all"`, which will cause your callback to
338 // receive the true name of the event as the first argument).
339 Events.trigger = function(name) {
340 if (!this._events) return this;
342 var length = Math.max(0, arguments.length - 1);
343 var args = Array(length);
344 for (var i = 0; i < length; i++) args[i] = arguments[i + 1];
346 eventsApi(triggerApi, this._events, name, void 0, args);
350 // Handles triggering the appropriate event callbacks.
351 var triggerApi = function(objEvents, name, callback, args) {
353 var events = objEvents[name];
354 var allEvents = objEvents.all;
355 if (events && allEvents) allEvents = allEvents.slice();
356 if (events) triggerEvents(events, args);
357 if (allEvents) triggerEvents(allEvents, [name].concat(args));
362 // A difficult-to-believe, but optimized internal dispatch function for
363 // triggering events. Tries to keep the usual cases speedy (most internal
364 // Backbone events have 3 arguments).
365 var triggerEvents = function(events, args) {
366 var ev, i = -1, l = events.length, a1 = args[0], a2 = args[1], a3 = args[2];
367 switch (args.length) {
368 case 0: while (++i < l) (ev = events[i]).callback.call(ev.ctx); return;
369 case 1: while (++i < l) (ev = events[i]).callback.call(ev.ctx, a1); return;
370 case 2: while (++i < l) (ev = events[i]).callback.call(ev.ctx, a1, a2); return;
371 case 3: while (++i < l) (ev = events[i]).callback.call(ev.ctx, a1, a2, a3); return;
372 default: while (++i < l) (ev = events[i]).callback.apply(ev.ctx, args); return;
376 // Aliases for backwards compatibility.
377 Events.bind = Events.on;
378 Events.unbind = Events.off;
380 // Allow the `Backbone` object to serve as a global event bus, for folks who
381 // want global "pubsub" in a convenient place.
382 _.extend(Backbone, Events);
387 // Backbone **Models** are the basic data object in the framework --
388 // frequently representing a row in a table in a database on your server.
389 // A discrete chunk of data and a bunch of useful, related methods for
390 // performing computations and transformations on that data.
392 // Create a new model with the specified attributes. A client id (`cid`)
393 // is automatically generated and assigned for you.
394 var Model = Backbone.Model = function(attributes, options) {
395 var attrs = attributes || {};
396 options || (options = {});
397 this.cid = _.uniqueId(this.cidPrefix);
398 this.attributes = {};
399 if (options.collection) this.collection = options.collection;
400 if (options.parse) attrs = this.parse(attrs, options) || {};
401 attrs = _.defaults({}, attrs, _.result(this, 'defaults'));
402 this.set(attrs, options);
404 this.initialize.apply(this, arguments);
407 // Attach all inheritable methods to the Model prototype.
408 _.extend(Model.prototype, Events, {
410 // A hash of attributes whose current and previous value differ.
413 // The value returned during the last failed validation.
414 validationError: null,
416 // The default name for the JSON `id` attribute is `"id"`. MongoDB and
417 // CouchDB users may want to set this to `"_id"`.
420 // The prefix is used to create the client id which is used to identify models locally.
421 // You may want to override this if you're experiencing name clashes with model ids.
424 // Initialize is an empty function by default. Override it with your own
425 // initialization logic.
426 initialize: function(){},
428 // Return a copy of the model's `attributes` object.
429 toJSON: function(options) {
430 return _.clone(this.attributes);
433 // Proxy `Backbone.sync` by default -- but override this if you need
434 // custom syncing semantics for *this* particular model.
436 return Backbone.sync.apply(this, arguments);
439 // Get the value of an attribute.
440 get: function(attr) {
441 return this.attributes[attr];
444 // Get the HTML-escaped value of an attribute.
445 escape: function(attr) {
446 return _.escape(this.get(attr));
449 // Returns `true` if the attribute contains a value that is not null
451 has: function(attr) {
452 return this.get(attr) != null;
455 // Special-cased proxy to underscore's `_.matches` method.
456 matches: function(attrs) {
457 return !!_.iteratee(attrs, this)(this.attributes);
460 // Set a hash of model attributes on the object, firing `"change"`. This is
461 // the core primitive operation of a model, updating the data and notifying
462 // anyone who needs to know about the change in state. The heart of the beast.
463 set: function(key, val, options) {
464 if (key == null) return this;
466 // Handle both `"key", value` and `{key: value}` -style arguments.
468 if (typeof key === 'object') {
472 (attrs = {})[key] = val;
475 options || (options = {});
478 if (!this._validate(attrs, options)) return false;
480 // Extract attributes and options.
481 var unset = options.unset;
482 var silent = options.silent;
484 var changing = this._changing;
485 this._changing = true;
488 this._previousAttributes = _.clone(this.attributes);
492 var current = this.attributes;
493 var changed = this.changed;
494 var prev = this._previousAttributes;
496 // For each `set` attribute, update or delete the current value.
497 for (var attr in attrs) {
499 if (!_.isEqual(current[attr], val)) changes.push(attr);
500 if (!_.isEqual(prev[attr], val)) {
503 delete changed[attr];
505 unset ? delete current[attr] : current[attr] = val;
509 if (this.idAttribute in attrs) this.id = this.get(this.idAttribute);
511 // Trigger all relevant attribute changes.
513 if (changes.length) this._pending = options;
514 for (var i = 0; i < changes.length; i++) {
515 this.trigger('change:' + changes[i], this, current[changes[i]], options);
519 // You might be wondering why there's a `while` loop here. Changes can
520 // be recursively nested within `"change"` events.
521 if (changing) return this;
523 while (this._pending) {
524 options = this._pending;
525 this._pending = false;
526 this.trigger('change', this, options);
529 this._pending = false;
530 this._changing = false;
534 // Remove an attribute from the model, firing `"change"`. `unset` is a noop
535 // if the attribute doesn't exist.
536 unset: function(attr, options) {
537 return this.set(attr, void 0, _.extend({}, options, {unset: true}));
540 // Clear all attributes on the model, firing `"change"`.
541 clear: function(options) {
543 for (var key in this.attributes) attrs[key] = void 0;
544 return this.set(attrs, _.extend({}, options, {unset: true}));
547 // Determine if the model has changed since the last `"change"` event.
548 // If you specify an attribute name, determine if that attribute has changed.
