//2014.11
// 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
(function() {
// Initial Setup
// -------------
// Save a reference to the global object (`window` in the browser, `exports`
// on the server).
//root是window;
var root = this;
//alert(root)
// Save the previous value of the `Backbone` variable, so that it can be
// restored later on, if `noConflict` is used.
//如果window.Backbone有对象，就保存上一个backbone，
//用来芳冲突的;
var previousBackbone = root.Backbone;
// Create local references to array methods we'll want to use later.
//快捷方法;
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;
//如果有模块化就直接exports为Backbone
//否者就让Backbone在window下面;
if (typeof exports !== 'undefined') {
Backbone = exports;
} else {
Backbone = root.Backbone = {};
}
// Current version of the library. Keep in sync with `package.json`.
//版本号
Backbone.VERSION = '1.0.0';
// Require Underscore, if we're on the server, and it's not already present.
//引用底线库_ underscore.js;
var _ = root._;
if (!_ && (typeof require !== 'undefined')) _ = require('underscore');
// For Backbone's purposes, jQuery, Zepto, Ender, or My Library (kidding) owns
// the `$` variable.
//引用选择器库
Backbone.$ = 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.
//....
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.
//给Backbone.sync(ajax)用的;
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
// ---------------
//backbone的继承引用了底线库中的_.extend方法;
// 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 = {
//事件绑定,name可以传
// "event1 event2 event3";
//或者"{event1 : function(){}, event2 : function(){}}"的格式;
//通过实例话对象，这个对象即可有使用事件 ==>> new 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.
//绑定一次即销毁
//想象成Express中的 next();
/*
//temp开始;
var next = mainFn = function(mainFn) {
var tempFn = mainFn;
var args = arguments;
return function(fn) {
tempFn.apply(window, args);
fn();
};
};
//temp结束;
//NODEJS的express框架中的next相当于这样的
var mainFn = function() {};
anotherFn = next(mainFn);
anotherFn( function(){xxxx} );
//利用闭包跑多次;
*/
once: function(name, callback, context) {
if (!eventsApi(this, 'once', name, [callback, context]) || !callback) return this;
var self = this;
var once = _.once(function() {
//取消事件绑定；
self.off(name, once);
//把同样的参数arguments跑原来的callback起来；
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) {
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可以是JSON;
names = name ? [name] : _.keys(this._events);
for (i = 0, l = names.length; i < l; i++) {
name = names[i];
//保存事件到events变量;
if (events = this._events[name]) {
//把原来的事件list清空;
this._events[name] = retain = [];
//没有callback就是清空所有的event;
if (callback || context) {
for (j = 0, k = events.length; j < k; j++) {
//ev就是fn了
ev = events[j];
//不满足任何一个条件就不push;
if ((callback && callback !== ev.callback && callback !== ev.callback._callback) || (context && context !== ev.context)) {
retain.push(ev);
}
}
}
//没有length就删除属性;
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).
trigger: function(name) {
if (!this._events) return this;
//可以传JSON或者是"event1 event2 event3 event4"的处理;
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);
//任何事件的触发都回触发"all"的事件;
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.
//obj为实例的对象,name为触发事件的名字(JSON || String);
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,
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).
//有点不明白何必要这样跑，有什么好处;
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);
}
};
var object = {};
_.extend(object, Backbone.Events);
//继承的所有的this都是obj,所以不会相互影响;
object.on("alert",
function(msg) {
alert("Triggered " + msg); //第一个走这边
});
var obj1 = {};
_.extend(obj1, Backbone.Events);
obj1.on("afterAlert",
function(arg) {
console.log(2);
console.log(arg);
});
//这个就是为obj绑定alert事件;
obj1.listenTo(object, "alert",
function() {
console.log(1); //第二个走这边
obj1.trigger("afterAlert"); //触发自己的事件;
});
obj1.listenTo(object, "alert",
function() {
console.log(3); //第三个走这边
obj1.trigger("afterAlert", "context"); //触发自己的事件;
});
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) {
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;
};
});
/*
Events.listenTo = function(obj, name, callback) {
var listeners = this._listeners || (this._listeners = {});
//为监听的对象添加listenerId;
//ID下面的value是指向自己的;
var id = obj._listenerId || (obj._listenerId = _.uniqueId('l'));
listeners[id] = obj;
if (typeof name === 'object') callback = this;
//就是为obj绑定事件名name的方法为callback;
//但是上下文context为this；
obj.on(name, callback, this);
return this;
};
*/
/*
var object = {};
_.extend(object, Backbone.Events);
//继承的所有的this都是obj,所以不会相互影响;
object.on("alert", function(msg) {
alert("Triggered " + msg);
});
object.trigger("alert", "an event");
*/
// 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.
