reakit
Version:
Toolkit for building accessible rich web apps with React
437 lines (312 loc) • 14 kB
Markdown
---
path: /docs/radio/
---
# Radio
Accessible `Radio` component that follows the [WAI-ARIA Radio Button/Group Pattern](https://www.w3.org/TR/wai-aria-practices/#radiobutton).
<carbon-ad></carbon-ad>
## Installation
```sh
npm install reakit
```
Learn more in [Get started](/docs/get-started/).
## Usage
```jsx
import { useRadioState, Radio, RadioGroup } from "reakit/Radio";
function Example() {
const radio = useRadioState();
return (
<RadioGroup {...radio} aria-label="fruits">
<label>
<Radio {...radio} value="apple" /> apple
</label>
<label>
<Radio {...radio} value="orange" /> orange
</label>
<label>
<Radio {...radio} value="watermelon" /> watermelon
</label>
</RadioGroup>
);
}
```
### Default value
To set a default value, you can pass the `value` of the current checked radio to the `state` property on `useRadioState`.
```jsx
import { useRadioState, Radio, RadioGroup } from "reakit/Radio";
function Example() {
const radio = useRadioState({ state: "orange" });
return (
<RadioGroup {...radio} aria-label="fruits">
<label>
<Radio {...radio} value="apple" /> apple
</label>
<label>
<Radio {...radio} value="orange" /> orange
</label>
<label>
<Radio {...radio} value="watermelon" /> watermelon
</label>
</RadioGroup>
);
}
```
## Accessibility
- `Radio` has role `radio`.
- `Radio` has `aria-checked` set to `true` when it's checked. Otherwise, `aria-checked` is set to `false`.
- `Radio` extends the accessibility features of [CompositeItem](/docs/composite/#accessibility), which means it uses the [roving tabindex](https://www.w3.org/TR/wai-aria-practices-1.1/#kbd_roving_tabindex) method to manage focus.
Learn more in [Accessibility](/docs/accessibility/).
## Composition
- `Radio` uses [CompositeItem](/docs/composite/), and is used by [FormRadio](/docs/form/) and [MenuItemRadio](/docs/radio/).
- `RadioGroup` uses [Composite](/docs/composite/).
Learn more in [Composition](/docs/composition/#props-hooks).
## Props
<!-- Automatically generated -->
### `useRadioState`
- **`baseId`**
<code>string</code>
ID that will serve as a base for all the items IDs.
- **`unstable_virtual`** <span title="Experimental">⚠️</span>
<code>boolean</code>
If enabled, the composite element will act as an
[aria-activedescendant](https://www.w3.org/TR/wai-aria-practices-1.1/#kbd_focus_activedescendant)
container instead of
[roving tabindex](https://www.w3.org/TR/wai-aria-practices/#kbd_roving_tabindex).
DOM focus will remain on the composite while its items receive virtual focus.
- **`rtl`**
<code>boolean</code>
Determines how `next` and `previous` functions will behave. If `rtl` is
set to `true`, they will be inverted. This only affects the composite
widget behavior. You still need to set `dir="rtl"` on HTML/CSS.
- **`orientation`**
<code>"horizontal" | "vertical" | undefined</code>
Defines the orientation of the composite widget. If the composite has a
single row or column (one-dimensional), the `orientation` value determines
which arrow keys can be used to move focus:
- `undefined`: all arrow keys work.
- `horizontal`: only left and right arrow keys work.
- `vertical`: only up and down arrow keys work.
It doesn't have any effect on two-dimensional composites.
- **`currentId`**
<code>string | null | undefined</code>
The current focused item `id`.
- `undefined` will automatically focus the first enabled composite item.
- `null` will focus the base composite element and users will be able to
navigate out of it using arrow keys.
- If `currentId` is initially set to `null`, the base composite element
itself will have focus and users will be able to navigate to it using
arrow keys.
- **`loop`**
<code>boolean | "horizontal" | "vertical"</code>
On one-dimensional composites:
- `true` loops from the last item to the first item and vice-versa.
- `horizontal` loops only if `orientation` is `horizontal` or not set.
- `vertical` loops only if `orientation` is `vertical` or not set.
- If `currentId` is initially set to `null`, the composite element will
be focused in between the last and first items.