549 hasChanged: function(attr) {
550 if (attr == null) return !_.isEmpty(this.changed);
551 return _.has(this.changed, attr);
554 // Return an object containing all the attributes that have changed, or
555 // false if there are no changed attributes. Useful for determining what
556 // parts of a view need to be updated and/or what attributes need to be
557 // persisted to the server. Unset attributes will be set to undefined.
558 // You can also pass an attributes object to diff against the model,
559 // determining if there *would be* a change.
560 changedAttributes: function(diff) {
561 if (!diff) return this.hasChanged() ? _.clone(this.changed) : false;
562 var old = this._changing ? this._previousAttributes : this.attributes;
564 for (var attr in diff) {
565 var val = diff[attr];
566 if (_.isEqual(old[attr], val)) continue;
569 return _.size(changed) ? changed : false;
572 // Get the previous value of an attribute, recorded at the time the last
573 // `"change"` event was fired.
574 previous: function(attr) {
575 if (attr == null || !this._previousAttributes) return null;
576 return this._previousAttributes[attr];
579 // Get all of the attributes of the model at the time of the previous
581 previousAttributes: function() {
582 return _.clone(this._previousAttributes);
585 // Fetch the model from the server, merging the response with the model's
586 // local attributes. Any changed attributes will trigger a "change" event.
587 fetch: function(options) {
588 options = _.extend({parse: true}, options);
590 var success = options.success;
591 options.success = function(resp) {
592 var serverAttrs = options.parse ? model.parse(resp, options) : resp;
593 if (!model.set(serverAttrs, options)) return false;
594 if (success) success.call(options.context, model, resp, options);
595 model.trigger('sync', model, resp, options);
597 wrapError(this, options);
598 return this.sync('read', this, options);
601 // Set a hash of model attributes, and sync the model to the server.
602 // If the server returns an attributes hash that differs, the model's
603 // state will be `set` again.
604 save: function(key, val, options) {
605 // Handle both `"key", value` and `{key: value}` -style arguments.
607 if (key == null || typeof key === 'object') {
611 (attrs = {})[key] = val;
614 options = _.extend({validate: true, parse: true}, options);
615 var wait = options.wait;
617 // If we're not waiting and attributes exist, save acts as
618 // `set(attr).save(null, opts)` with validation. Otherwise, check if
619 // the model will be valid when the attributes, if any, are set.
620 if (attrs && !wait) {
621 if (!this.set(attrs, options)) return false;
622 } else if (!this._validate(attrs, options)) {
626 // After a successful server-side save, the client is (optionally)
627 // updated with the server-side state.
629 var success = options.success;
630 var attributes = this.attributes;
631 options.success = function(resp) {
632 // Ensure attributes are restored during synchronous saves.
633 model.attributes = attributes;
634 var serverAttrs = options.parse ? model.parse(resp, options) : resp;
635 if (wait) serverAttrs = _.extend({}, attrs, serverAttrs);
636 if (serverAttrs && !model.set(serverAttrs, options)) return false;
637 if (success) success.call(options.context, model, resp, options);
638 model.trigger('sync', model, resp, options);
640 wrapError(this, options);
642 // Set temporary attributes if `{wait: true}` to properly find new ids.
643 if (attrs && wait) this.attributes = _.extend({}, attributes, attrs);
645 var method = this.isNew() ? 'create' : (options.patch ? 'patch' : 'update');
646 if (method === 'patch' && !options.attrs) options.attrs = attrs;
647 var xhr = this.sync(method, this, options);
649 // Restore attributes.
650 this.attributes = attributes;
655 // Destroy this model on the server if it was already persisted.
656 // Optimistically removes the model from its collection, if it has one.
657 // If `wait: true` is passed, waits for the server to respond before removal.
658 destroy: function(options) {
659 options = options ? _.clone(options) : {};
661 var success = options.success;
662 var wait = options.wait;
664 var destroy = function() {
665 model.stopListening();
666 model.trigger('destroy', model, model.collection, options);
669 options.success = function(resp) {
671 if (success) success.call(options.context, model, resp, options);
672 if (!model.isNew()) model.trigger('sync', model, resp, options);
677 _.defer(options.success);
679 wrapError(this, options);
680 xhr = this.sync('delete', this, options);
682 if (!wait) destroy();
686 // Default URL for the model's representation on the server -- if you're
687 // using Backbone's restful methods, override this to change the endpoint
688 // that will be called.
691 _.result(this, 'urlRoot') ||
692 _.result(this.collection, 'url') ||
694 if (this.isNew()) return base;
695 var id = this.get(this.idAttribute);
696 return base.replace(/[^\/]$/, '$&/') + encodeURIComponent(id);
699 // **parse** converts a response into the hash of attributes to be `set` on
700 // the model. The default implementation is just to pass the response along.
701 parse: function(resp, options) {
705 // Create a new model with identical attributes to this one.
707 return new this.constructor(this.attributes);
710 // A model is new if it has never been saved to the server, and lacks an id.
712 return !this.has(this.idAttribute);
715 // Check if the model is currently in a valid state.
716 isValid: function(options) {
717 return this._validate({}, _.defaults({validate: true}, options));
720 // Run validation against the next complete set of model attributes,
721 // returning `true` if all is well. Otherwise, fire an `"invalid"` event.
722 _validate: function(attrs, options) {
723 if (!options.validate || !this.validate) return true;
724 attrs = _.extend({}, this.attributes, attrs);
725 var error = this.validationError = this.validate(attrs, options) || null;
726 if (!error) return true;
727 this.trigger('invalid', this, error, _.extend(options, {validationError: error}));
733 // Underscore methods that we want to implement on the Model, mapped to the
734 // number of arguments they take.
735 var modelMethods = {keys: 1, values: 1, pairs: 1, invert: 1, pick: 0,
736 omit: 0, chain: 1, isEmpty: 1};
738 // Mix in each Underscore method as a proxy to `Model#attributes`.
739 addUnderscoreMethods(Model, modelMethods, 'attributes');
741 // Backbone.Collection
742 // -------------------
744 // If models tend to represent a single row of data, a Backbone Collection is
745 // more analogous to a table full of data ... or a small slice or page of that
746 // table, or a collection of rows that belong together for a particular reason
747 // -- all of the messages in this particular folder, all of the documents
748 // belonging to this particular author, and so on. Collections maintain
749 // indexes of their models, both in order, and for lookup by `id`.
751 // Create a new **Collection**, perhaps to contain a specific type of `model`.
752 // If a `comparator` is specified, the Collection will maintain
753 // its models in sort order, as they're added and removed.
