es6(16)--Decorator

//Decorator:修饰器，是一个函数用来修改类的行为
{
    //只读
    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');
    // }
    console.log(test.time())
}
{
    let typename=function(target,name,descriptor){
        target.myname="hello";
    }
    @typename
    class Test{

    }
    console.log(Test.myname)
}
//常用的修饰器的js库，core-decorators;cnpm install core-decorators --save-dev
{
    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();
}