Description
The Dropdown component is a fully custom-made component. This allows us to change its form based on context (small screens, touch devices, etc.)
When to use it:
When you need to provide a considerable amount of options to the user and do not have the space to do so. Other reasons may be because the hidden options may clutter the interface and need only be displayed after the user specifically requests it.
- when space is an issue (not enough)
- when you wish to reduce visual clutter
- when it is intuitive for the user to request the hidden content
When not to use it:
- do not use this if you have only a few menu options which could otherwise be shown such as Radio buttons or ToggleButtons.
NB: This pattern can be constructed in a number of ways to achieve a similar effect - from using the HTML 'select' element to custom building with divs, spans, and JavaScript.
Action Menu
The Dropdown component can easily be used as a so-called action button by setting the prop action_menu={true}
. In mobile view, the title/text will be hidden, only showing the icon and the DrawerList will open from the browser bottom.
Menu Button
The Dropdown component can easily be used as a so called menu button by setting the prop more_menu={true}
which shows then the more icon, appears as dots. You also could use prevent_selection={true}
together with an empty title title=""
and aria-label="Choose an item"
.
Accessibility
Both the Action Menu and the Menu Button (and if prevent_selection
is true), the Dropdown will use role="menu"
, instead of role="menuitems"
for better screen reader support.
Custom size
Changing the width of the Dropdown component by CSS is easy done by doing:
.dnb-dropdown {--dropdown-width: 20rem; /* custom width */}
You can also set the width directly, but then it has to be defined like so (including min-width
):
/** Because of the included label/status etc. we target the "__shell" */.dnb-dropdown__shell {width: 10rem;}/** In order to change only the drawer-list width */.dnb-dropdown .dnb-drawer-list__root {width: 10rem;}/** If more_menu={true} is used */.dnb-dropdown--is-popup .dnb-drawer-list__root {width: 10rem;}
Demos
Default dropdown
No value
is defined, but a title
is given.
const data = [ // Every data item can, beside "content" - contain what ever { // (optional) can be what ever selected_key: 'key_0', // (optional) is show instead of "content", once selected selected_value: 'Item 1 Value', // Item content as a string or array content: 'Item 1 Content', }, { selected_key: 'key_1', content: ['Item 2 Value', 'Item 2 Content'], }, { selected_value: ( <NumberFormat always_selectall ban> 11345678962 </NumberFormat> ), content: [ <NumberFormat key="ban" always_selectall ban> 11345678962 </NumberFormat>, 'Bank account number', ], }, { selected_key: 'key_2', selected_value: 'Item 3 Value', content: ['Item 3 Content A', 'Item 3 Content B'], }, { selected_key: 'key_3', selected_value: 'Item 4 Value', content: ['Item 4 Content A', <>Custom Component</>], }, ] render( <Dropdown data={data} label="Label" title="Please select a value" on_change={({ data }) => { console.log('on_change', data) }} />, )
Dropdown with different item content directions
<Dropdown label="Label" data={[ ['Vertical', 'alignment'], <> <P modifier="medium">Vertical</P> <P>alignment</P> </>, <Dropdown.HorizontalItem key="item-1"> <P modifier="medium" right="x-small"> Horizontal </P> <P>alignment</P> </Dropdown.HorizontalItem>, ]} />
Icon on left side
<Dropdown label="Label" icon_position="left" data={data} value={3} skip_portal={true} on_change={({ data: selectedDataItem }) => { console.log('on_change', selectedDataItem) }} on_show={() => { console.log('on_show') }} />
ActionMenu
The ActionMenu will change its characteristics in mobile view. It will hide the title, and the DrawerList will be placed on the bottom of the page.
<Dropdown title="ActionMenu" action_menu={true} align_dropdown="left" data={() => ({ trash: ( <> <Icon icon={trash} right /> Move to trash </> ), download: ( <> <Icon icon={download} right /> Download </> ), })} on_change={({ value }) => console.log('action:', value)} />
MoreMenu
No lasting selection will be made.
