// Backbone.js 1.1.0
(function() {
// 保存window对象
var root = this;
// 解决命名冲突(原理：保存一份Backbone变量，以便于交出Backbone命名空间)
var previousBackbone = root.Backbone;
var array = [];
var push = array.push;
var slice = array.slice;
var splice = array.splice;
// 创建命名空间，所有Backbone的类和模块都会添加到该命名空间下面
var Backbone;
if (typeof exports !== 'undefined') {
Backbone = exports;
} else {
// 暴露给window全局对象
Backbone = root.Backbone = {};
}
// 版本号
Backbone.VERSION = '1.1.0';
// 如果是服务器端javascript(Nodejs)，加载依赖的underscore
var _ = root._;
if (!_ && (typeof require !== 'undefined')) _ = require('underscore');
Backbone.$ = root.jQuery || root.Zepto || root.ender || root.$;
// 解决命名冲突，将Backbone命名空间变量返回
Backbone.noConflict = function() {
root.Backbone = previousBackbone;
return this;
};
// 老的浏览器不支持REST/HTTP，开启emulateHTTP选项，Backbone将通过POST方法伪造PUT和DELETE方法，
// 该请求会附带一个_method参数，同时会像服务器发送一个'X-HTTP-Method-Override'头
Backbone.emulateHTTP = false;
// 老的浏览器不支持直接发送'application/json'编码的请求，开启emulateJSON选项，
// Backbone会将JSON模型数据序列化为modal参数，请求会按照application/x-www-form-urlencoded的内容发送
Backbone.emulateJSON = false;
// Backbone事件模块，可以被mix到任意对象模块，它拥有让对象绑定和触发自定义事件的能力
// 事件在被绑定之前不需要事先声明，可以携带参数
// 示例：
// var object = {};
// _.extend(object, Backbone.Events);
// object.on('expand', function(){ alert('expanded'); });
// object.trigger('expand');
var Events = Backbone.Events = {
// 事件绑定，如果传递name参数为'all'，将会绑定到所有事件
on: function(name, callback, context) {
if (!eventsApi(this, 'on', name, [callback, context]) || !callback) return this;
// 保存所有事件对象到this._events对象
this._events || (this._events = {});
var events = this._events[name] || (this._events[name] = []);
events.push({
callback: callback,
context: context,
ctx: context || this
});
return this;
},
// 事件绑定，该事件只会被触发一次，触发之后会删除事件绑定
once: function(name, callback, context) {
if (!eventsApi(this, 'once', name, [callback, context]) || !callback) return this;
var self = this;
// underscore.js的once方法，保证参数中制定的方法只会执行一次
var once = _.once(function() {
self.off(name, once);
callback.apply(this, arguments);
});
once._callback = callback;
return this.on(name, once, context);
},
// 删除事件绑定
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;
// 不传递参数，则删除所有该对象绑定的所有回调函数
if (!name && !callback && !context) {
this._events = {};
return this;
}
// 如果不传递name参数，则删除所有绑定的回调函数
names = name ? [name] : _.keys(this._events);
for (i = 0, l = names.length; i < l; i++) {
name = names[i];
// 如果该事件存在回调函数
if (events = this._events[name]) {
this._events[name] = retain = [];
if (callback || context) {
for (j = 0, k = events.length; j < k; j++) {
ev = events[j];
// 判断callback/context是否相同，相同则删除，不相同则不删除
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;
},
// 触发一个该对象上绑定的一个事件类型的回调函数
trigger: function(name) {
if (!this._events) return this;
var args = slice.call(arguments, 1);
if (!eventsApi(this, 'trigger', name, args)) return this;
var events = this._events[name];
var allEvents = this._events.all;
if (events) triggerEvents(events, args);
if (allEvents) triggerEvents(allEvents, arguments);
return this;
},
// Tell this object to stop listening to either specific events ... or
// to every object it's currently listening to.