//Backbone的模型, MODEL这个是这个库的基本组件;
//这个东西比较多和杂;
var Model = Backbone.Model = function(attributes, options) {
var defaults;
var attrs = attributes || {};
options || (options = {});
this.cid = _.uniqueId('c');
this.attributes = {};
this.attributes = {};
//modelOptions 的值是 ["url", "urlRoot", "collection"]；
//相当于检索otpions里面的url，urlRoot，和collection，让this继承这几个东西;
//别的东西就不要继承了;
_.extend(this, _.pick(options, modelOptions));
if (options.parse) attrs = this.parse(attrs, options) || {};
if (defaults = _.result(this, 'defaults')) {
attrs = _.defaults({},
attrs, defaults);
}
//把所有的属性和方法全放到实例的attrs属性下面去;
this.set(attrs, options);
this.changed = {};
//initialize: function(){}是空的
this.initialize.apply(this, arguments);
};
// A list of options to be attached directly to the model, if provided.
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.
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.
//位实例添加initialize即覆盖这个原型方法;
initialize: function() {},
// Return a copy of the model's `attributes` object.
//当前元素下的所有的值是放在attributes里面的;
//把所有的属性克隆出来;
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() {
//触发backbone.sync,参数为传的参数;
//上下文context是this;
return Backbone.sync.apply(this, arguments);
},
// Get the value of an attribute.
//当前元素下的所有的值是放在attributes里面的;
get: function(attr) {
return this.attributes[attr];
},
// Get the HTML-escaped value of an attribute.
//解码escape;
escape: function(attr) {
return _.escape(this.get(attr));
},
// Returns `true` if the attribute contains a value that is not null
// or undefined.
//弱类型比较 null undefined "" ;
//null或者是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) {
//初始化参数;
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.
//options多数是自己用的;
unset = options.unset;
silent = options.silent;
//change是数组;
changes = [];
//保存本来changeing标识符;
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.
//attr就是一个json，而且可以是一个或者是多个key和value的;
for (attr in attrs) {
val = attrs[attr];
//如果
//如果和现在的属性不同了;
if (!_.isEqual(current[attr], val)) changes.push(attr);
//如果跟上一个只不同就设置changed，这个感觉不常用;
if (!_.isEqual(prev[attr], val)) {
this.changed[attr] = val;
} else {
delete this.changed[attr];
};
//删除属性或者，重新设置属性;
unset ? delete current[attr] : current[attr] = val;
}
// Trigger all relevant attribute changes.
if (!silent) {
if (changes.length) this._pending = true;
for (var i = 0,
l = changes.length; i < l; i++) {
//触发所有的模型属性对应的改变事件;
this.trigger('change:' + changes[i], this, current[changes[i]], options);
//别忘记了"trigger"会触发"all"事件;
}
}
// 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) {
this._pending = false;
//又触发了"change"事件;
this.trigger('change', this, options);
}
}
//我看着这些有什么收获吗？;
//逻辑清晰?
//参数分析?
//错误处理?
//我为什么看这个库?
//命名规范?
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.
//也是调用set而已;，而且随着了unset;
unset: function(attr, options) {
return this.set(attr, void 0, _.extend({},
options, {
unset: true
}));
},
// Clear all attributes on the model, firing `"change"`.
//遍历属性,也是调用unset;
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.
//查看是否改变;
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.
//查看上一次model对应的属性数据;
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
//上一次model所有的属性数据.
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;
//如果有成功的options.success方法就跑一下;
if (success) success(model, resp, options);
//同时触发sync事件;
//所以model.fetch()时候要有sync事件比较靠谱
//参数为model,resp,返回的数据;
model.trigger('sync', model, resp, options);
};
wrapError(this, options);
//同时触发sync.read事件; "read"好像就是GET;~。~！
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.
