es6(11)--Proxy,Reflect

  1 //Proxy,Reflect
  2 
  3 {
  4     let obj={
  5         time:'2018-06-25',
  6         name:'net',
  7         _r:123
  8     };
  9     let monitor = new Proxy(obj,{
 10         //拦截对象属性的读取
 11         get(target,key){
 12             return target[key].replace('2018','2019')
 13         },
 14         //拦截对象设置属性
 15         set(target,key,value){
 16             if(key==='name'){
 17                 return target[key]=value;
 18             }else{
 19                 return target[key];
 20             }
 21         },
 22         //拦截key in object 操作
 23         has(target,key){
 24             if(key==='name'){
 25                 return target[key];
 26             }else{
 27                 return false;
 28             }
 29         },
 30         //拦截delete
 31         deleteProperty(target,key){
 32             if(key.indexOf('_')>-1){
 33                 delete target[key];
 34                 return true;
 35             }else{
 36                 return target[key]
 37             }
 38         },
 39         //拦截Object.keys,Object.getOwnPropertySymbols,Object.getOwnPropertyNames
 40         ownKeys(target){
 41             return Object.keys(target).filter(item=>item!='time')
 42         }
 43     });
 44     console.log('get',monitor.time);
 45     monitor.name='web';
 46     console.log('set',monitor.name);
 47     console.log('has','name' in monitor);
 48     // delete monitor.time;
 49     // console.log('delete',monitor);
 50     // delete monitor._r;
 51     // console.log('delete',monitor);
 52      console.log('ownKeys',Object.keys(monitor));
 53 }
 54 {
 55 
 56     let obj={
 57         time:'2018-06-25',
 58         name:'net',
 59         _r:123
 60     };
 61     console.log('Reflect get',Reflect.get(obj,'time'))
 62     console.log('Reflect set',Reflect.set(obj,'time','2019-06-05'))
 63     console.log(obj);
 64     console.log('has',Reflect.has(obj,'name'))
 65 }
 66 //例子
 67 
 68 {
 69     function validator(target,validator){
 70 
 71         return new Proxy(target,{
 72             _validator:validator,
 73             set(target,key,value,proxy){
 74                 if(target.hasOwnProperty(key)){
 75                     let va=this._validator[key];
 76                     if(!!va(value)){
 77                         return Reflect.set(target,key,value,proxy)
 78                     }else{
 79                         throw Error(`不能设置${key}到${value}`)
 80                     }
 81                 }else{
 82                     throw Error(`${key} 不存在`)
 83                 }
 84             }
 85         })
 86     }
 87     const personValidators={
 88         name(val){
 89             return typeof val==='string'
 90         },
 91         age(val){
 92             return typeof val==='number'&&val>18
 93         }
 94     }
 95     class Person{
 96         constructor(name,age){
 97             this.age=age;
 98             this.name=name;
 99             return validator(this,personValidators)
100         }
101     }
102     const person = new Person('lilei',30);
103     console.info(person)
104     person.name="qqq qq";
105     console.info(person)
106 }