jquery ui widget 源码分析

jquery ui 的所有组件都是基于一个简单，可重用的widget。

这个widget是jquery ui的核心部分，实用它能实现一致的API，创建有状态的插件，而无需关心插件的内部转换。

$.widget( name, base, prototype )

widget一共有2或3个参数。base为可选。

这里之所以把base放在第二个参数里，主要是因为这样写代码更直观一些。（因为后面的prototype 是个代码非常长的大对象）。

name：第一个参数是一个包含一个命名空间和组件名称的字符串，通过”.”来分割。
命名空间必须有，它指向widget prototype存储的全局jQuery对象。
如果命名空间没有，widget factory将会为你生成。widget name是插件函数和原型的真实名称，
比如： jQuery.widget( “demo.multi”, {…} ) 将会生成 jQuery.demo , jQuery.demo.multi , and jQuery.demo.multi.prototype .

base：第二个参数（可选）是 widget prototype继承于什么对象。
例如jQuery UI有一个“mouse”的插件，它可以作为其他的插件提供的基础。
为了实现这个所有的基于mouse的插件比如draggable,
droppable可以这么做： jQuery.widget( "ui.draggable", $.ui.mouse, {...} );
如果没有这个参数，widget默认继承自“base widget” jQuery.Widget（注意jQuery.widget 和 jQuery.Widget不同） 。

prototype：最后一个参数是一个对象文字，它会转化为所有widget实例的prototype。widget factory会生成属性链，连接到她继承的widget的prototype。一直到最基本的 jQuery.Widget。

一旦你调用jQuery.widget，它会在jQuery prototype ( jQuery.fn )上生成一个新的可用方法对应于widget的名字，比如我们这个例子jQuery.fn.multi。 .fn方法是包含Dom元素的jquery对象和你生成的 widget prototyp实例的接口，为每一个jQuery对象生成一个新的widget的实例。

