downshift ğŸŽ
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Primitives to build simple, flexible, WAI-ARIA compliant React autocomplete, combobox or select dropdown components.

See the intro blog post and Episode 79 of the Full Stack Radio podcast


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Supports React and Preact size gzip size module formats: umd, cjs, and es

The problem

You need an autocomplete/combobox or a select experience in your application and you want it to be accessible. You also want it to be simple and flexible to account for your use cases. Finally, it should follow the ARIA design pattern for a combobox or a select, depending on your use case.

This solution

This library provides its users two main sets of solutions: the Downshift component and a set of hooks. The component is still the main part of the library, providing the autocomplete/combobox logic as a render prop. The hooks are newer and are going to be the way forward to providing accessibile experiences. Right now we support useSelect for select components, useCombobox for combobox/autocomplete inputs and useMultipleSelection to make the selection of multiple items easier for both the select and combobox elements.

Since both useCombobox and the component Downshift aim to provide accessibility to a combobox, we suggest trying the new useCombobox first. If you feel that Downshift still covers your use cases better then use the component instead. However, if these use cases should also be covered in useCombobox, make sure to create an issue to help us improve the hook. Both the hooks and the component are actively maintained but we are cool kids from the future and prefer to share React logic via hooks.

The README on this page convers only the component while each hook has its own README file. Check the hooks section for links to each. Both the component and the hooks are similar in many concepts so you can always switch between the documentation pages in order to find information.

Downshift component

This is a component that controls user interactions and state for you so you can create autocomplete/combobox or select dropdown components. It uses a render prop which gives you maximum flexibility with a minimal API because you are responsible for the rendering of everything and you simply apply props to what you're rendering.

This differs from other solutions which render things for their use case and then expose many options to allow for extensibility resulting in a bigger API that is less flexible as well as making the implementation more complicated and harder to contribute to.

NOTE: The original use case of this component is autocomplete, however the API is powerful and flexible enough to build things like dropdowns as well.

The React Hooks API

Downshift proved to be a versatile component to create not only combobox inputs, but also custom select elements and even multiple selection experiences. However, additional code was needed to make these experiences fully accessible, so we decided to create a dedicated React hook for them. Each hook handles a specific dropdown variation and aims to make it fully accessible.

You can check the progress in the hooks page. The hooks published so far are:

For examples on how to use the hooks check out our docsite!

Bundle size concerns

Adding the hooks into this repo increased the bundle size considerably. However, since we create the bundle with Rollup and export both <Downshift> and the hooks as modules, you should be able to have the library treeshaked (pruned) and receive only the code you need. Since version 3.4.8 BundlePhobia marked Downshift as both tree-shakeable and side-effect free.

Table of Contents

Installation

This module is distributed via npm which is bundled with node and should be installed as one of your project's dependencies:

npm install --save downshift

This package also depends on react. Please make sure you have it installed as well.

Note also this library supports preact out of the box. If you are using preact then use the corresponding module in the preact/dist folder. You can even import Downshift from 'downshift/preact' 👍

Usage

Try it out in the browser

import * as React from 'react'
import {render} from 'react-dom'
import Downshift from 'downshift'
const items = [
  {value: 'apple'},
  {value: 'pear'},
  {value: 'orange'},
  {value: 'grape'},
  {value: 'banana'},
]

