Owl Components

The Odoo Javascript framework uses a custom component framework called Owl. It is a declarative component system, loosely inspired by Vue and React. Components are defined using QWeb templates, enriched with some Owl specific directives. The official Owl documentation contains a complete reference and a tutorial.

Важно

Although the code can be found in the web module, it is maintained from a separate GitHub repository. Any modification to Owl should therefore be made through a pull request on https://github.com/odoo/owl.

Примечание

Currently, all Odoo versions (starting in version 14) share the same Owl version.

Using Owl components

The Owl documentation already documents in detail the Owl framework, so this page will only provide Odoo specific information. But first, let us see how we can make a simple component in Odoo.

const { useState } = owl.hooks;
const { xml } = owl.tags;

class MyComponent extends Component {
    setup() {
        this.state = useState({ value: 1 });
    }

    increment() {
        this.state.value++;
    }
}
MyComponent.template = xml
    `<div t-on-click="increment">
        <t t-esc="state.value">
    </div>`;

This example shows that Owl is available as a library in the global namespace as owl: it can simply be used like most libraries in Odoo. Note that we defined here the template as a static property, but without using the static keyword, which is not available in some browsers (Odoo javascript code should be Ecmascript 2019 compliant).

We define here the template in the javascript code, with the help of the xml helper. However, it is only useful to get started. In practice, templates in Odoo should be defined in an xml file, so they can be translated. In that case, the component should only define the template name.

In practice, most components should define 2 or 3 files, located at the same place: a javascript file (my_component.js), a template file (my_component.xml) and optionally a scss (or css) file (my_component.scss). These files should then be added to some assets bundle. The web framework will take care of loading the javascript/css files, and loading the templates into Owl.

Here is how the component above should be defined:

const { useState } = owl.hooks;

class MyComponent extends Component {
    ...
}
MyComponent.template = 'myaddon.MyComponent';

And the template is now located in the corresponding xml file:

<?xml version="1.0" encoding="UTF-8" ?>
<templates xml:space="preserve">

<t t-name="myaddon.MyComponent" owl="1">
  <div t-on-click="increment">
    <t t-esc="state.value"/>
  </div>
</t>

</templates>

Odoo code is not yet completely made in Owl, so it needs a way to tell the difference between Owl templates (new code) and old templates (for components). To do that in a backward-compatible way, all new templates should be defined with the owl attribute set to 1.

Примечание

Do not forget to set owl="1" in your Owl templates!

Примечание

Template names should follow the convention addon_name.ComponentName.

Смотри также

Best practices

First of all, components are classes, so they have a constructor. But constructors are special methods in javascript that are not overridable in any way. Since this is an occasionally useful pattern in Odoo, we need to make sure that no component in Odoo directly uses the constructor method. Instead, components should use the setup method:

// correct:
class MyComponent extends Component {
    setup() {
        // initialize component here
    }
}

// incorrect. Do not do that!
class IncorrectComponent extends Component {
    constructor(parent, props) {
        // initialize component here
    }
}

Another good practice is to use a consistent convention for template names: addon_name.ComponentName. This prevents name collision between odoo addons.

Reference List

The Odoo web client is built with Owl components. To make it easier, the Odoo javascript framework provides a suite of generic components that can be reused in some common situations, such as dropdowns, checkboxes or datepickers. This page explains how to use these generic components.

Technical Name

Short Description

CheckBox

a simple checkbox component with a label next to it

Dropdown

full-featured dropdown

CheckBox

Location

@web/core/checkbox/checkbox

Description

This is a simple checkbox component with a label next to it. The checkbox is linked to the label: the checkbox is toggled whenever the label is clicked.

<CheckBox value="boolean" disabled="boolean" t-on-change="onValueChange">
  Some Text
</CheckBox>

Props

Name

Type

Description

value

boolean

if true, the checkbox is checked, otherwise it is unchecked

disabled

boolean

if true, the checkbox is disabled, otherwise it is enabled

Location

@web/core/dropdown/dropdown and @web/core/dropdown/dropdown_item

Description

Dropdowns are surprisingly complicated components. They need to provide many features such as:

  • Toggle the item list on click

  • Direct siblings dropdowns: when one is open, toggle others on hover

  • Close on outside click

  • Optionally close the item list when an item is selected

  • Emit an event to inform which list item is clicked

  • Support sub dropdowns, up to any level

  • SIY: style it yourself

  • Configurable hotkey to open/close a dropdown or select a dropdown item

  • Keyboard navigation (arrows, tab, shift+tab, home, end, enter and escape)

  • Reposition itself whenever the page scrolls or is resized

  • Smartly chose the direction it should open (right-to-left direction is automatically handled).

