javaScript设计模式（一）观察者模式

哈哈。。写了一个钟，一点一点加功能。
 1 function Publisher(){
     this.subscribers = []; //存储订阅者
     this.news = [];  //存储要发布的消息
 }
 //使用“推”方式：由publisher推消息给Subscribers

 Publisher.prototype = {
     deliver : function(data){
         var that = this;
         this.subscribers.forEach(function(){
             that.news.forEach(function(fnElement){
                 fnElement(data);
             });
         });
         return this;
     },
     addNew : function(fn){
         this.news.push(fn);
         return this;
     }

 };
 function Subscriber(){
 //使用"推",订阅者没必要保存发布者。只要发布者保存订阅者就可以了
 //    this.publishers = [];
 }
 Subscriber.prototype = {
     subscribe : function(publisher){
         publisher.subscribers.push(this);
 //        this.publishers.push(publisher);
         return this;
     },
     unsubscribe : function(publisher){
         var that = this;
         publisher.subscribers = publisher.subscribers.filter(function(element){
             return element !== that;
         });

 /*        this.publishers = this.publishers.filter(function(element){
             return element !== publisher;
         });
 */
         return this;
     }
 };

 //example
 var f1 = function (data) {
     console.log(data + ', 赶紧干活了！');
 };

 var f2 = function (data) {
     console.log(data + ',不然没饭吃！');
 };

 var publ = new Publisher();
 publ.addNew(f1).addNew(f2);

 var subc01 = new Subscriber();
 subc01.subscribe(publ);

 var subc02 = new Subscriber();
 subc02.subscribe(publ);

 subc02.unsubscribe(publ);

 publ.deliver('你们');