/*! * jQuery UI Widget @VERSION * http://jqueryui.com * * Copyright 2014 jQuery Foundation and other contributors * Released under the MIT license. * http://jquery.org/license * * http://api.jqueryui.com/jQuery.widget/ *///这里判定是否支持amd or cmd 模式(function(factory) {if (typeof define === "function" && define.amd) {// AMD. Register as an anonymous module.define(["jquery"], factory);} else {// Browser globalsfactory(jQuery);}}(function($) {var widget_uuid = 0,//插件的实例化数量widget_slice = Array.prototype.slice; //数组的slice方法，这里的作用是将参赛arguments 转为真正的数组//清除插件的数据及缓存$.cleanData = (function(orig) {return function(elems) {for (var i = 0, elem;(elem = elems[i]) != null; i++) {try {// 重写cleanData方法，调用后触发每个元素的remove事件$(elem).triggerHandler("remove");// http://bugs.jquery.com/ticket/8235} catch (e) {}}orig(elems);};})($.cleanData);/** * widget工厂方法，用于创建插件 * @param name 包含命名空间的插件名称，格式 xx.xxx * @param base 需要继承的ui组件 * @param prototype 插件的实际代码 * @returns {Function} */$.widget = function(name, base, prototype) {var fullName, //插件全称existingConstructor, //原有的构造函数constructor, //当前构造函数basePrototype, //父类的Prototype// proxiedPrototype allows the provided prototype to remain unmodified// so that it can be used as a mixin for multiple widgets (#8876)proxiedPrototype = {},//可调用父类方法_spuer的prototype对象,扩展于prototypenamespace = name.split(".")[0];name = name.split(".")[1];fullName = namespace + "-" + name;//如果只有2个参数  base默认为Widget类，组件默认会继承base类的所有方法if (!prototype) {prototype = base;base = $.Widget;}//    console.log(base, $.Widget)// create selector for plugin//创建一个自定义的伪类选择器//如 $(':ui-menu') 则表示选择定义了ui-menu插件的元素$.expr[":"][fullName.toLowerCase()] = function(elem) {return !!$.data(elem, fullName);};// 判定命名空间对象是否存在，没有的话 则创建一个空对象$[namespace] = $[namespace] || {};//这里存一份旧版的插件，如果这个插件已经被使用或者定义了existingConstructor = $[namespace][name];//这个是插件实例化的主要部分//constructor存储了插件的实例，同时也创建了基于命名空间的对象//如$.ui.menuconstructor = $[namespace][name] = function(options, element) {// allow instantiation without "new" keyword//允许直接调用命名空间上的方法来创建组件//比如：$.ui.menu({},'#id') 这种方式创建的话，默认没有new 实例化。因为_createWidget是prototype上的方法，需要new关键字来实例化//通过 调用 $.ui.menu 来实例化插件if (!this._createWidget) {console.info(this)return new constructor(options, element);}// allow instantiation without initializing for simple inheritance// must use "new" keyword (the code above always passes args)//如果存在参数，则说明是正常调用插件//_createWidget是创建插件的核心方法if (arguments.length) {this._createWidget(options, element);}};// extend with the existing constructor to carry over any static properties//合并对象，将旧插件实例，及版本号、prototype合并到constructor$.extend(constructor, existingConstructor, {version: prototype.version,// copy the object used to create the prototype in case we need to// redefine the widget later//创建一个新的插件对象//将插件实例暴露给外部，可用户修改及覆盖_proto: $.extend({}, prototype),// track widgets that inherit from this widget in case this widget is// redefined after a widget inherits from it_childConstructors: []});//实例化父类 获取父类的  prototypebasePrototype = new base();// we need to make the options hash a property directly on the new instance// otherwise we'll modify the options hash on the prototype that we're// inheriting from//这里深复制一份optionsbasePrototype.options = $.widget.extend({}, basePrototype.options);//在传入的ui原型中有方法调用this._super 和this.__superApply会调用到base上（最基类上）的方法$.each(prototype, function(prop, value) {//如果val不是function 则直接给对象赋值字符串if (!$.isFunction(value)) {proxiedPrototype[prop] = value;return;}//如果val是functionproxiedPrototype[prop] = (function() {//两种调用父类函数的方法var _super = function() {//将当期实例调用父类的方法return base.prototype[prop].apply(this, arguments);},_superApply = function(args) {return base.prototype[prop].apply(this, args);};return function() {var __super = this._super,__superApply = this._superApply,returnValue;//                console.log(prop, value,this,this._super,'===')//                debugger;//在这里调用父类的函数this._super = _super;this._superApply = _superApply;returnValue = value.apply(this, arguments);this._super = __super;this._superApply = __superApply;//                console.log(this,value,returnValue,prop,'===')return returnValue;};})();});//    console.info(proxiedPrototype)//    debugger;//这里是实例化获取的内容constructor.prototype = $.widget.extend(basePrototype, {// TODO: remove support for widgetEventPrefix// always use the name + a colon as the prefix, e.g., draggable:start// don't prefix for widgets that aren't DOM-basedwidgetEventPrefix: existingConstructor ? (basePrototype.widgetEventPrefix || name) : name}, proxiedPrototype, {//重新把constructor指向 constructor 变量constructor: constructor,namespace: namespace,widgetName: name,widgetFullName: fullName});// If this widget is being redefined then we need to find all widgets that// are inheriting from it and redefine all of them so that they inherit from// the new version of this widget. We're essentially trying to replace one// level in the prototype chain.//这里判定插件是否被使用了。一般来说，都不会被使用的。