//copy构造函数;
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.
//验证方法;
//调用validate方法验证所有的属性;
//如果有问题就跑“invalid";
_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`.
//直接拿底线库的方法;
_.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 = {});
//初始化options;
if (options.url) this.url = options.url;
if (options.model) this.model = options.model;
if (options.comparator !== void 0) this.comparator = options.comparator;
/*
_reset会跑这些东西:
this.length = 0;
this.models = [];
this._byId = {};
*/
this._reset();
//初始化，用arguments为参数跑;
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.
//如果实例化的时候有传Model，这个会被覆盖;
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.
//学习了，这样就少写代码了;
sync: function() {
return Backbone.sync.apply(this, arguments);
},
// Add a model, or list of models to the set.
add: function(models, options) {
//变相的跳用Collection.set
return this.set(models, _.defaults(options || {},
addOptions));
},
// Remove a model, or a list of models from the set.
remove: function(models, options) {
//无论如何都要变成数组;
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;
//collection._byId保存的是model通过cid保存的值;
delete this._byId[model.id];
delete this._byId[model.cid];
index = this.indexOf(model);
this.models.splice(index, 1);
//length; collection有一个length属性，代表的是models的长度
this.length--;
//undefined为真;
//true为假;
if (!options.silent) {
options.index = index;
model.trigger('remove', model, this, options);
}
//删除collection的引用;
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.
/*
var C = Backbone.Collection.extend();
var c = new C;
c.set({1:2,3:4});
var Model = Backbone.Model.extend();
var m = new Model({2:2});
*/
set: function(models, options) {
/*
1 知识点：
前面进行所有的参数处理；
后面后面的代码都根据所有处理的参数进行处理；
2 知识点：
backbone的作者都有这么多注释；
命名就是一种注释;
*/
//setOptions = {add: true, remove: true, merge: true};
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;
//at应该是会返回指定index的内容 === Array.prototype.call.indexOf(collection.models,model);
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++) {
//为模型添加collection为this;
//如果传的事JSON就把JSON编程一个model;
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.
//如果模型存在;
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`.
//模型改变就触发all的事件
model.on('all', this._onModelEvent, this);
this._byId[model.cid] = model;
//collection._byId是model的一个副本，让model根据model的id排列;
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++) {
//触发每一个model的add事件
(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.
/*
var collection = new Backbone.Collection();
collection.on("reset",function(){console.log("reset is runing")});
collection.reset();
*/
reset: function(models, options) {
//初始化参数;
options || (options = {});
for (var i = 0,
l = this.models.length; i < l; i++) {
//把所有模型的models下的collection删除;
this._removeReference(this.models[i]);
}
options.previousModels = this.models;
this._reset();
//添加模型;
this.add(models, _.extend({
silent: true
},
options));
//触发reset;
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.
//by model或者 by id获取在collection中的值;
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.
//获取模型s的第几个;
at: function(index) {
return this.models[index];
},
// Return models with matching attributes. Useful for simple cases of
// `filter`.
//attr是model的属性;匹配所有collection对应的model;
where: function(attrs, first) {
if (_.isEmpty(attrs)) return first ? void 0 : [];
//遍历每一个model,find就返回model，要么返回过滤的位置;
return this[first ? 'find': 'filter'](function(model) {
for (var key in attrs) {
//遍历attrs，attrs是一个对象不要忘记了;，把这个值和model对应的key比较;
if (attrs[key] !== model.get(key)) return false;
}
return true;
});
},
// Return the first model with matching attributes. Useful for simple cases
// of `find`.
//第二个参数是true获取的是模型;
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);
};
});
/*调用model.keys相当于是 执行
_.forEach(model.models);
_.each(model.models);
_.collect(model.models);
*/
// 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...
//view的代码比想象中的要少
var View = Backbone.View = function(options) {
/*
function (prefix) {
var id = ++idCounter + '';
return prefix ? prefix + id : id;
};
*/
this.cid = _.uniqueId('view');
//设置选项配置;
//为什么要这样呢，只要这一些配置呢?
//['model', 'collection', 'el', 'id', 'attributes', 'className', 'tagName', 'events'];
this._configure(options || {});
this._ensureElement();
this.initialize.apply(this, arguments);
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.
