javascript类工厂构建

下面的代码基于javascript原型继承设计，轻量，好用。

 var initializing = false,
	fnTest = /xyz/.test(function() {
		xyz;
	}) ? /\b_super\b/ : /.*/;

var Class = function() {};
Class.extend = function(prop) {
	var _super = this.prototype;
	initializing = true;
	var prototype = new this();
	initializing = false;
	for (var name in prop) {
		prototype[name] = typeof prop[name] == "function" &&
			typeof _super[name] == "function" && fnTest.test(prop[name]) ?
			(function(name, fn) {
				return function() {
					var tmp = this._super;

					this._super = _super[name];

					var ret = fn.apply(this, arguments);
					this._super = tmp;

					return ret;
				};
			})(name, prop[name]) :
			prop[name];
	}
	function Class() {
		if (!initializing && this.init)
			this.init.apply(this, arguments);
	}
	Class.prototype = prototype;
	Class.prototype.constructor = Class;
	Class.extend = arguments.callee;
	return Class;
};

使用方式

var A = Class.extend({
    init :  function(){
        console.log('the class');
    }
});
//B继承A
var B = A.extend({
    init : function(){
        this._super();
    }
});
new B();