754 var Collection = Backbone.Collection = function(models, options) {
755 options || (options = {});
756 if (options.model) this.model = options.model;
757 if (options.comparator !== void 0) this.comparator = options.comparator;
759 this.initialize.apply(this, arguments);
760 if (models) this.reset(models, _.extend({silent: true}, options));
763 // Default options for `Collection#set`.
764 var setOptions = {add: true, remove: true, merge: true};
765 var addOptions = {add: true, remove: false};
767 // Splices `insert` into `array` at index `at`.
768 var splice = function(array, insert, at) {
769 at = Math.min(Math.max(at, 0), array.length);
770 var tail = Array(array.length - at);
771 var length = insert.length;
773 for (i = 0; i < tail.length; i++) tail[i] = array[i + at];
774 for (i = 0; i < length; i++) array[i + at] = insert[i];
775 for (i = 0; i < tail.length; i++) array[i + length + at] = tail[i];
778 // Define the Collection's inheritable methods.
779 _.extend(Collection.prototype, Events, {
781 // The default model for a collection is just a **Backbone.Model**.
782 // This should be overridden in most cases.
785 // Initialize is an empty function by default. Override it with your own
786 // initialization logic.
787 initialize: function(){},
789 // The JSON representation of a Collection is an array of the
790 // models' attributes.
791 toJSON: function(options) {
792 return this.map(function(model) { return model.toJSON(options); });
795 // Proxy `Backbone.sync` by default.
797 return Backbone.sync.apply(this, arguments);
800 // Add a model, or list of models to the set. `models` may be Backbone
801 // Models or raw JavaScript objects to be converted to Models, or any
802 // combination of the two.
803 add: function(models, options) {
804 return this.set(models, _.extend({merge: false}, options, addOptions));
807 // Remove a model, or a list of models from the set.
808 remove: function(models, options) {
809 options = _.extend({}, options);
810 var singular = !_.isArray(models);
811 models = singular ? [models] : models.slice();
812 var removed = this._removeModels(models, options);
813 if (!options.silent && removed.length) {
814 options.changes = {added: [], merged: [], removed: removed};
815 this.trigger('update', this, options);
817 return singular ? removed[0] : removed;
820 // Update a collection by `set`-ing a new list of models, adding new ones,
821 // removing models that are no longer present, and merging models that
822 // already exist in the collection, as necessary. Similar to **Model#set**,
823 // the core operation for updating the data contained by the collection.
824 set: function(models, options) {
825 if (models == null) return;
827 options = _.defaults({}, options, setOptions);
828 if (options.parse && !this._isModel(models)) {
829 models = this.parse(models, options) || [];
832 var singular = !_.isArray(models);
833 models = singular ? [models] : models.slice();
836 if (at != null) at = +at;
837 if (at < 0) at += this.length + 1;
845 var add = options.add;
846 var merge = options.merge;
847 var remove = options.remove;
850 var sortable = this.comparator && at == null && options.sort !== false;
851 var sortAttr = _.isString(this.comparator) ? this.comparator : null;
853 // Turn bare objects into model references, and prevent invalid models
856 for (i = 0; i < models.length; i++) {
859 // If a duplicate is found, prevent it from being added and
860 // optionally merge it into the existing model.
861 var existing = this.get(model);
863 if (merge && model !== existing) {
864 var attrs = this._isModel(model) ? model.attributes : model;
865 if (options.parse) attrs = existing.parse(attrs, options);
866 existing.set(attrs, options);
867 toMerge.push(existing);
868 if (sortable && !sort) sort = existing.hasChanged(sortAttr);
870 if (!modelMap[existing.cid]) {
871 modelMap[existing.cid] = true;
874 models[i] = existing;
876 // If this is a new, valid model, push it to the `toAdd` list.
878 model = models[i] = this._prepareModel(model, options);
881 this._addReference(model, options);
882 modelMap[model.cid] = true;
888 // Remove stale models.
890 for (i = 0; i < this.length; i++) {
891 model = this.models[i];
892 if (!modelMap[model.cid]) toRemove.push(model);
894 if (toRemove.length) this._removeModels(toRemove, options);
897 // See if sorting is needed, update `length` and splice in new models.
898 var orderChanged = false;
899 var replace = !sortable && add && remove;
900 if (set.length && replace) {
901 orderChanged = this.length !== set.length || _.some(this.models, function(m, index) {
902 return m !== set[index];
904 this.models.length = 0;
905 splice(this.models, set, 0);
906 this.length = this.models.length;
907 } else if (toAdd.length) {
908 if (sortable) sort = true;
909 splice(this.models, toAdd, at == null ? this.length : at);
910 this.length = this.models.length;
913 // Silently sort the collection if appropriate.
914 if (sort) this.sort({silent: true});
916 // Unless silenced, it's time to fire all appropriate add/sort/update events.
917 if (!options.silent) {
918 for (i = 0; i < toAdd.length; i++) {
919 if (at != null) options.index = at + i;
921 model.trigger('add', model, this, options);
923 if (sort || orderChanged) this.trigger('sort', this, options);
924 if (toAdd.length || toRemove.length || toMerge.length) {
930 this.trigger('update', this, options);
934 // Return the added (or merged) model (or models).
935 return singular ? models[0] : models;
938 // When you have more items than you want to add or remove individually,
939 // you can reset the entire set with a new list of models, without firing
940 // any granular `add` or `remove` events. Fires `reset` when finished.
941 // Useful for bulk operations and optimizations.
942 reset: function(models, options) {
943 options = options ? _.clone(options) : {};
944 for (var i = 0; i < this.models.length; i++) {
945 this._removeReference(this.models[i], options);
947 options.previousModels = this.models;
949 models = this.add(models, _.extend({silent: true}, options));
950 if (!options.silent) this.trigger('reset', this, options);
954 // Add a model to the end of the collection.
955 push: function(model, options) {
956 return this.add(model, _.extend({at: this.length}, options));
959 // Remove a model from the end of the collection.
960 pop: function(options) {
961 var model = this.at(this.length - 1);
962 return this.remove(model, options);
965 // Add a model to the beginning of the collection.
966 unshift: function(model, options) {
967 return this.add(model, _.extend({at: 0}, options));
970 // Remove a model from the beginning of the collection.
971 shift: function(options) {
972 var model = this.at(0);
973 return this.remove(model, options);
976 // Slice out a sub-array of models from the collection.
