Samuel Degueldre
df59ec49ae
t-call-context is a feature that's supposed to mask the rendering context completely, but currently the component remains available through `this`. This commit stops treating `this` as a reserved word, so that it's compiled to a lookup in the rendering context, and adds `this` to the rendering context when binding the component's rendering function. With these changes, `this` behaves the same as before when outside a t-call-context, but when the rendering context is overriden, the template can no longer access `this`. `this` still represents the instance of the component inside of the rendering function since it's needed by owl internally. A side-effect of this change is that now the rendering context is no longer the instance of the component by default, but is always an object with the component in its prototype chain. This was already the case before in some contexts (eg inside t-foreach, or inside components with a t-set/t-call anywhere in its template). This can cause issues in rare cases when a component method was called directly on the rendering context, as before this change, the method's bound this would be the component instance (except in a t-foreach, component with a t-set/t-call, etc), while after this change it is now never the component instance. When the method only reads on `this` there is no issue as all the components properties are available on the rendering contexts, but setting a value on `this` will write on the rendering context and not the component which is likely a mistake. While this is a breaking change, simply adding a t-set/t-call to any template would break components that would be broken by this change, with this in mind we decided to make this change anyway so that developers get the error as early as possible in the development cycle rather than having a seemingly inocuous change break code under them.
🦉 Owl Framework 🦉
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!
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
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: