Odoo Web Library (OWL) is a project to collect some useful, reusable, (hopefully) well designed building blocks for building web applications. However, since this is the basis for the Odoo web client, we will not hesitate to design the code here to better match the Odoo architecture/design principles.

The most important element of this repository is certainly the component system. It is designed to be:

declarative: the user interface should be described in term of the state of the application, not as a sequence of imperative steps.
composable: each widget can seamlessly be created in a parent widget by a simple directive in its template.
asynchronous rendering: the framework will transparently wait for each subwidgets to be ready before applying the rendering. It uses native promises under the hood.
uses QWeb as a template system: the templates are described in XML and follow the QWeb specification. This is a requirement for Odoo.
with an imperative escape hatch: if necessary, sub widgets can easily be manually created/destroyed.

Note: the code is written in typescript. This does not mean that the main web client will ever be converted to typescript (even though I would really like it).

Try it online

You can experiment with the OWL project online: https://odoo.github.io/owl/

Installing/Building

Some npm scripts are available:

Command	Description
npm install	install every dependency required for this project
npm run build	build a bundle of owl in the /dist/ folder
npm run build:es5	build a bundle of owl in the /dist/ folder (ES5 code)
npm run minify	minify the prebuilt owl.js file
npm run test	run all tests
npm run test:watch	run all tests, and keep a watcher

Documentation

The complete documentation can be found here. The most important sections are:

Examples

Here is a minimal Hello World example:

class HelloWorld extends owl.core.Component {
  inlineTemplate = `<div>Hello <t t-esc="props.name"/></div>`;
}

const env = {
  qweb: new owl.core.QWeb()
};

const hello = new HelloWorld(env, { name: "World" });
hello.mount(document.body);

The next example show how interactive widgets can be created and how widget composition works:

class Counter extends owl.core.Component {
  inlineTemplate = `
    <div>
      <button t-on-click="increment(-1)">-</button>
      <span style="font-weight:bold">Value: <t t-esc="state.value"/></span>
      <button t-on-click="increment(1)">+</button>
    </div>`;

  constructor(parent, props) {
    super(parent, props);
    this.state = {
      value: props.initialState || 0
    };
  }

  increment(delta) {
    this.updateState({ value: this.state.value + delta });
  }
}

class App extends owl.core.Component {
  inlineTemplate = `
    <div>
        <t t-widget="Counter" t-props="{initialState: 1}"/>
        <t t-widget="Counter" t-props="{initialState: 42}"/>
    </div>`;

  widgets = { Counter };
}

const env = {
  qweb: new owl.core.QWeb()
};

const app = new App(env);
app.mount(document.body);

More interesting examples on how to work with this web framework can be found in the examples/ folder:

License

OWL is GPL licensed.