render(
  <Downshift
    onChange={selection =>
      alert(selection ? `You selected ${selection.value}` : 'Selection Cleared')
    }
    itemToString={item => (item ? item.value : '')}
  >
    {({
      getInputProps,
      getItemProps,
      getLabelProps,
      getMenuProps,
      isOpen,
      inputValue,
      highlightedIndex,
      selectedItem,
      getRootProps,
    }) => (
      <div>
        <label {...getLabelProps()}>Enter a fruit</label>
        <div
          style={{display: 'inline-block'}}
          {...getRootProps({}, {suppressRefError: true})}
        >
          <input {...getInputProps()} />
        </div>
        <ul {...getMenuProps()}>
          {isOpen
            ? items
                .filter(item => !inputValue || item.value.includes(inputValue))
                .map((item, index) => (
                  <li
                    {...getItemProps({
                      key: item.value,
                      index,
                      item,
                      style: {
                        backgroundColor:
                          highlightedIndex === index ? 'lightgray' : 'white',
                        fontWeight: selectedItem === item ? 'bold' : 'normal',
                      },
                    })}
                  >
                    {item.value}
                  </li>
                ))
            : null}
        </ul>
      </div>
    )}
  </Downshift>,
  document.getElementById('root'),
)

The previous example without getRootProps is here.

Warning: The example without getRootProps is not fully accessible with screen readers as it's not possible to achieve the HTML structure suggested by ARIA. We recommend following the example with getRootProps. Examples on how to use Downshift component with and without getRootProps are on the docsite.

Downshift is the only component exposed by this package. It doesn't render anything itself, it just calls the render function and renders that. "Use a render prop!"! <Downshift>{downshift => <div>/* your JSX here! */</div>}</Downshift>.

Basic Props

This is the list of props that you should probably know about. There are some advanced props below as well.

children

function({}) | required

This is called with an object. Read more about the properties of this object in the section "Children Function".

itemToString

function(item: any) | defaults to: item => (item ? String(item) : '')

If your items are stored as, say, objects instead of strings, downshift still needs a string representation for each one (e.g., to set inputValue).

Note: This callback must include a null check: it is invoked with null whenever the user abandons input via <Esc>.

onChange

function(selectedItem: any, stateAndHelpers: object) | optional, no useful default

Called when the selected item changes, either by the user selecting an item or the user clearing the selection. Called with the item that was selected or null and the new state of downshift. (see onStateChange for more info on stateAndHelpers).

  • selectedItem: The item that was just selected. null if the selection was cleared.
  • stateAndHelpers: This is the same thing your children function is called with (see Children Function)

stateReducer

function(state: object, changes: object) | optional

🚨 This is a really handy power feature 🚨

This function will be called each time downshift sets its internal state (or calls your onStateChange handler for control props). It allows you to modify the state change that will take place which can give you fine grain control over how the component interacts with user updates without having to use Control Props. It gives you the current state and the state that will be set, and you return the state that you want to set.

  • state: The full current state of downshift.
  • changes: These are the properties that are about to change. This also has a type property which you can learn more about in the stateChangeTypes section.
const ui = (
  <Downshift stateReducer={stateReducer}>{/* your callback */}</Downshift>
)

function stateReducer(state, changes) {
  // this prevents the menu from being closed when the user
  // selects an item with a keyboard or mouse
  switch (changes.type) {
    case Downshift.stateChangeTypes.keyDownEnter:
    case Downshift.stateChangeTypes.clickItem:
      return {
        ...changes,
        isOpen: state.isOpen,
        highlightedIndex: state.highlightedIndex,
      }
    default:
      return changes
  }
}

NOTE: This is only called when state actually changes. You should not attempt to use this to handle events. If you wish to handle events, put your event handlers directly on the elements (make sure to use the prop getters though! For example: <input onBlur={handleBlur} /> should be <input {...getInputProps({onBlur: handleBlur})} />). Also, your reducer function should be "pure." This means it should do nothing other than return the state changes you want to have happen.

