var current = this.attributes;
var changed = this.changed;
var prev = this._previousAttributes;
// For each `set` attribute, update or delete the current value.
for (var attr in attrs) {
if (!_.isEqual(current[attr], val)) changes.push(attr);
if (!_.isEqual(prev[attr], val)) {
unset ? delete current[attr] : current[attr] = val;
if (this.idAttribute in attrs) this.id = this.get(this.idAttribute);
// Trigger all relevant attribute changes.
if (changes.length) this._pending = options;
for (var i = 0; i < changes.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;
this.trigger('change', this, options);
// 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) {
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 old = this._changing ? this._previousAttributes : this.attributes;
if (_.isEqual(old[attr], val)) continue;
return hasChanged ? changed : false;
// 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
previousAttributes: function() {
return _.clone(this._previousAttributes);
// Fetch the model from the server, merging the response with the model's
// local attributes. Any changed attributes will trigger a "change" event.
fetch: function(options) {
options = _.extend({parse: true}, options);
var success = options.success;
options.success = function(resp) {
var serverAttrs = options.parse ? model.parse(resp, options) : resp;
if (!model.set(serverAttrs, options)) return false;
if (success) success.call(options.context, 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) {
// Handle both `"key", value` and `{key: value}` -style arguments.
if (key == null || typeof key === 'object') {
options = _.extend({validate: true, parse: 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 (!this.set(attrs, options)) return false;
} else if (!this._validate(attrs, options)) {
// After a successful server-side save, the client is (optionally)
// updated with the server-side state.
var success = options.success;
var attributes = this.attributes;
options.success = function(resp) {
// Ensure attributes are restored during synchronous saves.
model.attributes = attributes;
var serverAttrs = options.parse ? model.parse(resp, options) : resp;
if (wait) serverAttrs = _.extend({}, attrs, serverAttrs);
if (serverAttrs && !model.set(serverAttrs, options)) return false;
if (success) success.call(options.context, model, resp, options);
model.trigger('sync', model, resp, options);
wrapError(this, options);
// Set temporary attributes if `{wait: true}` to properly find new ids.
if (attrs && wait) this.attributes = _.extend({}, attributes, attrs);
var method = this.isNew() ? 'create' : options.patch ? 'patch' : 'update';
if (method === 'patch' && !options.attrs) options.attrs = attrs;
var xhr = this.sync(method, this, options);
this.attributes = attributes;
// 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 success = options.success;
var destroy = function() {
model.trigger('destroy', model, model.collection, options);
options.success = function(resp) {
if (success) success.call(options.context, model, resp, options);
if (!model.isNew()) model.trigger('sync', model, resp, options);
_.defer(options.success);
wrapError(this, options);
xhr = this.sync('delete', this, options);
// Default URL for the model's representation on the server -- if you're
// using Backbone's restful methods, override this to change the endpoint
_.result(this, 'urlRoot') ||
_.result(this.collection, 'url') ||
if (this.isNew()) return base;
var id = this.get(this.idAttribute);
return base.replace(/[^\/]$/, '$&/') + encodeURIComponent(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) {
// Create a new model with identical attributes to this one.
return new this.constructor(this.attributes);
// A model is new if it has never been saved to the server, and lacks an id.
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;
this.trigger('invalid', this, error, _.extend(options, {validationError: error}));
// 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 = {});
this.preinitialize.apply(this, arguments);
if (options.model) this.model = options.model;
if (options.comparator !== void 0) this.comparator = options.comparator;
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};
// Splices `insert` into `array` at index `at`.
var splice = function(array, insert, at) {
at = Math.min(Math.max(at, 0), array.length);
var tail = Array(array.length - at);
var length = insert.length;
for (i = 0; i < tail.length; i++) tail[i] = array[i + at];
for (i = 0; i < length; i++) array[i + at] = insert[i];
for (i = 0; i < tail.length; i++) array[i + length + at] = tail[i];
// 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.
