アスペクト指向(AOP)

    //for AOP
    function _after(target, methodName, aspect) {

        var method = target[methodName];

        //overwrite the method.
        target[methodName] = function () {

            var args = Array.prototype.slice.call(arguments),
				  result;
            
            result = method.apply(this, arguments);
            args.push(result);
            args.push({
                target: this,
                methodName: methodName,
                method: method
            });

            return aspect.apply(this, args);
        };
    }

    function _apply(func, target, methodNames, aspect) {
    
        if (Object.prototype.toString.call(methodNames) !== '[object Array]') {
            methodNames = [methodNames];
        }

        var i = 0, mName;

        for (; mName = methodNames[i]; i++) {
            func(target, mName, aspect);
        }
    }

    function after(target, methodNames, aspect) {
    
        _apply(_after, target, methodNames, aspect);
    }