aop-test.js

Function.prototype.before = function (beforefn) {
  var _self = this; //保存原函数引用
  console.log('call before', this)
  return function () { //返回包含了原函数和新函数的"代理函数"
   console.log('call before, return', this, 'arg', arguments)
   beforefn.apply(this, arguments); //执行新函数，修正this
   console.log('call before return return', this, 'arg ',arguments, '_self ', _self)
   return _self.apply(this, arguments); //执行原函数
  }
 };
 Function.prototype.after = function (afterfn) {
  var _self = this;
  console.log('call after', this)
  return function () {
   console.log('call after return', this,  'arg ', arguments,  '_self ', _self)
   var ret = _self.apply(this, arguments);
   console.log('call after return return', this, 'arg', arguments)
   afterfn.apply(this, arguments);
   return ret;
  }
 };
 var func = function () {
  console.log("2")
 }
 func = func.before(function () {
  console.log("1");
 }).after(function () {
  console.log("3");
 } )
 func();
 /*
 call before ƒ () {
  console.log("2")
 }
call after ƒ () { //返回包含了原函数和新函数的"代理函数"
   console.log('call before, return', this, 'arg', arguments)
   beforefn.apply(this, arguments); //执行新函数，修正this
   console.log('call before return return', this, 'arg ',ar…
call after return Window {postMessage: ƒ, blur: ƒ, focus: ƒ, close: ƒ, parent: Window, …} arg  Arguments [callee: ƒ, Symbol(Symbol.iterator): ƒ]callee: ƒ ()length: 0Symbol(Symbol.iterator): ƒ values()__proto__: Object _self  ƒ () { //返回包含了原函数和新函数的"代理函数"
   console.log('call before, return', this, 'arg', arguments)
   beforefn.apply(this, arguments); //执行新函数，修正this
   console.log('call before return return', this, 'arg ',ar…
call before, return Window {postMessage: ƒ, blur: ƒ, focus: ƒ, close: ƒ, parent: Window, …} arg Arguments [callee: ƒ, Symbol(Symbol.iterator): ƒ]
1
call before return return Window {postMessage: ƒ, blur: ƒ, focus: ƒ, close: ƒ, parent: Window, …} arg  Arguments [callee: ƒ, Symbol(Symbol.iterator): ƒ] _self  ƒ () {
  console.log("2")
 }
2
call after return return Window {postMessage: ƒ, blur: ƒ, focus: ƒ, close: ƒ, parent: Window, …} arg Arguments [callee: ƒ, Symbol(Symbol.iterator): ƒ]
3
 */