// Backbone.js 1.0.0
// (c) 2010-2013 Jeremy Ashkenas, DocumentCloud Inc.
// Backbone may be freely distributed under the MIT license.
// For all details and documentation:
// http://backbonejs.org
/*
* 注释 一只柯楠
*/
(function(){
// Initial Setup
// -------------
// Save a reference to the global object (`window` in the browser, `exports`
// on the server).
// 保存window为局部变量，加快速度
var root = this;
// Save the previous value of the `Backbone` variable, so that it can be
// restored later on, if `noConflict` is used.
// 保存之前的backbone
var previousBackbone = root.Backbone;
// Create local references to array methods we'll want to use later.
// 常用方法保存
var array = [];
var push = array.push;
var slice = array.slice;
var splice = array.splice;
// The top-level namespace. All public Backbone classes and modules will
// be attached to this. Exported for both the browser and the server.
var Backbone;
if (typeof exports !== 'undefined') {
Backbone = exports;
} else {
Backbone = root.Backbone = {};
}
// Current version of the library. Keep in sync with `package.json`.
Backbone.VERSION = '1.0.0';
// Require Underscore, if we're on the server, and it's not already present.
// 获取underscore的方法集合
var _ = root._;
if (!_ && (typeof require !== 'undefined')) _ = require('underscore');
// For Backbone's purposes, jQuery, Zepto, Ender, or My Library (kidding) owns
// the `$` variable.
// 获取基础库
Backbone.$ = root.jQuery || root.Zepto || root.ender || root.$;
// Runs Backbone.js in *noConflict* mode, returning the `Backbone` variable
// to its previous owner. Returns a reference to this Backbone object.
// 将Backbone命名空间让给之前的库(可能是undefined)
Backbone.noConflict = function() {
root.Backbone = previousBackbone;
return this;
};
// Turn on `emulateHTTP` to support legacy HTTP servers. Setting this option
// will fake `"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 ... 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');
//事件方法集合
var Events = Backbone.Events = {
// Bind an event to a `callback` function. Passing `"all"` will bind
// the callback to all events fired.
//还可以这么用 event.on({'test': function(){}}, context)
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.
// 只执行一次，之后就会删除掉
once: function(name, callback, context) {
if (!eventsApi(this, 'once', name, [callback, context]) || !callback) return this;
var self = this;
//只执行一次的函数
var once = _.once(function() {
self.off(name, once);
callback.apply(this, arguments);
});
//保存_callback
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.
// 删除监听函数集合
off: function(name, callback, context) {
var retain, ev, events, names, i, l, j, k;
if (!this._events || !eventsApi(this, 'off', name, [callback, context])) return this;
if (!name && !callback && !context) {
this._events = {};
return this;
}
//name参数存在，则删除name，否则删除所有
names = name ? [name] : _.keys(this._events);
for (i = 0, l = names.length; i < l; i++) {
name = names[i];
//回调函数集合events
if (events = this._events[name]) {
//重置函数集合
this._events[name] = retain = [];
if (callback || context) {
//遍历监听函数集合
for (j = 0, k = events.length; j < k; j++) {
ev = events[j];
//如果有制定callback这删除指定callback的函数，保存不等于callback的方法，即是删除等于callback的方法
//_callback是once方法绑定的事件
if ((callback && callback !== ev.callback && callback !== ev.callback._callback) ||
(context && context !== ev.context)) {
retain.push(ev);
}
}
}
if (!retain.length) 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).
// 触发指定事件
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];
//所有事件都执行的函数集合
var allEvents = this._events.all;
if (events) triggerEvents(events, args);
if (allEvents) triggerEvents(allEvents, arguments);
return this;
},
// 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 listeners = this._listeners;
if (!listeners) return this;
var deleteListener = !name && !callback;
if (typeof name === 'object') callback = this;
if (obj) (listeners = {})[obj._listenerId] = obj;
for (var id in listeners) {
listeners[id].off(name, callback, this);
if (deleteListener) delete this._listeners[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.
// 但name是一个【对象】或者【'click touchstart'】是用于迭代执行
var eventsApi = function(obj, action, name, rest) {
if (!name) return true;
// Handle event maps.
if (typeof name === 'object') {
for (var key in name) {
//this['on']('click', function(){}, )
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, l = names.length; i < l; 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).
