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-activedescendant
pattern. - 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-part
attribute 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
id
to theuseMachine
hook. 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
id
of 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
value
property 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.
name
— The property key in thevalue
context that this option is for.type
— The type of option item. Either"checkbox"
or"radio"
.value
— The value of the option item.
The machine invokes an onValueChange
callback when an radio or checkbox option
checked state changes. This callback is invoked with the name
of the option
and its new value.
const [state, send] = useMachine( menu.machine({ value: { order: "", type: [] }, onValueChange(data) { // data => { name: string, value: string | string[] } console.log("values changed", data.value) }, }), )
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="option-item"][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="option-item"][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="option-item"][data-state="checked"] { /* styles for checked state */ }
Methods and Properties
Machine Context
The menu machine exposes the following context properties:
ids
Partial<{ 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.value
Record<string, string | string[]>
The values of radios and checkboxes in the menu.onValueChange
(details: ValueChangeDetails) => void
Callback to be called when the menu values change (for radios and checkboxes).highlightedId
string
The `id` of the active menu item.onSelect
(details: SelectionDetails) => void
Function called when a menu item is selected.anchorPoint
Point
The positioning point for the menu. Can be set by the context menu trigger or the button trigger.loop
boolean
Whether to loop the keyboard navigation.positioning
PositioningOptions
The options used to dynamically position the menucloseOnSelect
boolean
Whether to close the menu when an option is selectedaria-label
string
The accessibility label for the menuopen
boolean
Whether the menu is openonOpenChange
(details: OpenChangeDetails) => void
Function called when the menu opens or closesopen.controlled
boolean
Whether the menu's open state is controlled by the userdir
"ltr" | "rtl"
The document's text/writing direction.id
string
The unique identifier of the machine.getRootNode
() => ShadowRoot | Node | Document
A root node to correctly resolve document in custom environments. E.x.: Iframes, Electron.onPointerDownOutside
(event: PointerDownOutsideEvent) => void
Function called when the pointer is pressed down outside the componentonFocusOutside
(event: FocusOutsideEvent) => void
Function called when the focus is moved outside the componentonInteractOutside
(event: InteractOutsideEvent) => void
Function called when an interaction happens outside the component
Machine API
The menu api
exposes the following methods:
isOpen
boolean
Whether the menu is openopen
() => void
Function to open the menuclose
() => void
Function to close the menuhighlightedId
string
The id of the currently highlighted menuitemsetHighlightedId
(id: string) => void
Function to set the highlighted menuitemsetParent
(parent: Service) => void
Function to register a parent menu. This is used for submenussetChild
(child: Service) => void
Function to register a child menu. This is used for submenusvalue
Record<string, string | string[]>
The value of the menu options itemsetValue
(name: string, value: any) => void
Function to set the value of the menu options itemreposition
(options?: Partial<PositioningOptions>) => void
Function to reposition the popovergetOptionItemState
(props: OptionItemProps) => OptionItemState
Returns the state of the option itemgetItemState
(props: ItemProps) => ItemState
Returns 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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