“Private” properties inheritance in Javascript

Question

I wanted to structure my javascript application with a modular pattern, as such:

APP = (function() {
    // Private stuff
    var _privateVariable = 'private',
        _priv = 'priv'

    _privateMethod = function(){ /* */ };

    // Exposed API
    return {
        publicVariable : 'public',
        publicMethod   : function(){ 
             return _privateVariable
        };
    }());

Then I want to be able to extend the application through plugin-like modules; for example, using jQuery:

$.extend(true, APP, (function() {
    // Child private stuff
    var _privateVariable = 'childPrivate',

    // Exposed API
    return {

    }()))

What I am trying to achieve is either one of the following:

1. When calling APP.publicMethod() after extending it, I want to return 'childPrivate' and not 'private' ;
2. Be able to access _priv from the extended exposed API .

In summary, I would like that the private variables defined in the parent module would be inherited in the child module as private members of the child.

Answer 1

With this structure you can't do that. Take a look at an awesome post by John Resig on how to achieve inheritance in javascript: http://ejohn.org/blog/simple-javascript-inheritance/