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backbone.js
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backbone.js
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// Backbone.js 1.1.2
// (c) 2010-2014 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
// Backbone may be freely distributed under the MIT license.
// For all details and documentation:
// http://backbonejs.org
(function(root, factory) {
// Set up Backbone appropriately for the environment. Start with AMD.
if (typeof define === 'function' && define.amd) {
define(['underscore', 'jquery', 'exports'], function(_, $, exports) {
// Export global even in AMD case in case this script is loaded with
// others that may still expect a global Backbone.
root.Backbone = factory(root, exports, _, $);
});
// Next for Node.js or CommonJS. jQuery may not be needed as a module.
} else if (typeof exports !== 'undefined') {
var _ = require('underscore');
factory(root, exports, _);
// Finally, as a browser global.
} else {
root.Backbone = factory(root, {}, root._, (root.jQuery || root.Zepto || root.ender || root.$));
}
}(this, function(root, Backbone, _, $) {
// Initial Setup
// -------------
// Save the previous value of the `Backbone` variable, so that it can be
// restored later on, if `noConflict` is used.
var previousBackbone = root.Backbone;
// Create local references to array methods we'll want to use later.
var array = [];
var slice = array.slice;
// Current version of the library. Keep in sync with `package.json`.
Backbone.VERSION = '1.1.2';
// For Backbone's purposes, jQuery, Zepto, Ender, or My Library (kidding) owns
// the `$` variable.
Backbone.$ = $;
// Runs Backbone.js in *noConflict* mode, returning the `Backbone` variable
// to its previous owner. Returns a reference to this Backbone object.
Backbone.noConflict = function() {
root.Backbone = previousBackbone;
return this;
};
// Turn on `emulateHTTP` to support legacy HTTP servers. Setting this option
// will fake `"PATCH"`, `"PUT"` and `"DELETE"` requests via the `_method` parameter and
// set a `X-Http-Method-Override` header.
Backbone.emulateHTTP = false;
// Turn on `emulateJSON` to support legacy servers that can't deal with direct
// `application/json` requests ... this will encode the body as
// `application/x-www-form-urlencoded` instead and will send the model in a
// form param named `model`.
Backbone.emulateJSON = false;
// Backbone.Events
// ---------------
// A module that can be mixed in to *any object* in order to provide it with
// custom events. You may bind with `on` or remove with `off` callback
// functions to an event; `trigger`-ing an event fires all callbacks in
// succession.
//
// var object = {};
// _.extend(object, Backbone.Events);
// object.on('expand', function(){ alert('expanded'); });
// object.trigger('expand');
//
var Events = Backbone.Events = {
// Bind an event to a `callback` function. Passing `"all"` will bind
// the callback to all events fired.
on: function(name, callback, context) {
if (!eventsApi(this, 'on', name, [callback, context]) || !callback) return this;
this._events || (this._events = {});
var events = this._events[name] || (this._events[name] = []);
events.push({callback: callback, context: context, ctx: context || this});
return this;
},
// Bind an event to only be triggered a single time. After the first time
// the callback is invoked, it will be removed.
once: function(name, callback, context) {
if (!eventsApi(this, 'once', name, [callback, context]) || !callback) return this;
var self = this;
var once = _.once(function() {
self.off(name, once);
callback.apply(this, arguments);
});
once._callback = callback;
return this.on(name, once, context);
},
// Remove one or many callbacks. If `context` is null, removes all
// callbacks with that function. If `callback` is null, removes all
// callbacks for the event. If `name` is null, removes all bound
// callbacks for all events.
off: function(name, callback, context) {
if (!this._events || !eventsApi(this, 'off', name, [callback, context])) return this;
// Remove all callbacks for all events.
if (!name && !callback && !context) {
this._events = void 0;
return this;
}
var names = name ? [name] : _.keys(this._events);
for (var i = 0, length = names.length; i < length; i++) {
name = names[i];
// Bail out if there are no events stored.
var events = this._events[name];
if (!events) continue;
// Remove all callbacks for this event.
if (!callback && !context) {
delete this._events[name];
continue;
}
// Find any remaining events.
var remaining = [];
for (var j = 0, k = events.length; j < k; j++) {
var event = events[j];
if (
callback && callback !== event.callback &&
callback !== event.callback._callback ||
context && context !== event.context
) {
remaining.push(event);
}
}
// Replace events if there are any remaining. Otherwise, clean up.