978 return slice.apply(this.models, arguments);
981 // Get a model from the set by id.
983 if (obj == null) return void 0;
984 var id = this.modelId(this._isModel(obj) ? obj.attributes : obj);
985 return this._byId[obj] || this._byId[id] || this._byId[obj.cid];
988 // Returns `true` if the model is in the collection.
990 return this.get(obj) != null;
993 // Get the model at the given index.
994 at: function(index) {
995 if (index < 0) index += this.length;
996 return this.models[index];
999 // Return models with matching attributes. Useful for simple cases of
1001 where: function(attrs, first) {
1002 return this[first ? 'find' : 'filter'](attrs);
1005 // Return the first model with matching attributes. Useful for simple cases
1007 findWhere: function(attrs) {
1008 return this.where(attrs, true);
1011 // Force the collection to re-sort itself. You don't need to call this under
1012 // normal circumstances, as the set will maintain sort order as each item
1014 sort: function(options) {
1015 var comparator = this.comparator;
1016 if (!comparator) throw new Error('Cannot sort a set without a comparator');
1017 options || (options = {});
1019 var length = comparator.length;
1020 if (_.isFunction(comparator)) comparator = _.bind(comparator, this);
1022 // Run sort based on type of `comparator`.
1023 if (length === 1 || _.isString(comparator)) {
1024 this.models = this.sortBy(comparator);
1026 this.models.sort(comparator);
1028 if (!options.silent) this.trigger('sort', this, options);
1032 // Pluck an attribute from each model in the collection.
1033 pluck: function(attr) {
1034 return this.map(attr + '');
1037 // Fetch the default set of models for this collection, resetting the
1038 // collection when they arrive. If `reset: true` is passed, the response
1039 // data will be passed through the `reset` method instead of `set`.
1040 fetch: function(options) {
1041 options = _.extend({parse: true}, options);
1042 var success = options.success;
1043 var collection = this;
1044 options.success = function(resp) {
1045 var method = options.reset ? 'reset' : 'set';
1046 collection[method](resp, options);
1047 if (success) success.call(options.context, collection, resp, options);
1048 collection.trigger('sync', collection, resp, options);
1050 wrapError(this, options);
1051 return this.sync('read', this, options);
1054 // Create a new instance of a model in this collection. Add the model to the
1055 // collection immediately, unless `wait: true` is passed, in which case we
1056 // wait for the server to agree.
1057 create: function(model, options) {
1058 options = options ? _.clone(options) : {};
1059 var wait = options.wait;
1060 model = this._prepareModel(model, options);
1061 if (!model) return false;
1062 if (!wait) this.add(model, options);
1063 var collection = this;
1064 var success = options.success;
1065 options.success = function(m, resp, callbackOpts) {
1066 if (wait) collection.add(m, callbackOpts);
1067 if (success) success.call(callbackOpts.context, m, resp, callbackOpts);
1069 model.save(null, options);
1073 // **parse** converts a response into a list of models to be added to the
1074 // collection. The default implementation is just to pass it through.
1075 parse: function(resp, options) {
1079 // Create a new collection with an identical list of models as this one.
1081 return new this.constructor(this.models, {
1083 comparator: this.comparator
1087 // Define how to uniquely identify models in the collection.
1088 modelId: function(attrs) {
1089 return attrs[this.model.prototype.idAttribute || 'id'];
1092 // Private method to reset all internal state. Called when the collection
1093 // is first initialized or reset.
1094 _reset: function() {
1100 // Prepare a hash of attributes (or other model) to be added to this
1102 _prepareModel: function(attrs, options) {
1103 if (this._isModel(attrs)) {
1104 if (!attrs.collection) attrs.collection = this;
1107 options = options ? _.clone(options) : {};
1108 options.collection = this;
1109 var model = new this.model(attrs, options);
1110 if (!model.validationError) return model;
1111 this.trigger('invalid', this, model.validationError, options);
1115 // Internal method called by both remove and set.
1116 _removeModels: function(models, options) {
1118 for (var i = 0; i < models.length; i++) {
1119 var model = this.get(models[i]);
1120 if (!model) continue;
1122 var index = this.indexOf(model);
1123 this.models.splice(index, 1);
1126 // Remove references before triggering 'remove' event to prevent an
1127 // infinite loop. #3693
1128 delete this._byId[model.cid];
1129 var id = this.modelId(model.attributes);
1130 if (id != null) delete this._byId[id];
1132 if (!options.silent) {
1133 options.index = index;
1134 model.trigger('remove', model, this, options);
1137 removed.push(model);
1138 this._removeReference(model, options);
1143 // Method for checking whether an object should be considered a model for
1144 // the purposes of adding to the collection.
1145 _isModel: function(model) {
1146 return model instanceof Model;
1149 // Internal method to create a model's ties to a collection.
1150 _addReference: function(model, options) {
1151 this._byId[model.cid] = model;
1152 var id = this.modelId(model.attributes);
1153 if (id != null) this._byId[id] = model;
1154 model.on('all', this._onModelEvent, this);
1157 // Internal method to sever a model's ties to a collection.
1158 _removeReference: function(model, options) {
1159 delete this._byId[model.cid];
1160 var id = this.modelId(model.attributes);
1161 if (id != null) delete this._byId[id];
1162 if (this === model.collection) delete model.collection;
1163 model.off('all', this._onModelEvent, this);
1166 // Internal method called every time a model in the set fires an event.
1167 // Sets need to update their indexes when models change ids. All other
1168 // events simply proxy through. "add" and "remove" events that originate
1169 // in other collections are ignored.
1170 _onModelEvent: function(event, model, collection, options) {
1172 if ((event === 'add' || event === 'remove') && collection !== this) return;
1173 if (event === 'destroy') this.remove(model, options);
1174 if (event === 'change') {
1175 var prevId = this.modelId(model.previousAttributes());
1176 var id = this.modelId(model.attributes);
1177 if (prevId !== id) {
1178 if (prevId != null) delete this._byId[prevId];
1179 if (id != null) this._byId[id] = model;
1183 this.trigger.apply(this, arguments);
1188 // Underscore methods that we want to implement on the Collection.