To solve these issues once and for all, the Odoo framework provides a set of two components: a Dropdown component (the actual dropdown), and DropdownItem, for each element in the item list.

<Dropdown>
  <t t-set-slot="toggler">
    <!-- "toggler" slot content is rendered inside a button -->
    Click me to toggle the dropdown menu !
  </t>
  <!-- "default" slot content is rendered inside a div -->
  <DropdownItem t-on-dropdown-item-selected="selectItem1">Menu Item 1</DropdownItem>
  <DropdownItem t-on-dropdown-item-selected="selectItem2">Menu Item 2</DropdownItem>
</Dropdown>

Props

A <Dropdown/> component is simply a <div class="dropdown"/> having a <button class="dropdown-toggle"/> next to menu div (<div class="dropdown-menu"/>). The button is responsible for the menu being present in the DOM or not.

Dropdown

Type

Description

startOpen

boolean

initial dropdown open state (defaults to false)

menuClass

string

additional css class applied to the dropdown menu <div class="dropdown-menu"/>

togglerClass

string

additional css class applied to the toggler <button class="dropdown-toggle"/>

hotkey

string

hotkey to toggle the opening through keyboard

beforeOpen

function

hook to execute logic just before opening. May be asynchronous.

manualOnly

boolean

if true, only toggle the dropdown when the button is clicked on (defaults to false)

title

string

title attribute content for the <button class="dropdown-toggle"/> (default: none)

position

string

defines the desired menu opening position. RTL direction is automatically applied. Should be a valid usePosition hook position. (default: bottom-start)

toggler

"parent" or undefined

when set to "parent" the <button class="dropdown-toggle"/> is not rendered (thus toggler slot is ignored) and the toggling feature is handled by the parent node (e.g. use case: pivot cells). (default: undefined)

A <DropdownItem/> is simply a span (<span class="dropdown-item"/>). When a <DropdownItem/> is selected, it emits a custom dropdown-item-selected event containing its payload. (see OWL Business Events). So, to react to such an event, one needs to define an event listener on the dropdown-item-selected event.

DropdownItem

Type

Description

payload

Object

payload that will be added to the dropdown-item-selected event (default to null)

parentClosingMode

none | closest | all

when the item is selected, control which parent dropdown will get closed: none, closest or all (default = all)

hotkey

string

optional hotkey to select the item

href

string

if provided the DropdownItem will become an <a href="value" class="dropdown-item"/> instead of a <span class="dropdown-item"/>. (default: not provided)

title

string

optional title attribute which will be passed to the root node of the DropdownItem. (default: not provided)

Technical notes

The rendered DOM is structured like this:

<div class="dropdown">
    <button class="dropdown-toggle">Click me !</button>
    <!-- following <div/> will or won't appear in the DOM depending on the state controlled by the preceding button -->
    <div class="dropdown-menu">
        <span class="dropdown-item">Menu Item 1</span>
        <span class="dropdown-item">Menu Item 2</span>
    </div>
</div>

To properly use a <Dropdown/> component, you need to populate two OWL slots :

  • toggler slot: it contains the toggler elements of your dropdown and is rendered inside the dropdown button (unless the toggler prop is set to parent),

  • default slot: it contains the elements of the dropdown menu itself and is rendered inside the <div class="dropdown-menu"/>. Although it is not mandatory, there is usually at least one DropdownItem inside the menu slot.

When several dropdowns share the same parent element in the DOM, then they are considered part of a group, and will notify each other about their state changes. This means that when one of these dropdowns is open, the others will automatically open themselves on mouse hover, without the need for a click.

Example: Direct Siblings Dropdown

When one dropdown toggler is clicked (File , Edit or About), the others will open themselves on hover.

