JavaScript之子类构建工具

(function(){
	var initializing = false;
	var superPattern = /xyz/.test(function(){ xyz; }) ? /\b_super\b/ : /.*/;
	
	Object.subClass = function(properties){//给Object添加一个subClass方法
		var _super = this.prototype;//初始化超类
		initailizing = true;
		var proto = new this();
		
		for(var name in properties){
			proto[name] = typeof properties[name] == "function" && typeof _super[name] == "function" && superPattern.test(properties[name]) ?
			(function(name,fn){//定义一个重载函数
				return function(){
					var tmp = this._super;

					this._super = _super[name];

					var ret = fn.apply(this,arguments);
					this._super = tmp;
					return ret;
				}
			})(name,properties[name]) : properties[name];  
		}
	}

	function Class(){
		if(!initializing && this.init){//创建一个仿真类构造器
			this.init.apply(this.arguments);
		}
		
		Class.prototype = proto;//设置类的原型

		Class.constructor = Class;//重载构造器引用

		Class.subClass = arguments.callee;//让类继续可扩展

		return Class;		
	}	
})()