proxy和reflect

Posted 2020-10-09 anthonyliu

1.proxy

用来拦截在一个对象上的指定操,如：

var engineer = { name: ‘Joe Sixpack‘, salary: 50 };

var interceptor = {
  //不仅仅有set方法，还有get...等通用的方法
  set: function (receiver, property, value) {
        console.log(property, ‘is changed to‘, value);
        receiver[property] = value;
   }
};

engineer = new Proxy(engineer, interceptor);
engineer.salary = 60; //salary is changed to 60

 也可以应用在多继承：

var foo = {
    foo: function () {
        console.log("foo")
    }
};
var bar = {
    bar: function () {
        console.log("bar")
    }
};

var sonOfFooBar = new Proxy({}, {
    get: function (target, name) {
        console.log("target=",target);
        return target[name] || foo[name] || bar[name];
    }
})
sonOfFooBar.foo();   //"foo",有foo方法,继承自对象foo
sonOfFooBar.bar();   //"bar",也有bar方法,继承自对象bar