本篇文章转载自我的个人博客
Proxy
Proxy可以理解为在对象前架设一个拦截层(过滤与改写)
定义:
var proxy = new Proxy(target,handler);
自带方法:
get(target,propKey,receiver);
set(target,propKey,value,receiver);
has(target,propKey);
deleteProperty(target,propKey);
ownKeys(target);
getOwnPropertyDescriptor(target,propKey);
defineProperty(target, propKey, propDesc);
preventExtensions(target);
getPrototypeOf(target);
isExtensible(target);
setPrototypeOf(target,proto);
apply(target,object,args);
construct(target,args);
get(target, name)
var person = {
name: '张三'
};
var handler = {
get: function(target, name) {
if (name in target) {
return person[name];
} else {
throw new ReferenceError(`${name} don't exist.`);
}
}
};
var proxy = new Proxy(person, handler);
proxy.name; //'张三'
proxy.age; //报错