1189 // 90% of the core usefulness of Backbone Collections is actually implemented
1191 var collectionMethods = {forEach: 3, each: 3, map: 3, collect: 3, reduce: 0,
1192 foldl: 0, inject: 0, reduceRight: 0, foldr: 0, find: 3, detect: 3, filter: 3,
1193 select: 3, reject: 3, every: 3, all: 3, some: 3, any: 3, include: 3, includes: 3,
1194 contains: 3, invoke: 0, max: 3, min: 3, toArray: 1, size: 1, first: 3,
1195 head: 3, take: 3, initial: 3, rest: 3, tail: 3, drop: 3, last: 3,
1196 without: 0, difference: 0, indexOf: 3, shuffle: 1, lastIndexOf: 3,
1197 isEmpty: 1, chain: 1, sample: 3, partition: 3, groupBy: 3, countBy: 3,
1198 sortBy: 3, indexBy: 3, findIndex: 3, findLastIndex: 3};
1200 // Mix in each Underscore method as a proxy to `Collection#models`.
1201 addUnderscoreMethods(Collection, collectionMethods, 'models');
1206 // Backbone Views are almost more convention than they are actual code. A View
1207 // is simply a JavaScript object that represents a logical chunk of UI in the
1208 // DOM. This might be a single item, an entire list, a sidebar or panel, or
1209 // even the surrounding frame which wraps your whole app. Defining a chunk of
1210 // UI as a **View** allows you to define your DOM events declaratively, without
1211 // having to worry about render order ... and makes it easy for the view to
1212 // react to specific changes in the state of your models.
1214 // Creating a Backbone.View creates its initial element outside of the DOM,
1215 // if an existing element is not provided...
1216 var View = Backbone.View = function(options) {
1217 this.cid = _.uniqueId('view');
1218 _.extend(this, _.pick(options, viewOptions));
1219 this._ensureElement();
1220 this.initialize.apply(this, arguments);
1223 // Cached regex to split keys for `delegate`.
1224 var delegateEventSplitter = /^(\S+)\s*(.*)$/;
1226 // List of view options to be set as properties.
1227 var viewOptions = ['model', 'collection', 'el', 'id', 'attributes', 'className', 'tagName', 'events'];
1229 // Set up all inheritable **Backbone.View** properties and methods.
1230 _.extend(View.prototype, Events, {
1232 // The default `tagName` of a View's element is `"div"`.
1235 // jQuery delegate for element lookup, scoped to DOM elements within the
1236 // current view. This should be preferred to global lookups where possible.
1237 $: function(selector) {
1238 return this.$el.find(selector);
1241 // Initialize is an empty function by default. Override it with your own
1242 // initialization logic.
1243 initialize: function(){},
1245 // **render** is the core function that your view should override, in order
1246 // to populate its element (`this.el`), with the appropriate HTML. The
1247 // convention is for **render** to always return `this`.
1248 render: function() {
1252 // Remove this view by taking the element out of the DOM, and removing any
1253 // applicable Backbone.Events listeners.
1254 remove: function() {
1255 this._removeElement();
1256 this.stopListening();
1260 // Remove this view's element from the document and all event listeners
1261 // attached to it. Exposed for subclasses using an alternative DOM
1262 // manipulation API.
1263 _removeElement: function() {
1267 // Change the view's element (`this.el` property) and re-delegate the
1268 // view's events on the new element.
1269 setElement: function(element) {
1270 this.undelegateEvents();
1271 this._setElement(element);
1272 this.delegateEvents();
1276 // Creates the `this.el` and `this.$el` references for this view using the
1277 // given `el`. `el` can be a CSS selector or an HTML string, a jQuery
1278 // context or an element. Subclasses can override this to utilize an
1279 // alternative DOM manipulation API and are only required to set the
1280 // `this.el` property.
1281 _setElement: function(el) {
1282 this.$el = el instanceof Backbone.$ ? el : Backbone.$(el);
1283 this.el = this.$el[0];
1286 // Set callbacks, where `this.events` is a hash of
1288 // *{"event selector": "callback"}*
1291 // 'mousedown .title': 'edit',
1292 // 'click .button': 'save',
1293 // 'click .open': function(e) { ... }
1296 // pairs. Callbacks will be bound to the view, with `this` set properly.
1297 // Uses event delegation for efficiency.
1298 // Omitting the selector binds the event to `this.el`.
1299 delegateEvents: function(events) {
1300 events || (events = _.result(this, 'events'));
1301 if (!events) return this;
1302 this.undelegateEvents();
1303 for (var key in events) {
1304 var method = events[key];
1305 if (!_.isFunction(method)) method = this[method];
1306 if (!method) continue;
1307 var match = key.match(delegateEventSplitter);
1308 this.delegate(match[1], match[2], _.bind(method, this));
1313 // Add a single event listener to the view's element (or a child element
1314 // using `selector`). This only works for delegate-able events: not `focus`,
1315 // `blur`, and not `change`, `submit`, and `reset` in Internet Explorer.
1316 delegate: function(eventName, selector, listener) {
1317 this.$el.on(eventName + '.delegateEvents' + this.cid, selector, listener);
1321 // Clears all callbacks previously bound to the view by `delegateEvents`.
1322 // You usually don't need to use this, but may wish to if you have multiple
1323 // Backbone views attached to the same DOM element.
1324 undelegateEvents: function() {
1325 if (this.$el) this.$el.off('.delegateEvents' + this.cid);
1329 // A finer-grained `undelegateEvents` for removing a single delegated event.
1330 // `selector` and `listener` are both optional.
1331 undelegate: function(eventName, selector, listener) {
1332 this.$el.off(eventName + '.delegateEvents' + this.cid, selector, listener);
1336 // Produces a DOM element to be assigned to your view. Exposed for
1337 // subclasses using an alternative DOM manipulation API.
1338 _createElement: function(tagName) {
1339 return document.createElement(tagName);
1342 // Ensure that the View has a DOM element to render into.
1343 // If `this.el` is a string, pass it through `$()`, take the first
1344 // matching element, and re-assign it to `el`. Otherwise, create
1345 // an element from the `id`, `className` and `tagName` properties.
1346 _ensureElement: function() {
1348 var attrs = _.extend({}, _.result(this, 'attributes'));
1349 if (this.id) attrs.id = _.result(this, 'id');
1350 if (this.className) attrs['class'] = _.result(this, 'className');
1351 this.setElement(this._createElement(_.result(this, 'tagName')));
1352 this._setAttributes(attrs);
1354 this.setElement(_.result(this, 'el'));
1358 // Set attributes from a hash on this view's element. Exposed for
1359 // subclasses using an alternative DOM manipulation API.
