Select

Enhance authored trigger, value, and listbox anatomy. Custom element

Choosing between components

Select replaces the native control with an authored trigger and listbox, which costs JavaScript. If plain text options are enough, Native Select is the better default.

Select

Copy this markup

<ui-select value="ready">
  <label id="release-status-label">Release status</label>
  <input type="hidden" name="status" value="ready">
  <button class="ui-button" data-ui-part="trigger" type="button" aria-labelledby="release-status-label">
    <span data-ui-part="label">Ready</span>
  </button>
  <div id="release-status-listbox" role="listbox" popover="auto">
    <div role="option" data-ui-value="draft">Draft</div>
    <div role="option" data-ui-value="ready">Ready</div>
    <div role="option" data-ui-value="published">Published</div>
  </div>
</ui-select>

Install

Styles and registration

import '@timelessui/components/css/tokens.css'
import '@timelessui/components/css/button.css'
import '@timelessui/components/css/select.css'
import '@timelessui/components/css/listbox.css'
import '@timelessui/components/css/popover.css'
import '@timelessui/components/define/ui-select'

Anatomy

Parts are authored in your own markup and identified by the selector below, so your CSS can target the same anatomy without loading Timeless styles. Required parts must be present for the component to work. Private data-ui-internal-* hooks are written by the runtime and must never be authored.

Part	Required	Selector	Purpose
trigger	Yes	[data-ui-part~='trigger']	Native button that opens the listbox.
listbox	Yes	[role='listbox']	The option container and popover surface.
option	Yes	[role='option']	One option. Its value comes from value, then data-ui-value, then the element id.
label	No	[data-ui-part~='label']	Element inside the trigger that shows the selected label.

Attributes

Every value below is implemented by the stylesheets this component ships. Boolean attributes are presence-based: author the attribute with no value, or omit it.

Attribute	Values	Default	Description
open	presence	absent	Present to render the listbox open on load.
placement	bottom · top · right · left	bottom	Preferred side of the trigger for the listbox surface.
value	any string	—	The option selected on load and after a form reset. Mirror it onto a hidden input to submit with a form.

Element API

Attributes above are the authoring surface. These are the DOM properties and events the registered element adds once it upgrades.

<ui-select>

Property	Type	Notes
open	boolean	Reflects the open attribute, documented above.
placement	'bottom' | 'top' | 'right' | 'left'	Reflects the placement attribute, documented above.
defaultValue	string	Reflects the value attribute, documented above.
value	string	Live value. Assigning it does not rewrite the authored default and does not dispatch transition events.

Event	Detail	Description
ui-before-change	CustomEvent<SelectChangeDetail>	Cancelable proposal dispatched before the selected option changes. Call preventDefault() to reject the transition and keep the current value.
ui-change	CustomEvent<SelectChangeDetail>	Dispatched after the selected option has changed. Bubbles and is composed.

Styling

Root identity: ui-select. Required stylesheets: tokens.css, button.css, select.css, listbox.css, popover.css.

This component adds no custom properties of its own. Restyle it through the design tokens or your own CSS.

Design tokens this component reads (34)

These are global Atmosphere tokens. Change them once at the theme level rather than per component.

--ui-accent · --ui-accent-soft · --ui-bg-accent · --ui-bg-accent-active · --ui-bg-accent-hover · --ui-bg-control · --ui-bg-control-active · --ui-bg-control-hover · --ui-bg-control-muted · --ui-bg-danger · --ui-bg-danger-active · --ui-bg-danger-hover · --ui-bg-surface · --ui-bg-surface-raised · --ui-disabled-opacity · --ui-duration-fast · --ui-ease-standard · --ui-fg · --ui-fg-muted · --ui-focus · --ui-line · --ui-radius-control · --ui-radius-lg · --ui-radius-md · --ui-radius-sm · --ui-shadow-control-accent · --ui-shadow-control-active · --ui-shadow-control-danger · --ui-shadow-floating · --ui-shadow-outline-control · --ui-space-1 · --ui-space-2 · --ui-space-3 · --ui-space-4

Accessibility

Keep the native elements, roles, and relationships shown in the example. Timeless adds only the state and keyboard coordination the platform does not already provide, and it never supplies your accessible names — those depend on your content.

Follows the Select-Only Combobox pattern from the ARIA Authoring Practices Guide.

Key	Action
Enter / Space	Open the listbox, or commit the active option when it is already open.
Arrow keys	Move the active option while the listbox is open.
Escape	Close the listbox without changing the value.
Printable characters	Typeahead over the option labels.

The trigger keeps focus and the active option is announced through aria-activedescendant. Light dismiss comes from the Popover API. Mirror value onto a hidden input to submit with a form.

Verify in context

Automated checks cover axe WCAG 2.2 A and AA rules on every documented route. Keyboard, zoom, forced-colors, and screen-reader review still belong to your application.

Before JavaScript runs

The markup above is complete and usable on its own: native controls submit, labels associate, and authored ARIA is already correct. Registration adds state synchronisation, focus management, and keyboard coordination on top of it.

More examples

Open Select in StoryLite for variants, controls, and manual testing.