JS实现self的resend_javascript技巧



ECMA V5定义了一个期待已久的方法：Object.getPrototypeOf，它可以无视型别信息得到某对象的原型（[[prototype]]），基于此，我们可以构造出一个resend：（请用Chrome 5、IE9预览第三版测试）
代码如下:
obj.resend = function() {
var pof = Object.getPrototypeOf;
var has = function() {......} // hasOwnProperty的封装
var make = function(obj, old) {
return function(name, args) {
var step = pof(obj),
r;
while (step && !has(step, name)) step = pof(step);
if (!step) throw new Error('Unable to resend: method missing');

var foundMethod = step[name];
var backup = arguments.callee;
this.resend = make(this, backup);
r = foundMethod.apply(this, Array.prototype.slice.call(arguments, 1));
this.resend = old;
return r
}
};

return function(name, args__) {
var rv;
var old = this.resend;
this.resend = make(this, old);
rv = this.resend.apply(this, arguments);
this.resend = original;
return rv;
}
}()