packages/react-aria/docs/slider/useSlider.mdx
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import {Layout} from '@react-spectrum/docs'; export default Layout;
import docs from 'docs:@react-aria/slider'; import {HeaderInfo, FunctionAPI, TypeContext, InterfaceType, TypeLink, PageDescription} from '@react-spectrum/docs'; import packageData from '@react-aria/slider/package.json'; import statelyDocs from 'docs:@react-stately/slider'; import i18nDocs from 'docs:@react-aria/i18n'; import Anatomy from './anatomy.svg'; import ChevronRight from '@spectrum-icons/workflow/ChevronRight';
<PageDescription>{docs.exports.useSlider.description}</PageDescription>
<HeaderInfo packageData={packageData} componentNames={['useSlider', 'useSliderThumb']} sourceData={[ {type: 'W3C', url: 'https://www.w3.org/WAI/ARIA/apg/patterns/slider/'} ]} />
The <input type="range">
HTML element can be used to build a slider, however it is
very difficult to style cross browser. useSlider and useSliderThumb help achieve accessible
sliders that can be styled as needed.
group of slider elements via ARIA<output> elementSliders consist of a track element showing the range of available values, one or more thumbs showing the current values, an optional <output> element displaying the current values textually, and a label. The thumbs can be dragged to allow a user to change their value. In addition, the track can be clicked to move the nearest thumb to that position.
useSlider returns several sets of props and you should spread each one onto the appropriate element:
<TypeContext.Provider value={docs.links}> <InterfaceType properties={docs.links[docs.exports.useSlider.return.id].properties} /> </TypeContext.Provider>
If there is no visual label, an aria-label or aria-labelledby prop must be passed instead
to identify the element to screen readers.
useSliderThumb returns props that you should spread onto the appropriate elements, along with states for styling:
<TypeContext.Provider value={docs.links}> <InterfaceType properties={docs.links[docs.exports.useSliderThumb.return.id].properties} /> </TypeContext.Provider>
If there is no visual label, an aria-label or aria-labelledby prop must be passed instead
to identify each thumb to screen readers.
Slider state is managed by the <TypeLink links={statelyDocs.links} type={statelyDocs.exports.useSliderState} /> hook.
This example shows how to build a simple horizontal slider with a single thumb. In addition, it includes a label
which can be clicked to focus the slider thumb, and an <output> element to display the current slider value as
text. This is formatted using a locale aware number formatter provided by the useNumberFormatter hook.
The <input> element inside the thumb is used to represent the slider to assistive technology, and is hidden from view
using the VisuallyHidden component. The thumb also uses the useFocusRing hook to
display using a different color when it is keyboard focused (try tabbing to it).
import {useSlider, useSliderThumb} from '@react-aria/slider';
import {useSliderState} from '@react-stately/slider';
import {useFocusRing} from '@react-aria/focus';
import {VisuallyHidden} from '@react-aria/visually-hidden';
import {mergeProps} from '@react-aria/utils';
import {useNumberFormatter} from '@react-aria/i18n';
function Slider(props) {
let trackRef = React.useRef(null);
let numberFormatter = useNumberFormatter(props.formatOptions);
let state = useSliderState({...props, numberFormatter});
let {
groupProps,
trackProps,
labelProps,
outputProps
} = useSlider(props, state, trackRef);
return (
<div {...groupProps} className={`slider ${state.orientation}`}>
{props.label &&
<div className="label-container">
<label {...labelProps}>{props.label}</label>
<output {...outputProps}>
{state.getThumbValueLabel(0)}
</output>
</div>
}
<div {...trackProps} ref={trackRef} className={`track ${state.isDisabled ? 'disabled' : ''}`}>
<Thumb index={0} state={state} trackRef={trackRef} name={props.name} />
</div>
</div>
);
}
function Thumb(props) {
let {state, trackRef, index, name} = props;
let inputRef = React.useRef(null);
let {thumbProps, inputProps, isDragging} = useSliderThumb({
index,
trackRef,
inputRef,
name
}, state);
let {focusProps, isFocusVisible} = useFocusRing();
return (
<div
{...thumbProps}
className={`thumb ${isFocusVisible ? 'focus' : ''} ${isDragging ? 'dragging' : ''}`}>
<VisuallyHidden>
<input ref={inputRef} {...mergeProps(inputProps, focusProps)} />
</VisuallyHidden>
</div>
);
}
<Slider label="Opacity" />
.slider {
display: flex;
}
.slider.horizontal {
flex-direction: column;
width: 300px;
}
.slider.vertical {
height: 150px;
}
.label-container {
display: flex;
justify-content: space-between;
}
.slider.horizontal .track {
height: 30px;
width: 100%;
}
/* track line */
.track:before {
content: attr(x);
display: block;
position: absolute;
background: gray;
}
.slider.horizontal .track:before {
height: 3px;
width: 100%;
top: 50%;
transform: translateY(-50%);
}
.slider.vertical .track {
width: 30px;
height: 100%;
}
.slider.vertical .track:before {
width: 3px;
height: 100%;
left: 50%;
transform: translateX(-50%);
}
.thumb {
width: 20px;
height: 20px;
border-radius: 50%;
background: gray;
}
.thumb.dragging {
background: dimgray;
}
.thumb.focus {
background: orange;
}
.slider.horizontal .thumb {
top: 50%;
}
.slider.vertical .thumb {
left: 50%;
}
.track.disabled {
opacity: 0.4;
}
This example shows how to build a slider with multiple thumbs. The thumb component is the same one shown in the previous
example. The main difference in this example is that there are two <Thumb> elements rendered with different index props.