// 遍历执行监听函数，call函数的性能优于apply，所以switch做判断
var triggerEvents = function(events, args) {
var ev, i = -1, l = events.length, a1 = args[0], a2 = args[1], a3 = args[2];
switch (args.length) {
//0个参数时，拿出保存监听函数的对象ev，call成ev的.ctx来执行
case 0: while (++i < l) (ev = events[i]).callback.call(ev.ctx); return;
//1个参数时，拿出保存监听函数的对象ev，call成ev的.ctx来执行
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);
}
};
var listenMethods = {listenTo: 'on', listenToOnce: 'once'};
// 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.
_.each(listenMethods, function(implementation, method) {
//Event['listenTo']
Events[method] = function(obj, name, callback) {
var listeners = this._listeners || (this._listeners = {});
var id = obj._listenerId || (obj._listenerId = _.uniqueId('l'));
listeners[id] = obj;
if (typeof name === 'object') callback = this;
obj[implementation](name, callback, this);
return this;
};
});
// 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 defaults;
//属性对象
var attrs = attributes || {};
options || (options = {});
//获取独一ID
this.cid = _.uniqueId('c');
//属性保存
this.attributes = {};
//把一些方法引用到this
_.extend(this, _.pick(options, modelOptions));
//判断用户传入options.parse是为真，则使用继承Model的对象的parse方法返回的对象赋给attrs
if (options.parse) attrs = this.parse(attrs, options) || {};
//获取继承的Model的对象是否存在defaults属性
if (defaults = _.result(this, 'defaults')) {
attrs = _.defaults({}, attrs, defaults);
}
this.set(attrs, options);
this.changed = {};
this.initialize.apply(this, arguments);
};
// A list of options to be attached directly to the model, if provided.
// 这些方法直接在this上加一个引用
var modelOptions = ['url', 'urlRoot', 'collection'];
// Attach all inheritable methods to the Model prototype.
_.extend(Model.prototype, Events, {
// A hash of attributes whose current and previous value differ.
// 修改过的属性的散列表
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.
// 验证一下
if (!this._validate(attrs, options)) return false;
// Extract attributes and options.
// 提取属性
unset = options.unset;
silent = options.silent;
changes = [];
changing = this._changing;
this._changing = true;
//如果不是正在修改,后面如果是第一次的set导致的再次调用set方法，则为假
if (!changing) {
//保留老的attributes;
this._previousAttributes = _.clone(this.attributes);
//重置修改的属性;
this.changed = {};
}
//current是当前的属性列表， prev是从前的属性列表, attrs是要修改的属性列表
current = this.attributes, prev = this._previousAttributes;
// Check for changes of `id`.
// 检查并进行id修改
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];
//如果传入的属性不等于当前的，则加入修改列表
if (!_.isEqual(current[attr], val)) changes.push(attr);
//保存本次修改的列表
if (!_.isEqual(prev[attr], val)) {
this.changed[attr] = val;
} else {
delete this.changed[attr];
}
//如果unset为真，则删除attributes里面的属性，否则赋给attributes属性
unset ? delete current[attr] : current[attr] = val;
}
// Trigger all relevant attribute changes.
//如果silent为真，则不进行事件触发
if (!silent) {
if (changes.length) this._pending = true;
//trigger修改属性事件
for (var i = 0, l = changes.length; i < l; i++) {
//触发修改属性的事件
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.
// 如果此次set的调用是前一个set导致的，即触发trigger('change'+changes[i])导致的递归,则结束
if (changing) return this;
//如果silent为真，则不进行事件触发
if (!silent) {
//这里有个while的原因是，可能trigger时进行了set方法，然后this._pending又变成了ture，再次进行触发change事件
while (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.
// 删除属性
unset: function(attr, options) {
return this.set(attr, void 0, _.extend({}, options, {unset: true}));
},
// Clear all attributes on the model, firing `"change"`.
// 清空属性列表
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.
// 检测某个属性是否修改了,不传参数则若有修改则为真(检查所有)
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.
// 检查参数对象和属性列表的区别
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.
// 返回修改前的属性值
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.
// 返回修改前的属性列表
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;
//重载success方法
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;
}
// If we're not waiting and attributes exist, save acts as `set(attr).save(null, opts)`.
if (attrs && (!options || !options.wait) && !this.set(attrs, options)) return false;
options = _.extend({validate: true}, options);
// Do not persist invalid models.
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 = 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.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 + (base.charAt(base.length - 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.id == null;
},
// 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'];
// Mix in each Underscore method as a proxy to `Model#attributes`.