if (remaining.length) {
this._events[name] = remaining;
} else {
delete this._events[name];
}
}
return this;
},
// Trigger one or many events, firing all bound callbacks. Callbacks are
// passed the same arguments as `trigger` is, apart from the event name
// (unless you're listening on `"all"`, which will cause your callback to
// receive the true name of the event as the first argument).
trigger: function(name) {
if (!this._events) return this;
var args = slice.call(arguments, 1);
if (!eventsApi(this, 'trigger', name, args)) return this;
var events = this._events[name];
var allEvents = this._events.all;
if (events) triggerEvents(events, args);
if (allEvents) triggerEvents(allEvents, arguments);
return this;
},
// Inversion-of-control versions of `on` and `once`. Tell *this* object to
// listen to an event in another object ... keeping track of what it's
// listening to.
listenTo: function(obj, name, callback) {
var listeningTo = this._listeningTo || (this._listeningTo = {});
var id = obj._listenId || (obj._listenId = _.uniqueId('l'));
listeningTo[id] = obj;
if (!callback && typeof name === 'object') callback = this;
obj.on(name, callback, this);
return this;
},
listenToOnce: function(obj, name, callback) {
if (typeof name === 'object') {
for (var event in name) this.listenToOnce(obj, event, name[event]);
return this;
}
var cb = _.once(function() {
this.stopListening(obj, name, cb);
callback.apply(this, arguments);
});
cb._callback = callback;
return this.listenTo(obj, name, cb);
},
// Tell this object to stop listening to either specific events ... or
// to every object it's currently listening to.
stopListening: function(obj, name, callback) {
var listeningTo = this._listeningTo;
if (!listeningTo) return this;
var remove = !name && !callback;
if (!callback && typeof name === 'object') callback = this;
if (obj) (listeningTo = {})[obj._listenId] = obj;
for (var id in listeningTo) {
obj = listeningTo[id];
obj.off(name, callback, this);
if (remove || _.isEmpty(obj._events)) delete this._listeningTo[id];
}
return this;
}
};
// Regular expression used to split event strings.
var eventSplitter = /\s+/;
// Implement fancy features of the Events API such as multiple event
// names `"change blur"` and jQuery-style event maps `{change: action}`
// in terms of the existing API.
var eventsApi = function(obj, action, name, rest) {
if (!name) return true;
// Handle event maps.
if (typeof name === 'object') {
for (var key in name) {
obj[action].apply(obj, [key, name[key]].concat(rest));
}
return false;
}
// Handle space separated event names.
if (eventSplitter.test(name)) {
var names = name.split(eventSplitter);
for (var i = 0, length = names.length; i < length; i++) {
obj[action].apply(obj, [names[i]].concat(rest));
}
return false;
}
return true;
};
// A difficult-to-believe, but optimized internal dispatch function for
// triggering events. Tries to keep the usual cases speedy (most internal
// Backbone events have 3 arguments).
var triggerEvents = function(events, args) {
var ev, i = -1, l = events.length, a1 = args[0], a2 = args[1], a3 = args[2];
switch (args.length) {
case 0: while (++i < l) (ev = events[i]).callback.call(ev.ctx); return;
case 1: while (++i < l) (ev = events[i]).callback.call(ev.ctx, a1); return;
case 2: while (++i < l) (ev = events[i]).callback.call(ev.ctx, a1, a2); return;
case 3: while (++i < l) (ev = events[i]).callback.call(ev.ctx, a1, a2, a3); return;
default: while (++i < l) (ev = events[i]).callback.apply(ev.ctx, args); return;
}
};
// Aliases for backwards compatibility.
Events.bind = Events.on;
Events.unbind = Events.off;
// Allow the `Backbone` object to serve as a global event bus, for folks who
// want global "pubsub" in a convenient place.
_.extend(Backbone, Events);
// Backbone.Model
// --------------
// Backbone **Models** are the basic data object in the framework --
// frequently representing a row in a table in a database on your server.
// A discrete chunk of data and a bunch of useful, related methods for
// performing computations and transformations on that data.
// Create a new model with the specified attributes. A client id (`cid`)
// is automatically generated and assigned for you.
var Model = Backbone.Model = function(attributes, options) {
var attrs = attributes || {};
options || (options = {});
this.cid = _.uniqueId('c');
this.attributes = {};
if (options.collection) this.collection = options.collection;
if (options.parse) attrs = this.parse(attrs, options) || {};
attrs = _.defaults({}, attrs, _.result(this, 'defaults'));
this.set(attrs, options);
this.changed = {};
this.initialize.apply(this, arguments);
};
// Attach all inheritable methods to the Model prototype.
_.extend(Model.prototype, Events, {
// A hash of attributes whose current and previous value differ.
changed: null,
// The value returned during the last failed validation.
validationError: null,
// The default name for the JSON `id` attribute is `"id"`. MongoDB and
// CouchDB users may want to set this to `"_id"`.
idAttribute: 'id',
// Initialize is an empty function by default. Override it with your own
// initialization logic.
initialize: function(){},
// Return a copy of the model's `attributes` object.
toJSON: function(options) {
return _.clone(this.attributes);
},
// Proxy `Backbone.sync` by default -- but override this if you need
// custom syncing semantics for *this* particular model.
sync: function() {
return Backbone.sync.apply(this, arguments);
},
// Get the value of an attribute.
get: function(attr) {
return this.attributes[attr];
},
// Get the HTML-escaped value of an attribute.
escape: function(attr) {
return _.escape(this.get(attr));
},
// Returns `true` if the attribute contains a value that is not null
// or undefined.
has: function(attr) {
return this.get(attr) != null;
},
// Set a hash of model attributes on the object, firing `"change"`. This is
// the core primitive operation of a model, updating the data and notifying
// anyone who needs to know about the change in state. The heart of the beast.
set: function(key, val, options) {
var attr, attrs, unset, changes, silent, changing, prev, current;
if (key == null) return this;
// Handle both `"key", value` and `{key: value}` -style arguments.
if (typeof key === 'object') {
attrs = key;
options = val;
} else {
(attrs = {})[key] = val;
}
options || (options = {});
// Run validation.
if (!this._validate(attrs, options)) return false;
// Extract attributes and options.
unset = options.unset;
silent = options.silent;
changes = [];
changing = this._changing;
this._changing = true;
if (!changing) {
this._previousAttributes = _.clone(this.attributes);
this.changed = {};
}
current = this.attributes, prev = this._previousAttributes;
// Check for changes of `id`.
if (this.idAttribute in attrs) this.id = attrs[this.idAttribute];
// For each `set` attribute, update or delete the current value.
for (attr in attrs) {
val = attrs[attr];
if (!_.isEqual(current[attr], val)) changes.push(attr);
if (!_.isEqual(prev[attr], val)) {
this.changed[attr] = val;
} else {
delete this.changed[attr];
}
unset ? delete current[attr] : current[attr] = val;
}
// Trigger all relevant attribute changes.
if (!silent) {
if (changes.length) this._pending = options;
for (var i = 0, length = changes.length; i < length; i++) {
this.trigger('change:' + changes[i], this, current[changes[i]], options);
}
}
// You might be wondering why there's a `while` loop here. Changes can
// be recursively nested within `"change"` events.
if (changing) return this;
if (!silent) {
while (this._pending) {
options = this._pending;
this._pending = false;
this.trigger('change', this, options);
}
}
this._pending = false;
this._changing = false;
return this;
},
// Remove an attribute from the model, firing `"change"`. `unset` is a noop
// if the attribute doesn't exist.
unset: function(attr, options) {
return this.set(attr, void 0, _.extend({}, options, {unset: true}));
},
// Clear all attributes on the model, firing `"change"`.
clear: function(options) {
var attrs = {};
for (var key in this.attributes) attrs[key] = void 0;
return this.set(attrs, _.extend({}, options, {unset: true}));
},
// Determine if the model has changed since the last `"change"` event.
// If you specify an attribute name, determine if that attribute has changed.
hasChanged: function(attr) {
if (attr == null) return !_.isEmpty(this.changed);
return _.has(this.changed, attr);
},
// Return an object containing all the attributes that have changed, or
// false if there are no changed attributes. Useful for determining what
// parts of a view need to be updated and/or what attributes need to be
// persisted to the server. Unset attributes will be set to undefined.