//因为插件的开发者都是我们自己，呵呵if (existingConstructor) {$.each(existingConstructor._childConstructors, function(i, child) {var childPrototype = child.prototype;// redefine the child widget using the same prototype that was// originally used, but inherit from the new version of the base$.widget(childPrototype.namespace + "." + childPrototype.widgetName, constructor, child._proto);});// remove the list of existing child constructors from the old constructor// so the old child constructors can be garbage collecteddelete existingConstructor._childConstructors;} else {//父类添加当前插件的实例 主要用于作用域链查找 不至于断层base._childConstructors.push(constructor);}//将此方法挂在jQuery对象上$.widget.bridge(name, constructor);return constructor;};//扩展jq的extend方法，实际上类似$.extend(true,..) 深复制$.widget.extend = function(target) {var input = widget_slice.call(arguments, 1),inputIndex = 0,inputLength = input.length,key, value;for (; inputIndex < inputLength; inputIndex++) {for (key in input[inputIndex]) {value = input[inputIndex][key];if (input[inputIndex].hasOwnProperty(key) && value !== undefined) {// Clone objectsif ($.isPlainObject(value)) {target[key] = $.isPlainObject(target[key]) ? $.widget.extend({}, target[key], value) :// Don't extend strings, arrays, etc. with objects$.widget.extend({}, value);// Copy everything else by reference} else {target[key] = value;}}}}return target;};//bridge 是设计模式的一种，这里将对象转为插件调用$.widget.bridge = function(name, object) {var fullName = object.prototype.widgetFullName || name;//这里就是插件了//这部分的实现主要做了几个工作，也是制作一个优雅的插件的主要代码//1、初次实例化时将插件对象缓存在dom上，后续则可直接调用，避免在相同元素下widget的多实例化。简单的说，就是一个单例方法。//2、合并用户提供的默认设置选项options//3、可以通过调用插件时传递字符串来调用插件内的方法。如:$('#id').menu('hide') 实际就是实例插件并调用hide()方法。//4、同时限制外部调用“_”下划线的私有方法$.fn[name] = function(options) {var isMethodCall = typeof options === "string",args = widget_slice.call(arguments, 1),returnValue = this;// allow multiple hashes to be passed on init.//可以简单认为是$.extend(true,options,args[0],...),args可以是一个参数或是数组options = !isMethodCall && args.length ? $.widget.extend.apply(null, [options].concat(args)) : options;//这里对字符串和对象分别作处理if (isMethodCall) {this.each(function() {var methodValue, instance = $.data(this, fullName);//如果传递的是instance则将this返回。if (options === "instance") {returnValue = instance;return false;}if (!instance) {return $.error("cannot call methods on " + name + " prior to initialization; " + "attempted to call method '" + options + "'");}//这里对私有方法的调用做了限制，直接调用会抛出异常事件if (!$.isFunction(instance[options]) || options.charAt(0) === "_") {return $.error("no such method '" + options + "' for " + name + " widget instance");}//这里是如果传递的是字符串，则调用字符串方法，并传递对应的参数.//比如插件有个方法hide(a,b); 有2个参数：a，b//则调用时$('#id').menu('hide',1,2);//1和2 分别就是参数a和b了。methodValue = instance[options].apply(instance, args);if (methodValue !== instance && methodValue !== undefined) {returnValue = methodValue && methodValue.jquery ? returnValue.pushStack(methodValue.get()) : methodValue;return false;}});} else {this.each(function() {var instance = $.data(this, fullName);if (instance) {instance.option(options || {});//这里每次都调用init方法if (instance._init) {instance._init();}} else {//缓存插件实例$.data(this, fullName, new object(options, this));}});}return returnValue;};};//这里是真正的widget基类$.Widget = function( /* options, element */ ) {};$.Widget._childConstructors = [];$.Widget.prototype = {widgetName: "widget",//用来决定事件的名称和插件提供的callbacks的关联。// 比如dialog有一个close的callback，当close的callback被执行的时候，一个dialogclose的事件被触发。// 事件的名称和事件的prefix+callback的名称。widgetEventPrefix 默认就是控件的名称，但是如果事件需要不同的名称也可以被重写。// 比如一个用户开始拖拽一个元素,我们不想使用draggablestart作为事件的名称，我们想使用dragstart，所以我们可以重写事件的prefix。// 如果callback的名称和事件的prefix相同，事件的名称将不会是prefix。// 它阻止像dragdrag一样的事件名称。widgetEventPrefix: "",defaultElement: "<div>",//属性会在创建模块时被覆盖options: {disabled: false,// callbackscreate: null},_createWidget: function(options, element) {element = $(element || this.defaultElement || this)[0];this.element = $(element);this.uuid = widget_uuid++;this.eventNamespace = "." + this.widgetName + this.uuid;this.options = $.widget.extend({}, this.options, this._getCreateOptions(), options);this.bindings = $();this.hoverable = $();this.focusable = $();if (element !== this) {//            debugger$.data(element, this.widgetFullName, this);this._on(true, this.element, {remove: function(event) {if (event.target === element) {this.destroy();}}});this.document = $(element.style ?// element within the documentelement.ownerDocument :// element is window or documentelement.document || element);this.window = $(this.document[0].defaultView || this.document[0].parentWindow);}this._create();//创建插件时，有个create的回调this._trigger("create", null, this._getCreateEventData());this._init();},_getCreateOptions: $.noop,_getCreateEventData: $.noop,_create: $.noop,_init: $.noop,//销毁模块：去除绑定事件、去除数据、去除样式、属性destroy: function() {this._destroy();// we can probably remove the unbind calls in 2.0// all event bindings should go through this._on()this.element.unbind(this.eventNamespace).removeData(this.widgetFullName)// support: jquery <1.6.3// http://bugs.jquery.com/ticket/9413.removeData($.camelCase(this.widgetFullName));this.widget().unbind(this.eventNamespace).removeAttr("aria-disabled").removeClass(this.widgetFullName + "-disabled " + "ui-state-disabled");// clean up events and statesthis.bindings.unbind(this.eventNamespace);this.hoverable.removeClass("ui-state-hover");this.focusable.removeClass("ui-state-focus");},_destroy: $.noop,widget: function() {return this.element;},//设置选项函数option: function(key, value) {var options = key,parts, curOption, i;if (arguments.length === 0) {// don't return