javascript之Publish/Subscribe模式

  发布/订阅，是一种由两个部分构成:发布者和订阅者的消息传递模式。发布者将消息发布到特定频道，而订阅者接听频道，当频道上有消息发布时将接收到通知。

1、用javascript实现Pub/Sub模式代码：

 1 var PubSub = {
 2            //订阅
 3            subscribe : function(ev,callback){
 4                 this._callback || (this._callback = {});
 5                 (this._callback[ev] || (this._callback[ev] = [])).push(callback);
 6                 return this;
 7             },
 8             //取消订阅
 9             unsubscribe : function(ev){
10                 if(!this._callback || !this._callback[ev]){
11                     return this;
12                 }
13                 this._callback[ev] = null;
14                 delete this._callback[ev];
15                 return this;
16             },
17              //发布
18             publish : function(){
19                 var callback, list, i, length, args = [].slice.call(arguments,0), ev = args.shift();
20                 if(!(callback = this._callback) || !(list = this._callback[ev])){
21                     return this;
22                 }
23                 for(i = 0, length = list.length; i < length; i++){
24                       list[i].apply(this, args);
25                 }
26                 return this;
27             }
28     };
29     PubSub.subscribe('wen',function(){alert('Wen!!!');}).publish('wen').unsubscribe('wen').publish('wen');
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posted on 2013-10-10 00:20  shiny_bender  阅读(737)  评论(0)  编辑  收藏  举报

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