_.each(modelMethods, function(method) {
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 analagous 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.url) this.url = options.url;
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, merge: false, 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, _.defaults(options || {}, addOptions));
},
// Remove a model, or a list of models from the set.
remove: function(models, options) {
models = _.isArray(models) ? models.slice() : [models];
options || (options = {});
var i, l, index, model;
for (i = 0, l = models.length; i < l; i++) {
model = this.get(models[i]);
if (!model) continue;
delete this._byId[model.id];
delete this._byId[model.cid];
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);
}
return this;
},
// 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);
if (!_.isArray(models)) models = models ? [models] : [];
var i, l, model, attrs, existing, sort;
var at = options.at;
var sortable = this.comparator && (at == null) && options.sort !== false;
var sortAttr = _.isString(this.comparator) ? this.comparator : null;
var toAdd = [], toRemove = [], modelMap = {};
// Turn bare objects into model references, and prevent invalid models
// from being added.
for (i = 0, l = models.length; i < l; i++) {
if (!(model = this._prepareModel(models[i], options))) continue;
// If a duplicate is found, prevent it from being added and
// optionally merge it into the existing model.
if (existing = this.get(model)) {
if (options.remove) modelMap[existing.cid] = true;
if (options.merge) {
existing.set(model.attributes, options);
if (sortable && !sort && existing.hasChanged(sortAttr)) sort = true;
}
// This is a new model, push it to the `toAdd` list.
} else if (options.add) {
toAdd.push(model);
// Listen to added models' events, and index models for lookup by
// `id` and by `cid`.
model.on('all', this._onModelEvent, this);
this._byId[model.cid] = model;
if (model.id != null) this._byId[model.id] = model;
}
}
// Remove nonexistent models if appropriate.
if (options.remove) {
for (i = 0, l = this.length; i < l; ++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) {
if (sortable) sort = true;
this.length += toAdd.length;
if (at != null) {
splice.apply(this.models, [at, 0].concat(toAdd));
} else {
push.apply(this.models, toAdd);
}
}
// Silently sort the collection if appropriate.
if (sort) this.sort({silent: true});
if (options.silent) return this;
// Trigger `add` events.
for (i = 0, l = toAdd.length; i < l; i++) {
(model = toAdd[i]).trigger('add', model, this, options);
}
// Trigger `sort` if the collection was sorted.
if (sort) this.trigger('sort', this, options);
return this;
},
// 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 = {});
for (var i = 0, l = this.models.length; i < l; i++) {
this._removeReference(this.models[i]);
}
options.previousModels = this.models;
this._reset();
this.add(models, _.extend({silent: true}, options));
if (!options.silent) this.trigger('reset', this, options);
return this;
},
// Add a model to the end of the collection.
push: function(model, options) {
model = this._prepareModel(model, options);
this.add(model, _.extend({at: this.length}, options));
return model;
},
// 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) {
model = this._prepareModel(model, options);
this.add(model, _.extend({at: 0}, options));
return model;
},
// 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(begin, end) {
return this.models.slice(begin, end);
},
// Get a model from the set by id.
get: function(obj) {
if (obj == null) return void 0;
return this._byId[obj.id != null ? obj.id : obj.cid || obj];
},
// Get the model at the given index.
at: function(index) {
return this.models[index];
},
// Return models with matching attributes. Useful for simple cases of
// `filter`.
where: function(attrs, first) {
if (_.isEmpty(attrs)) return first ? void 0 : [];
return this[first ? 'find' : 'filter'](function(model) {
for (var key in attrs) {
if (attrs[key] !== model.get(key)) return false;
}
return true;
});
},
// 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;
},
// Figure out the smallest index at which a model should be inserted so as
// to maintain order.
sortedIndex: function(model, value, context) {
value || (value = this.comparator);
var iterator = _.isFunction(value) ? value : function(model) {
return model.get(value);
};
return _.sortedIndex(this.models, model, iterator, context);
},
// 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(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);
},
// 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 (attrs instanceof Model) {
if (!attrs.collection) attrs.collection = this;
return attrs;
}
options || (options = {});
options.collection = this;
var model = new this.model(attrs, options);
if (!model._validate(attrs, options)) {
this.trigger('invalid', this, attrs, options);
return false;
}
return model;
},
// Internal method to sever a model's ties to a collection.
_removeReference: function(model) {
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 (model && event === 'change:' + model.idAttribute) {
delete this._byId[model.previous(model.idAttribute)];
if (model.id != null) this._byId[model.id] = model;
}
this.trigger.apply(this, arguments);
}
});
// Underscore methods that we want to implement on the Collection.