Advanced Props

initialSelectedItem

any | defaults to null

Pass an item or an array of items that should be selected when downshift is initialized.

initialInputValue

string | defaults to ''

This is the initial input value when downshift is initialized.

initialHighlightedIndex

number/null | defaults to defaultHighlightedIndex

This is the initial value to set the highlighted index to when downshift is initialized.

initialIsOpen

boolean | defaults to defaultIsOpen

This is the initial isOpen value when downshift is initialized.

defaultHighlightedIndex

number/null | defaults to null

This is the value to set the highlightedIndex to anytime downshift is reset, when the selection is cleared, when an item is selected or when the inputValue is changed.

defaultIsOpen

boolean | defaults to false

This is the value to set the isOpen to anytime downshift is reset, when the the selection is cleared, or when an item is selected.

selectedItemChanged

function(prevItem: any, item: any) | defaults to: (prevItem, item) => (prevItem !== item)

Used to determine if the new selectedItem has changed compared to the previous selectedItem and properly update Downshift's internal state.

getA11yStatusMessage

function({/* see below */}) | default messages provided in English

This function is passed as props to a Status component nested within and allows you to create your own assertive ARIA statuses.

A default getA11yStatusMessage function is provided that will check resultCount and return "No results are available." or if there are results , "resultCount results are available, use up and down arrow keys to navigate. Press Enter key to select."

The object you are passed to generate your status message has the following properties:

property type description
highlightedIndex number/null The currently highlighted index
highlightedItem any The value of the highlighted item
inputValue string The current input value
isOpen boolean The isOpen state
itemToString function(any) The itemToString function (see props) for getting the string value from one of the options
previousResultCount number The total items showing in the dropdown the last time the status was updated
resultCount number The total items showing in the dropdown
selectedItem any The value of the currently selected item

onSelect

function(selectedItem: any, stateAndHelpers: object) | optional, no useful default

Called when the user selects an item, regardless of the previous selected item. Called with the item that was selected and the new state of downshift. (see onStateChange for more info on stateAndHelpers).

  • selectedItem: The item that was just selected
  • stateAndHelpers: This is the same thing your children function is called with (see Children Function)

onStateChange

function(changes: object, stateAndHelpers: object) | optional, no useful default

This function is called anytime the internal state changes. This can be useful if you're using downshift as a "controlled" component, where you manage some or all of the state (e.g., isOpen, selectedItem, highlightedIndex, etc) and then pass it as props, rather than letting downshift control all its state itself. The parameters both take the shape of internal state ({highlightedIndex: number, inputValue: string, isOpen: boolean, selectedItem: any}) but differ slightly.

  • changes: These are the properties that actually have changed since the last state change. This also has a type property which you can learn more about in the stateChangeTypes section.
  • stateAndHelpers: This is the exact same thing your children function is called with (see Children Function)

Tip: This function will be called any time any state is changed. The best way to determine whether any particular state was changed, you can use changes.hasOwnProperty('propName').

NOTE: This is only called when state actually changes. You should not attempt to use this to handle events. If you wish to handle events, put your event handlers directly on the elements (make sure to use the prop getters though! For example: <input onBlur={handleBlur} /> should be <input {...getInputProps({onBlur: handleBlur})} />).

onInputValueChange

function(inputValue: string, stateAndHelpers: object) | optional, no useful default

Called whenever the input value changes. Useful to use instead or in combination of onStateChange when inputValue is a controlled prop to avoid issues with cursor positions.

  • inputValue: The current value of the input
  • stateAndHelpers: This is the same thing your children function is called with (see Children Function)

itemCount

number | optional, defaults the number of times you call getItemProps

This is useful if you're using some kind of virtual listing component for "windowing" (like react-virtualized).

highlightedIndex

number | control prop (read more about this in the Control Props section)

The index that should be highlighted

inputValue

string | control prop (read more about this in the Control Props section)

The value the input should have

isOpen

boolean | control prop (read more about this in the Control Props section)

Whether the menu should be considered open or closed. Some aspects of the downshift component respond differently based on this value (for example, if isOpen is true when the user hits "Enter" on the input field, then the item at the highlightedIndex item is selected).

selectedItem

any/Array(any) | control prop (read more about this in the Control Props section)

The currently selected item.

id

string | defaults to a generated ID

You should not normally need to set this prop. It's only useful if you're server rendering items (which each have an id prop generated based on the downshift id). For more information see the FAQ below.