a reference to the internal hash//返回一个新的对象，不是内部数据的引用return $.widget.extend({}, this.options);}if (typeof key === "string") {// handle nested keys, e.g., "foo.bar" => { foo: { bar: ___ } }options = {};parts = key.split(".");key = parts.shift();if (parts.length) {curOption = options[key] = $.widget.extend({}, this.options[key]);for (i = 0; i < parts.length - 1; i++) {curOption[parts[i]] = curOption[parts[i]] || {};curOption = curOption[parts[i]];}key = parts.pop();if (arguments.length === 1) {return curOption[key] === undefined ? null : curOption[key];}curOption[key] = value;} else {if (arguments.length === 1) {return this.options[key] === undefined ? null : this.options[key];}options[key] = value;}}this._setOptions(options);return this;},_setOptions: function(options) {var key;for (key in options) {this._setOption(key, options[key]);}return this;},_setOption: function(key, value) {this.options[key] = value;if (key === "disabled") {this.widget().toggleClass(this.widgetFullName + "-disabled", !! value);// If the widget is becoming disabled, then nothing is interactiveif (value) {this.hoverable.removeClass("ui-state-hover");this.focusable.removeClass("ui-state-focus");}}return this;},enable: function() {return this._setOptions({disabled: false});},disable: function() {return this._setOptions({disabled: true});},_on: function(suppressDisabledCheck, element, handlers) {var delegateElement, instance = this;// no suppressDisabledCheck flag, shuffle argumentsif (typeof suppressDisabledCheck !== "boolean") {handlers = element;element = suppressDisabledCheck;suppressDisabledCheck = false;}// no element argument, shuffle and use this.elementif (!handlers) {handlers = element;element = this.element;delegateElement = this.widget();} else {// accept selectors, DOM elementselement = delegateElement = $(element);this.bindings = this.bindings.add(element);}$.each(handlers, function(event, handler) {function handlerProxy() {// allow widgets to customize the disabled handling// - disabled as an array instead of boolean// - disabled class as method for disabling individual partsif (!suppressDisabledCheck && (instance.options.disabled === true || $(this).hasClass("ui-state-disabled"))) {return;}return (typeof handler === "string" ? instance[handler] : handler).apply(instance, arguments);}// copy the guid so direct unbinding worksif (typeof handler !== "string") {handlerProxy.guid = handler.guid = handler.guid || handlerProxy.guid || $.guid++;}var match = event.match(/^([\w:-]*)\s*(.*)$/),eventName = match[1] + instance.eventNamespace,selector = match[2];if (selector) {delegateElement.delegate(selector, eventName, handlerProxy);} else {element.bind(eventName, handlerProxy);}});},_off: function(element, eventName) {eventName = (eventName || "").split(" ").join(this.eventNamespace + " ") + this.eventNamespace;element.unbind(eventName).undelegate(eventName);},_delay: function(handler, delay) {function handlerProxy() {return (typeof handler === "string" ? instance[handler] : handler).apply(instance, arguments);}var instance = this;return setTimeout(handlerProxy, delay || 0);},_hoverable: function(element) {this.hoverable = this.hoverable.add(element);this._on(element, {mouseenter: function(event) {$(event.currentTarget).addClass("ui-state-hover");},mouseleave: function(event) {$(event.currentTarget).removeClass("ui-state-hover");}});},_focusable: function(element) {this.focusable = this.focusable.add(element);this._on(element, {focusin: function(event) {$(event.currentTarget).addClass("ui-state-focus");},focusout: function(event) {$(event.currentTarget).removeClass("ui-state-focus");}});},_trigger: function(type, event, data) {var prop, orig, callback = this.options[type];data = data || {};event = $.Event(event);event.type = (type === this.widgetEventPrefix ? type : this.widgetEventPrefix + type).toLowerCase();// the original event may come from any element// so we need to reset the target on the new eventevent.target = this.element[0];// copy original event properties over to the new eventorig = event.originalEvent;if (orig) {for (prop in orig) {if (!(prop in event)) {event[prop] = orig[prop];}}}this.element.trigger(event, data);return !($.isFunction(callback) && callback.apply(this.element[0], [event].concat(data)) === false || event.isDefaultPrevented());}};$.each({show: "fadeIn",hide: "fadeOut"}, function(method, defaultEffect) {$.Widget.prototype["_" + method] = function(element, options, callback) {if (typeof options === "string") {options = {effect: options};}var hasOptions, effectName = !options ? method : options === true || typeof options === "number" ? defaultEffect : options.effect || defaultEffect;options = options || {};if (typeof options === "number") {options = {duration: options};}hasOptions = !$.isEmptyObject(options);options.complete = callback;if (options.delay) {element.delay(options.delay);}if (hasOptions && $.effects && $.effects.effect[effectName]) {element[method](options);} else if (effectName !== method && element[effectName]) {element[effectName](options.duration, options.easing, callback);} else {element.queue(function(next) {$(this)[method]();if (callback) {callback.call(element[0]);}next();});}};});return $.widget;}));