// 90% of the core usefulness of Backbone Collections is actually implemented
// right here:
var methods = ['forEach', 'each', 'map', 'collect', 'reduce', 'foldl',
'inject', 'reduceRight', 'foldr', 'find', 'detect', 'filter', 'select',
'reject', 'every', 'all', 'some', 'any', 'include', 'contains', 'invoke',
'max', 'min', 'toArray', 'size', 'first', 'head', 'take', 'initial', 'rest',
'tail', 'drop', 'last', 'without', 'indexOf', 'shuffle', 'lastIndexOf',
'isEmpty', 'chain'];
// Mix in each Underscore method as a proxy to `Collection#models`.
_.each(methods, function(method) {
Collection.prototype[method] = function() {
var args = slice.call(arguments);
args.unshift(this.models);
return _[method].apply(_, args);
};
});
// Underscore methods that take a property name as an argument.
var attributeMethods = ['groupBy', 'countBy', 'sortBy'];
// Use attributes instead of properties.
_.each(attributeMethods, function(method) {
Collection.prototype[method] = function(value, context) {
var iterator = _.isFunction(value) ? value : function(model) {
return model.get(value);
};
return _[method](this.models, iterator, context);
};
});
// Backbone.View
// -------------
// Backbone Views are almost more convention than they are actual code. A View
// is simply a JavaScript object that represents a logical chunk of UI in the
// DOM. This might be a single item, an entire list, a sidebar or panel, or
// even the surrounding frame which wraps your whole app. Defining a chunk of
// UI as a **View** allows you to define your DOM events declaratively, without
// having to worry about render order ... and makes it easy for the view to
// react to specific changes in the state of your models.
// Creating a Backbone.View creates its initial element outside of the DOM,
// if an existing element is not provided...
var View = Backbone.View = function(options) {
this.cid = _.uniqueId('view');
this._configure(options || {});
//拿到view外围元素this.$el
this._ensureElement();
this.initialize.apply(this, arguments);
//代理事件
this.delegateEvents();
};
// Cached regex to split keys for `delegate`.
var delegateEventSplitter = /^(\S+)\s*(.*)$/;
// List of view options to be merged as properties.
var viewOptions = ['model', 'collection', 'el', 'id', 'attributes', 'className', 'tagName', 'events'];
// Set up all inheritable **Backbone.View** properties and methods.
_.extend(View.prototype, Events, {
// The default `tagName` of a View's element is `"div"`.
tagName: 'div',
// jQuery delegate for element lookup, scoped to DOM elements within the
// current view. This should be prefered to global lookups where possible.
// 获取外围元素内的某些元素
$: function(selector) {
return this.$el.find(selector);
},
// Initialize is an empty function by default. Override it with your own
// initialization logic.
initialize: function(){},
// **render** is the core function that your view should override, in order
// to populate its element (`this.el`), with the appropriate HTML. The
// convention is for **render** to always return `this`.
render: function() {
return this;
},
// Remove this view by taking the element out of the DOM, and removing any
// applicable Backbone.Events listeners.
remove: function() {
this.$el.remove();
this.stopListening();
return this;
},
// Change the view's element (`this.el` property), including event
// re-delegation.
setElement: function(element, delegate) {
if (this.$el) this.undelegateEvents();
this.$el = element instanceof Backbone.$ ? element : Backbone.$(element);
this.el = this.$el[0];
if (delegate !== false) this.delegateEvents();
return this;
},
// Set callbacks, where `this.events` is a hash of
//
// *{"event selector": "callback"}*
//
// {
// 'mousedown .title': 'edit',
// 'click .button': 'save'
// 'click .open': function(e) { ... }
// }
//
// pairs. Callbacks will be bound to the view, with `this` set properly.
// Uses event delegation for efficiency.
// Omitting the selector binds the event to `this.el`.
// This only works for delegate-able events: not `focus`, `blur`, and
// not `change`, `submit`, and `reset` in Internet Explorer.
// 绑定代理事件
delegateEvents: function(events) {
if (!(events || (events = _.result(this, 'events')))) return this;
this.undelegateEvents();
for (var key in events) {
var method = events[key];
if (!_.isFunction(method)) method = this[events[key]];
if (!method) continue;
var match = key.match(delegateEventSplitter);
var eventName = match[1], selector = match[2];
method = _.bind(method, this);
eventName += '.delegateEvents' + this.cid;
if (selector === '') {
this.$el.on(eventName, method);
} else {
this.$el.on(eventName, selector, method);
}
}
return this;
},
// Clears all callbacks previously bound to the view with `delegateEvents`.