$: function(selector) {
return this.$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.$el.remove();
this.stopListening();
return this;
},
// Change the view's element (`this.el` property), including event
// re-delegation.
setElement: function(element, delegate) {
//如果已经有$el就把事件的代理去掉;
if (this.$el) this.undelegateEvents();
//获取新元素到$el;
this.$el = element instanceof Backbone.$ ? element: Backbone.$(element);
//el为原生的元素;
this.el = this.$el[0];
//添加事件代理;
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.
delegateEvents: function(events) {
//没有events或者_.result(this, 'events')this.$el的没有事件列表
//就return;
if (! (events || (events = _.result(this, 'events')))) return this;
this.undelegateEvents();
for (var key in events) {
var method = events[key];
if (!_.isFunction(method)) method = this[events[key]];
if (!method) continue;
var match = key.match(delegateEventSplitter);
/*
var v = new View({
//两种绑定事件的方法;
clickFn : function(){
console.log(1)
},
event : {
click .xx : clickFn,
click #yy: function(){}
}
});
*/
// "click .xx" ==> ["click .xx", click ,.xx];
// "click #xx" ==> ["click #xx", click ,#xx];
var eventName = match[1],
selector = match[2];
//绑定上下文为Backbone.View;
method = _.bind(method, this);
//事件的命名空间;
// click.delegateEvents12
// mousedown.delegateEvents34
//cid为collection的id是唯一的;
eventName += '.delegateEvents' + this.cid;
if (selector === '') {
this.$el.on(eventName, method);
} else {
this.$el.on(eventName, selector, method);
}
}
return this;
},
// Clears all callbacks previously bound to the view with `delegateEvents`.
// You usually don't need to use this, but may wish to if you have multiple
// Backbone views attached to the same DOM element.
undelegateEvents: function() {
//取消事件代理;
//取消对应命名空间下的事件;
this.$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.
_configure: function(options) {
//用户传进来的数据;
//_.result(this, 'options')是直接跑 this['options'];
if (this.options) options = _.extend({},
_.result(this, 'options'), options);
//把options里面的所有viewOptions的东西全部拿出来;
//var viewOptions = ['model', 'collection', 'el', 'id', 'attributes', 'className', 'tagName', 'events'];
//this.options只要这些东西;
_.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) {
//初始化需要的属性attributes;
var attrs = _.extend({},
_.result(this, 'attributes'));
//设置新建元素的id
if (this.id) attrs.id = _.result(this, 'id');
//设置新建元素的className
if (this.className) attrs['class'] = _.result(this, 'className');
//默认的this.tagName是div;
var $el = Backbone.$('<' + _.result(this, 'tagName') + '>').attr(attrs);
this.setElement($el, false);
} else {
//这个传的事字符串;
//为什么不直接用 this.el呢?
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的sync(ajax)模块;
Backbone.sync = function(method, model, options) {
var type = methodMap[method];
/*
Backbone.emulateHTTP
false
Backbone.emulateJSON
false
*/
// 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.
//URL为model或者是collection的URL;
if (!options.url) {
params.url = _.result(model, 'url') || urlError();
}
// Ensure that we have the appropriate request data.
//使用XHR进行请求;
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.
//模拟FORM方式提交表单
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.
//低版本的XHR为 ACTIVEXOBJECT对象;
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.
// Backbone.ajax就是发送请求了,有回调的话直接走回调了;
//xhr有请求成功或者失败的回调;
var xhr = options.xhr = Backbone.ajax(_.extend(params, options));
//同时会触发绑定自定义事件"request"
model.trigger('request', model, xhr, options);
return xhr;
/*
为Model或者Collection绑定URL;
所以无论是fetch还是sync都是对指定URL的请求，返回的结果参数为xhr;
回调的参数顺序为 model , xhr ,options;
*/
};
// 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.
var optionalParam = /\((.*?)\)/g;
var namedParam = /(\(\?)?:\w+/g;
var splatParam = /\*\w+/g;
var escapeRegExp = /[\-{}\[\]+?.,\\\^$|#\s]/g;
// Set up all inheritable **Backbone.Router** properties and methods.
_.extend(Router.prototype, Events, {
// Initialize is an empty function by default. Override it with your own
// initialization logic.
initialize: function() {},
// Manually bind a single named route to a callback. For example:
//
// this.route('search/:query/p:num', 'search', function(query, num) {
// ...
