Menu
An accessible dropdown and context menu that is used to display a list of actions or options that a user can choose.
Features
- Support for items, labels, groups of items.
- Focus is fully managed using
aria-activedescendantpattern. - Typeahead to allow focusing items by typing text.
- Keyboard navigation support including arrow keys, home/end, page up/down.
Installation
To use the menu machine in your project, run the following command in your command line:
This command will install the framework agnostic menu logic and the reactive utilities for your framework of choice.
Anatomy
To set up the menu correctly, you'll need to understand its anatomy and how we name its parts.
Each part includes a
data-partattribute to help identify them in the DOM.
Usage
First, import the menu package into your project
import * as menu from "@zag-js/menu"
The menu package exports two key functions:
machine— The state machine logic for the menu widget.connect— The function that translates the machine's state to JSX attributes and event handlers.
You'll need to provide a unique
idto theuseMachinehook. This is used to ensure that every part has a unique identifier.
Next, import the required hooks and functions for your framework and use the menu machine in your project 🔥
Listening for item selection
When a menu item is clicked, the onSelect callback is invoked.
const [state, send] = useMachine( menu.machine({ onSelect(details) { // details => { value: string } console.log("selected value is ", details.value) }, }), )
Listening for open state changes
When a menu is opened or closed, the onOpenChange callback is invoked.
const [state, send] = useMachine( menu.machine({ onOpenChange(details) { // details => { open: boolean } console.log("open state is ", details.open) }, }), )
Grouping menu items
When the number of menu items gets much, it might be useful to group related menu items. To achieve this:
- Wrap the menu items within an element.
- Spread the
api.groupProps(...)JSX properties unto the element, providing anid. - Render a label for the menu group, providing the
idof the group element.
//... <div {...api.contentProps}> {/* ... */} <hr {...api.separatorProps} /> <p {...api.getLabelProps({ htmlFor: "account" })}>Accounts</p> <div {...api.getGroupProps({ id: "account" })}> <button {...api.getItemProps({ id: "account-1" })}>Account 1</button> <button {...api.getItemProps({ id: "account-2" })}>Account 2</button> </div> </div> //...
Checkbox and Radio option items
To use checkbox or radio option items, you'll need to:
- Add a
valueproperty to the machine's context whose value is an object describing the state of the option items. - Use the
api.getOptionItemProps(...)function to get the props for the option item.
A common requirement for the option item that you pass the name, value and
type properties.
type— The type of option item. Either"checkbox"or"radio".value— The value of the option item.checked— The checked state of the option item.onCheckedChange— The callback to invoke when the checked state changes.
Styling guide
Earlier, we mentioned that each menu part has a data-part attribute added to
them to select and style them in the DOM.
Open and closed state
When the menu is open or closed, the content and trigger parts will have the
data-state attribute.
[data-part="content"][data-state="open|closed"] { /* styles for open or closed state */ } [data-part="trigger"][data-state="open|closed"] { /* styles for open or closed state */ }
Highlighted item state
When an item is highlighted, via keyboard navigation or pointer, it is given a
data-highlighted attribute.
[data-part="item"][data-highlighted] { /* styles for highlighted state */ } [data-part="item"][data-type="radio|checkbox"][data-highlighted] { /* styles for highlighted state */ }
Disabled item state
When an item or an option item is disabled, it is given a data-disabled
attribute.
[data-part="item"][data-disabled] { /* styles for disabled state */ } [data-part="item"][data-type="radio|checkbox"][data-disabled] { /* styles for disabled state */ }
Using arrows
When using arrows within the menu, you can style it using css variables.
[data-part="arrow"] { --arrow-size: 20px; --arrow-background: red; }
Checked option item state
When an option item is checked, it is given a data-state attribute.
[data-part="item"][data-type="radio|checkbox"][data-state="checked"] { /* styles for checked state */ }
Methods and Properties
Machine Context
The menu machine exposes the following context properties:
idsPartial<{ trigger: string; contextTrigger: string; content: string; label(id: string): string; group(id: string): string; positioner: string; arrow: string; }>The ids of the elements in the menu. Useful for composition.highlightedValuestringThe value of the highlighted menu item.onHighlightChange(details: HighlightChangeDetails) => voidFunction called when the highlighted menu item changes.onSelect(details: SelectionDetails) => voidFunction called when a menu item is selected.anchorPointPointThe positioning point for the menu. Can be set by the context menu trigger or the button trigger.loopFocusbooleanWhether to loop the keyboard navigation.positioningPositioningOptionsThe options used to dynamically position the menucloseOnSelectbooleanWhether to close the menu when an option is selectedaria-labelstringThe accessibility label for the menuopenbooleanWhether the menu is openonOpenChange(details: OpenChangeDetails) => voidFunction called when the menu opens or closesopen.controlledbooleanWhether the menu's open state is controlled by the usertypeaheadbooleanWhether the pressing printable characters should trigger typeahead navigationdir"ltr" | "rtl"The document's text/writing direction.idstringThe unique identifier of the machine.getRootNode() => ShadowRoot | Node | DocumentA root node to correctly resolve document in custom environments. E.x.: Iframes, Electron.onEscapeKeyDown(event: KeyboardEvent) => voidFunction called when the escape key is pressedonPointerDownOutside(event: PointerDownOutsideEvent) => voidFunction called when the pointer is pressed down outside the componentonFocusOutside(event: FocusOutsideEvent) => voidFunction called when the focus is moved outside the componentonInteractOutside(event: InteractOutsideEvent) => voidFunction called when an interaction happens outside the component
Machine API
The menu api exposes the following methods:
openbooleanWhether the menu is opensetOpen(open: boolean) => voidFunction to open or close the menuhighlightedValuestringThe id of the currently highlighted menuitemsetHighlightedValue(value: string) => voidFunction to set the highlighted menuitemsetParent(parent: Service) => voidFunction to register a parent menu. This is used for submenussetChild(child: Service) => voidFunction to register a child menu. This is used for submenusreposition(options?: Partial<PositioningOptions>) => voidFunction to reposition the popovergetOptionItemState(props: OptionItemProps) => OptionItemStateReturns the state of the option itemgetItemState(props: ItemProps) => ItemStateReturns the state of the menu item
Accessibility
Uses aria-activedescendant pattern to manage focus movement among menu items.
Keyboard Interactions
- SpaceActivates/Selects the highlighted item
- EnterActivates/Selects the highlighted item
- ArrowDownHighlights the next item in the menu
- ArrowUpHighlights the previous item in the menu
- ArrowRightArrowLeftWhen focus is on trigger, opens or closes the submenu depending on reading direction.
- EscCloses the menu and moves focus to the trigger
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