Dropdown

Dropdown also known as Select, is used to choose an item from a collection of options.

Import#


import { Dropdown } from 'primereact/dropdown';

Basic#

Dropdown is used as a controlled component with value and onChange properties along with an options collection. Label and value of an option are defined with the optionLabel and optionValue properties respectively. Default property name for the optionLabel is label and value for the optionValue. If optionValue is omitted and the object has no value property, the object itself becomes the value of an option. Note that, when options are simple primitive values such as a string array, no optionLabel and optionValue would be necessary.


<Dropdown value={selectedCity} onChange={(e) => setSelectedCity(e.value)} options={cities} optionLabel="name" 
    placeholder="Select a City" className="w-full md:w-14rem" />

Editable#

When editable is present, the input can also be entered with typing.


<Dropdown value={selectedCity} onChange={(e) => setSelectedCity(e.value)} options={cities} optionLabel="name" 
    editable placeholder="Select a City" className="w-full md:w-14rem" />

Group#

Options can be grouped when a nested data structures is provided. To define the label of a group optionGroupLabel property is needed and also optionGroupChildren is required to define the property that refers to the children of a group.


<Dropdown value={selectedCity} onChange={(e) => setSelectedCity(e.value)} options={groupedCities} optionLabel="label" 
    optionGroupLabel="label" optionGroupChildren="items" optionGroupTemplate={groupedItemTemplate} className="w-full md:w-14rem" placeholder="Select a City" />

Template#

Options and the selected option display support templating with itemTemplate and valueTemplate properties respectively.


<Dropdown value={selectedCountry} onChange={(e) => setSelectedCountry(e.value)} options={countries} optionLabel="name" placeholder="Select a Country" 
    valueTemplate={selectedCountryTemplate} itemTemplate={countryOptionTemplate} className="w-full md:w-14rem" />

Filter#

Dropdown provides built-in filtering that is enabled by adding the filter property.


<Dropdown value={selectedCountry} onChange={(e) => setSelectedCountry(e.value)} options={countries} optionLabel="name" placeholder="Select a Country" 
    filter valueTemplate={selectedCountryTemplate} itemTemplate={countryOptionTemplate} className="w-full md:w-14rem" />

Clear Icon#

When showClear is enabled, a clear icon is added to reset the Dropdown.


<Dropdown value={selectedCity} onChange={(e) => setSelectedCity(e.value)} options={cities} optionLabel="name" 
    showClear placeholder="Select a City" className="w-full md:w-14rem" />

Virtual Scroll#

VirtualScroller is used to render a long list of options efficiently like 100K records in this demo. The configuration is done with virtualScrollerOptions property, refer to the VirtualScroller for more information about the available options as it is used internally by Dropdown.


<Dropdown value={selectedItem} onChange={(e) => setSelectedItem(e.value)} options={items} virtualScrollerOptions={{ itemSize: 38 }} 
    placeholder="Select Item" className="w-full md:w-14rem" />

Float Label#

A floating label appears on top of the input field when focused.

Select a City


<span className="p-float-label">
    <Dropdown inputId="dd-city" value={selectedCity} onChange={(e) => setSelectedCity(e.value)} options={cities} optionLabel="name" className="w-full md:w-14rem" />
    <label htmlFor="dd-city">Select a City</label>
</span>

Invalid#

Invalid state style is added using the p-invalid class to indicate a failed validation.


<Dropdown value={selectedCity} onChange={(e) => setSelectedCity(e.value)} options={cities} optionLabel="name" 
    placeholder="Select a City" className="p-invalid w-full md:w-14rem" />

Disabled#

When disabled is present, the element cannot be edited and focused.


<Dropdown disabled placeholder="Select a City" className="w-full md:w-14rem" />

Form#

Compatibility with popular React form libraries.

Formik#

Formik is a popular library for handling forms in React.