// preinitialize is an empty function by default. You can override it with a function
// or object. preinitialize will run before any instantiation logic is run in the Collection.
preinitialize: function(){},
// Initialize is an empty function by default. Override it with your own
initialize: function(){},
// The JSON representation of a Collection is an array of the
toJSON: function(options) {
return this.map(function(model) { return model.toJSON(options); });
// Proxy `Backbone.sync` by default.
return Backbone.sync.apply(this, arguments);
// Add a model, or list of models to the set. `models` may be Backbone
// Models or raw JavaScript objects to be converted to Models, or any
// combination of the two.
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) {
options = _.extend({}, options);
var singular = !_.isArray(models);
models = singular ? [models] : models.slice();
var removed = this._removeModels(models, options);
if (!options.silent && removed.length) {
options.changes = {added: [], merged: [], removed: removed};
this.trigger('update', this, options);
return singular ? removed[0] : removed;
// 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) {
if (models == null) return;
options = _.extend({}, setOptions, options);
if (options.parse && !this._isModel(models)) {
models = this.parse(models, options) || [];
var singular = !_.isArray(models);
models = singular ? [models] : models.slice();
if (at != null) at = +at;
if (at > this.length) at = this.length;
if (at < 0) at += this.length + 1;
var merge = options.merge;
var remove = options.remove;
var sortable = this.comparator && at == null && options.sort !== false;
var sortAttr = _.isString(this.comparator) ? this.comparator : null;
// Turn bare objects into model references, and prevent invalid models
for (i = 0; i < models.length; i++) {
// If a duplicate is found, prevent it from being added and
// optionally merge it into the existing model.
var existing = this.get(model);
if (merge && model !== existing) {
var attrs = this._isModel(model) ? model.attributes : model;
if (options.parse) attrs = existing.parse(attrs, options);
existing.set(attrs, options);
if (sortable && !sort) sort = existing.hasChanged(sortAttr);
if (!modelMap[existing.cid]) {
modelMap[existing.cid] = true;
// If this is a new, valid model, push it to the `toAdd` list.
model = models[i] = this._prepareModel(model, options);
this._addReference(model, options);
modelMap[model.cid] = true;
for (i = 0; i < this.length; i++) {
if (!modelMap[model.cid]) toRemove.push(model);
if (toRemove.length) this._removeModels(toRemove, options);
// See if sorting is needed, update `length` and splice in new models.
var orderChanged = false;
var replace = !sortable && add && remove;
if (set.length && replace) {
orderChanged = this.length !== set.length || _.some(this.models, function(m, index) {
splice(this.models, set, 0);
this.length = this.models.length;
} else if (toAdd.length) {
if (sortable) sort = true;
splice(this.models, toAdd, at == null ? this.length : at);
this.length = this.models.length;
// Silently sort the collection if appropriate.
if (sort) this.sort({silent: true});
// Unless silenced, it's time to fire all appropriate add/sort/update events.
for (i = 0; i < toAdd.length; i++) {
if (at != null) options.index = at + i;
model.trigger('add', model, this, options);
if (sort || orderChanged) this.trigger('sort', this, options);
if (toAdd.length || toRemove.length || toMerge.length) {
this.trigger('update', 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; i < this.models.length; i++) {
this._removeReference(this.models[i], options);
options.previousModels = this.models;
models = this.add(models, _.extend({silent: true}, options));
if (!options.silent) this.trigger('reset', this, options);
// 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.
var model = this.at(this.length - 1);
return this.remove(model, options);
// 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) {
return this.remove(model, options);
// Slice out a sub-array of models from the collection.
return slice.apply(this.models, arguments);
// Get a model from the set by id, cid, model object with id or cid
// properties, or an attributes object that is transformed through modelId.
if (obj == null) return void 0;
return this._byId[obj] ||
this._byId[this.modelId(this._isModel(obj) ? obj.attributes : obj)] ||
obj.cid && this._byId[obj.cid];
It is recommended that you Edit text format, this type of Fix handles quite a lot in one request
