oojs 5.0.0



OOjs is a JavaScript library for working with objects.

Key features include inheritance, mixins and utilities for working with objects.

/* Example */
( function ( oo ) {
    function Animal() {}
    function Magic() {}
    function Unicorn() {
        Animal.call( this );
        Magic.call( this );
    oo.inheritClass( Unicorn, Animal );
    oo.mixinClass( Unicorn, Magic );
}( OO ) );

Quick start

This library is available as an npm package! Install it right away:

npm install oojs

Or clone the repo, git clone https://gerrit.wikimedia.org/r/oojs/core.

ECMAScript 5

OOjs requires a modern ECMAScript 5 environment. It is not necessarily compatible with ES3 engines (such as for IE 6-8). For ES3 environments, the old 1.x releases are available but not recommended.


If your project uses jQuery, use the optimised oojs.jquery.js build instead.

This build assumes jQuery is present and omits various chunks of code in favour of references to jQuery.

jQuery 3.0.0 or higher is required.


We use the Semantic Versioning guidelines as much as possible.

Releases will be numbered in the following format:


For more information on SemVer, please visit http://semver.org/.

Bug tracker

Found a bug? Please report it in the issue tracker!


Release process:

$ cd path/to/oojs/
$ git remote update
$ git checkout -B release -t origin/master

# Ensure tests pass
$ npm install-test

# Avoid using "npm version patch" because that creates
# both a commit and a tag, and we shouldn't tag until after
# the commit is merged.

# Update release notes
# Copy the resulting list into a new section on History.md
$ git log --format='* %s (%aN)' --no-merges --reverse v$(node -e 'console.log(require("./package.json").version);')...HEAD
$ edit History.md

# Update the version number
$ edit package.json

$ git add -p
$ git commit -m "Tag vX.X.X"
$ git review

# After merging:
$ git remote update
$ git checkout origin/master
$ git tag "vX.X.X"
$ git push --tags
$ npm publish