// You usually don't need to use this, but may wish to if you have multiple
// Backbone views attached to the same DOM element.
// 删除事件代理
undelegateEvents: function() {
this.$el.off('.delegateEvents' + this.cid);
return this;
},
// Performs the initial configuration of a View with a set of options.
// Keys with special meaning *(e.g. model, collection, id, className)* are
// attached directly to the view. See `viewOptions` for an exhaustive
// list.
//把options加到this.options上，提取部分属性到this上去
_configure: function(options) {
if (this.options) options = _.extend({}, _.result(this, 'options'), options);
_.extend(this, _.pick(options, viewOptions));
this.options = options;
},
// Ensure that the View has a DOM element to render into.
// If `this.el` is a string, pass it through `$()`, take the first
// matching element, and re-assign it to `el`. Otherwise, create
// an element from the `id`, `className` and `tagName` properties.
_ensureElement: function() {
if (!this.el) {
var attrs = _.extend({}, _.result(this, 'attributes'));
if (this.id) attrs.id = _.result(this, 'id');
if (this.className) attrs['class'] = _.result(this, 'className');
var $el = Backbone.$('<' + _.result(this, 'tagName') + '>').attr(attrs);
this.setElement($el, false);
} else {
this.setElement(_.result(this, 'el'), false);
}
}
});
// Backbone.sync
// -------------
// Override this function to change the manner in which Backbone persists
// models to the server. You will be passed the type of request, and the
// model in question. By default, makes a RESTful Ajax request
// to the model's `url()`. Some possible customizations could be:
//
// * Use `setTimeout` to batch rapid-fire updates into a single request.
// * Send up the models as XML instead of JSON.
// * Persist models via WebSockets instead of Ajax.
//
// Turn on `Backbone.emulateHTTP` in order to send `PUT` and `DELETE` requests
// as `POST`, with a `_method` parameter containing the true HTTP method,
// as well as all requests with the body as `application/x-www-form-urlencoded`
// instead of `application/json` with the model in a param named `model`.
// Useful when interfacing with server-side languages like **PHP** that make
// it difficult to read the body of `PUT` requests.
Backbone.sync = function(method, model, options) {
var type = methodMap[method];
// Default options, unless specified.
_.defaults(options || (options = {}), {
emulateHTTP: Backbone.emulateHTTP,
emulateJSON: Backbone.emulateJSON
});
// Default JSON-request options.
var params = {type: type, dataType: 'json'};
// Ensure that we have a URL.
if (!options.url) {
params.url = _.result(model, 'url') || urlError();
}
// Ensure that we have the appropriate request data.
if (options.data == null && model && (method === 'create' || method === 'update' || method === 'patch')) {
params.contentType = 'application/json';
params.data = JSON.stringify(options.attrs || model.toJSON(options));
}
// For older servers, emulate JSON by encoding the request into an HTML-form.
if (options.emulateJSON) {
params.contentType = 'application/x-www-form-urlencoded';
params.data = params.data ? {model: params.data} : {};
}
// For older servers, emulate HTTP by mimicking the HTTP method with `_method`
// And an `X-HTTP-Method-Override` header.
if (options.emulateHTTP && (type === 'PUT' || type === 'DELETE' || type === 'PATCH')) {
params.type = 'POST';
if (options.emulateJSON) params.data._method = type;
var beforeSend = options.beforeSend;
options.beforeSend = function(xhr) {
xhr.setRequestHeader('X-HTTP-Method-Override', type);
if (beforeSend) return beforeSend.apply(this, arguments);
};
}
// Don't process data on a non-GET request.
if (params.type !== 'GET' && !options.emulateJSON) {
params.processData = false;
}
// If we're sending a `PATCH` request, and we're in an old Internet Explorer
// that still has ActiveX enabled by default, override jQuery to use that
// for XHR instead. Remove this line when jQuery supports `PATCH` on IE8.
if (params.type === 'PATCH' && window.ActiveXObject &&
!(window.external && window.external.msActiveXFilteringEnabled)) {
params.xhr = function() {
return new ActiveXObject("Microsoft.XMLHTTP");
};
}
// Make the request, allowing the user to override any Ajax options.
var xhr = options.xhr = Backbone.ajax(_.extend(params, options));
model.trigger('request', model, xhr, options);
return xhr;
};
// Map from CRUD to HTTP for our default `Backbone.sync` implementation.
var methodMap = {
'create': 'POST',
'update': 'PUT',
'patch': 'PATCH',
'delete': 'DELETE',
'read': 'GET'
};
// Set the default implementation of `Backbone.ajax` to proxy through to `$`.
