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Classify.js is a library that allows for cross platform and cross browser Object Oriented Javascript class definitions using classical inheritance and namespaces behind the prototype syntax in an easy to use interface function.

Classify.js Build Status

Classify.js is a library that allows for cross platform and cross browser Object Oriented Javascript class definitions using classical inheritance and namespaces behind the prototype syntax in an easy to use interface function. Classify also provides "bound" properties that passes the calling context as the first argument, and "static" properties for static properties and methods on the object definition.

Classify is tested in IE 6+, Firefox 2+, Safari 3+, Chrome 3+, and Opera 10+, NodeJs. Selenium Test Status


Creating a class

var Pet = Classify({
    type : "",
    eaten : null,
    init : function(type) { // constructor method 
        this.type = type;
        // don't assign objects to the prototype, because it 
        // will be same reference in all instances 
        this.eaten = [];
    eat : function(food) {


var Dog = Classify(Pet, {
    breed : "",
    init : function(breed) {
        this.breed = breed;

Mixins/Multiple Inheritance

// Implementations will only be attached to the prototype 
var feline_traits = {
    is_asleep : false,
    sleep : function() {
        this.is_asleep = true;
    wake : function() {
        this.is_asleep = false;
var Cat = Classify(Pet, [ feline_traits ], {
    breed : "",
    init : function(breed) {
        this.breed = breed;

Static Properties/Methods

// Static properties can be defined with the "$$static$$" prefix 
// or defined in bulk with $$static$$ : {prop1:1, prop2:2} 
var Bird = Classify(Pet, {
    breed : "",
    init : function(breed) {
        this.breed = Bird.validateBreed(breed);
    $$static$$BREEDS : {
        parrot : "Parrot",
        canary : "Canary"
    $$static$$validateBreed : function(breed) {
        return Bird.BREEDS[breed] || "Unknown";


// Auto bound properties can be defined with the "$$bind$$" prefix 
// or defined in bulk with $$bind$$ : {prop1:function(){}, prop2:function(){}} 
var Pig = Classify(Pet, {
    init : function() {
    $$bind$$speak : function(event) {
        // this can now be called within the class with this.speak() 
        // special property $$context added for the duration of this 
        // method to pass along the calling context, with "this" is 
        // still the instance 
var p = new Pig();
// <a href="#oink" id="some-link">Click me!</a> 
document.getElementById("some-link").addEventListener("click", p.speak);

Calling overridden parent methods

var Dog = Classify(Pet, {
    breed : "",
    init : function(breed) {
        // "this.$$parent" is the parent of the calling method 
        this.breed = breed;
    eat : function() {
        // the dog can only eat fish... 
    eatBiscuit : function() {
        // using "this.$$apply" can call any method in the parent prototype 
        // with an array of arguments similar to "Function.apply()" 
        // this will call with the argument biscuit 
        // shortcut for, [ "biscuit" ]); 
        this.$$apply("eat", [ "biscuit" ]);
    eatDogFood : function() {
        // using "this.$$call" can call any method in the parent prototype 
        // with a set of arguments similar to "" 
        // this will call with the argument biscuit 
        // shortcut for, "biscuit"); 
        this.$$call("eat", "biscuit");