// You can also pass an attributes object to diff against the model,
// determining if there *would be* a change.
changedAttributes: function(diff) {
if (!diff) return this.hasChanged() ? _.clone(this.changed) : false;
var val, changed = false;
var old = this._changing ? this._previousAttributes : this.attributes;
for (var attr in diff) {
if (_.isEqual(old[attr], (val = diff[attr]))) continue;
(changed || (changed = {}))[attr] = val;
}
return changed;
},
// Get the previous value of an attribute, recorded at the time the last
// `"change"` event was fired.
previous: function(attr) {
if (attr == null || !this._previousAttributes) return null;
return this._previousAttributes[attr];
},
// Get all of the attributes of the model at the time of the previous
// `"change"` event.
previousAttributes: function() {
return _.clone(this._previousAttributes);
},
// Fetch the model from the server. If the server's representation of the
// model differs from its current attributes, they will be overridden,
// triggering a `"change"` event.
fetch: function(options) {
options = options ? _.clone(options) : {};
if (options.parse === void 0) options.parse = true;
var model = this;
var success = options.success;
options.success = function(resp) {
if (!model.set(model.parse(resp, options), options)) return false;
if (success) success(model, resp, options);
model.trigger('sync', model, resp, options);
};
wrapError(this, options);
return this.sync('read', this, options);
},
// Set a hash of model attributes, and sync the model to the server.
// If the server returns an attributes hash that differs, the model's
// state will be `set` again.
save: function(key, val, options) {
var attrs, method, xhr, attributes = this.attributes;
// Handle both `"key", value` and `{key: value}` -style arguments.
if (key == null || typeof key === 'object') {
attrs = key;
options = val;
} else {
(attrs = {})[key] = val;
}
options = _.extend({validate: true}, options);
// If we're not waiting and attributes exist, save acts as
// `set(attr).save(null, opts)` with validation. Otherwise, check if
// the model will be valid when the attributes, if any, are set.
if (attrs && !options.wait) {
if (!this.set(attrs, options)) return false;
} else {
if (!this._validate(attrs, options)) return false;
}
// Set temporary attributes if `{wait: true}`.
if (attrs && options.wait) {
this.attributes = _.extend({}, attributes, attrs);
}
// After a successful server-side save, the client is (optionally)
// updated with the server-side state.
if (options.parse === void 0) options.parse = true;
var model = this;
var success = options.success;
options.success = function(resp) {
// Ensure attributes are restored during synchronous saves.
model.attributes = attributes;
var serverAttrs = model.parse(resp, options);
if (options.wait) serverAttrs = _.extend(attrs || {}, serverAttrs);
if (_.isObject(serverAttrs) && !model.set(serverAttrs, options)) {
return false;
}
if (success) success(model, resp, options);
model.trigger('sync', model, resp, options);
};
wrapError(this, options);
method = this.isNew() ? 'create' : (options.patch ? 'patch' : 'update');
if (method === 'patch' && !options.attrs) options.attrs = attrs;
xhr = this.sync(method, this, options);
// Restore attributes.
if (attrs && options.wait) this.attributes = attributes;
return xhr;
},
// Destroy this model on the server if it was already persisted.
// Optimistically removes the model from its collection, if it has one.
// If `wait: true` is passed, waits for the server to respond before removal.
destroy: function(options) {
options = options ? _.clone(options) : {};
var model = this;
var success = options.success;
var destroy = function() {
model.stopListening();
model.trigger('destroy', model, model.collection, options);
};
options.success = function(resp) {
if (options.wait || model.isNew()) destroy();
if (success) success(model, resp, options);
if (!model.isNew()) model.trigger('sync', model, resp, options);
};
if (this.isNew()) {
options.success();
return false;
}
wrapError(this, options);
var xhr = this.sync('delete', this, options);
if (!options.wait) destroy();
return xhr;
},
// Default URL for the model's representation on the server -- if you're
// using Backbone's restful methods, override this to change the endpoint
// that will be called.
url: function() {
var base =
_.result(this, 'urlRoot') ||
_.result(this.collection, 'url') ||
urlError();
if (this.isNew()) return base;
return base.replace(/([^\/])$/, '$1/') + encodeURIComponent(this.id);
},
// **parse** converts a response into the hash of attributes to be `set` on
// the model. The default implementation is just to pass the response along.
parse: function(resp, options) {
return resp;
},
// Create a new model with identical attributes to this one.
clone: function() {
return new this.constructor(this.attributes);
},
// A model is new if it has never been saved to the server, and lacks an id.
isNew: function() {
return !this.has(this.idAttribute);
},
// Check if the model is currently in a valid state.
isValid: function(options) {
return this._validate({}, _.extend(options || {}, { validate: true }));
},
// Run validation against the next complete set of model attributes,
// returning `true` if all is well. Otherwise, fire an `"invalid"` event.