stopListening: function(obj, name, callback) {
var listeningTo = this._listeningTo;
if (!listeningTo) return this;
var remove = !name && !callback;
if (!callback && typeof name === 'object') callback = this;
if (obj)(listeningTo = {})[obj._listenId] = obj;
for (var id in listeningTo) {
obj = listeningTo[id];
obj.off(name, callback, this);
if (remove || _.isEmpty(obj._events)) delete this._listeningTo[id];
}
return this;
}
};
// 用于切割多个事件的正则，比如'click mouseover'
var eventSplitter = /\s+/;
// 处理多个事件的绑定，比如"change blur"或者'{chage: action}'
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;
};
// 触发事件优化，尝试保持常用场景下的效率，方便触发事件时，传递给callback的参数问题
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);
}
};
// listenTo方法和listenToOnce方法
// 给一个对象监听另一个对象的某一事件的能力，当另一个对象的某个事件触发时，将会执行当前这个对象的回调函数
var listenMethods = {
listenTo: 'on',
listenToOnce: 'once'
};
_.each(listenMethods, function(implementation, method) {
Events[method] = function(obj, name, callback) {
var listeningTo = this._listeningTo || (this._listeningTo = {});
var id = obj._listenId || (obj._listenId = _.uniqueId('l'));
listeningTo[id] = obj;
if (!callback && typeof name === 'object') callback = this;
obj[implementation](name, callback, this);
return this;
};
});
Events.bind = Events.on;
Events.unbind = Events.off;
// 将Events对象fix到Backbone对象
_.extend(Backbone, Events);
// Modal模型对象
// Modal是Backbone框架最基础的数据对象，可以代表服务器上数据库中的一行表数据
// 表示一个数据模型以及与这个数据模型相关的操作
var Model = Backbone.Model = function(attributes, options) {
var attrs = attributes || {}; // 数据
options || (options = {}); // 配置项
this.cid = _.uniqueId('c');
this.attributes = {};
if (options.collection) this.collection = options.collection;
if (options.parse) attrs = this.parse(attrs, options) || {};
attrs = _.defaults({}, attrs, _.result(this, 'defaults'));
this.set(attrs, options);
this.changed = {};
this.initialize.apply(this, arguments);
};
// Attach all inheritable methods to the Model prototype.
_.extend(Model.prototype, Events, {
// 记录当前数据对象下哪些属性改变了
changed: null,
// The value returned during the last failed validation.
validationError: null,
// 数据的id属性模式是什么
idAttribute: 'id',
// 构造函数，用户重写
initialize: function() {},
// 得到模型的数据(attributes属性)
toJSON: function(options) {
return _.clone(this.attributes);
},
// 默认用Backbone.sync请求，用户可重写
sync: function() {
return Backbone.sync.apply(this, arguments);
},
// 取值
get: function(attr) {
return this.attributes[attr];
},
// 取值并转义
escape: function(attr) {
return _.escape(this.get(attr));
},
// 检查是否存在某属性(该属性值不等于null/undefined)
has: function(attr) {
return this.get(attr) != null;
},
// Modal对象核心操作，更新模型数据并通知监听该模型的对象，会触发'change'事件
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') {
// 如果key是一个对象
attrs = key;
options = val;
} else {
(attrs = {})[key] = val;
}
options || (options = {});
// 验证数据合法性
if (!this._validate(attrs, options)) return false;
// Extract attributes and options.
unset = options.unset; // 设置数据 or 全部设置undefined
silent = options.silent; // 标识是否要触发'change'事件
changes = []; // 所有的改变了的数据集合
changing = this._changing; // 是否正在改变
this._changing = true; // set函数中处于正在改变的状态
if (!changing) {
this._previousAttributes = _.clone(this.attributes);
this.changed = {};
}
// 保存之前数据集合
current = this.attributes, prev = this._previousAttributes;
// 如果attrs数据中指定了id属性
if (this.idAttribute in attrs) this.id = attrs[this.idAttribute];
// 遍历attrs数据集合，更新或删除数据
for (attr in attrs) {
val = attrs[attr];
if (!_.isEqual(current[attr], val)) changes.push(attr); // 数据已经改变，则推入changes
if (!_.isEqual(prev[attr], val)) {
this.changed[attr] = val;
} else {
delete this.changed[attr];
}
unset ? delete current[attr] : current[attr] = val;
}
// Trigger all relevant attribute changes.
if (!silent) {
if (changes.length) this._pending = true;
for (var i = 0, l = changes.length; i < l; i++) {
// 触发'change:属性名'事件
this.trigger('change:' + changes[i], this, current[changes[i]], options);
}
}
if (changing) return this;
if (!silent) {
// 避免'change'事件的嵌套调用
while (this._pending) {
this._pending = false;
this.trigger('change', this, options);
}
}
this._pending = false;
this._changing = false;
return this;
},
// 删除数据中指定的属性值
unset: function(attr, options) {
return this.set(attr, void 0, _.extend({}, options, {
unset: true
}));
},
// 删除数据中所有的属性值
clear: function(options) {
var attrs = {};
for (var key in this.attributes) attrs[key] = void 0;
return this.set(attrs, _.extend({}, options, {
unset: true
}));
},
// 数据中是否有数据已经修改，可以传递某一个属性名
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.
