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');