// creating/retrieving a namespace 
var namespace = Classify("Life");
// OR 
var namespace = Classify.Namespace.from("Life", {} /* any object can be a coerced into a namespace */);
// note that this cannot be accessed with 'Classify("Life");' 
// if global access is needed use 'Classify.Namespace.from("Life", {}, true);' 
method 1: through the namespace objects
// creating classes within a namespace 
namespace.create("Reptile", {
    species : "",
    init : function(species) {
        this.species = species;
// retrieving classes within a namespace 
var Reptile = namespace.get("Reptile");
// extending classes within a namespace 
namespace.create("Tortoise", "Reptile", {
    init : function() {
// retrieving classes within a namespace 
var Tortoise = namespace.get("Tortoise");
namespace.create("Tortoise.DesertTortoise", "Tortoise", {
    age : null,
    init : function() {
        this.age = 0;
// retrieving classes within a namespace 
var DesertTortoise = namespace.get("Tortoise.DesertTortoise");
// instances 
var pet = new DesertTortoise();
pet instanceof Tortoise;
pet instanceof Reptile;
pet.getNamespace() === namespace;
// removing a class within a namespace 
// checking a class within a namespace 
method 2: through the Classify function
// creating classes within a namespace 
Classify("Life", "Reptile", {
    species : "",
    init : function(species) {
        this.species = species;
// OR using a "/" will denote namespace/classname 
Classify("Life/Reptile", {
    species : "",
    init : function(species) {
        this.species = species;
// retrieving classes within a namespace 
var Reptile = Classify("Life", "Reptile");
// OR using a "/" will denote namespace/classname 
var Reptile = Classify("Life/Reptile");
// extending classes within a namespace 
// Classify("Life", "Tortoise", "Reptile", { 
Classify("Life/Tortoise", "Reptile", {
    init : function() {
// retrieving classes within a namespace 
var Tortoise = Classify("Life/Tortoise");
Classify("Life/Tortoise.DesertTortoise", "Tortoise", {
    age : null,
    init : function() {
        this.age = 0;
// retrieving classes within a namespace 
var DesertTortoise = Classify("Life/Tortoise.DesertTortoise");
// instances 
var pet = new DesertTortoise();
pet instanceof Tortoise;
pet instanceof Reptile;
pet.getNamespace() === namespace;


var Reptile = Classify("Life/Reptile");
// instances 
var pet = new Reptile("tortoise");
pet instanceof Reptile;
// instances 
var pet = new Classify("Life/Reptile", [ "tortoise" ])
pet instanceof Reptile;
!(pet instanceof Classify);


(function(Classify) {
    // here you can use the Classify object and remove the global reference to it 
    // this function is only available on browser environments 


Classify is CommonJS compliant and can be used in the browser scope or the server scope.

In the browser:

<script src="path/to/classify.js" type="text/javascript"></script>
<!-- Classify() is now in the global context -->

In NodeJs environment:

npm install classifyjs
var Classify = require("classifyjs").Classify;

With an AMD loader like RequireJS:

    "paths" : {
        "classify" : "path/to/classify"
}, [ "classify" ], function(Classify) {

Building the Source

Classify uses the grunt build system. Building Classify requires node.js and a command line gzip program.

# Install grunt.
$ npm install -g grunt-cli bower
# Clone the Classify git repo.
$ git clone git://
$ cd Classify
# Install node modules.
$ npm install
$ bower install
# Run grunt.
$ grunt

Running the tests:

$ grunt test

For saucelabs users, test can be run from the test task with:

$ export SAUCE_USERNAME=[saucelabs username]
$ export SAUCE_ACCESS_KEY=[saucelabs access token]

To skip the saucelabs tests

$ grunt test:local

There are many other tasks that can be run through grunt. For a list of all tasks:

$ grunt --help



Adding `priority` property to mutators to allow for mutator processing order


Ability to set internal references for namespaces created with `Namespace.from()`


BREAKING CHANGE: Renaming more additional internal props for consistiency
    Namespace.nsname => Namespace.$$nsname
    Namespace.nsref => Namespace.$$nsref


BREAKING CHANGE: the mutator prefix is now $$\w+$$
BREAKING CHANGE: underscores are no longer allowed in mutator names
BREAKING CHANGE: multiple mutators can be specified in the mutator prefix separated by an _
BREAKING CHANGE: the mutator prefix is always removed regardless if there is a mutator attached or not
greedy mutators can be added to always be run onPropAdd and onPropRemove
    // prefix change 
    { __mutator_prop : 1 } => { $$mutator$$ : 1 }
    // multiple mutators 
    { $$mutate1_mutate2$$ : 1 }
    // greedy mutators 
    addMutator({ greedy : true })
    // prefix removed when attached to an object 
    $$abc$$prop : 1 => prop : 1


