apply()拦截proxy

对apply运用的理解

根据看到的案例得出的结论，当使用apply拦截的时候，target应该是一个函数，而且生成的proxy实例应该以函数的方式调用

let mark = {name: 'kf', book: 'vue'}
    let target = {a: 'a', b:'b'}; // 因为不是函数，会导致报错
    let hander = {
      apply(target,ctx,args) {
        console.log(target,ctx,args)
        return 'I am the proxy'
      }
    }
    let p = new Proxy(target,hander)
    console.log(p(age=8,sex='男'))
    console.log(p.call(mark,age=8,sex='男'))
    console.log(p.apply(mark,[age=8,sex='男']))

报错：Uncaught TypeError: p is not a function

参数说明

// apply方法拦截函数的调用、call和apply操作。
 // apply方法可以接受三个参数，分别是目标对象、目标对象的上下文对象（this）和目标对象的参数数组。
    let handler = {
      apply (target,ctx,args) {
        return Reflect.applay(...arguments)
      }
    }

demo1:

let target = function(name="kate") {return 'I am the target' };
    let hander = {
      apply(target,ctx,args) {
        console.log(target,ctx,args)
        return 'I am the proxy'
      }
    }
    let p = new Proxy(target,hander)
    console.log(p())

打印结果：

demo2:

let target = function(name="kate") {return 'I am the target' };
    let hander = {
      apply(target,ctx,args) {
        console.log(target,ctx,args)
        return 'I am the proxy'
      }
    }
    let p = new Proxy(target,hander)
    console.log(p(age=8,sex='男'))

demo3

let mark = {name: 'kf', book: 'vue'}
    let target = function(name="kate") {return 'I am the target' };
    let hander = {
      apply(target,ctx,args) {
        console.log(target,ctx,args)
        return 'I am the proxy'
      }
    }
    let p = new Proxy(target,hander)
    console.log(p.call(mark,age=8,sex='男'))
    console.log(p.apply(mark,[age=8,sex='男']))