// Override this if you'd like to use a different library.
Backbone.ajax = function() {
return Backbone.$.ajax.apply(Backbone.$, arguments);
};
// Backbone.Router
// ---------------
// Routers map faux-URLs to actions, and fire events when routes are
// matched. Creating a new one sets its `routes` hash, if not set statically.
var Router = Backbone.Router = function(options) {
options || (options = {});
if (options.routes) this.routes = options.routes;
this._bindRoutes();
this.initialize.apply(this, arguments);
};
// Cached regular expressions for matching named param parts and splatted
// parts of route strings.
// 匹配括号和括号里的内容
var optionalParam = /\((.*?)\)/g;
// :asdfasdf
var namedParam = /(\(\?)?:\w+/g;
var splatParam = /\*\w+/g;
var escapeRegExp = /[\-{}\[\]+?.,\\\^$|#\s]/g;
// Set up all inheritable **Backbone.Router** properties and methods.
_.extend(Router.prototype, Events, {
// Initialize is an empty function by default. Override it with your own
// initialization logic.
initialize: function(){},
// Manually bind a single named route to a callback. For example:
//
// this.route('search/:query/p:num', 'search', function(query, num) {
// ...
// });
//route是用来匹配hash
//name是名字
//callback是注册函数
route: function(route, name, callback) {
if (!_.isRegExp(route)) route = this._routeToRegExp(route);
if (_.isFunction(name)) {
callback = name;
name = '';
}
if (!callback) callback = this[name];
var router = this;
Backbone.history.route(route, function(fragment) {
var args = router._extractParameters(route, fragment);
callback && callback.apply(router, args);
router.trigger.apply(router, ['route:' + name].concat(args));
router.trigger('route', name, args);
Backbone.history.trigger('route', router, name, args);
});
return this;
},
// Simple proxy to `Backbone.history` to save a fragment into the history.
navigate: function(fragment, options) {
Backbone.history.navigate(fragment, options);
return this;
},
// Bind all defined routes to `Backbone.history`. We have to reverse the
// order of the routes here to support behavior where the most general
// routes can be defined at the bottom of the route map.
// 绑定参数传入的routes对象的散列表监听
_bindRoutes: function() {
if (!this.routes) return;
this.routes = _.result(this, 'routes');
var route, routes = _.keys(this.routes);
while ((route = routes.pop()) != null) {
this.route(route, this.routes[route]);
}
},
// Convert a route string into a regular expression, suitable for matching
// against the current location hash.
// 转化成正则
_routeToRegExp: function(route) {
route = route.replace(escapeRegExp, '\\$&')
//把括号里的内容替换成(?:)不获取
.replace(optionalParam, '(?:$1)?')
// :sadasdf替换成:[^\/]
.replace(namedParam, function(match, optional){
return optional ? match : '([^\/]+)';
})
//把*\w+（*test）替换成(.*?)
.replace(splatParam, '(.*?)');
//返回正则
return new RegExp('^' + route + '$');
},
// Given a route, and a URL fragment that it matches, return the array of
// extracted decoded parameters. Empty or unmatched parameters will be
// treated as `null` to normalize cross-browser behavior.
// 解析一下url
_extractParameters: function(route, fragment) {
var params = route.exec(fragment).slice(1);
return _.map(params, function(param) {
return param ? decodeURIComponent(param) : null;
});
}
});
// Backbone.History
// ----------------
// Handles cross-browser history management, based on either
// [pushState](http://diveintohtml5.info/history.html) and real URLs, or
// [onhashchange](https://developer.mozilla.org/en-US/docs/DOM/window.onhashchange)
// and URL fragments. If the browser supports neither (old IE, natch),
// falls back to polling.
var History = Backbone.History = function() {
this.handlers = [];
_.bindAll(this, 'checkUrl');
// Ensure that `History` can be used outside of the browser.
if (typeof window !== 'undefined') {
this.location = window.location;
this.history = window.history;
}
};
// Cached regex for stripping a leading hash/slash and trailing space.
// #或者/ 或者空格开头，同样可以以上结尾
var routeStripper = /^[#\/]|\s+$/g;
// Cached regex for stripping leading and trailing slashes.
// /开头，或者/结尾
var rootStripper = /^\/+|\/+$/g;
// Cached regex for detecting MSIE.
// 检测IE
var isExplorer = /msie [\w.]+/;
// Cached regex for removing a trailing slash.
