javascript extends

Class.js

var Class = (function () {
    initial = false;

    // var _mix = function(target, source) {
    //     for (var k in source) {
    //         if (!target.hasOwnProperty(k)) {
    //             target[k] = source[k];
    //         }
    //     }
    //     return target;
    // }

    var reg = /\b_super\b/;

    var _extend = function(props) {
        var _super = this.prototype;
        initial = true;
        var prototype = new this();
        initial = false;

        // var items = [].slice.call(arguments) || [];
        // var item   
        // while(item = items.shift()) {
        //     // 支持构造函数
        //     _mix(prototype, item.prototype || item);
        // }
        for (var name in props) {
            prototype[name] = typeof props[name] === 'function' && typeof prototype[name] === 'function' && reg.test(props[name]) ?
            (function(fn, name) {
                return function() {
                    var temp = this._super;
                    this._super = _super[name];
                    var ret = fn.apply(this, [].slice.call(arguments));
                    this._super = temp;
                    return ret;
                }
            })(props[name], name) : props[name];
        }

        function SubClass() {
            if (!initial && this.init) {
                this.init.apply(this, arguments);
            }
        }

        SubClass.prototype = prototype;

        SubClass.extend = _extend;

        return SubClass;
    }

    function Class() {

    }

    Class.extend = _extend;
    return Class;

})();