How to internally call an overriden method using the Revealing Prototype Pattern

Question

I'm currently struggling with some concepts and syntax for the Revealing Prototype Pattern in Javascript. Could you guys help me understand it?

What I am trying to achieve: call an overridden method from another method of the base class.

How I did it:

1. Base class:

   var Base = function() {
       //...
   };
   Base.prototype = function() {
       var init = function() {
           console.log('init');
           customInit.call(this);
       },
       customInit = function() {
           console.log('custom init source');
       };
   
       return {
           init: init,
           customInit: customInit
       };
   } ();
   

2. Extended class:

   var Extended = function () {
       //...
   };
   Extended.prototype = new Base();
   Extended.prototype.customInit = function () {
       console.log('custom init extended');
   };
   

3. Call to extended class:

   window.addEventListener('load', function (){
       var myObject = new Extended();
       myObject.init();
       myObject.customInit();
   });
   

The call to customInit from outside of the class executes the overriden version of the method (what I want), while the call from within the class still calls the "base" version of the method (not what I want).

Is this normal? Is there any workaround to achieve this?

Answer 1

some modification of your code (1 line):

.......
var init = function() {
    console.log('init');
    //customInit.call(this);
    this.customInit.call(this);
},
.....

Answer 2

You can call a parent function in child with Parents.prototype. some function.call(this, param1, param2)

For more info you can check out this answer:https://stackoverflow.com/a/16063711/1641941