<Toast ref={toast} />
<Dropdown
    inputId="city"
    name="city"
    value={formik.values.city}
    options={cities}
    optionLabel="name"
    placeholder="Select a City"
    onChange={(e) => {
        formik.setFieldValue('city', e.value);
    }}
/>
{getFormErrorMessage('city')}
<Button type="submit" label="Submit" />

Hook Form#

React Hook Form is another popular React library to handle forms.


<Toast ref={toast} />
<Controller
    name="city"
    control={control}
    rules={{ required: 'City is required.' }}
    render={({ field, fieldState }) => (
        <Dropdown
            value={field.value}
            optionLabel="name"
            placeholder="Select a City"
            name="city"
            options={cities}
            control={control}
            onChange={(e) => field.onChange(e.value)}
            className={classNames({ 'p-invalid': fieldState.error })}
        />
    )}
/>
{getFormErrorMessage('city')}
<Button type="submit" label="Submit" />

Style#

Following is the list of structural style classes, for theming classes visit theming page.

Name	Element
p-dropdown	Container element.
p-dropdown-label	Element to display label of selected option.
p-dropdown-trigger	Icon element.
p-dropdown-panel	Icon element.
p-dropdown-items-wrapper	Wrapper element of items list.
p-dropdown-items	List element of items.
p-dropdown-item	An item in the list.
p-dropdown-filter-container	Container of filter input.
p-dropdown-filter	Filter element.
p-dropdown-open	Container element when overlay is visible.

Accessibility guide documents the specification of this component based on WCAG guidelines, the implementation is in progress.

Accessibility#

Screen Reader

Value to describe the component can either be provided with aria-labelledby or aria-label props. The dropdown element has a combobox role in addition to aria-haspopup and aria-expanded attributes. If the editable option is enabled aria-autocomplete is also added. The relation between the combobox and the popup is created with aria-controls and aria-activedescendant attribute is used to instruct screen reader which option to read during keyboard navigation within the popup list.

The popup list has an id that refers to the aria-controls attribute of the combobox element and uses listbox as the role. Each list item has an option role, an id to match the aria-activedescendant of the input element along with aria-label, aria-selected and aria-disabled attributes.

If filtering is enabled, filterInputProps can be defined to give aria-* props to the filter input element.


<span id="dd1">Options</span>
<Dropdown aria-labelledby="dd1" />

<Dropdown aria-label="Options" />

Closed State Keyboard Support

Key	Function
tab	Moves focus to the dropdown element.
space	Opens the popup and moves visual focus to the selected option, if there is none then first option receives the focus.
down arrow	Opens the popup and moves visual focus to the selected option, if there is none then first option receives the focus.
up arrow	Opens the popup and moves visual focus to the selected option, if there is none then last option receives the focus.

Popup Keyboard Support

Key	Function
tab	Moves focus to the next focusable element in the popup, if there is none then first focusable element receives the focus.
shift + tab	Moves focus to the previous focusable element in the popup, if there is none then last focusable element receives the focus.
enter	Selects the focused option and closes the popup.
space	Selects the focused option and closes the popup.
escape	Closes the popup, moves focus to the dropdown element.
down arrow	Moves focus to the next option, if there is none then visual focus does not change.
up arrow	Moves focus to the previous option, if there is none then visual focus does not change.
right arrow	If the dropdown is editable, removes the visual focus from the current option and moves input cursor to one character left.
left arrow	If the dropdown is editable, removes the visual focus from the current option and moves input cursor to one character right.
home	If the dropdown is editable, moves input cursor at the end, if not then moves focus to the first option.
end	If the dropdown is editable, moves input cursor at the beginning, if not then moves focus to the last option.
any printable character	Moves focus to the option whose label starts with the characters being typed if dropdown is not editable.

Filter Input Keyboard Support

Key	Function
enter	Closes the popup and moves focus to the dropdown element.
escape	Closes the popup and moves focus to the dropdown element.