Which JavaScript Library Has the Most Comprehensive Class Inheritance Support?

Question

After playing with a dozen different JavaScript Libraries such as Prototype, jQuery, YUI, just to name a few, I found every different library has a different way of simulating some sort of Class Hierarchy and provide some sort of Class Inheritance support. (Other than jQuery) Other than being very annoyed that when you create a new class, it has to be library dependent, unless you do the plain old way.

I'm wondering which library offers the best support for class inheritance in general and why.

I hope maybe one day JavaScript Library authors can agree on one style for Class creation and inheritance.

Answer 1

I think Microsoft Ajax implements it just perfectly (with namespaces, inheritance & interfaces etc.)

Sample:

Type.registerNamespace("Demo");

Demo.Person = function(firstName, lastName, emailAddress) {
    this._firstName = firstName;
    this._lastName = lastName;
    this._emailAddress = emailAddress;
}

Demo.Person.prototype = {

    getFirstName: function() {
        return this._firstName;
    },

    getLastName: function() {
        return this._lastName;
    },

    getName: function() {
        return this._firstName + ' ' + this._lastName;
    },

    dispose: function() {
        alert('bye ' + this.getName());
    }
}
Demo.Person.registerClass('Demo.Person', null, Sys.IDisposable);

// Notify ScriptManager that this is the end of the script.
if (typeof(Sys) !== 'undefined') Sys.Application.notifyScriptLoaded();

Answer 2

Check out Prototype. Here's a sample:

// properties are directly passed to `create` method
var Person = Class.create({
  initialize: function(name) {
    this.name = name;
  },
  say: function(message) {
    return this.name + ': ' + message;
  }
});

// when subclassing, specify the class you want to inherit from
var Pirate = Class.create(Person, {
  // redefine the speak method
  say: function($super, message) {
    return $super(message) + ', yarr!';
  }
});

var john = new Pirate('Long John');
john.say('ahoy matey');
// -> "Long John: ahoy matey, yarr!"

Answer 3

Base2 has simple inheritance mechanism , See John Resig's post on this ( comments in the post are also interesting ) .

Something to also keep in mind is that trying to do simulate classic OO in javascipt has been getting lot of flak lately ( although it was explored very enthusiastically in the initial days of great JS library revolution )

Answer 4

Well, first you should ask if you want a library that tries to emulate classical inheritance or one that goes more for JS's native prototypal inheritance.

DUI (the Digg User Interface library) is a jQuery addon that takes Prototype's old model and extends it in a much more intuitive way, allowing for nested static and dynamic classes, namespaces, support for the dontEnum bit and more. Documentation is available on Digg's GitHub. I think you'll find it pretty robust.

Disclosure: I work for Digg and wrote DUI ;)

Answer 5

I found out there is a Javascript Framework modeled after Ruby:

Js.Class

Another good one is:

Joose-js (modeled after moose (perl) )

I prefer Josse, because it seems to be more actively developed, and the syntax looks neat too!

Any thoughts??? (Maybe this should be another question??)

Answer 6

You might also be interested in qooxdoo, a framework for creating rich internet applications (RIAs). It includes a comprehensive OO layer, which aims at being powerful, elegant and fast:

See the following section in the manual, which has all the details: http://qooxdoo.org/documentation/0.8#object_orientation

Answer 7

I find mootools to be everything I need for inheritence. It uses the basic motif of Extends and Implements of many other OO languages.

One of the developers goes over it in detail in his comparison to jquery:

http://jqueryvsmootools.com

You don't need the whole library either. You can just download their Class model and ignore the rest (animation, dom manipulation, etc).

Answer 8

You should try Classy:

http://classy.pocoo.org/

It is simple and really small but has everything I need when constructing my classes.

Answer 9

Just pick whichever one "tastes" best to you. In the end, they all use prototypal inheritance behind the scenes, so they all have roughly the same level of functionality.

If you want a high-powered traditional class system, use GWT and program in pure Java.

Personally I prefer Ext's component system, but that's because Ext components actually have a full lifecycle (initialization, rendering, state persistence and destruction), which in turn allows component plugins that don't break with minor updates to the library.