es6(11)--Proxy,Reflect

//Proxy,Reflect

{
    let obj={
        time:'2018-06-25',
        name:'net',
        _r:123
    };
    let monitor = new Proxy(obj,{
        //拦截对象属性的读取
        get(target,key){
            return target[key].replace('2018','2019')
        },
        //拦截对象设置属性
        set(target,key,value){
            if(key==='name'){
                return target[key]=value;
            }else{
                return target[key];
            }
        },
        //拦截key in object 操作
        has(target,key){
            if(key==='name'){
                return target[key];
            }else{
                return false;
            }
        },
        //拦截delete
        deleteProperty(target,key){
            if(key.indexOf('_')>-1){
                delete target[key];
                return true;
            }else{
                return target[key]
            }
        },
        //拦截Object.keys,Object.getOwnPropertySymbols,Object.getOwnPropertyNames
        ownKeys(target){
            return Object.keys(target).filter(item=>item!='time')
        }
    });
    console.log('get',monitor.time);
    monitor.name='web';
    console.log('set',monitor.name);
    console.log('has','name' in monitor);
    // delete monitor.time;
    // console.log('delete',monitor);
    // delete monitor._r;
    // console.log('delete',monitor);
     console.log('ownKeys',Object.keys(monitor));
}
{

    let obj={
        time:'2018-06-25',
        name:'net',
        _r:123
    };
    console.log('Reflect get',Reflect.get(obj,'time'))
    console.log('Reflect set',Reflect.set(obj,'time','2019-06-05'))
    console.log(obj);
    console.log('has',Reflect.has(obj,'name'))
}
//例子

{
    function validator(target,validator){

        return new Proxy(target,{
            _validator:validator,
            set(target,key,value,proxy){
                if(target.hasOwnProperty(key)){
                    let va=this._validator[key];
                    if(!!va(value)){
                        return Reflect.set(target,key,value,proxy)
                    }else{
                        throw Error(`不能设置${key}到${value}`)
                    }
                }else{
                    throw Error(`${key} 不存在`)
                }
            }
        })
    }
    const personValidators={
        name(val){
            return typeof val==='string'
        },
        age(val){
            return typeof val==='number'&&val>18
        }
    }
    class Person{
        constructor(name,age){
            this.age=age;
            this.name=name;
            return validator(this,personValidators)
        }
    }
    const person = new Person('lilei',30);
    console.info(person)
    person.name="qqq qq";
    console.info(person)
}