On two-dimensional composites:
- `true` loops from the last row/column item to the first item in the
same row/column and vice-versa. If it's the last item in the last row, it
moves to the first item in the first row and vice-versa.
- `horizontal` loops only from the last row item to the first item in
the same row.
- `vertical` loops only from the last column item to the first item in
the column row.
- If `currentId` is initially set to `null`, vertical loop will have no
effect as moving down from the last row or up from the first row will
focus the composite element.
- If `wrap` matches the value of `loop`, it'll wrap between the last
item in the last row or column and the first item in the first row or
column and vice-versa.
- **`wrap`**
<code>boolean | "horizontal" | "vertical"</code>
**Has effect only on two-dimensional composites**. If enabled, moving to
the next item from the last one in a row or column will focus the first
item in the next row or column and vice-versa.
- `true` wraps between rows and columns.
- `horizontal` wraps only between rows.
- `vertical` wraps only between columns.
- If `loop` matches the value of `wrap`, it'll wrap between the last
item in the last row or column and the first item in the first row or
column and vice-versa.
- **`shift`**
<code>boolean</code>
**Has effect only on two-dimensional composites**. If enabled, moving up
or down when there's no next item or the next item is disabled will shift
to the item right before it.
- **`state`**
<code>string | number | undefined</code>
The `value` attribute of the current checked radio.
### `Radio`
- **`disabled`**
<code>boolean | undefined</code>
Same as the HTML attribute.
- **`focusable`**
<code>boolean | undefined</code>
When an element is `disabled`, it may still be `focusable`. It works
similarly to `readOnly` on form elements. In this case, only
`aria-disabled` will be set.
- **`id`**
<code>string | undefined</code>
Same as the HTML attribute.
- **`value`**
<code>string | number</code>
Same as the `value` attribute.
- **`checked`**
<code>boolean | undefined</code>
Same as the `checked` attribute.
<details><summary>17 state props</summary>
> These props are returned by the state hook. You can spread them into this component (`{...state}`) or pass them separately. You can also provide these props from your own state logic.
- **`baseId`**
<code>string</code>
ID that will serve as a base for all the items IDs.
- **`unstable_virtual`** <span title="Experimental">⚠️</span>
<code>boolean</code>
If enabled, the composite element will act as an
[aria-activedescendant](https://www.w3.org/TR/wai-aria-practices-1.1/#kbd_focus_activedescendant)
container instead of
[roving tabindex](https://www.w3.org/TR/wai-aria-practices/#kbd_roving_tabindex).
DOM focus will remain on the composite while its items receive virtual focus.
- **`orientation`**
<code>"horizontal" | "vertical" | undefined</code>
Defines the orientation of the composite widget. If the composite has a
single row or column (one-dimensional), the `orientation` value determines
which arrow keys can be used to move focus:
- `undefined`: all arrow keys work.
- `horizontal`: only left and right arrow keys work.
- `vertical`: only up and down arrow keys work.
It doesn't have any effect on two-dimensional composites.
- **`unstable_moves`** <span title="Experimental">⚠️</span>
<code>number</code>
Stores the number of moves that have been performed by calling `move`,
`next`, `previous`, `up`, `down`, `first` or `last`.
- **`currentId`**
<code>string | null | undefined</code>
The current focused item `id`.
- `undefined` will automatically focus the first enabled composite item.
- `null` will focus the base composite element and users will be able to
navigate out of it using arrow keys.
- If `currentId` is initially set to `null`, the base composite element
itself will have focus and users will be able to navigate to it using
arrow keys.
- **`items`**
<code>Item[]</code>
Lists all the composite items with their `id`, DOM `ref`, `disabled` state
and `groupId` if any. This state is automatically updated when
`registerItem` and `unregisterItem` are called.
- **`registerItem`**
<code>(item: Item) => void</code>
Registers a composite item.
- **`unregisterItem`**
<code>(id: string) => void</code>
Unregisters a composite item.
- **`setCurrentId`**
<code title="(value: SetStateAction<string | null | undefined>) => void">(value: SetStateAction<string | null | undefine...</code>
Sets `currentId`. This is different from `composite.move` as this only
updates the `currentId` state without moving focus. When the composite
widget gets focused by the user, the item referred by the `currentId`
state will get focus.