// 检测/
var trailingSlash = /\/$/;
// Has the history handling already been started?
// 是否开始的标记
History.started = false;
// Set up all inheritable **Backbone.History** properties and methods.
_.extend(History.prototype, Events, {
// The default interval to poll for hash changes, if necessary, is
// twenty times a second.
interval: 50,
// Gets the true hash value. Cannot use location.hash directly due to bug
// in Firefox where location.hash will always be decoded.
// 获取hansh,无#
getHash: function(window) {
var match = (window || this).location.href.match(/#(.*)$/);
return match ? match[1] : '';
},
// Get the cross-browser normalized URL fragment, either from the URL,
// the hash, or the override.
// 获取hash
getFragment: function(fragment, forcePushState) {
if (fragment == null) {
if (this._hasPushState || !this._wantsHashChange || forcePushState) {
fragment = this.location.pathname;
var root = this.root.replace(trailingSlash, '');
if (!fragment.indexOf(root)) fragment = fragment.substr(root.length);
} else {
fragment = this.getHash();
}
}
return fragment.replace(routeStripper, '');
},
// Start the hash change handling, returning `true` if the current URL matches
// an existing route, and `false` otherwise.
// 开始监听hash变化
start: function(options) {
//如果已经开始过了
if (History.started) throw new Error("Backbone.history has already been started");
History.started = true;
// Figure out the initial configuration. Do we need an iframe?
// Is pushState desired ... is it available?
// 判断pushState是否可以用，否则用iframe
this.options = _.extend({}, {root: '/'}, this.options, options);
this.root = this.options.root;
//显式禁用
this._wantsHashChange = this.options.hashChange !== false;
this._wantsPushState = !!this.options.pushState;
this._hasPushState = !!(this.options.pushState && this.history && this.history.pushState);
var fragment = this.getFragment();
var docMode = document.documentMode;
var oldIE = (isExplorer.exec(navigator.userAgent.toLowerCase()) && (!docMode || docMode <= 7));
// Normalize root to always include a leading and trailing slash.
this.root = ('/' + this.root + '/').replace(rootStripper, '/');
if (oldIE && this._wantsHashChange) {
//ie
this.iframe = Backbone.$('<iframe src="javascript:0" tabindex="-1" />').hide().appendTo('body')[0].contentWindow;
this.navigate(fragment);
}
// Depending on whether we're using pushState or hashes, and whether
// 'onhashchange' is supported, determine how we check the URL state.
if (this._hasPushState) {
Backbone.$(window).on('popstate', this.checkUrl);
} else if (this._wantsHashChange && ('onhashchange' in window) && !oldIE) {
//注册事件
Backbone.$(window).on('hashchange', this.checkUrl);
} else if (this._wantsHashChange) {
this._checkUrlInterval = setInterval(this.checkUrl, this.interval);
}
// Determine if we need to change the base url, for a pushState link
// opened by a non-pushState browser.
this.fragment = fragment;
var loc = this.location;
var atRoot = loc.pathname.replace(/[^\/]$/, '$&/') === this.root;
// If we've started off with a route from a `pushState`-enabled browser,
// but we're currently in a browser that doesn't support it...
if (this._wantsHashChange && this._wantsPushState && !this._hasPushState && !atRoot) {
this.fragment = this.getFragment(null, true);
this.location.replace(this.root + this.location.search + '#' + this.fragment);
// Return immediately as browser will do redirect to new url
return true;
// Or if we've started out with a hash-based route, but we're currently
// in a browser where it could be `pushState`-based instead...
} else if (this._wantsPushState && this._hasPushState && atRoot && loc.hash) {
this.fragment = this.getHash().replace(routeStripper, '');
this.history.replaceState({}, document.title, this.root + this.fragment + loc.search);
}
if (!this.options.silent) return this.loadUrl();
},
// Disable Backbone.history, perhaps temporarily. Not useful in a real app,
// but possibly useful for unit testing Routers.
// 停止监听hash变化
stop: function() {
Backbone.$(window).off('popstate', this.checkUrl).off('hashchange', this.checkUrl);
clearInterval(this._checkUrlInterval);
History.started = false;
},
// Add a route to be tested when the fragment changes. Routes added later
// may override previous routes.
// 新增插入监听的hash格式和回调函数,使用unshift，而不是push，所以后期加入的优先级高于前面加入的
route: function(route, callback) {
this.handlers.unshift({route: route, callback: callback});
},
// Checks the current URL to see if it has changed, and if it has,
// calls `loadUrl`, normalizing across the hidden iframe.