1360 _setAttributes: function(attributes) {
1361 this.$el.attr(attributes);
1369 // Override this function to change the manner in which Backbone persists
1370 // models to the server. You will be passed the type of request, and the
1371 // model in question. By default, makes a RESTful Ajax request
1372 // to the model's `url()`. Some possible customizations could be:
1374 // * Use `setTimeout` to batch rapid-fire updates into a single request.
1375 // * Send up the models as XML instead of JSON.
1376 // * Persist models via WebSockets instead of Ajax.
1378 // Turn on `Backbone.emulateHTTP` in order to send `PUT` and `DELETE` requests
1379 // as `POST`, with a `_method` parameter containing the true HTTP method,
1380 // as well as all requests with the body as `application/x-www-form-urlencoded`
1381 // instead of `application/json` with the model in a param named `model`.
1382 // Useful when interfacing with server-side languages like **PHP** that make
1383 // it difficult to read the body of `PUT` requests.
1384 Backbone.sync = function(method, model, options) {
1385 var type = methodMap[method];
1387 // Default options, unless specified.
1388 _.defaults(options || (options = {}), {
1389 emulateHTTP: Backbone.emulateHTTP,
1390 emulateJSON: Backbone.emulateJSON
1393 // Default JSON-request options.
1394 var params = {type: type, dataType: 'json'};
1396 // Ensure that we have a URL.
1398 params.url = _.result(model, 'url') || urlError();
1401 // Ensure that we have the appropriate request data.
1402 if (options.data == null && model && (method === 'create' || method === 'update' || method === 'patch')) {
1403 params.contentType = 'application/json';
1404 params.data = JSON.stringify(options.attrs || model.toJSON(options));
1407 // For older servers, emulate JSON by encoding the request into an HTML-form.
1408 if (options.emulateJSON) {
1409 params.contentType = 'application/x-www-form-urlencoded';
1410 params.data = params.data ? {model: params.data} : {};
1413 // For older servers, emulate HTTP by mimicking the HTTP method with `_method`
1414 // And an `X-HTTP-Method-Override` header.
1415 if (options.emulateHTTP && (type === 'PUT' || type === 'DELETE' || type === 'PATCH')) {
1416 params.type = 'POST';
1417 if (options.emulateJSON) params.data._method = type;
1418 var beforeSend = options.beforeSend;
1419 options.beforeSend = function(xhr) {
1420 xhr.setRequestHeader('X-HTTP-Method-Override', type);
1421 if (beforeSend) return beforeSend.apply(this, arguments);
1425 // Don't process data on a non-GET request.
1426 if (params.type !== 'GET' && !options.emulateJSON) {
1427 params.processData = false;
1430 // Pass along `textStatus` and `errorThrown` from jQuery.
1431 var error = options.error;
1432 options.error = function(xhr, textStatus, errorThrown) {
1433 options.textStatus = textStatus;
1434 options.errorThrown = errorThrown;
1435 if (error) error.call(options.context, xhr, textStatus, errorThrown);
1438 // Make the request, allowing the user to override any Ajax options.
1439 var xhr = options.xhr = Backbone.ajax(_.extend(params, options));
1440 model.trigger('request', model, xhr, options);
1444 // Map from CRUD to HTTP for our default `Backbone.sync` implementation.
1453 // Set the default implementation of `Backbone.ajax` to proxy through to `$`.
1454 // Override this if you'd like to use a different library.
1455 Backbone.ajax = function() {
1456 return Backbone.$.ajax.apply(Backbone.$, arguments);
1462 // Routers map faux-URLs to actions, and fire events when routes are
1463 // matched. Creating a new one sets its `routes` hash, if not set statically.
1464 var Router = Backbone.Router = function(options) {
1465 options || (options = {});
1466 if (options.routes) this.routes = options.routes;
1468 this.initialize.apply(this, arguments);
1471 // Cached regular expressions for matching named param parts and splatted
1472 // parts of route strings.
1473 var optionalParam = /\((.*?)\)/g;
1474 var namedParam = /(\(\?)?:\w+/g;
1475 var splatParam = /\*\w+/g;
1476 var escapeRegExp = /[\-{}\[\]+?.,\\\^$|#\s]/g;
1478 // Set up all inheritable **Backbone.Router** properties and methods.
1479 _.extend(Router.prototype, Events, {
1481 // Initialize is an empty function by default. Override it with your own
1482 // initialization logic.
1483 initialize: function(){},
1485 // Manually bind a single named route to a callback. For example:
1487 // this.route('search/:query/p:num', 'search', function(query, num) {
1491 route: function(route, name, callback) {
1492 if (!_.isRegExp(route)) route = this._routeToRegExp(route);
1493 if (_.isFunction(name)) {
1497 if (!callback) callback = this[name];
1499 Backbone.history.route(route, function(fragment) {
1500 var args = router._extractParameters(route, fragment);
1501 if (router.execute(callback, args, name) !== false) {
1502 router.trigger.apply(router, ['route:' + name].concat(args));
1503 router.trigger('route', name, args);
1504 Backbone.history.trigger('route', router, name, args);
1510 // Execute a route handler with the provided parameters. This is an
1511 // excellent place to do pre-route setup or post-route cleanup.
1512 execute: function(callback, args, name) {
1513 if (callback) callback.apply(this, args);
1516 // Simple proxy to `Backbone.history` to save a fragment into the history.
1517 navigate: function(fragment, options) {
1518 Backbone.history.navigate(fragment, options);
1522 // Bind all defined routes to `Backbone.history`. We have to reverse the
1523 // order of the routes here to support behavior where the most general
1524 // routes can be defined at the bottom of the route map.
1525 _bindRoutes: function() {
1526 if (!this.routes) return;
1527 this.routes = _.result(this, 'routes');
1528 var route, routes = _.keys(this.routes);
1529 while ((route = routes.pop()) != null) {
1530 this.route(route, this.routes[route]);
1534 // Convert a route string into a regular expression, suitable for matching
1535 // against the current location hash.
1536 _routeToRegExp: function(route) {
1537 route = route.replace(escapeRegExp, '\\$&')
1538 .replace(optionalParam, '(?:$1)?')
1539 .replace(namedParam, function(match, optional) {
1540 return optional ? match : '([^/?]+)';
1542 .replace(splatParam, '([^?]*?)');
1543 return new RegExp('^' + route + '(?:\\?([\\s\\S]*))?$');
1546 // Given a route, and a URL fragment that it matches, return the array of
1547 // extracted decoded parameters. Empty or unmatched parameters will be
1548 // treated as `null` to normalize cross-browser behavior.