// 返回一个已经改变了的属性名的集合，如果没有改变，返回false
// 可以传递一个数据集合进行对比
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;
},
// 返回change事件触发之前记录的上一次数据
previous: function(attr) {
if (attr == null || !this._previousAttributes) return null;
return this._previousAttributes[attr];
},
// 返回所有change事件触发之前的数据集合
previousAttributes: function() {
return _.clone(this._previousAttributes);
},
// 从服务器端获取数据集合请求
// 如果服务器端的数据与当前数据不一致，会覆盖当前数据并触发change事件
fetch: function(options) {
options = options ? _.clone(options) : {};
if (options.parse === void 0) options.parse = true;
var model = this;
var success = options.success;
options.success = function(resp) {
if (!model.set(model.parse(resp, options), options)) return false;
if (success) success(model, resp, options);
model.trigger('sync', model, resp, options);
};
wrapError(this, options);
return this.sync('read', this, options);
},
// 同步数据模型到服务器端
// 如果服务器端处理返回一个改变了的数据集合，会执行Modal.set
save: function(key, val, options) {
var attrs, method, xhr, attributes = this.attributes;
// Handle both `"key", value` and `{key: value}` -style arguments.
if (key == null || typeof key === 'object') {
attrs = key;
options = val;
} else {
(attrs = {})[key] = val;
}
options = _.extend({
validate: true
}, options);
// If we're not waiting and attributes exist, save acts as
// `set(attr).save(null, opts)` with validation. Otherwise, check if
// the model will be valid when the attributes, if any, are set.
if (attrs && !options.wait) {
if (!this.set(attrs, options)) return false;
} else {
if (!this._validate(attrs, options)) return false;
}
// Set temporary attributes if `{wait: true}`.
if (attrs && options.wait) {
this.attributes = _.extend({}, attributes, attrs);
}
// After a successful server-side save, the client is (optionally)
// updated with the server-side state.
if (options.parse === void 0) options.parse = true;
var model = this;
var success = options.success;
options.success = function(resp) {
// Ensure attributes are restored during synchronous saves.
model.attributes = attributes;
var serverAttrs = model.parse(resp, options);
if (options.wait) serverAttrs = _.extend(attrs || {}, serverAttrs);
if (_.isObject(serverAttrs) && !model.set(serverAttrs, options)) {
return false;
}
if (success) success(model, resp, options);
model.trigger('sync', model, resp, options);
};
wrapError(this, options);
method = this.isNew() ? 'create' : (options.patch ? 'patch' : 'update');
if (method === 'patch') options.attrs = attrs;
xhr = this.sync(method, this, options);
// Restore attributes.
