设计模式-mediator-复杂实现

mediator.js

//Mediator 
(function(root){
	//生成特定callback ID, 利于检索
	function guidGenerator() {}
	//订阅者 
	function Subscriber(fn, options, context) {
		if(!this instanceof Subscriber){
			return new Subscriber(fn, options, context);
		}else{
			this.id = guidGenerator();
			this.fn = fn;
			this.options = options;
			this.context = context;
			this.topic = null;
		}
	}
	//Topic 包含子topic
	function Topic (namespace) {
		if(!this instanceof Topic){
			return new Topic(namespace);
		}else {
			this.namespace = namespace;
			//Topic的回调函数数组, [Subscriber]
			this._callbacks = [];
			//子topic 列表
			this._topics = {};
			//在递归查询时阻止重复递归
			this.stopped = false;
		}
	}

	Topic.prototype = {
		// 为Topic 添加Subscriber
		AddSubscriber : function (fn, options, context){
			var callback = new Subscriber(fn, options, context);
			this._callbacks.push(callback);
			callback.topic = this;
			return callback
		},
		StopPropagation:function() {
			this.stopped = true;
		},
		GetSubscriber:function(identifier) {
			//在本Topic的回调函数列表里寻找订阅者
			for(var x = 0,y=this._callbacks.length;x<y;x++){
				if(this._callbacks[x].id == identifier ||this._callbacks[x].fn == identifier){
					return this._callbacks[x];
				}
			}
			//Topic中没有该订阅者
			//在子topic中递归寻找订阅者
			for(var z in this._topics){
				if(this._topics.hasOwnProperty(z)){
					var sub = this._topics[z].GetSubscriber(identifier);
					if(sub!==undefined){
						return sub;
					}
				}
			}
		},
		//添加子topic
		AddTopic:function(topic) {
			this._topics[topic] = new Topic((this.namespace?this.namespace+":":"")+topic);
		},
		//检查是否有某个子topic
		HasTopic:function (topic){
			return this._topics[topic];
		},
		//返回某个子topic
		returnTopic:function(topic){
			return this._topics[topic];
		},
		//移除订阅者
		removeSubscriber:function(identifier){
			if(!identifier){
				//清空订阅者
				this._callbacks = [];
				//清空子topic的订阅者
				for(var z in this._topics) {
					if(this._topics.hasOwnProperty(z)){
						this._topics[z].removeSubscriber(identifier);
					}
				}
			}
			//删除Topic的identifer的Subscriber
			for (var y=0,x = this._callbacks.length;y<x;y++){
				if(this._callbacks[y].fn == identifier||this._callbacks[y].id ==identifier){
					this._callbacks[y].topic = null;
					this._callbacks.splice(y,1);
					x--;
					y--;
				}
			}
		},
		//发布事件,递归发布
		Publish:function (data){
			//发布给callbacks
			for(var y = 0,x = this._callbacks.length;y<x;y++){
				var callback = this._callbacks[y],l;
				callback.fn.apply(callback.context,data);
				l = this._callbacks.length;
			  if(l<x){
			  	y--;
			  	x=l;
			  }
			}
			//子topic 执行递归  发布数据
			for(var x in this._topics){
				if(!this.stopped){
					if(this._topics.hasOwnProperty(x)){
						this._topics[x].Publish(data)
					}
				}
			}
			this.stopped = false;
		}
	};
	//用于添加Topic, Subscriber
	function Mediator(){
		if(!this instanceof Mediator){
			return new Mediator();
		}else {
			this._topics = new Topic("");
		}
	}
	Mediator.prototype = {
		//允许inbox:messages:new:read命名空间
		GetTopic:function(namespace){
			//拆分命名空间
			var topic = this._topics,namespaceHierarchy = namespace.split(":");
			if(namespace===""){
				return topic;
			}
			//对namespace 递归查找 topic
			if(namespaceHierarchy.length>0){
				for(var i = 0,j = namespaceHierarchy.length;i<j;i++){
					if(!topic.HasTopic(namespaceHierarchy[i]) ){
						//没有topiac则添加
						topic.AddTopic(namespaceHierarchy[i]);
					}
					//进入下一级topic
					topic = topic.returnTopic(namespaceHierarchy[i]);
				}
			}
			//返回最深层topic
			return topic;
		},
		//订阅消息  
		Subscribe:function(topicName, fn, options, context){
			var options = options ||{},
			 	context = context ||{},
			 	topic = this.GetTopic(topicName),
			 	sub = topic.AddSubscriber(fn,options,context);
			return sub;
		},
		//
		GetSubscriber :function(identifier , topic) {
			return this.GetTopic(topic ||"").GetSubscriber(identifier);
		},
		//
		Remove:function(topicName, identifier){
			this.GetTopic(topicName).removeSubscriber(identifier);
		},
		//
		Publish:function(topicName){
			//获取参数列表 
			var args = Array.prototype.slice.callback(arguments,1),
				topic = this.GetTopic(topicName);

				args.push(topic);
				this.GetTopic(topicName).Publish(args);
		}
	};

	root.Mediator = Mediator;
	Mediator.Topic = Topic;
	Mediator.Subscriber = Subscriber;

})(window);