How to override a javascript IIFE returned method in an object?

问题

I have one IIFE content which looks like this:

var A = (function() { 
     var method1 = function() { 
         alert("PARENT METHOD");
     }
     var method2 = function() {
        method1();
     }

    return {
        method1: method1,
        method2: method2
    }
})();

I want to override this method1 in another javascript object in a way when this method2 executes then it will call the overriden method1, not this original method1. Thanks in advance.

回答1:

You are going to need to use prototype in order to accomplish this the way you would like. Take a look at the example below.

var A = (function() { 
		 var api = function(){}
     
     api.prototype.method1 = function() { 
         console.log("PARENT METHOD");
     }
     
     api.prototype.method2 = function() {
        this.method1();
     }

    return new api();
})();

A.method2();
A.method1 = function() { console.log('child method');}
A.method2();

回答2:

If I understand what you're asking then you can just set the value of method2 (in your API object) to the overridden method (B's method1 in this example). Since A is created using IIFE, the object containing the overridden method must be declared before A or you will wind up with a reference error.

var B = {
  method1: function() {
    console.log('This is method2 in B!');
  }
}

var A = (function() {
  var method1 = function() {
    alert("PARENT METHOD");
  }
  var method2 = function() {
    method1();
  }

  return {
    method1: method1,
    method2: B.method1
  }
})();


//call A.method2
A.method2();

来源：https://stackoverflow.com/questions/51427062/how-to-override-a-javascript-iife-returned-method-in-an-object