In addition, the <output> element uses state.getThumbValueLabel for each thumb to display the selected range.
function RangeSlider(props) {
let trackRef = React.useRef(null);
let numberFormatter = useNumberFormatter(props.formatOptions);
let state = useSliderState({...props, numberFormatter});
let {
groupProps,
trackProps,
labelProps,
outputProps
} = useSlider(props, state, trackRef);
return (
<div {...groupProps} className={`slider ${state.orientation}`}>
{props.label &&
<div className="label-container">
<label {...labelProps}>{props.label}</label>
<output {...outputProps}>
{`${state.getThumbValueLabel(0)} - ${state.getThumbValueLabel(1)}`}
</output>
</div>
}
<div {...trackProps} ref={trackRef} className={`track ${state.isDisabled ? 'disabled' : ''}`}>
<Thumb index={0} state={state} trackRef={trackRef} />
<Thumb index={1} state={state} trackRef={trackRef} />
</div>
</div>
);
}
<RangeSlider
label="Price Range"
formatOptions={{style: 'currency', currency: 'USD'}}
maxValue={500}
defaultValue={[100, 350]}
step={10} />
The following examples show how to use the Slider and RangeSlider components created in the above examples.
Sliders are horizontally oriented by default. The orientation prop can be set to "vertical" to create a vertical slider.
This example also uses aria-label rather than label to create a slider with no visible label.
<Slider
orientation="vertical"
aria-label="Opacity"
maxValue={1}
step={0.01} />
The value prop paired with the onChange event can be used to make a slider controlled. The value must fall between the Slider's minimum and maximum values, which default to 0 and 100 respectively. The onChange event receives the new slider value as a parameter, which can be used to update state.
function Example() {
let [value, setValue] = React.useState(25);
return (
<>
<Slider
label="Cookies to buy"
value={value}
onChange={setValue} />
<p>Current value: {value}</p>
</>
);
}
Multi thumb sliders specify their values as an array rather than a single number.
function Example() {
let [value, setValue] = React.useState([25, 75]);
return (
<>
<RangeSlider
label="Range"
value={value}
onChange={setValue} />
<p>Current value: {value.join(' – ')}</p>
</>
);
}
The onChangeEnd prop can be used to handle when a user stops dragging a slider, whereas the onChange prop is called as the user drags.
function Example() {
let [value, setValue] = React.useState(25);
return (
<>
<Slider
label="Cookies to buy"
defaultValue={value}
onChangeEnd={setValue} />
<p>Current value: {value}</p>
</>
);
}
By default, slider values are percentages between 0 and 100. A different scale can be used by setting the minValue and maxValue props.
<Slider
label="Cookies to buy"
minValue={50}
maxValue={150}
defaultValue={100} />
Values are formatted as a percentage by default, but this can be modified by using the formatOptions prop to specify a different format.
formatOptions is compatible with the option parameter of Intl.NumberFormat and is applied based on the current locale.
<Slider
label="Currency"
formatOptions={{style: 'currency', currency: 'JPY'}}
defaultValue={60} />
The step prop can be used to snap the value to certain increments. The steps are calculated
starting from the minimum. For example, if minValue={2}, and step={3}, the valid step values would be 2, 5, 8, 11, etc.
This example allows increments of 5 between 0 and 100.
<Slider
label="Amount"
formatOptions={{style: 'currency', currency: 'USD'}}
minValue={0}
maxValue={100}
step={5} />
A slider can be disabled using the isDisabled prop.
<Slider
label="Cookies to share"
defaultValue={25}
isDisabled />
useSliderThumb supports the name prop for integration with HTML forms.
<Slider
label="Opacity"
defaultValue={50}
name="opacity" />
Formatting the value that should be displayed in the value label or aria-valuetext
is handled by <TypeLink links={statelyDocs.links} type={statelyDocs.exports.useSliderState} />.
The formatting can be controlled using the formatOptions prop.
If you want to change locales, the <TypeLink links={i18nDocs.links} type={i18nDocs.exports.I18nProvider} />
must be somewhere in the hierarchy above the Slider.
This will tell the formatter what locale to use.
In right-to-left languages, the slider should be mirrored. The label is right-aligned, the value is left-aligned. Ensure that your CSS accounts for this.