OWL and the web client

Components, templates, hooks and services; registering field widgets; patching existing components; when JavaScript is the right tool.

In this lesson

Components, templates and hooks
Registries, services and patching
When to use JavaScript

Key points

class extends Component; static template/props; setup() with hooks
useState, onWillStart, onMounted, useRef, useService('orm' | 'action' | 'notification')
registry.category('fields'|'actions'|'systray').add(...); patch()
UI in JS; business rules in Python

Real-world example

A team enforced a discount limit in a JavaScript patch on the order form. Imported orders and the website ignored it. Moving the rule into Python (action_confirm and a constraint) enforced it everywhere; the JS was reduced to a friendly warning.

Questions and answers

Which bundle should a back-end widget be added to?

web.assets_backend.

What does patch() let you do?

Modify an existing class's methods (for example a core component) without copying it.

Read the full lesson, worked example and quiz