_validate: function(attrs, options) {
if (!options.validate || !this.validate) return true;
attrs = _.extend({}, this.attributes, attrs);
var error = this.validationError = this.validate(attrs, options) || null;
if (!error) return true;
this.trigger('invalid', this, error, _.extend(options, {validationError: error}));
return false;
}
});
// Underscore methods that we want to implement on the Model.
var modelMethods = ['keys', 'values', 'pairs', 'invert', 'pick', 'omit', 'chain', 'isEmpty'];
// Mix in each Underscore method as a proxy to `Model#attributes`.
_.each(modelMethods, function(method) {
if (!_[method]) return;
Model.prototype[method] = function() {
var args = slice.call(arguments);
args.unshift(this.attributes);
return _[method].apply(_, args);
};
});
// Backbone.Collection
// -------------------
// If models tend to represent a single row of data, a Backbone Collection is
// more analogous to a table full of data ... or a small slice or page of that
// table, or a collection of rows that belong together for a particular reason
// -- all of the messages in this particular folder, all of the documents
// belonging to this particular author, and so on. Collections maintain
// indexes of their models, both in order, and for lookup by `id`.
// Create a new **Collection**, perhaps to contain a specific type of `model`.
// If a `comparator` is specified, the Collection will maintain
// its models in sort order, as they're added and removed.
var Collection = Backbone.Collection = function(models, options) {
options || (options = {});
if (options.model) this.model = options.model;
if (options.comparator !== void 0) this.comparator = options.comparator;
this._reset();
this.initialize.apply(this, arguments);
if (models) this.reset(models, _.extend({silent: true}, options));
};
// Default options for `Collection#set`.
var setOptions = {add: true, remove: true, merge: true};
var addOptions = {add: true, remove: false};
// Define the Collection's inheritable methods.
_.extend(Collection.prototype, Events, {
// The default model for a collection is just a **Backbone.Model**.
// This should be overridden in most cases.
model: Model,
// Initialize is an empty function by default. Override it with your own
// initialization logic.
initialize: function(){},
// The JSON representation of a Collection is an array of the
// models' attributes.
toJSON: function(options) {
return this.map(function(model){ return model.toJSON(options); });
},
// Proxy `Backbone.sync` by default.
sync: function() {
return Backbone.sync.apply(this, arguments);
},
// Add a model, or list of models to the set.
add: function(models, options) {
return this.set(models, _.extend({merge: false}, options, addOptions));
},
// Remove a model, or a list of models from the set.
remove: function(models, options) {
var singular = !_.isArray(models);
models = singular ? [models] : _.clone(models);
options || (options = {});
for (var i = 0, length = models.length; i < length; i++) {
var model = models[i] = this.get(models[i]);
if (!model) continue;
var id = this.modelId(model.attributes);
if (id != null) delete this._byId[id];
delete this._byId[model.cid];
var index = this.indexOf(model);
this.models.splice(index, 1);
this.length--;
if (!options.silent) {
options.index = index;
model.trigger('remove', model, this, options);
}
this._removeReference(model, options);
}
return singular ? models[0] : models;
},
// Update a collection by `set`-ing a new list of models, adding new ones,
// removing models that are no longer present, and merging models that
// already exist in the collection, as necessary. Similar to **Model#set**,
// the core operation for updating the data contained by the collection.
set: function(models, options) {
options = _.defaults({}, options, setOptions);
if (options.parse) models = this.parse(models, options);
var singular = !_.isArray(models);
models = singular ? (models ? [models] : []) : models.slice();
var id, model, attrs, existing, sort;
var at = options.at;
if (at < 0) at += this.length + 1;
var sortable = this.comparator && (at == null) && options.sort !== false;
var sortAttr = _.isString(this.comparator) ? this.comparator : null;
var toAdd = [], toRemove = [], modelMap = {};
var add = options.add, merge = options.merge, remove = options.remove;
var order = !sortable && add && remove ? [] : false;
var orderChanged = false;
// Turn bare objects into model references, and prevent invalid models
// from being added.
