firefox/toolkit/content/widgets/moz-toggle

MozToggle

moz-toggle is a toggle element that can be used to switch between two states. It may be helpful to think of it as a button that can be pressed or unpressed, corresponding with "on" and "off" states.

<moz-toggle pressed
            label="Toggle label"
            description="This is a demo toggle for the docs.">
</moz-toggle>

When to use

• Use a toggle for binary controls like on/off or enabled/disabled.
• Use when the action is performed immediately and doesn't require confirmation or form submission.
• A toggle is like a switch. If it would be appropriate to use a switch in the physical world for this action, it is likely appropriate to use a toggle in software.

When not to use

• If another action is required to execute the choice, use a checkbox (i.e. a toggle should not generally be used as part of a form).

Code

The source for moz-toggle can be found under toolkit/content/widgets/moz-toggle. You can find an examples of moz-toggle in use in the Firefox codebase in both about:preferences and about:addons.

moz-toggle can be imported into .html/.xhtml files:

<script type="module" src="chrome://global/content/elements/moz-toggle.mjs"></script>

And used as follows:

<moz-toggle pressed
            label="Label for the toggle"
            description="Longer explanation of what the toggle is for"
            aria-label="Toggle label if label text isn't visible"></moz-toggle>

Fluent usage

Generally the label, description, and aria-label properties of moz-toggle will be provided via Fluent attributes. To get this working you will need to specify a data-l10n-id as well as data-l10n-attrs if you're providing a label and a description:

<moz-toggle data-l10n-id="with-label-and-description"
            data-l10n-attrs="label, description"></moz-toggle>

In which case your Fluent messages will look something like this:

with-label-and-description =
  .label = Label text goes here
  .description = Description text goes here

You do not have to specify data-l10n-attrs if you're only using an aria-label:

<moz-toggle data-l10n-id="with-aria-label-only"></moz-toggle>

with-aria-label-only =
  .aria-label = aria-label text goes here

Nested fields

moz-toggle supports nested or dependent fields via a nested named slot. These fields will be rendered below the toggle element, and will be indented to visually indicate dependence. Any nested fields will mirror the disabled state of the toggle and will also become disabled whenever the toggle is not pressed.

When nesting fields it's important to wrap the elements in a moz-fieldset to indicate to assistive technologies that the fields are related, and to provide a label for the group of controls:

<moz-fieldset label="Label for the group">
  <moz-toggle label="Parent toggle" pressed>
    <moz-checkbox slot="nested" label="Nested checkbox one" value="one"></moz-checkbox>
    <moz-checkbox slot="nested" label="Nested checkbox two" value="two" checked></moz-checkbox>
  </moz-toggle>
</moz-fieldset>

<moz-fieldset label="Label for the group">
  <moz-toggle label="Parent toggle" pressed>
    <moz-checkbox slot="nested" label="Nested checkbox one" value="one"></moz-checkbox>
    <moz-checkbox slot="nested" label="Nested checkbox two" value="two" checked></moz-checkbox>
  </moz-toggle>
</moz-fieldset>