Class based components with hooks, reactive state and concurrent mode

Try it online! you can experiment with the Owl framework in an online playground.

Project Overview

The Odoo Web Library (Owl) is a smallish (~<20kb gzipped) UI framework built by Odoo for its products. Owl is a modern framework, written in Typescript, taking the best ideas from React and Vue in a simple and consistent way. Owl's main features are:

• a declarative component system,
• a fine grained reactivity system similar to Vue,
• hooks
• fragments
• asynchronous rendering

Owl components are defined with ES6 classes and xml templates, uses an underlying virtual DOM, integrates beautifully with hooks, and the rendering is asynchronous.

Quick links:

• documentation,
• changelog (from Owl 1.x to 2.x),
• playground

Example

Here is a short example to illustrate interactive components:

const { Component, useState, mount, xml } = owl;

class Counter extends Component {
  static template = xml`
    <button t-on-click="() => state.value = state.value + props.increment">
      Click Me! [<t t-esc="state.value"/>]
    </button>`;

  state = useState({ value: 0 });
}

class Root extends Component {
  static template = xml`
    <span>Hello Owl</span>
    <Counter increment="2"/>`;

  static components = { Counter };
}

mount(Root, document.body);

Note that the counter component is made reactive with the useState hook. Also, all examples here uses the xml helper to define inline templates. But this is not mandatory, many applications will load templates separately.

More interesting examples can be found on the playground application.

Documentation

Learning Owl

Are you new to Owl? This is the place to start!

• Tutorial: create a TodoList application
• How to start an Owl project
• How to test Components

Reference

• Overview
• App
• Component
• Component Lifecycle
• Concurrency Model
• Dev mode
• Dynamic sub components
• Environment
• Error Handling
• Event Handling
• Form Input Bindings
• Fragments
• Hooks
• Loading Templates
• Mounting a component
• Portal
• Precompiling templates
• Props
• Props Validation
• Reactivity
• Rendering SVG
• Refs
• Slots
• Sub components
• Sub templates
• Templates (Qweb)
• Translations
• Utils

Other Topics

• Notes On Owl Architecture
• Comparison with React/Vue
• Why did Odoo build Owl?
• Changelog (from owl 1.x to 2.x)
• Notes on compiled templates
• Owl devtools extension

Installing Owl

Owl is available on npm and can be installed with the following command:

npm install @odoo/owl

If you want to use a simple <script> tag, the last release can be downloaded here:

• owl

Installing Owl devtools

The Owl devtools browser extension is also available in the release: Unzip the owl-devtools.zip file and follow the instructions depending on your browser:

Chrome

Go to your chrome extensions admin panel, activate developer mode and click on Load unpacked. Select the devtools-chrome folder and that's it, your extension is active! There is a convenient refresh button on the extension card (still on the same admin page) to update your code. Do note that if you got some problems, you may need to completly remove and reload the extension to completly refresh the extension.

Firefox

Go to the address about:debugging#/runtime/this-firefox and click on Load temporary Add-on.... Select any file in the devtools-firefox folder and that's it, your extension is active! Here, you can use the reload button to refresh the extension.

Note that you may have to open another window or reload your tab to see the extension working. Also note that the extension will only be active on pages that have a sufficient version of owl.