<Dropdown more_menu={true} size="small" title="Choose an item" data={() => [ <Link href="/" key="item-1"> Go to this Link </Link>, 'Or press on me', <>Custom component</>, ]} right="small" /> <Dropdown prevent_selection={true} align_dropdown="right" size="small" title={null} aria-label="Choose an item" data={() => ({ first: ( <Link href="/" key="item-1"> Go to this Link </Link> ), second: 'Or press on me', third: <>Custom component</>, })} right="small" /> <Dropdown more_menu={true} title="Choose an item" data={[ <Link href="/" key="item-1"> Go to this Link </Link>, 'Or press on me', <>Custom component</>, ]} right="small" /> <Dropdown prevent_selection={true} align_dropdown="right" title={null} aria-label="Choose an item" data={() => ({ first: ( <Link href="/" key="item-1"> Go to this Link </Link> ), second: 'Or press on me', third: <>Custom component</>, })} on_change={({ value }) => { console.log('on_change', value) }} on_select={({ active_item }) => { console.log('on_select', active_item) }} />
Dropdown as tertiary variant
<Dropdown variant="tertiary" independent_width={true} icon_position="left" align_dropdown="left" data={data} />
Custom item events
const CustomComponent = () => ( <CustomComponentInner onTouchStart={preventDefault} onClick={(e) => { console.log('Do something different') preventDefault(e) }} > Custom event handler </CustomComponentInner> ) const CustomComponentInner = styled.span` display: block; width: 100%; margin: -1rem -2rem -1rem -1rem; padding: 1rem 2rem 1rem 1rem; ` const preventDefault = (e) => { e.stopPropagation() e.preventDefault() } render( <Dropdown action_menu right label="Label" title="Choose an item" data={() => ({ first: ( <Link href="/" key="item-1"> Go to this Link </Link> ), second: 'Or press on me', third: <CustomComponent key="item-2" />, })} on_change={({ value }) => { console.log('More menu:', value) }} suffix={<HelpButton title="Modal Title">Modal content</HelpButton>} />, )
Dropdown in different sizes
Four sizes are available: small
, default
, medium
and large
<Flex.Vertical> <Dropdown label="Label" size="default" data={() => data} /> <Dropdown label="Label" size="medium" data={() => data} /> <Dropdown label="Label" size="large" data={() => data} /> </Flex.Vertical>
Custom width
const CustomWidthOne = styled(Dropdown)` .dnb-dropdown__shell { width: 10rem; } ` const CustomWidthTwo = styled(Dropdown)` &.dnb-dropdown--is-popup .dnb-drawer-list__root { width: 12rem; } ` const CustomWidthThree = styled(Dropdown)` /** Change the "__shell" width */ .dnb-dropdown__shell { width: 10rem; } /** Change the "__list" width */ .dnb-drawer-list__root { width: 20rem; } ` const CustomWidthFour = styled(Dropdown)` width: 60%; min-width: 224px; /** 14rem (please use pixels on min-width!) */ max-width: 25rem; /** In case we have a label */ .dnb-form-label + .dnb-dropdown__inner { width: 100%; } ` render( <Flex.Vertical> <CustomWidthOne label="Label" size="default" icon_position="left" data={data} /> <CustomWidthTwo label="Label" size="small" more_menu data={data} /> <CustomWidthThree label="Label" size="large" align_dropdown="right" data={data} /> <CustomWidthFour title="Min and max width" stretch={true} data={data} /> </Flex.Vertical>, )
Dropdown with status
And vertical label layout.
<Dropdown data={data} label="Label" label_direction="vertical" status="Message to the user" />
Findable list
With long list to make it scrollable and searchable
const scrollableData = [ { content: 'A', }, { content: 'B', }, { selected_value: ( <NumberFormat always_selectall ban> 11345678962 </NumberFormat> ), content: [ <NumberFormat key="ban-1" always_selectall ban> 11345678962 </NumberFormat>, 'C', ], }, { selected_value: ( <NumberFormat always_selectall ban> 15349648901 </NumberFormat> ), content: [ <NumberFormat key="ban-2" always_selectall ban> 15349648901 </NumberFormat>, 'D', ], }, { content: 'E', }, { selected_key: 'key_1', selected_value: 'Find me by keypress', content: ['F', 'F', 'F', 'F'], }, { content: 'G', }, { content: 'H', }, ] render( <Dropdown data={scrollableData} value="key_1" // use either index (5) or selected_key: 'key_1' label="Label" />, )
Disabled dropdown
<Dropdown disabled data={['Disabled Dropdown']} label="Label" />
Disabled tertiary dropdown
<Dropdown disabled variant="tertiary" data={['Disabled Dropdown']} label="Disabled tertiary dropdown" />
DrawerList opened
Only to visualize and used for visual testing