// });
//
route: function(route, name, callback) {
if (!_.isRegExp(route)) route = this._routeToRegExp(route);
if (_.isFunction(name)) {
callback = name;
name = '';
}
if (!callback) callback = this[name];
var router = this;
Backbone.history.route(route,
function(fragment) {
var args = router._extractParameters(route, fragment);
callback && callback.apply(router, args);
router.trigger.apply(router, ['route:' + name].concat(args));
router.trigger('route', name, args);
Backbone.history.trigger('route', router, name, args);
});
return this;
},
// Simple proxy to `Backbone.history` to save a fragment into the history.
navigate: function(fragment, options) {
Backbone.history.navigate(fragment, options);
return this;
},
// Bind all defined routes to `Backbone.history`. We have to reverse the
// order of the routes here to support behavior where the most general
// routes can be defined at the bottom of the route map.
_bindRoutes: function() {
if (!this.routes) return;
//就是this.routes,如果类有routes方法，会先执行routes方法，把返回值给this.routes;
this.routes = _.result(this, 'routes');
var route, routes = _.keys(this.routes);
while ((route = routes.pop()) != null) {
//把所有key和触发的fn发送到this.route;
this.route(route, this.routes[route]);
}
},
// Convert a route string into a regular expression, suitable for matching
// against the current location hash.
_routeToRegExp: function(route) {
route = route.replace(escapeRegExp, '\\$&').replace(optionalParam, '(?:$1)?').replace(namedParam,
function(match, optional) {
return optional ? match: '([^\/]+)';
}).replace(splatParam, '(.*?)');
return new RegExp('^' + route + '$');
},
// 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.
_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.
//所有的route都在这边会走一遍;
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.
var routeStripper = /^[#\/]|\s+$/g;
// Cached regex for stripping leading and trailing slashes.
var rootStripper = /^\/+|\/+$/g;
// Cached regex for detecting MSIE.
var isExplorer = /msie [\w.]+/;
// Cached regex for removing a trailing slash.
var trailingSlash = /\/$/;
// Has the history handling already been started?
History.started = false;
// Set up all inheritable **Backbone.History** properties and methods.
_.extend(History.prototype, Events, {
// The default interval to poll for hash changes, if necessary, is
// twenty times a second.
interval: 50,
// Gets the true hash value. Cannot use location.hash directly due to bug
// in Firefox where location.hash will always be decoded.
getHash: function(window) {
var match = (window || this).location.href.match(/#(.*)$/);
return match ? match[1] : '';
},
// Get the cross-browser normalized URL fragment, either from the URL,
// the hash, or the override.
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.
start: function(options) {
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?
this.options = _.extend({},
{
root: '/'
},
this.options, options);
this.root = this.options.root;
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) {
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) {
Backbone.$(window).on('hashchange', this.checkUrl);
} else if (this._wantsHashChange) {
this._checkUrlInterval = setInterval(this.checkUrl, this.interval);
}
// Determine if we need to change the base url, for a pushState link
// opened by a non-pushState browser.
this.fragment = fragment;
var loc = this.location;
var atRoot = loc.pathname.replace(/[^\/]$/, '$&/') === this.root;
// If we've started off with a route from a `pushState`-enabled browser,
// but we're currently in a browser that doesn't support it...
if (this._wantsHashChange && this._wantsPushState && !this._hasPushState && !atRoot) {
this.fragment = this.getFragment(null, true);
this.location.replace(this.root + this.location.search + '#' + this.fragment);
// Return immediately as browser will do redirect to new url
return true;
// Or if we've started out with a hash-based route, but we're currently
// in a browser where it could be `pushState`-based instead...
} else if (this._wantsPushState && this._hasPushState && atRoot && loc.hash) {
this.fragment = this.getHash().replace(routeStripper, '');
this.history.replaceState({},
document.title, this.root + this.fragment + loc.search);
}
if (!this.options.silent) return this.loadUrl();
},
// Disable Backbone.history, perhaps temporarily. Not useful in a real app,
// but possibly useful for unit testing Routers.
stop: function() {
Backbone.$(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.
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.
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`.
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.
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.
_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);
