4.4 proxy 的一些属性

var user = {
    id : 1,
    name : 'Tom',
    age : 10,
    school : 'primary school',
    sister:{   
        name:'Alice',
        age:12
    }

}
var handler = {
    get(target,prop){
        if(prop == 'id'){
            return undefined;
        }
        //return target[prop];
        return Reflect.get(target,prop);  
    },
 
    set(target,prop,value){
        if(prop == 'id' || prop == 'name' ){
            console.log(`Property ${prop} modification is not allowed.`)
        }else{
            //target[prop] = value;
            return Reflect.set(target,prop,value); 
        }
    },
 
    deleteProperty(target,prop){
        console.log('deleteProperty is called');
        return Reflect.deleteProperty(target,prop);  
    }
};

var proxyUser = new Proxy(user,handler); 

// console.log(proxyUser)
// console.log(proxyUser.id); //undefined
// console.log(proxyUser.name); // Tom
// console.log(proxyUser.age);  //10
// console.log(proxyUser.school);  //primary school
// console.log(proxyUser.sister.age);  //12
 
// 改变属性值
// proxyUser.id = 2;   //Property id modification is not allowed.
// proxyUser.name = 'Jack';  //Property name modification is not allowed.
// proxyUser.age = 9;  
// proxyUser.sister.age = 13;  
// console.log(user);// 改变proxyUser,user里面的值也变了

// 新增属性
// proxyUser.gender = 'boy';
// console.log(user);

 
// delete proxyUser.age;
// console.log(user);
 
proxyUser.sister.age=14;//内层对象属性值更改ok
console.log(user.sister.age);