- **`next`**
<code>(unstable_allTheWay?: boolean | undefined) => void</code>
Moves focus to the next item.
- **`previous`**
<code>(unstable_allTheWay?: boolean | undefined) => void</code>
Moves focus to the previous item.
- **`up`**
<code>(unstable_allTheWay?: boolean | undefined) => void</code>
Moves focus to the item above.
- **`down`**
<code>(unstable_allTheWay?: boolean | undefined) => void</code>
Moves focus to the item below.
- **`first`**
<code>() => void</code>
Moves focus to the first item.
- **`last`**
<code>() => void</code>
Moves focus to the last item.
- **`state`**
<code>string | number | undefined</code>
The `value` attribute of the current checked radio.
- **`setState`**
<code title="(value: SetStateAction<string | number | undefined>) => void">(value: SetStateAction<string | number | undefi...</code>
Sets `state`.
</details>
### `RadioGroup`
- **`disabled`**
<code>boolean | undefined</code>
Same as the HTML attribute.
- **`focusable`**
<code>boolean | undefined</code>
When an element is `disabled`, it may still be `focusable`. It works
similarly to `readOnly` on form elements. In this case, only
`aria-disabled` will be set.
<details><summary>12 state props</summary>
> These props are returned by the state hook. You can spread them into this component (`{...state}`) or pass them separately. You can also provide these props from your own state logic.
- **`baseId`**
<code>string</code>
ID that will serve as a base for all the items IDs.
- **`unstable_virtual`** <span title="Experimental">⚠️</span>
<code>boolean</code>
If enabled, the composite element will act as an
[aria-activedescendant](https://www.w3.org/TR/wai-aria-practices-1.1/#kbd_focus_activedescendant)
container instead of
[roving tabindex](https://www.w3.org/TR/wai-aria-practices/#kbd_roving_tabindex).
DOM focus will remain on the composite while its items receive virtual focus.
- **`orientation`**
<code>"horizontal" | "vertical" | undefined</code>
Defines the orientation of the composite widget. If the composite has a
single row or column (one-dimensional), the `orientation` value determines
which arrow keys can be used to move focus:
- `undefined`: all arrow keys work.
- `horizontal`: only left and right arrow keys work.
- `vertical`: only up and down arrow keys work.
It doesn't have any effect on two-dimensional composites.
- **`currentId`**
<code>string | null | undefined</code>
The current focused item `id`.
- `undefined` will automatically focus the first enabled composite item.
- `null` will focus the base composite element and users will be able to
navigate out of it using arrow keys.
- If `currentId` is initially set to `null`, the base composite element
itself will have focus and users will be able to navigate to it using
arrow keys.
- **`wrap`**
<code>boolean | "horizontal" | "vertical"</code>
**Has effect only on two-dimensional composites**. If enabled, moving to
the next item from the last one in a row or column will focus the first
item in the next row or column and vice-versa.
- `true` wraps between rows and columns.
- `horizontal` wraps only between rows.
- `vertical` wraps only between columns.
- If `loop` matches the value of `wrap`, it'll wrap between the last
item in the last row or column and the first item in the first row or
column and vice-versa.
- **`unstable_moves`** <span title="Experimental">⚠️</span>
<code>number</code>
Stores the number of moves that have been performed by calling `move`,
`next`, `previous`, `up`, `down`, `first` or `last`.
- **`groups`**
<code>Group[]</code>
Lists all the composite groups with their `id` and DOM `ref`. This state
is automatically updated when `registerGroup` and `unregisterGroup` are
called.
- **`items`**
<code>Item[]</code>
Lists all the composite items with their `id`, DOM `ref`, `disabled` state
and `groupId` if any. This state is automatically updated when
`registerItem` and `unregisterItem` are called.
- **`setCurrentId`**
<code title="(value: SetStateAction<string | null | undefined>) => void">(value: SetStateAction<string | null | undefine...</code>
Sets `currentId`. This is different from `composite.move` as this only
updates the `currentId` state without moving focus. When the composite
widget gets focused by the user, the item referred by the `currentId`
state will get focus.
- **`first`**
<code>() => void</code>
Moves focus to the first item.
- **`last`**
<code>() => void</code>
Moves focus to the last item.
- **`move`**
<code>(id: string | null) => void</code>
Moves focus to a given item ID.
</details>