BREAKING CHANGE: Class.toString now returns the init method body
BREAKING CHANGE: Renaming internal properties and certain magic properties.
BREAKING CHANGE: Change behavior of the bind mutator to make context a property instead of a argument.
    // calling parent method 
    this.parent => this.$$parent
    this.invoke => this.$$apply
    adding this.$$call
    // internal variables 
    Class.superclass => Class.$$superclass
    Class.subclass => Class.$$subclass
    Class.implement => Class.$$implement
    Class.mutators => Class.$$mutator
    Class.applicate => Class.$$apply
    Class.__isclass_ => Class.$$isclass
    // bind mutator 
    function(context) {} => function() { this.$$context; }
    // shortcuts 
    removed this.self, use Class.prototype.constructor/this.constructor instead


Removing Observer and observable mutator from core. Now in Classify-Observable[]


Pass arguments to onInit mutators


Allow for mutators to be defined on a per class/namespace level
Ability to create mutators out of any object
Convert to grunt build system


Fix requirejs and amd definitions, remove async autoloader to support it


Android Mobile thinks typeof RegExp == "function"


Allow init mutators to override constructor return value & throw on scalar values
Adding null value to the prototype for observable properties
Observer properties don't need to go through objectDefineProperty


BREAKING CHANGE, implements overrides extends when defining a class that institutes both
Use ES5 Object.create when possible


Fix issue when extending non Classify objects overriding special properties
Global namespace is now a property of Classify on
Updated Observers to have a 'on' alias and be able to bind events to be fired only once
Using Object.prototype.hasOwnProperty instead of .hasOwnProperty


The called context is passed in as argument 1 for auto bound functions


Refactoring internals so that adding and removing mutators can be externalized
Added mutator to auto bind functions to a class instance


Fix case where classes are added as properties of other classes


Added ability to add non wrapped methods to the class prototype


Adding Travis-ci config file
Fix issue with IE6-9 when extending from non Classify classes
General bug fixes, removing support for IE<6


Renaming Class.Extend to Class.extend


Ability to delay event listeners from being triggered in observers


Ability to add statics and observers in a container


Fix issue with adding overriding functions to a parent prototype


Only fire observer listeners when the value has changed


fixing parent invocation using applicate in default invoke method


Ability to inherit from objects that are not created with Classify.create.
Allow Classify to be AMD compatible.
extend utility function that "extends" objects with properties from other objects in a shallow manner
fix issue with class invocation of "invoke" when class is a direct property of a namespace
"get" in namespace cascades into "GLOBAL" namespace classes
groundwork for ability to extend native and non create objects
Removing check for native objects (IE doesn't allow extending native objects).
throw Error objects instead of strings


better detection of parameters for using Classify function ("namespace/classname" for retrieval)
minification optimizations
quicker access to the GLOBAL namespace


ability to inherit the parent invoke method if not defined
exporting provide to the Classify object
GLOBAL namespace that all namespaced classes can inherit from


ability to get a class definition synchronously and asynchronously in Classify
ability to test if a namespace exists
adding Classify.noConflict for conflict free usage of Classify


using more standardized nomenclature
"_construct_" => "init"
"_invoke_" => "invoke"
"_apply_" => "applicate"
"_parent_" => "parent"
"_self_" => "self"


ability to create and destory classes created within namespaces
better checking of enumerable keys in IE < 9
bugfix on Extend functionality
Classify function endpoint has ability to to get namespace and create classes within the namespace
fixing issue with adding multiple properties to a class with the addProperty call
"get" in namespace takes in a callback and passes in the class
global references
namespacing functionality
only export classify to root object if it's a browser
pulled out the body of invoke to apply and default invoke will call apply
the exported object is created using the internal Create method
updated to "use strict";


Classify copyright 2011-2013 by Wei Kin Huang.

Build Tools: Grunt, QUnit, Benchmark.js, UglifyJS, JsHint, JsCoverage.

All code released under the MIT License.

Fork me to show support and help fix bugs!