// 注册在hanshchange变化的函数，判断是否变化了然后执行
checkUrl: function(e) {
var current = this.getFragment();
if (current === this.fragment && this.iframe) {
current = this.getFragment(this.getHash(this.iframe));
}
if (current === this.fragment) return false;
if (this.iframe) this.navigate(current);
this.loadUrl() || this.loadUrl(this.getHash());
},
// Attempt to load the current URL fragment. If a route succeeds with a
// match, returns `true`. If no defined routes matches the fragment,
// returns `false`.
// 判断是否在需要监听的hash格式内，并且回调相关函数
loadUrl: function(fragmentOverride) {
var fragment = this.fragment = this.getFragment(fragmentOverride);
var matched = _.any(this.handlers, function(handler) {
if (handler.route.test(fragment)) {
handler.callback(fragment);
return true;
}
});
return matched;
},
// Save a fragment into the hash history, or replace the URL state if the
// 'replace' option is passed. You are responsible for properly URL-encoding
// the fragment in advance.
//
// The options object can contain `trigger: true` if you wish to have the
// route callback be fired (not usually desirable), or `replace: true`, if
// you wish to modify the current URL without adding an entry to the history.
// 换到某个hash，fragment是hash,options可以传入trigger(是否触发),repace是否
navigate: function(fragment, options) {
if (!History.started) return false;
if (!options || options === true) options = {trigger: options};
fragment = this.getFragment(fragment || '');
if (this.fragment === fragment) return;
this.fragment = fragment;
var url = this.root + fragment;
// If pushState is available, we use it to set the fragment as a real URL.
if (this._hasPushState) {
this.history[options.replace ? 'replaceState' : 'pushState']({}, document.title, url);
// If hash changes haven't been explicitly disabled, update the hash
// fragment to store history.
} else if (this._wantsHashChange) {
this._updateHash(this.location, fragment, options.replace);
if (this.iframe && (fragment !== this.getFragment(this.getHash(this.iframe)))) {
// Opening and closing the iframe tricks IE7 and earlier to push a
// history entry on hash-tag change. When replace is true, we don't
// want this.
if(!options.replace) this.iframe.document.open().close();
this._updateHash(this.iframe.location, fragment, options.replace);
}
// If you've told us that you explicitly don't want fallback hashchange-
// based history, then `navigate` becomes a page refresh.
} else {
return this.location.assign(url);
}
if (options.trigger) this.loadUrl(fragment);
},
// Update the hash location, either replacing the current entry, or adding
// a new one to the browser history.
// 修改hash
_updateHash: function(location, fragment, replace) {
if (replace) {
var href = location.href.replace(/(javascript:|#).*$/, '');
location.replace(href + '#' + fragment);
} else {
// Some browsers require that `hash` contains a leading #.
location.hash = '#' + fragment;
}
}
});
// Create the default Backbone.history.
Backbone.history = new History;
// Helpers
// -------
// Helper function to correctly set up the prototype chain, for subclasses.
// Similar to `goog.inherits`, but uses a hash of prototype properties and
// class properties to be extended.
var extend = function(protoProps, staticProps) {
var parent = this;
var child;
// The constructor function for the new subclass is either defined by you
// (the "constructor" property in your `extend` definition), or defaulted
// by us to simply call the parent's constructor.
if (protoProps && _.has(protoProps, 'constructor')) {
child = protoProps.constructor;
} else {
child = function(){ return parent.apply(this, arguments); };
}
// Add static properties to the constructor function, if supplied.
_.extend(child, parent, staticProps);
// Set the prototype chain to inherit from `parent`, without calling
// `parent`'s constructor function.
var Surrogate = function(){ this.constructor = child; };
Surrogate.prototype = parent.prototype;
child.prototype = new Surrogate;
// Add prototype properties (instance properties) to the subclass,
// if supplied.
if (protoProps) _.extend(child.prototype, protoProps);
// Set a convenience property in case the parent's prototype is needed
// later.
child.__super__ = parent.prototype;
return child;
};
// Set up inheritance for the model, collection, router, view and history.
Model.extend = Collection.extend = Router.extend = View.extend = History.extend = extend;
// Throw an error when a URL is needed, and none is supplied.
var urlError = function() {
throw new Error('A "url" property or function must be specified');
};
// Wrap an optional error callback with a fallback error event.
var wrapError = function (model, options) {
var error = options.error;
options.error = function(resp) {
if (error) error(model, resp, options);
model.trigger('error', model, resp, options);
};
};
}).call(this);
