Core utilities for Aria UI
npm install @aria-ui/coreA compact and efficient toolkit for building reactive web components. It powers the Aria UI library, but it can also be used independently.
Uses signals to manage state reactively and automatically update the DOM in response to state changes. It's powered by the mature and battle-tested @preact/signals-core library.
Shares signals easily across widely nested HTML elements through context.
A comprehensive collection of utilities for DOM interactions, enabling declarative management of attributes, styles, and event listeners.
#### Properties
events: EventDeclarations\<Events\>
props: PropDeclarations\<Props\>
setup: (element, options) => void
---
A read-only signal that holds a reactive value.
#### Accessors
get value(): T
###### Deprecated
#### Methods
get(): T
Get the signal's current value.
peek(): T
Get the signal's current value without subscribing.
---
#### Properties
emit: EventEmitter\<Events\>
state: SignalState\<Props\>
---
A mutable signal that can be used to manage reactive state changes.
#### Accessors
set value(value): void
###### Deprecated
#### Methods
get(): T
Get the signal's current value.
peek(): T
Get the signal's current value without subscribing.
set(value): void
Set the value of the signal.
---
An interface thats can be used to register event listeners.
#### Properties
addEventListener: (type, listener) => void
removeEventListener: (type, listener) => void
type BaseElementConstructor\BaseElement & Props
---
type EventDeclaration = \{ bubbles?: boolean; cancelable?: boolean; composed?: boolean; \}
Defines options for an event.
#### Properties
bubbles?: boolean
Whether the event bubbles.
###### Default
false
cancelable?: boolean
Whether the event is cancelable.
###### Default
true
composed?: boolean
Whether the event is composed.
###### Default
false
---
type EventDeclarations\{ [EventType in keyof Required
Map of event types to EventDeclaration options.
---
type EventEmitter\type, detail) => void
---
type PropDeclaration\attribute?: boolean \| string; default: T; fromAttribute?: (value) => T; toAttribute?: (value) => string \| null; \}
Defines options for a property.
#### Properties
attribute?: boolean \| string
Indicates how and whether the property becomes an observed attribute. If the value is false, the property is not added to observedAttributes. If true or absent, the kebab-case version of the property name is observed (e.g. fooBar becomes foo-bar). If a string, the string value is observed (e.g attribute: 'custom-foo-bar').
default: T
The default value of the property.
fromAttribute?: (value) => T
Called to convert an attribute value to a property value.
toAttribute?: (value) => string \| null
Called to convert a property value to an attribute value.
---
type PropDeclarations\{ [K in keyof Required
Map of props to PropDeclaration options.
function defineCustomElement\options): BaseElementConstructor\<Props\>
Defines a custom element constructor.
---
function defineEmit\element, events): (type, detail) => void
---
function getStateFromProps\props): SignalState\<Props\>
---
function registerCustomElement(name, element): void
Adds the given custom element to the custom element registry.
A context is a way to provide and consume signals in a HTML tree.
#### Methods
provide(element, signal): void
Provides a signal to all children of the element.
---
function createContext\key, defaultValue): Context\<T\>
Creates a new context.
function useAnimationFrame(element, effect): () => void
Executes an effect in the next animation frame.
The given effect function will be called when the element is connected, and when the dependencies change afterward.
effect could return a function callback. callback will be called in the next animation frame.
callback could return a function dispose. dispose will be called when the effect is disposed.
---
function useAriaAttribute\element, key, compute): VoidFunction
Sets the computed attribute of the element when it's connected.
This is a TypeScript type-safe version of useAttribute.
---
function useAriaRole(element, role): VoidFunction
Sets the role attribute of the element when it's connected.
You can pass a string or a compute function that returns a string.
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function useAttribute(element, key, compute): VoidFunction
Sets the computed attribute of the element when it's connected.
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function useEventListener\element, type, listener, options?): VoidFunction
Registers an event listener on the element.
---
function useQuerySelector\element, selector, options): ReadonlySignal\<null \| E\>
Returns the first element matching the given selector.
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function useQuerySelectorAll\element, selector, options): ReadonlySignal\<NodeListOf\<E\>\>
Returns all elements matching the given selector.
---
function useStyle\element, key, compute): VoidFunction
Sets the computed style of the element when it's connected.
Base class for all custom elements in Aria UI. It implements the ConnectableElement interface.
#### Constructors
##### Constructor
new BaseElement(): BaseElement
---
Any HTML element that has implemented the addConnectedCallback method.
#### Properties
addConnectedCallback: (callback) => void
Registers a callback to be called when the element is connected to the DOM. This callback can return a cleanup function that will be called when the element is disconnected from the DOM.
type SignalState\{ [K in keyof Required
A plain object containing signals.
---
function assignProps\defaultProps, props?): Readonly\<T\>
Merges two objects, with the second object taking precedence. Only keys present in the first object will be included in the result.
---
function mapSignals\values): SignalState\<T\>
Maps every value in the given object to a signal.
#### Deprecated
---
function mapValues\signals): T
Maps every signal in the given object to its current value.
#### Deprecated
type SignalValue\S _extends_ Signal\T : never
Extracts the value type from a signal type.
---
const batch: \<T\>(fn) => T = _batch
Groups multiple signal updates into a single batch, optimizing performance by reducing the number of updates.
This is a re-export of batch from @preact/signals-core.
---
const untracked: \<T\>(fn) => T = _untracked
Executes a given computation without automatically tracking its dependencies, useful for avoiding unnecessary re-computations.
This is a re-export of untracked from @preact/signals-core.
---
function createComputed\fn): ReadonlySignal\<T\>
Creates a computed signal that automatically updates its value based on the reactive dependencies it uses. Computed signals are read-only and are used to derive state from other signals, recalculating their value when dependencies change.
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function createSignal\value): Signal\<T\>
Creates and returns a new signal with the given initial value. Signals are reactive data sources that can be read and written to, allowing components to reactively update when their values change.
---
function useEffect(element, callback): () => void
Registers a callback to be called when the given element is connected to the DOM. It will track which signals are accessed and re-run their callback when those signals change. The callback can return a cleanup function that will be called when the effect is destroyed.
The effect will be destroyed and all signals it was subscribed to will be unsubscribed from, when the element is disconnected from the DOM. You can also manually destroy the effect by calling the returned function.