jQuery1.4源码学习五

jQuery提供了data存取和队列，queue依赖于data，实际开发中用得比较少，简单扫两眼。

 

// 自定义属性var expando = "jQuery" + now(), uuid = 0, windowData = {};var emptyObject = {};jQuery.extend({cache: {},expando:expando,// The following elements throw uncatchable exceptions if you// attempt to add expando properties to them.// 不能添加data的元素noData: {"embed": true,"object": true,"applet": true}, //存取elem元素的数据 //data按uuid存在jQuery.cache里，uuid存在elem扩展属性expando上data: function( elem, name, data ) {if ( elem.nodeName && jQuery.noData[elem.nodeName.toLowerCase()] ) {return;}elem = elem == window ?//如果elem是window，expando存在windowData对象里windowData :elem;var id = elem[ expando ], cache = jQuery.cache, thisCache;// Handle the case where there's no name immediatelyif ( !name && !id ) {return null;}// Compute a unique ID for the elementif ( !id ) { id = ++uuid;}// Avoid generating a new cache unless none exists and we// want to manipulate it.if ( typeof name === "object" ) {elem[ expando ] = id;thisCache = cache[ id ] = jQuery.extend(true, {}, name);} else if ( cache[ id ] ) {thisCache = cache[ id ];} else if ( typeof data === "undefined" ) {thisCache = emptyObject;} else {thisCache = cache[ id ] = {};}// Prevent overriding the named cache with undefined valuesif ( data !== undefined ) {elem[ expando ] = id;thisCache[ name ] = data;}return typeof name === "string" ? thisCache[ name ] : thisCache;},removeData: function( elem, name ) {if ( elem.nodeName && jQuery.noData[elem.nodeName.toLowerCase()] ) {return;}elem = elem == window ?windowData :elem;var id = elem[ expando ], cache = jQuery.cache, thisCache = cache[ id ];// If we want to remove a specific section of the element's data// 删除指定name的dataif ( name ) {if ( thisCache ) {// Remove the section of cache datadelete thisCache[ name ];// If we've removed all the data, remove the element's cacheif ( jQuery.isEmptyObject(thisCache) ) {jQuery.removeData( elem );}}// Otherwise, we want to remove all of the element's data// 删除所有data} else {// Clean up the element expandotry {delete elem[ expando ];} catch( e ) {// IE has trouble directly removing the expando// but it's ok with using removeAttributeif ( elem.removeAttribute ) {elem.removeAttribute( expando );}}// Completely remove the data cachedelete cache[ id ];}}});jQuery.fn.extend({data: function( key, value ) {if ( typeof key === "undefined" && this.length ) {return jQuery.data( this[0] );} else if ( typeof key === "object" ) {return this.each(function() {jQuery.data( this, key );});}var parts = key.split(".");parts[1] = parts[1] ? "." + parts[1] : "";if ( value === undefined ) {var data = this.triggerHandler("getData" + parts[1] + "!", [parts[0]]);if ( data === undefined && this.length ) {data = jQuery.data( this[0], key );}return data === undefined && parts[1] ?this.data( parts[0] ) :data;} else {return this.trigger("setData" + parts[1] + "!", [parts[0], value]).each(function() {jQuery.data( this, key, value );});}},removeData: function( key ) {return this.each(function() {jQuery.removeData( this, key );});}});//队列，用jQuery.data()存数据jQuery.extend({//进列queue: function( elem, type, data ) {if ( !elem ) {return;}type = (type || "fx") + "queue";var q = jQuery.data( elem, type );// Speed up dequeue by getting out quickly if this is just a lookup// 没有data参数直接返回if ( !data ) {return q || [];}if ( !q || jQuery.isArray(data) ) {q = jQuery.data( elem, type, jQuery.makeArray(data) );} else {q.push( data );}return q;}, //出列dequeue: function( elem, type ) {type = type || "fx";var queue = jQuery.queue( elem, type ), fn = queue.shift();// If the fx queue is dequeued, always remove the progress sentinelif ( fn === "inprogress" ) {fn = queue.shift();}if ( fn ) {// Add a progress sentinel to prevent the fx queue from being// automatically dequeuedif ( type === "fx" ) {queue.unshift("inprogress");}fn.call(elem, function() {jQuery.dequeue(elem, type);});}}});jQuery.fn.extend({queue: function( type, data ) {//缺省type参数时，type默认为fxif ( typeof type !== "string" ) {data = type;type = "fx";}if ( data === undefined ) {return jQuery.queue( this[0], type );}return this.each(function( i, elem ) {var queue = jQuery.queue( this, type, data );if ( type === "fx" && queue[0] !== "inprogress" ) {jQuery.dequeue( this, type );}});},dequeue: function( type ) {return this.each(function() {jQuery.dequeue( this, type );});},// Based off of the plugin by Clint Helfers, with permission.// http://blindsignals.com/index.php/2009/07/jquery-delay/// Set a timer to delay execution of subsequent items in the queue// 延时执行队列后续的itemdelay: function( time, type ) {time = jQuery.fx ? jQuery.fx.speeds[time] || time : time;type = type || "fx";return this.queue( type, function() {var elem = this;setTimeout(function() {jQuery.dequeue( elem, type );}, time );});},clearQueue: function( type ) {return this.queue( type || "fx", [] );}});