if (attrs && options.wait) this.attributes = attributes;
return xhr;
},
// 销毁删除数据，服务器端更新，触发destory事件
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;
},
// Modal请求的url
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;
},
// 克隆本Modal对象
clone: function() {
return new this.constructor(this.attributes);
},
// 如果模型数据为同步至服务器，认定其是新的
isNew: function() {
return this.id == null;
},
// 检查当前Modal是否合法
isValid: function(options) {
return this._validate({}, _.extend(options || {}, {
validate: true
}));
},
// 验证模型数据合法性，如果不合法，触发'invalid'事件
// 需要自己写validate函数
_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;
}
});
// 给Modal添加underscore的几个方法
var modelMethods = ['keys', 'values', 'pairs', 'invert', 'pick', 'omit'];
_.each(modelMethods, function(method) {
Model.prototype[method] = function() {
var args = slice.call(arguments);
args.unshift(this.attributes);
return _[method].apply(_, args);
};
});
// Backbone.Collection
// Backbone集合类
// 集合是Modal的有序集合，模型中触发的事件都会反映到集合中
var Collection = Backbone.Collection = function(models, options) {
options || (options = {});
if (options.model) this.model = options.model; // 模型
// 如果设置了comparator，模型会根据comparator进行排序
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));
};
// 默认参数
var setOptions = {
add: true,
remove: true,
merge: true
};
var addOptions = {
add: true,
remove: false
};
_.extend(Collection.prototype, Events, {
model: Model,
initialize: function() {},
toJSON: function(options) {
return this.map(function(model) {
return model.toJSON(options);
});
},
sync: function() {
return Backbone.sync.apply(this, arguments);
},
// 添加一个模型实例
add: function(models, options) {
return this.set(models, _.extend({
// 不合并
merge: false
}, options, addOptions));
},
// 删除一个modal，触发remove事件
remove: function(models, options) {
var singular = !_.isArray(models);
models = singular ? [models] : _.clone(models);
options || (options = {});
var i, l, index, model;
for (i = 0, l = models.length; i < l; i++) {
model = models[i] = 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 singular ? models[0] : models;
},
// 重新设置集合的模型列表
set: function(models, options) {
options = _.defaults({}, options, setOptions);
if (options.parse) models = this.parse(models, options);
var singular = !_.isArray(models);
models = singular ? (models ? [models] : []) : _.clone(models);
var i, l, id, model, attrs, existing, sort;
var at = options.at;
var targetModel = this.model;
var sortable = this.comparator && (at == null) && options.sort !== false;
var sortAttr = _.isString(this.comparator) ? this.comparator : null;
var toAdd = [],
toRemove = [],
modelMap = {};
var add = options.add,
merge = options.merge,
remove = options.remove;
var order = !sortable && add && remove ? [] : false;
// Turn bare objects into model references, and prevent invalid models
// from being added.
for (i = 0, l = models.length; i < l; i++) {
attrs = models[i];
if (attrs instanceof Model) {
id = model = attrs;
} else {
id = attrs[targetModel.prototype.idAttribute];
}
// If a duplicate is found, prevent it from being added and
// optionally merge it into the existing model.
if (existing = this.get(id)) {
if (remove) modelMap[existing.cid] = true;
if (merge) {
attrs = attrs === model ? model.attributes : attrs;
if (options.parse) attrs = existing.parse(attrs, options);
existing.set(attrs, options);
if (sortable && !sort && existing.hasChanged(sortAttr)) sort = true;
}
models[i] = existing;
// If this is a new, valid model, push it to the `toAdd` list.
} else if (add) {
model = models[i] = this._prepareModel(attrs, options);
if (!model) continue;
toAdd.push(model);
// 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;
}
if (order) order.push(existing || model);
}
// Remove nonexistent models if appropriate.
if (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 || (order && order.length)) {
if (sortable) sort = true;
this.length += toAdd.length;
if (at != null) {
for (i = 0, l = toAdd.length; i < l; i++) {
this.models.splice(at + i, 0, toAdd[i]);
}
} else {
if (order) this.models.length = 0;
var orderedModels = order || toAdd;
for (i = 0, l = orderedModels.length; i < l; i++) {
this.models.push(orderedModels[i]);
}
}
}
// Silently sort the collection if appropriate.
if (sort) this.sort({
silent: true
});
// Unless silenced, it's time to fire all appropriate add/sort events.
if (!options.silent) {
for (i = 0, l = toAdd.length; i < l; i++) {
(model = toAdd[i]).trigger('add', model, this, options);
}
if (sort || (order && order.length)) this.trigger('sort', this, options);
}
// Return the added (or merged) model (or models).
return singular ? models[0] : models;
},
// When you have more items than you want to add or remove individually,
// you can reset the entire set with a new list of models, without firing
// any granular `add` or `remove` events. Fires `reset` when finished.
// Useful for bulk operations and optimizations.
reset: function(models, options) {
options || (options = {});
for (var i = 0, l = this.models.length; i < l; i++) {
this._removeReference(this.models[i]);
}
options.previousModels = this.models;
this._reset();
models = this.add(models, _.extend({
silent: true
}, options));
if (!options.silent) this.trigger('reset', this, options);
return models;
},
// Add a model to the end of the collection.
push: function(model, options) {
return this.add(model, _.extend({
at: this.length
}, options));
},
// Remove a model from the end of the collection.
pop: function(options) {
var model = this.at(this.length - 1);
this.remove(model, options);
return model;
},
// Add a model to the beginning of the collection.
unshift: function(model, options) {
return this.add(model, _.extend({
at: 0
}, options));
},
// Remove a model from the beginning of the collection.