1549 _extractParameters: function(route, fragment) {
1550 var params = route.exec(fragment).slice(1);
1551 return _.map(params, function(param, i) {
1552 // Don't decode the search params.
1553 if (i === params.length - 1) return param || null;
1554 return param ? decodeURIComponent(param) : null;
1563 // Handles cross-browser history management, based on either
1564 // [pushState](http://diveintohtml5.info/history.html) and real URLs, or
1565 // [onhashchange](https://developer.mozilla.org/en-US/docs/DOM/window.onhashchange)
1566 // and URL fragments. If the browser supports neither (old IE, natch),
1567 // falls back to polling.
1568 var History = Backbone.History = function() {
1570 this.checkUrl = _.bind(this.checkUrl, this);
1572 // Ensure that `History` can be used outside of the browser.
1573 if (typeof window !== 'undefined') {
1574 this.location = window.location;
1575 this.history = window.history;
1579 // Cached regex for stripping a leading hash/slash and trailing space.
1580 var routeStripper = /^[#\/]|\s+$/g;
1582 // Cached regex for stripping leading and trailing slashes.
1583 var rootStripper = /^\/+|\/+$/g;
1585 // Cached regex for stripping urls of hash.
1586 var pathStripper = /#.*$/;
1588 // Has the history handling already been started?
1589 History.started = false;
1591 // Set up all inheritable **Backbone.History** properties and methods.
1592 _.extend(History.prototype, Events, {
1594 // The default interval to poll for hash changes, if necessary, is
1595 // twenty times a second.
1598 // Are we at the app root?
1599 atRoot: function() {
1600 var path = this.location.pathname.replace(/[^\/]$/, '$&/');
1601 return path === this.root && !this.getSearch();
1604 // Does the pathname match the root?
1605 matchRoot: function() {
1606 var path = this.decodeFragment(this.location.pathname);
1607 var rootPath = path.slice(0, this.root.length - 1) + '/';
1608 return rootPath === this.root;
1611 // Unicode characters in `location.pathname` are percent encoded so they're
1612 // decoded for comparison. `%25` should not be decoded since it may be part
1613 // of an encoded parameter.
1614 decodeFragment: function(fragment) {
1615 return decodeURI(fragment.replace(/%25/g, '%2525'));
1618 // In IE6, the hash fragment and search params are incorrect if the
1619 // fragment contains `?`.
1620 getSearch: function() {
1621 var match = this.location.href.replace(/#.*/, '').match(/\?.+/);
1622 return match ? match[0] : '';
1625 // Gets the true hash value. Cannot use location.hash directly due to bug
1626 // in Firefox where location.hash will always be decoded.
1627 getHash: function(window) {
1628 var match = (window || this).location.href.match(/#(.*)$/);
1629 return match ? match[1] : '';
1632 // Get the pathname and search params, without the root.
1633 getPath: function() {
1634 var path = this.decodeFragment(
1635 this.location.pathname + this.getSearch()
1636 ).slice(this.root.length - 1);
1637 return path.charAt(0) === '/' ? path.slice(1) : path;
1640 // Get the cross-browser normalized URL fragment from the path or hash.
1641 getFragment: function(fragment) {
1642 if (fragment == null) {
1643 if (this._usePushState || !this._wantsHashChange) {
1644 fragment = this.getPath();
1646 fragment = this.getHash();
1649 return fragment.replace(routeStripper, '');
1652 // Start the hash change handling, returning `true` if the current URL matches
1653 // an existing route, and `false` otherwise.
1654 start: function(options) {
1655 if (History.started) throw new Error('Backbone.history has already been started');
1656 History.started = true;
1658 // Figure out the initial configuration. Do we need an iframe?
1659 // Is pushState desired ... is it available?
1660 this.options = _.extend({root: '/'}, this.options, options);
1661 this.root = this.options.root;
1662 this._wantsHashChange = this.options.hashChange !== false;
1663 this._hasHashChange = 'onhashchange' in window && (document.documentMode === void 0 || document.documentMode > 7);
1664 this._useHashChange = this._wantsHashChange && this._hasHashChange;
1665 this._wantsPushState = !!this.options.pushState;
1666 this._hasPushState = !!(this.history && this.history.pushState);
1667 this._usePushState = this._wantsPushState && this._hasPushState;
1668 this.fragment = this.getFragment();
1670 // Normalize root to always include a leading and trailing slash.
1671 this.root = ('/' + this.root + '/').replace(rootStripper, '/');
1673 // Transition from hashChange to pushState or vice versa if both are
1675 if (this._wantsHashChange && this._wantsPushState) {
1677 // If we've started off with a route from a `pushState`-enabled
1678 // browser, but we're currently in a browser that doesn't support it...
1679 if (!this._hasPushState && !this.atRoot()) {
1680 var rootPath = this.root.slice(0, -1) || '/';
1681 this.location.replace(rootPath + '#' + this.getPath());
1682 // Return immediately as browser will do redirect to new url
1685 // Or if we've started out with a hash-based route, but we're currently
1686 // in a browser where it could be `pushState`-based instead...
1687 } else if (this._hasPushState && this.atRoot()) {
1688 this.navigate(this.getHash(), {replace: true});
1693 // Proxy an iframe to handle location events if the browser doesn't
1694 // support the `hashchange` event, HTML5 history, or the user wants
1695 // `hashChange` but not `pushState`.
1696 if (!this._hasHashChange && this._wantsHashChange && !this._usePushState) {
1697 this.iframe = document.createElement('iframe');
1698 this.iframe.src = 'javascript:0';
1699 this.iframe.style.display = 'none';
1700 this.iframe.tabIndex = -1;
1701 var body = document.body;
1702 // Using `appendChild` will throw on IE < 9 if the document is not ready.
1703 var iWindow = body.insertBefore(this.iframe, body.firstChild).contentWindow;
1704 iWindow.document.open();
1705 iWindow.document.close();
1706 iWindow.location.hash = '#' + this.fragment;
1709 // Add a cross-platform `addEventListener` shim for older browsers.
1710 var addEventListener = window.addEventListener || function(eventName, listener) {
1711 return attachEvent('on' + eventName, listener);
1714 // Depending on whether we're using pushState or hashes, and whether
1715 // 'onhashchange' is supported, determine how we check the URL state.
