跟踪对象是否已更改 [英] Track whether object changed

问题描述

// A simple Javascript Object / String
var object = "hello";

// Imagine a button in the DOM, and if it's clicked the object value will change
document.getElementById("button").onclick = function(){
   window.object = "hello world";
}

// Now I would like to track and do something when the object is changed, ex:
object.onreadystatechange = function(){
   alert(object);
}

注意：这听起来很愚蠢，因为我可以得到改变在按钮上的 onclick 事件中，但这不是我想要的，我想严格跟踪对象本身的变化以供任何使用，上面的代码是只是一个例子。

Note: This could sound stupid, because I could get the change in the onclick event on the button, but this is not what I want, I want strictly to track the change on the object itself for any kind of use, the above code is is just an example.

推荐答案

你可以用get和set方法把它变成一个实际的对象：

Well you can make it an actual oject with get and set methods:

// A simple Javascript Object 
var object = new (function(){
    this.text = 'hello';

    this.setText = function(msg){
         this.text = msg
         //on change event
    }
})();

// Imagine a button in the DOM, and if it's clicked the object value will change
document.getElementById("button").onclick = function(){
   object.setText('New Text');
}

这是一个演示小提琴： http://jsfiddle.net/maniator/BSYpz/

Here is a demo fiddle: http://jsfiddle.net/maniator/BSYpz/

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