shift: function(options) {
var model = this.at(0);
this.remove(model, options);
return model;
},
// Slice out a sub-array of models from the collection.
slice: function() {
return slice.apply(this.models, arguments);
},
// Get a model from the set by id.
get: function(obj) {
if (obj == null) return void 0;
return this._byId[obj.id] || this._byId[obj.cid] || this._byId[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;
},
// Pluck an attribute from each model in the collection.
pluck: function(attr) {
return _.invoke(this.models, 'get', attr);
},
// Fetch the default set of models for this collection, resetting the
// collection when they arrive. If `reset: true` is passed, the response
// data will be passed through the `reset` method instead of `set`.
fetch: function(options) {
options = options ? _.clone(options) : {};
if (options.parse === void 0) options.parse = true;
var success = options.success;
var collection = this;
options.success = function(resp) {
var method = options.reset ? 'reset' : 'set';
collection[method](resp, options);
if (success) success(collection, resp, options);
collection.trigger('sync', collection, resp, options);
};
wrapError(this, options);
return this.sync('read', this, options);
},
// Create a new instance of a model in this collection. Add the model to the
// collection immediately, unless `wait: true` is passed, in which case we
// wait for the server to agree.
create: function(model, options) {
options = options ? _.clone(options) : {};
if (!(model = this._prepareModel(model, options))) return false;
if (!options.wait) this.add(model, options);
var collection = this;
var success = options.success;
options.success = function(model, resp, options) {
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 ? _.clone(options) : {};
options.collection = this;
var model = new this.model(attrs, options);
if (!model.validationError) return model;
this.trigger('invalid', this, model.validationError, options);
return false;
},
// 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', 'difference', '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视图类
// 使用非常方便，可以与任意的模版引擎兼容，它不会影响html和css代码
// 基本原理： 将界面组织到逻辑视图，把视图关联到一个模型，当模型数据改变的时候更新视图
var View = Backbone.View = function(options) {
this.cid = _.uniqueId('view');
options || (options = {});
_.extend(this, _.pick(options, viewOptions));
this._ensureElement();
this.initialize.apply(this, arguments);
this.delegateEvents();
};
// Cached regex to split keys for `delegate`.
var delegateEventSplitter = /^(\S+)\s*(.*)$/;
// view中的关键属性
var viewOptions = ['model', 'collection', 'el', 'id', 'attributes', 'className', 'tagName', 'events'];
_.extend(View.prototype, Events, {
// 视图的tagName在没有设置el的时候默认会用div作为tagName
tagName: 'div',
// jQuery delegate for element lookup, scoped to DOM elements within the
// current view. This should be preferred to global lookups where possible.
// 查找元素
$: function(selector) {
return this.$el.find(selector);
},
initialize: function() {},
// 每个视图类应该实现自己的render方法
render: function() {
return this;
},
// 移除元素，并停止监听
remove: function() {
this.$el.remove();
this.stopListening();
return this;
},
// Change the view's element (`this.el` property), including event
// re-delegation.
// 设置元素，并重新设置事件代理
setElement: function(element, delegate) {
// 先删除事件代理
if (this.$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.
// 设置视图的事件代理
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;
},
// 解除所有事件代理
undelegateEvents: function() {
this.$el.off('.delegateEvents' + this.cid);
return this;
},
// Ensure that the View has a DOM element to render into.
// If `this.el` is a string, pass it through `$()`, take the first
// matching element, and re-assign it to `el`. Otherwise, create
// an element from the `id`, `className` and `tagName` properties.
// 确保视图类有一个DOM元素可以render
// 优先考虑用el属性创建
_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' && noXhrPatch) {
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;
};
var noXhrPatch = typeof window !== 'undefined' && !! window.ActiveXObject && !(window.XMLHttpRequest && (new XMLHttpRequest).dispatchEvent);
// Map from CRUD to HTTP for our default `Backbone.sync` implementation.