1716 if (this._usePushState) {
1717 addEventListener('popstate', this.checkUrl, false);
1718 } else if (this._useHashChange && !this.iframe) {
1719 addEventListener('hashchange', this.checkUrl, false);
1720 } else if (this._wantsHashChange) {
1721 this._checkUrlInterval = setInterval(this.checkUrl, this.interval);
1724 if (!this.options.silent) return this.loadUrl();
1727 // Disable Backbone.history, perhaps temporarily. Not useful in a real app,
1728 // but possibly useful for unit testing Routers.
1730 // Add a cross-platform `removeEventListener` shim for older browsers.
1731 var removeEventListener = window.removeEventListener || function(eventName, listener) {
1732 return detachEvent('on' + eventName, listener);
1735 // Remove window listeners.
1736 if (this._usePushState) {
1737 removeEventListener('popstate', this.checkUrl, false);
1738 } else if (this._useHashChange && !this.iframe) {
1739 removeEventListener('hashchange', this.checkUrl, false);
1742 // Clean up the iframe if necessary.
1744 document.body.removeChild(this.iframe);
1748 // Some environments will throw when clearing an undefined interval.
1749 if (this._checkUrlInterval) clearInterval(this._checkUrlInterval);
1750 History.started = false;
1753 // Add a route to be tested when the fragment changes. Routes added later
1754 // may override previous routes.
1755 route: function(route, callback) {
1756 this.handlers.unshift({route: route, callback: callback});
1759 // Checks the current URL to see if it has changed, and if it has,
1760 // calls `loadUrl`, normalizing across the hidden iframe.
1761 checkUrl: function(e) {
1762 var current = this.getFragment();
1764 // If the user pressed the back button, the iframe's hash will have
1765 // changed and we should use that for comparison.
1766 if (current === this.fragment && this.iframe) {
1767 current = this.getHash(this.iframe.contentWindow);
1770 if (current === this.fragment) return false;
1771 if (this.iframe) this.navigate(current);
1775 // Attempt to load the current URL fragment. If a route succeeds with a
1776 // match, returns `true`. If no defined routes matches the fragment,
1778 loadUrl: function(fragment) {
1779 // If the root doesn't match, no routes can match either.
1780 if (!this.matchRoot()) return false;
1781 fragment = this.fragment = this.getFragment(fragment);
1782 return _.some(this.handlers, function(handler) {
1783 if (handler.route.test(fragment)) {
1784 handler.callback(fragment);
1790 // Save a fragment into the hash history, or replace the URL state if the
1791 // 'replace' option is passed. You are responsible for properly URL-encoding
1792 // the fragment in advance.
1794 // The options object can contain `trigger: true` if you wish to have the
1795 // route callback be fired (not usually desirable), or `replace: true`, if
1796 // you wish to modify the current URL without adding an entry to the history.
1797 navigate: function(fragment, options) {
1798 if (!History.started) return false;
1799 if (!options || options === true) options = {trigger: !!options};
1801 // Normalize the fragment.
1802 fragment = this.getFragment(fragment || '');
1804 // Don't include a trailing slash on the root.
1805 var rootPath = this.root;
1806 if (fragment === '' || fragment.charAt(0) === '?') {
1807 rootPath = rootPath.slice(0, -1) || '/';
1809 var url = rootPath + fragment;
1811 // Strip the hash and decode for matching.
1812 fragment = this.decodeFragment(fragment.replace(pathStripper, ''));
1814 if (this.fragment === fragment) return;
1815 this.fragment = fragment;
1817 // If pushState is available, we use it to set the fragment as a real URL.
1818 if (this._usePushState) {
1819 this.history[options.replace ? 'replaceState' : 'pushState']({}, document.title, url);
1821 // If hash changes haven't been explicitly disabled, update the hash
1822 // fragment to store history.
1823 } else if (this._wantsHashChange) {
1824 this._updateHash(this.location, fragment, options.replace);
1825 if (this.iframe && fragment !== this.getHash(this.iframe.contentWindow)) {
1826 var iWindow = this.iframe.contentWindow;
1828 // Opening and closing the iframe tricks IE7 and earlier to push a
1829 // history entry on hash-tag change. When replace is true, we don't
1831 if (!options.replace) {
1832 iWindow.document.open();
1833 iWindow.document.close();
1836 this._updateHash(iWindow.location, fragment, options.replace);
1839 // If you've told us that you explicitly don't want fallback hashchange-
1840 // based history, then `navigate` becomes a page refresh.
1842 return this.location.assign(url);
1844 if (options.trigger) return this.loadUrl(fragment);
1847 // Update the hash location, either replacing the current entry, or adding
1848 // a new one to the browser history.
1849 _updateHash: function(location, fragment, replace) {
1851 var href = location.href.replace(/(javascript:|#).*$/, '');
1852 location.replace(href + '#' + fragment);
1854 // Some browsers require that `hash` contains a leading #.
1855 location.hash = '#' + fragment;
1861 // Create the default Backbone.history.
1862 Backbone.history = new History;
1867 // Helper function to correctly set up the prototype chain for subclasses.
1868 // Similar to `goog.inherits`, but uses a hash of prototype properties and
1869 // class properties to be extended.
1870 var extend = function(protoProps, staticProps) {
1874 // The constructor function for the new subclass is either defined by you
1875 // (the "constructor" property in your `extend` definition), or defaulted
1876 // by us to simply call the parent constructor.
1877 if (protoProps && _.has(protoProps, 'constructor')) {
1878 child = protoProps.constructor;
1880 child = function(){ return parent.apply(this, arguments); };
1883 // Add static properties to the constructor function, if supplied.
1884 _.extend(child, parent, staticProps);
1886 // Set the prototype chain to inherit from `parent`, without calling
1887 // `parent`'s constructor function and add the prototype properties.
1888 child.prototype = _.create(parent.prototype, protoProps);
1889 child.prototype.constructor = child;
1891 // Set a convenience property in case the parent's prototype is needed
1893 child.__super__ = parent.prototype;
1898 // Set up inheritance for the model, collection, router, view and history.
1899 Model.extend = Collection.extend = Router.extend = View.extend = History.extend = extend;
1901 // Throw an error when a URL is needed, and none is supplied.
1902 var urlError = function() {
1903 throw new Error('A "url" property or function must be specified');
1906 // Wrap an optional error callback with a fallback error event.
1907 var wrapError = function(model, options) {
1908 var error = options.error;
1909 options.error = function(resp) {
1910 if (error) error.call(options.context, model, resp, options);
1911 model.trigger('error', model, resp, options);