设计模式之观察者模式

1、JSpubsub 3 varpubsub=; (function (q) var topics = , subUid = -q.publish = function (topic, args) if(!topicstopic) return false;setTimeout(function () var subscribers = len = subscribers ? subscribers.length : while (len-) subscriberslen.func(topic,args);, return 正文（版本一介pubsub.subscribe(example1,func

2、tionpubsub.subscribe(example1,function(topics,data) console.log(topics + : + data);pubsub.publish(example1, hello world!); pubsub.publish(example1,test,a,b,c);pubsub.publish(example1,color:blue,text:hello q.subscribe = function (topic, func) if (!topicstopic) topicstopic=;vartoken=(+subUid).toString

3、(); token:token, func: funcreturn q.unsubscribe=function(token) for (var m in topics) if (topicsm) for(vari=0,j=topicsm.length;ij;i+) if (topicsmi.token = token) topicsm.splice(i,1); return token;return functionObserver() this.fns = ;functionObserver() this.fns = ;Ototype = subscribe:function(fn)uns

4、ubscribe: function (fn) this.fns=this.fns.filter(function (el) if(el!=fn) return el;update: function (o, thisObj) varscope=thisObj|window; function (el) vartestSubscription=pubsub.subscribe(example1,function(topics, data) console.log(topics + : + pubsub.publish(example1, hello world!); pubsub.publis

5、h(example1,test,a,b,c);pubsub.publish(example1,color:blue,text:hello setTimeout(function, pubsub.publish(example1,helloagain!(thiswillfail);版本filterforEachfilterforEachif (!Atotype.forEach) Atotype.forEach=function(fn,thisObj)var scope = thisObj | for(vari=0,j=this.length;ij;+i) fn.call(scope, thisi

6、, i, this);if (!Atotype.filter) Atotype.filter=function(fn,thisObj) var scope = thisObj | window;var a = for(vari=0,j=this.length;ij;+i) if (!fn.call(scope, thisi, i, this) el.call(scope, var o = new var f1 = function (data) console.log(Robbin: + datavar f2 = function (data) console.log(Randall: + d

7、atao.update(Tomf1 o.update(Tom2blogger user2blogger userobserver.make 2 var observer = addSubscriber: function (callback) this.subscribersthis.subscribers.length=callback;removeSubscriber: function (callback) for(vari=0;ithis.subscribers.length;i+) if (this.subscribersi = callback) delete publish: f

8、unction (what) for (var i = 0; i this.subscribers.length; i+) if (typeof this.subscribersi = function) omake: function (o) for (var i in this) oi = thisi; o.subscribers=;return 版本使用方法就比较简单了，订阅不同的回调函数，以便可以注册到不同的观察者对象里（可以同时注册到多个观察者对象里var tom = read: 使用方法就比较简单了，订阅不同的回调函数，以便可以注册到不同的观察者对象里（可以同时注册到多个观察者对象

9、里var tom = read: function (what) console.log(Tomvar mm = show: function (what) console.log(mm/ 订阅 blogger.recommend(123);/调用发布blogger.recommend(456); user.vote(789); /调用发布jQuery版var blogger = recommend: function (id) varmsgduduid; var user = vote: function (id) varmsg!ID=id; jQuery1.7on/off jQuery j

10、Query1.7on/off jQuery 3 function handle(e, a, b, c) e是事件对象，不需要关注 console.log(a + b + c);$.subscribe(/some/topic, $.publish(/some/topic, a, b, c); $.unsubscribe(/some/topic, handle); $.subscribe(/some/topic,function(e,a,b,c) console.log(a + b + c);$.publish(/some/topic, a, b, c); (function ($) var o = $.subscribe = function () o.on.apply(o,arguments);$.unsubscribe = function () o.off.apply(o, $.publish = function () o