for (var i = 0, length = models.length; i < length; i++) {
attrs = models[i];
// If a duplicate is found, prevent it from being added and
// optionally merge it into the existing model.
if (existing = this.get(attrs)) {
if (remove) modelMap[existing.cid] = true;
if (merge && attrs !== existing) {
attrs = this._isModel(attrs) ? attrs.attributes : attrs;
if (options.parse) attrs = existing.parse(attrs, options);
existing.set(attrs, options);
if (sortable && !sort && existing.hasChanged(sortAttr)) sort = true;
}
models[i] = existing;
// If this is a new, valid model, push it to the `toAdd` list.
} else if (add) {
model = models[i] = this._prepareModel(attrs, options);
if (!model) continue;
toAdd.push(model);
this._addReference(model, options);
}
// Do not add multiple models with the same `id`.
model = existing || model;
if (!model) continue;
id = this.modelId(model.attributes);
if (order && (model.isNew() || !modelMap[id])) {
order.push(model);
// Check to see if this is actually a new model at this index.
orderChanged = orderChanged || !this.models[i] || model.cid !== this.models[i].cid;
}
modelMap[id] = true;
}
// Remove nonexistent models if appropriate.
if (remove) {
for (var i = 0, length = this.length; i < length; i++) {
if (!modelMap[(model = this.models[i]).cid]) toRemove.push(model);
}
if (toRemove.length) this.remove(toRemove, options);
}
// See if sorting is needed, update `length` and splice in new models.
if (toAdd.length || orderChanged) {
if (sortable) sort = true;
this.length += toAdd.length;
if (at != null) {
for (var i = 0, length = toAdd.length; i < length; i++) {
this.models.splice(at + i, 0, toAdd[i]);
}
} else {
if (order) this.models.length = 0;
var orderedModels = order || toAdd;
for (var i = 0, length = orderedModels.length; i < length; i++) {
this.models.push(orderedModels[i]);
}
}
}
// Silently sort the collection if appropriate.
if (sort) this.sort({silent: true});
// Unless silenced, it's time to fire all appropriate add/sort events.
if (!options.silent) {
var addOpts = at != null ? _.clone(options) : options;
for (var i = 0, length = toAdd.length; i < length; i++) {
if (at != null) addOpts.index = at + i;
(model = toAdd[i]).trigger('add', model, this, addOpts);
}
if (sort || orderChanged) this.trigger('sort', this, options);
}
// Return the added (or merged) model (or models).
return singular ? models[0] : models;
},
// When you have more items than you want to add or remove individually,
// you can reset the entire set with a new list of models, without firing
// any granular `add` or `remove` events. Fires `reset` when finished.
// Useful for bulk operations and optimizations.
reset: function(models, options) {
options = options ? _.clone(options) : {};
for (var i = 0, length = this.models.length; i < length; i++) {
this._removeReference(this.models[i], options);
}
options.previousModels = this.models;
this._reset();
models = this.add(models, _.extend({silent: true}, options));
if (!options.silent) this.trigger('reset', this, options);
return models;
},
// Add a model to the end of the collection.
push: function(model, options) {
return this.add(model, _.extend({at: this.length}, options));
},
// Remove a model from the end of the collection.
pop: function(options) {
var model = this.at(this.length - 1);
this.remove(model, options);
return model;
},
// Add a model to the beginning of the collection.
unshift: function(model, options) {
return this.add(model, _.extend({at: 0}, options));
},
// Remove a model from the beginning of the collection.
shift: function(options) {
var model = this.at(0);
this.remove(model, options);
return model;
},
// Slice out a sub-array of models from the collection.
slice: function() {
return slice.apply(this.models, arguments);
},
// Get a model from the set by id.
get: function(obj) {
if (obj == null) return void 0;
var id = this.modelId(this._isModel(obj) ? obj.attributes : obj);
return this._byId[obj] || this._byId[id] || this._byId[obj.cid];
},
// Get the model at the given index.
at: function(index) {
if (index < 0) index += this.length;
return this.models[index];
},
// Return models with matching attributes. Useful for simple cases of
// `filter`.
