React Aria Accordion

This accordion component aims to follow the guidelines set out in the WAI-ARIA Authoring Practices 1.1 and uses the render props pattern to be as flexible as possible.

It is purposefully missing the ability for a section to be auto collapsed on expanding another. Read Design decisions for more information.

Demo

Demo

Table of contents

• Installation
• Example usage
• Using <Header /> correctly
• API
  • <Accordion />
  • <Section />
  • <Header />
  • <Panel />
  • initialiseForSsr
• Design decisions
• Technical decisions
• Contributors

Installation

npm install react-aria-accordion

Example usage

Given the flexible nature of the component it would be best to wrap each component and style them as is appropriate for your use case.

// Accordion/Accordion
import Accordion from 'react-aria-accordion';

const MyAccordion = ({ children, ...rest }) => (
  <Accordion>
    {() => <div>{children}</div>}
  </Accordion>
);

export default MyAccordion;

// Accordion/Section
import { Section } from 'react-aria-accordion';

const MySection = ({ onToggle, defaultExpanded, children }) => (
  <Section onToggle={onToggle} defaultExpanded={defaultExpanded}>
    {({ getSectionProps }) => <div {...getSectionProps()}>{children}</div>}
  </Section>
);

export default MySection;

// Accordion/Header
import { Header } from 'react-aria-accordion';

// Using native html elements

const MyHeader = ({ title }) => (
  <Header>
    {({ getButtonToggleProps }) => (
      <h1>
        <button {...getButtonToggleProps()}>{title}</button>
      </h1>
    )}
  </Header>
);

// Using custom html elements

const MyHeader = ({ title }) => (
  <Header headingLevel={1}>
    {({ getHeadingProps, getElementToggleProps }) => (
      <div {...getHeadingProps()}>
        <div {...getElementToggleProps()}>{title}</div>
      </div>
    )}
  </Header>
);

export default Header;

// Accordion/Panel
import { Panel } from 'react-aria-accordion';

const MyPanel = ({ children }) => (
  <Panel>
    {({ getPanelProps }) => (
      <div {...getPanelProps()}>
        {children}
      </div>
    )}
  </Panel>
);

export default MyPanel;

// Accordion/index
export { default } from './Accordion';
export { default as Section } from './Section';
export { default as Header } from './Header';
export { default as Panel } from './Panel';

This would allow the following:

import Accordion, { Section, Header, Panel } from './Accordion';

<Accordion>
  <Section
    defaultExpanded
    onToggle={
      (nextExpanded) => console.log(`First section is ${nextExpanded ? 'expanded' : 'collapsed'}`)
    }
  >
    <Header title="Names" />
    <Panel>
      {listOfNames}
    </Panel>
  </Section>
  <Section>
    <Header title="Contact details" />
    <Panel>
      {listOfContactDetails}
    </Panel>
  </Section>
  <Section>
    <Header title="Other" />
    <Panel>
      {other}
    </Panel>
  </Section>
</Accordion>

Server Sider Rendering (SSR)

An additional initialiseForSsr function is required when using SSR so that the DOM matches when using client hydration:

import { renderToString } from 'react-dom/server';
import { initialiseForSsr } from 'react-aria-accordion';

initialiseForSsr();
renderToString(<App />);

Using <Header /> correctly

The title for the accordion section must be wrapped in exactly one button and one heading. The following 2 examples offer the same semantics. Where possible use native html elements.

const header = (
  <Header>
    {({ getButtonToggleProps }) => (
      <h2>
        <button {...getButtonToggleProps()}>Title</button>
      </h2>
    )}
  </Header>
);

const header = (
  <Header headingLevel={2}>
    {({ getHeadingProps, getElementToggleProps }) => (
      <div {...getHeadingProps()}>
        <div {...getElementToggleProps()}>Title</div>
      </div>
    )}
  </Header>
);

If you want to include a menu next to the title, then make sure the menu is not inside the heading element.

const header = (
  <Header>
    {({ getButtonToggleProps }) => (
      <Fragment>
        <h2>
          <button {...getButtonToggleProps()}>Title</button>
        </h2>
        <Menu />
      </Fragment>
    )}
  </Header>
);

API

<Accordion />

children

function({}) | required

This is called with an object.

Property	Type	Description
expandAllSections	function()	Expands all sections.
collapseAllSections	function()	Collapses all sections.

<Section />

defaultExpanded

boolean | defaults to false

This is the initial expanded value.

expanded

boolean | control prop

onToggle

function(nextExpanded: boolean) | defaults to undefined

children

function({}) | required

This is called with an object.

Property	Type	Description
getSectionProps	function(props: object)	Returns the props you should apply to the element you render.
expanded	boolean	The expanded state of the section.

<Header />

disabled

boolean | defaults to false

headingLevel

number | defaults to 1

children

function({}) | required

This is called with an object.

Property	Type	Description
getHeadingProps	function(props: object)	Returns the props you should apply to the heading element you render when not using <h# />.
getButtonToggleProps	function(props: object)	Returns the props you should apply to the toggle element you render when using <button />.
getElementToggleProps	function(props: object)	Returns the props you should apply to the toggle element you render when not using <button />.
expanded	boolean	The expanded state of the section.

<Panel />

children

function({}) | required

This is called with an object.

Property	Type	Description
getPanelProps	function(props: object)	Returns the props you should apply to the element you render.
expanded	boolean	The expanded state of the section.

initialiseForSsr

function()

See Server Side Rendering (SSR) for more details.

Design decisions

No auto collapse behaviour

The aim of this component is to be used in projects to help developers feel confident they are making their websites as accessible as possible using relevant aria-* properties.

Automatic collapsing of sections can disorientate some users, particularly if scroll behaviour is also associated. For example, if a user is using magnification software they may not realise that expanding one section has collapsed another.

Data presented within a section may be comparable with another, therefore having more than one section expanded at a time may be a useful feature for your users.

Collapsing and expanding multiple sections manually may make your website difficult to use, so this component provides the functionality to collapse and expand all sections at once. Given this behaviour will need to be triggered by a user there are less usability concerns.

Technical decisions

Why expanded is available for Section, Header & Panel

The reason the same render prop is available is so that it's possible to wrap each component as shown in Example usage without having to pass your own expanded prop to Header and Panel.

Using querySelectorAll in <Accordion />

You may think that using a lifecycle method like componentWillMount in <Section /> would suffice, however it wouldn't cope with the following scenario:

<Accordion>
  <Section>A</Section>
  {showSection ? <Section>B</Section> : null}
  <Section>C</Section>
</Accordion>

If showSection starts as false and switches to true later, then componenetWillMount will fire for Section B, leaving the accordion no ability to know the ordering of the sections. Having to manually specify the order of a <Section /> would be a burden on the developer.

Contributors

Thanks goes to these wonderful people (emoji key):

Kenneth Gray 💻 📖 ⚠️ 💡	Koji Wakayama 💻

This project follows the all-contributors specification. Contributions of any kind are welcome!