ES6-----学习系列十七（Decorator）

{
  let readonly=function(target,name,descriptor){
    descriptor.writable=false;
    return descriptor
  };

  class Test{
    @readonly
    time(){
      return ‘2017-03-11‘
    }
  }

  let test=new Test();

  // test.time=function(){
  //   console.log(‘reset time‘);
  // }; 将报错  如果修改的话

  console.log(test.time());
}

{
  let typename=function(target,name,descriptor){
    target.myname=‘hello‘;
  }

  @typename
  class Test{

  }

  console.log(‘类修饰符‘,Test.myname);//hello
  // 第三方库修饰器的js库：core-decorators; npm install core-decorators
}

{
  let log=(type)=>{
    return function(target,name,descriptor){
      let src_method=descriptor.value;
      descriptor.value=(...arg)=>{
        src_method.apply(target,arg);
        console.info(`log ${type}`);
      }
    }
  }

  class AD{
    @log(‘show‘)
    show(){
      console.info(‘ad is show‘)
    }
    @log(‘click‘)
    click(){
      console.info(‘ad is click‘);
    }
  }

  let ad=new AD();
  ad.show();
  ad.click();
}