<div t-on-dropdown-item-selected="onItemSelected">
  <Dropdown>
    <t t-set-slot="toggler">File</t>
    <DropdownItem payload="'file-open'">Open</DropdownItem>
    <DropdownItem payload="'file-new-document'">New Document</DropdownItem>
    <DropdownItem payload="'file-new-spreadsheet'">New Spreadsheet</DropdownItem>
  </Dropdown>
  <Dropdown>
    <t t-set-slot="toggler">Edit</t>
    <DropdownItem payload="'edit-undo'">Undo</DropdownItem>
    <DropdownItem payload="'edit-redo'">Redo</DropdownItem>
    <DropdownItem payload="'edit-find'">Search</DropdownItem>
  </Dropdown>
  <Dropdown>
    <t t-set-slot="toggler">About</t>
    <DropdownItem payload="'about-help'">Help</DropdownItem>
    <DropdownItem payload="'about-update'">Check update</DropdownItem>
  </Dropdown>
</div>

Example: Multi-level Dropdown (with t-call)

This example shows how one could make a File dropdown menu, with submenus for the New and Save as... sub elements.

<t t-name="addon.Dropdown.File" owl="1">
  <Dropdown t-on-dropdown-item-selected="onItemSelected">
    <t t-set-slot="toggler">File</t>
    <DropdownItem payload="'file-open'">Open</DropdownItem>
    <t t-call="addon.Dropdown.File.New"/>
    <DropdownItem payload="'file-save'">Save</DropdownItem>
    <t t-call="addon.Dropdown.File.Save.As"/>
  </Dropdown>
</t>

<t t-name="addon.Dropdown.File.New" owl="1">
  <Dropdown>
    <t t-set-slot="toggler">New</t>
    <DropdownItem payload="'file-new-document'">Document</DropdownItem>
    <DropdownItem payload="'file-new-spreadsheet'">Spreadsheet</DropdownItem>
  </Dropdown>
</t>

<t t-name="addon.Dropdown.File.Save.As" owl="1">
  <Dropdown>
    <t t-set-slot="toggler">Save as...</t>
    <DropdownItem payload="'file-save-as-csv'">CSV</DropdownItem>
    <DropdownItem payload="'file-save-as-pdf'">PDF</DropdownItem>
  </Dropdown>
</t>

Example: Multi-level Dropdown (nested)

<Dropdown t-on-dropdown-item-selected="onItemSelected">
  <t t-set-slot="toggler">File</t>
  <DropdownItem payload="'file-open'">Open</DropdownItem>
  <Dropdown>
    <t t-set-slot="toggler">New</t>
    <DropdownItem payload="'file-new-document'">Document</DropdownItem>
    <DropdownItem payload="'file-new-spreadsheet'">Spreadsheet</DropdownItem>
  </Dropdown>
  <DropdownItem payload="'file-save'">Save</DropdownItem>
  <Dropdown>
    <t t-set-slot="toggler">Save as...</t>
    <DropdownItem payload="'file-save-as-csv'">CSV</DropdownItem>
    <DropdownItem payload="'file-save-as-pdf'">PDF</DropdownItem>
  </Dropdown>
</Dropdown>

Example: Recursive Multi-level Dropdown

In this example, we recursively call a template to display a tree-like structure.

<t t-name="addon.MainTemplate" owl="1">
  <div t-on-dropdown-item-selected="onItemSelected">
    <t t-call="addon.RecursiveDropdown">
      <t t-set="name" t-value="'Main Menu'" />
      <t t-set="items" t-value="state.menuItems" />
    </t>
  </div>
</t>

<t t-name="addon.RecursiveDropdown" owl="1">
  <Dropdown>
    <t t-set-slot="toggler"><t t-esc="name"/></t>
      <t t-foreach="items" t-as="item" t-key="item.id">

        <!-- If this item has no child: make it a <DropdownItem/> -->
        <t t-if="!item.childrenTree.length">
          <DropdownItem payload="item" t-esc="item.name"/>
        </t>
        <!-- Else: recursively call the current dropdown template. -->
        <t t-else="" t-call="addon.RecursiveDropdown">
          <t t-set="name" t-value="item.name" />
          <t t-set="items" t-value="item.childrenTree" />
        </t>

      </t>
    </t>
  </Dropdown>
</t>