Prototypal Inheritance for Modules

object-create-from-module.js

/**
* Prototypal Inheritance for Modules
*
* Prototypal inheritance in its generic case was described by Douglas Crockford at http://javascript.crockford.com/prototypal.html
* However it doesn't work with modules (http://addyosmani.com/largescalejavascript/). This implementation allows to inherit from modules
*
* @author Dmitry Sheiko
* @version object-create-from-module.js, v 1.0
* @license MIT
* @copyright (c) Dmitry Sheiko http://dsheiko.com
**/

(function(){
    "use strict";

    Function.prototype.createInstance = function () {
        var key, module = this, members = module.apply(this, arguments), Fn = function () {};
        members.hasOwnProperty( "__extends__" ) && members[ "__extends__" ]
            && (module.prototype = members[ "__extends__" ].createInstance()); 
        Fn.prototype = module.prototype; // Link to the supertype
        for (key in members) { // Mix in members
            if (members.hasOwnProperty(key)) {
                Fn.prototype[key] = members[key];
            }
        }
        return new Fn();
    };

    // Usage example
    var AbstractModule = function () {
        return {
            inheritedProp : "inherited property",
            publicProp : "original property"
        };
    },
        ConcreteModule = function () {
            var _privateVar = "private";
            return {
                __extends__: AbstractModule, // ConcreteModule extends AbstractModule
                getPrivate : function () {
                    return _privateVar;
                },
                publicProp : "overriden property"
            };
        };

    // Make an instance of ConcreteModule
    var o = ConcreteModule.createInstance();

    console.log(o instanceof ConcreteModule); // true
    console.log(o instanceof AbstractModule); // true
    console.log(o.getPrivate()); // private
    console.log(o.publicProp); // overriden property
    console.log(o.constructor.prototype.publicProp); // original property

}());