Emulate super in javascript

Question

Basically is there a good elegant mechanism to emulate super with syntax that is as simple as one of the following

• this.$super.prop()

Answer 1

JsFiddle:

What is wrong with this?

'use strict';

function Class() {}
Class.extend = function (constructor, definition) {
    var key, hasOwn = {}.hasOwnProperty, proto = this.prototype, temp, Extended;

    if (typeof constructor !== 'function') {
        temp = constructor;
        constructor = definition || function () {};
        definition = temp;
    }
    definition = definition || {};

    Extended = constructor;
    Extended.prototype = new this();

    for (key in definition) {
        if (hasOwn.call(definition, key)) {
            Extended.prototype[key] = definition[key];
        }
    }

    Extended.prototype.constructor = Extended;

    for (key in this) {
        if (hasOwn.call(this, key)) {
            Extended[key] = this[key];
        }
    }

    Extended.$super = proto;
    return Extended;
};

Usage:

var A = Class.extend(function A () {}, {
    foo: function (n) { return n;}
});
var B = A.extend(function B () {}, {
    foo: function (n) {
        if (n > 100) return -1;
        return B.$super.foo.call(this, n+1);
    }
});
var C = B.extend(function C () {}, {
    foo: function (n) {
        return C.$super.foo.call(this, n+2);
    }
});

var c = new C();
document.write(c.foo(0) + '
'); //3
A.prototype.foo = function(n) { return -n; };
document.write(c.foo(0)); //-3

Example usage with privileged methods instead of public methods.

var A2 = Class.extend(function A2 () {
    this.foo = function (n) {
        return n;
    };
});
var B2 = A2.extend(function B2 () {
    B2.$super.constructor();
    this.foo = function (n) {
        if (n > 100) return -1;
        return B2.$super.foo.call(this, n+1);
    };
});
var C2 = B2.extend(function C2 () {
    C2.$super.constructor();
    this.foo = function (n) {
        return C2.$super.foo.call(this, n+2);
    };
});

//you must remember to constructor chain
//if you don't then C2.$super.foo === A2.prototype.foo

var c = new C2();
document.write(c.foo(0) + '
'); //3