code from http://www.alloyteam.com/2013/05/javascript-code-with-aop-improvement/

AOP.js

Function.prototype.before = function(func){
  var __self =this;
	return function(){
		var ret = func.apply(this, arguments);
		if(ret===false){
			return false;
		}
		__self.apply(this, arguments);
		return ret;
	}
}

Function.prototype.after = function(func){
	var __self =this;
	return function(){
		var ret = __self.apply(this, arguments);
		if(ret===false){
			return false;
		}
		func.apply(this, arguments);
		return ret;
	}
}

var f = function(){
	console.log(1);
}

f = f.before(function(){
	console.log(0);
});

f = f.after(function(){
	console.log(2);
});

f(); // 0 \ 1 \ 2