var methodMap = {
'create': 'POST',
'update': 'PUT',
'patch': 'PATCH',
'delete': 'DELETE',
'read': 'GET'
};
// ajax方法，采用jQuery/Zepto的ajax方法
Backbone.ajax = function() {
return Backbone.$.ajax.apply(Backbone.$, arguments);
};
// Backbone.Router
// Router
// 采用键值对的方式，将hash映射到相应的处理函数上
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 = /[\-{}\[\]+?.,\\\^$|#\s]/g;
_.extend(Router.prototype, Events, {
initialize: function() {},
// Manually bind a single named route to a callback. For example:
// this.route('search/:query/p:num', 'search', function(query, num) {
// });
route: function(route, name, callback) {
if (!_.isRegExp(route)) route = this._routeToRegExp(route);
if (_.isFunction(name)) {
callback = name;
name = '';
}
if (!callback) callback = this[name];
var router = this;
Backbone.history.route(route, function(fragment) {
var args = router._extractParameters(route, fragment);
callback && callback.apply(router, args);
router.trigger.apply(router, ['route:' + name].concat(args));
router.trigger('route', name, args);
Backbone.history.trigger('route', router, name, args);
});
return this;
},
// Simple proxy to `Backbone.history` to save a fragment into the history.
navigate: function(fragment, options) {
Backbone.history.navigate(fragment, options);
return this;
},
// Bind all defined routes to `Backbone.history`. We have to reverse the
// order of the routes here to support behavior where the most general
// routes can be defined at the bottom of the route map.
_bindRoutes: function() {
if (!this.routes) return;
this.routes = _.result(this, 'routes');
var route, routes = _.keys(this.routes);
while ((route = routes.pop()) != null) {
this.route(route, this.routes[route]);
}
},
// Convert a route string into a regular expression, suitable for matching
// against the current location hash.
_routeToRegExp: function(route) {
route = route.replace(escapeRegExp, '\\$&')
.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.
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 = /\/$/;
// Cached regex for stripping urls of hash and query.
var pathStripper = /[?#].*$/;
// Has the history handling already been started?
History.started = false;
// Set up all inheritable **Backbone.History** properties and methods.
_.extend(History.prototype, Events, {
// 检查hash变化的interval time
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hash值
getHash: function(window) {
var match = (window || this).location.href.match(/#(.*)$/);
return match ? match[1] : '';
},
// Get the cross-browser normalized URL fragment, either from the URL,
// the hash, or the override.
getFragment: function(fragment, forcePushState) {
if (fragment == null) {
if (this._hasPushState || !this._wantsHashChange || forcePushState) {
fragment = this.location.pathname;
var root = this.root.replace(trailingSlash, '');
if (!fragment.indexOf(root)) fragment = fragment.slice(root.length);
} else {
fragment = this.getHash();
}
}
return fragment.replace(routeStripper, '');
},
// Start the hash change handling, returning `true` if the current URL matches
// an existing route, and `false` otherwise.
start: function(options) {
if (History.started) throw new Error("Backbone.history has already been started");
History.started = true;
// Figure out the initial configuration. Do we need an iframe?
// Is pushState desired ... is it available?
this.options = _.extend({
root: '/'
}, this.options, options);
this.root = this.options.root;
this._wantsHashChange = this.options.hashChange !== false;
this._wantsPushState = !! this.options.pushState;
this._hasPushState = !! (this.options.pushState && this.history && this.history.pushState);
var fragment = this.getFragment();
var docMode = document.documentMode;
var oldIE = (isExplorer.exec(navigator.userAgent.toLowerCase()) && (!docMode || docMode <= 7));
// Normalize root to always include a leading and trailing slash.
this.root = ('/' + this.root + '/').replace(rootStripper, '/');
if (oldIE && this._wantsHashChange) {
this.iframe = Backbone.$('<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;
// Transition from hashChange to pushState or vice versa if both are
// requested.
if (this._wantsHashChange && this._wantsPushState) {
// 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._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._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();
},
// 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(fragment) {
fragment = this.fragment = this.getFragment(fragment);
return _.any(this.handlers, function(handler) {
if (handler.route.test(fragment)) {
handler.callback(fragment);
return true;
}
});
},
// 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
};
var url = this.root + (fragment = this.getFragment(fragment || ''));
// Strip the fragment of the query and hash for matching.
fragment = fragment.replace(pathStripper, '');
if (this.fragment === fragment) return;
this.fragment = fragment;
// Don't include a trailing slash on the root.
if (fragment === '' && url !== '/') url = url.slice(0, -1);
// 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) return 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);
本文详细解读 Backbone.js 框架的核心组件，包括 Model、Collection、View 和 Router 的工作原理及实现细节，揭示其如何通过事件驱动模型、视图和路由之间的交互，构建高效响应式的 Web 应用。
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