inputId

string | defaults to a generated ID

Used for aria attributes and the id prop of the element (input) you use getInputProps with.

labelId

string | defaults to a generated ID

Used for aria attributes and the id prop of the element (label) you use getLabelProps with.

menuId

string | defaults to a generated ID

Used for aria attributes and the id prop of the element (ul) you use getMenuProps with.

getItemId

function(index) | defaults to a function that generates an ID based on the index

Used for aria attributes and the id prop of the element (li) you use getInputProps with.

environment

window | defaults to window

This prop is only useful if you're rendering downshift within a different window context from where your JavaScript is running; for example, an iframe or a shadow-root. If the given context is lacking document and/or add|removeEventListener on its prototype (as is the case for a shadow-root) then you will need to pass in a custom object that is able to provide access to these properties for downshift.

onOuterClick

function(stateAndHelpers: object) | optional

A helper callback to help control internal state of downshift like isOpen as mentioned in this issue. The same behavior can be achieved using onStateChange, but this prop is provided as a helper because it's a fairly common use-case if you're controlling the isOpen state:

const ui = (
  <Downshift
    isOpen={this.state.menuIsOpen}
    onOuterClick={() => this.setState({menuIsOpen: false})}
  >
    {/* your callback */}
  </Downshift>
)

This callback will only be called if isOpen is true.

scrollIntoView

function(node: HTMLElement, menuNode: HTMLElement) | defaults to internal implementation

This allows you to customize how the scrolling works when the highlighted index changes. It receives the node to be scrolled to and the root node (the root node you render in downshift). Internally we use compute-scroll-into-view so if you use that package then you wont be adding any additional bytes to your bundle :)

stateChangeTypes

There are a few props that expose changes to state (onStateChange and stateReducer). For you to make the most of these APIs, it's important for you to understand why state is being changed. To accomplish this, there's a type property on the changes object you get. This type corresponds to a Downshift.stateChangeTypes property.

The list of all possible values this type property can take is defined in this file and is as follows:

  • Downshift.stateChangeTypes.unknown
  • Downshift.stateChangeTypes.mouseUp
  • Downshift.stateChangeTypes.itemMouseEnter
  • Downshift.stateChangeTypes.keyDownArrowUp
  • Downshift.stateChangeTypes.keyDownArrowDown
  • Downshift.stateChangeTypes.keyDownEscape
  • Downshift.stateChangeTypes.keyDownEnter
  • Downshift.stateChangeTypes.clickItem
  • Downshift.stateChangeTypes.blurInput
  • Downshift.stateChangeTypes.changeInput
  • Downshift.stateChangeTypes.keyDownSpaceButton
  • Downshift.stateChangeTypes.clickButton
  • Downshift.stateChangeTypes.blurButton
  • Downshift.stateChangeTypes.controlledPropUpdatedSelectedItem
  • Downshift.stateChangeTypes.touchEnd

See stateReducer for a concrete example on how to use the type property.

Control Props

downshift manages its own state internally and calls your onChange and onStateChange handlers with any relevant changes. The state that downshift manages includes: isOpen, selectedItem, inputValue, and highlightedIndex. Your Children function (read more below) can be used to manipulate this state and can likely support many of your use cases.

However, if more control is needed, you can pass any of these pieces of state as a prop (as indicated above) and that state becomes controlled. As soon as this.props[statePropKey] !== undefined, internally, downshift will determine its state based on your prop's value rather than its own internal state. You will be required to keep the state up to date (this is where onStateChange comes in really handy), but you can also control the state from anywhere, be that state from other components, redux, react-router, or anywhere else.

Note: This is very similar to how normal controlled components work

Last updated Popular

v5.4.0

Install

npm install downshift
yarn add downshift

BUNDLE SIZE

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CDNs

extras

Contributors

  • downshift-js