where: function(attrs, first) {
var matches = _.matches(attrs);
return this[first ? 'find' : 'filter'](function(model) {
return matches(model.attributes);
});
},
// Return the first model with matching attributes. Useful for simple cases
// of `find`.
findWhere: function(attrs) {
return this.where(attrs, true);
},
// Force the collection to re-sort itself. You don't need to call this under
// normal circumstances, as the set will maintain sort order as each item
// is added.
sort: function(options) {
if (!this.comparator) throw new Error('Cannot sort a set without a comparator');
options || (options = {});
// Run sort based on type of `comparator`.
if (_.isString(this.comparator) || this.comparator.length === 1) {
this.models = this.sortBy(this.comparator, this);
} else {
this.models.sort(_.bind(this.comparator, this));
}
if (!options.silent) this.trigger('sort', this, options);
return this;
},
// Pluck an attribute from each model in the collection.
pluck: function(attr) {
return _.invoke(this.models, 'get', attr);
},
// Fetch the default set of models for this collection, resetting the
// collection when they arrive. If `reset: true` is passed, the response
// data will be passed through the `reset` method instead of `set`.
fetch: function(options) {
options = options ? _.clone(options) : {};
if (options.parse === void 0) options.parse = true;
var success = options.success;
var collection = this;
options.success = function(resp) {
var method = options.reset ? 'reset' : 'set';
collection[method](resp, options);
if (success) success(collection, resp, options);
collection.trigger('sync', collection, resp, options);
};
wrapError(this, options);
return this.sync('read', this, options);
},
// Create a new instance of a model in this collection. Add the model to the
// collection immediately, unless `wait: true` is passed, in which case we
// wait for the server to agree.
create: function(model, options) {
options = options ? _.clone(options) : {};
if (!(model = this._prepareModel(model, options))) return false;
if (!options.wait) this.add(model, options);
var collection = this;
var success = options.success;
options.success = function(model, resp) {
if (options.wait) collection.add(model, options);
if (success) success(model, resp, options);
};
model.save(null, options);
return model;
},
// **parse** converts a response into a list of models to be added to the
// collection. The default implementation is just to pass it through.
parse: function(resp, options) {
return resp;
},
// Create a new collection with an identical list of models as this one.
clone: function() {
return new this.constructor(this.models, {
model: this.model,
comparator: this.comparator
});
},
// Define how to uniquely identify models in the collection.
modelId: function (attrs) {
return attrs[this.model.prototype.idAttribute || 'id'];
},
// Private method to reset all internal state. Called when the collection
// is first initialized or reset.
_reset: function() {
this.length = 0;
this.models = [];
this._byId = {};
},
// Prepare a hash of attributes (or other model) to be added to this
// collection.
_prepareModel: function(attrs, options) {
if (this._isModel(attrs)) {
if (!attrs.collection) attrs.collection = this;
return attrs;
}
options = options ? _.clone(options) : {};
options.collection = this;
var model = new this.model(attrs, options);
if (!model.validationError) return model;
this.trigger('invalid', this, model.validationError, options);
return false;
},
// Method for checking whether an object should be considered a model for
// the purposes of adding to the collection.
_isModel: function (model) {
return model instanceof Model;
},
// Internal method to create a model's ties to a collection.
_addReference: function(model, options) {
this._byId[model.cid] = model;
var id = this.modelId(model.attributes);
if (id != null) this._byId[id] = model;
model.on('all', this._onModelEvent, this);
},
// Internal method to sever a model's ties to a collection.
_removeReference: function(model, options) {
if (this === model.collection) delete model.collection;
model.off('all', this._onModelEvent, this);
},
// Internal method called every time a model in the set fires an event.
// Sets need to update their indexes when models change ids. All other
// events simply proxy through. "add" and "remove" events that originate
// in other collections are ignored.
_onModelEvent: function(event, model, collection, options) {
if ((event === 'add' || event === 'remove') && collection !== this) return;
if (event === 'destroy') this.remove(model, options);
if (event === 'change') {
var prevId = this.modelId(model.previousAttributes());
var id = this.modelId(model.attributes);
if (prevId !== id) {
if (prevId != null) delete this._byId[prevId];
if (id != null) this._byId[id] = model;
}
}
this.trigger.apply(this, arguments);