JS原生實現觀察者模式

參考文章一

參考文章二

function Observer(){
	this.handles = {};
}

Observer.prototype = {
	subscribe:function(type,handle){
		if(!this.handles[type]){
			this.handles[type] = [];
		}
		this.handles[type].push(handle);
	},
	unsubscribe:function(type,handle){
		var listener = this.handles[type];
		if(listener){
			if(!handle){
				listener.length = 0;
			}else{
				for(var i = 0;i < listener.length;i++){
					if(listener[i] === handle){
						listener.splice(i,1);
					}
				}
			}
		}
	},
	publish:function(type,event){
		if(!this.handles[type]){
			return false;
		}
		for(var i = 0;i < this.handles[type].length;i++){
			var handle = this.handles[type][i];
			handle(event);
		}
	}
}

var p = new Observer();
var fn = function(name){
	console.log('mm:'+name);
}
p.subscribe('mm',fn);
p.publish('mm','123321'); //"mm:123321"
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