Accordion Example

Important Note About Use of This Example

Note: This is an illustrative example of one way of using ARIA that conforms with the ARIA specification.

There may be support gaps in some browser and assistive technology combinations, especially for mobile/touch devices. Testing code based on this example with assistive technologies is essential before considering use in production systems.
The ARIA-AT project plans to provide measurements of this example's assistive technology support by the end of 2020.
Robust accessibility can be further optimized by choosing implementation patterns that maximize use of semantic HTML and heeding the warning that No ARIA is better than Bad ARIA.

The below example section contains a simple personal information input form divided into 3 sections that demonstrates the design pattern for accordion. In this implementation, one panel of the accordion is always expanded, and only one panel may be expanded at a time.

Example

Name:

Email:

Phone:

Extension:

Country:

City/Province:

Accessibility Features

The visual design includes features intended to help users understand that the accordion provides enhanced keyboard navigation functions. When an accordion header button has keyboard focus, the styling of the accordion container and all its header buttons is changed.

When any accordion header button receives focus:

The border encompassing the entire accordion changes color.
The background color of the accordion header buttons changes.

The focused accordion header button:

Has a border that encompasses both the header text and icon.
Has a background color that distinguishes it from the other accordion buttons that are not focused.

Keyboard Support

Key	Function
`Space` or `Enter`	When focus is on the accordion header of a collapsed section, expands the section.
`Tab`	Moves focus to the next focusable element. All focusable elements in the accordion are included in the page `Tab` sequence.
`Shift + Tab`	Moves focus to the previous focusable element. All focusable elements in the accordion are included in the page `Tab` sequence.
`Down Arrow`	When focus is on an accordion header, moves focus to the next accordion header. When focus is on last accordion header, moves focus to first accordion header.
`Up Arrow`	When focus is on an accordion header, moves focus to the previous accordion header. When focus is on first accordion header, moves focus to last accordion header.
`Home`	When focus is on an accordion header, moves focus to the first accordion header.
`End`	When focus is on an accordion header, moves focus to the last accordion header.

Role, Property, State, and Tabindex Attributes

Role	Attribute	Element	Usage
		`h3`	Element that serves as an accordion header. Each accordion header element contains a button that controls the visibility of its content panel. The example uses heading level 3 so it fits correctly within the outline of the page; the example is contained in a section titled with a level 2 heading.
	`aria-expanded="true"`	`button`	Set to `true` when the Accordion panel is expanded, otherwise set to `false`.
	`aria-controls="ID"`	`button`	Points to the ID of the panel which the header controls.
	`aria-disabled="true"`	`button`	If the accordion panel is expanded and is not allowed to be collapsed, then set to `true`.
`region`		`div`	Creates a landmark region that contains the currently expanded accordion panel.
	`aria-labelledby="IDREF"`	`div`	Defines the accessible name for the `region` element. References the accordion header button that expands and collapses the region. `region` elements are required to have an accessible name to be identified as a landmark.

Javascript and CSS Source Code

CSS: accordion.css
JavaScript: accordion.js

HTML Source Code

<div class="demo-block">
  <!-- Accordion Configuration Options
  
  data-allow-toggle
    Allow for each toggle to both open and close its section. Makes it possible for all sections to be closed. Assumes only one section may be open.
  
  data-allow-multiple
    Allow for multiple accordion sections to be expanded at the same time. Assumes data-allow-toggle otherwise the toggle on open sections would be disabled.
  __________
  
  Ex:
    <div id="accordionGroup" class="Accordion" data-allow-multiple>
  
    <div id="accordionGroup" class="Accordion" data-allow-toggle>
  -->
  <div id="accordionGroup" class="Accordion">
    <h3>
      <button type="button"
              aria-expanded="true"
              class="Accordion-trigger"
              aria-controls="sect1"
              id="accordion1id">
        <span class="Accordion-title">
          Personal Information
          <span class="Accordion-icon"></span>
        </span>
      </button>
    </h3>
    <div id="sect1"
         role="region"
         aria-labelledby="accordion1id"
         class="Accordion-panel">
      <div>
        <!-- Variable content within section, may include any type of markup or interactive widgets. -->
        <fieldset>
          <p>
            <label for="cufc1">
              Name
              <span aria-hidden="true">
                *
              </span>
              :
            </label>
            <input type="text"
                   value=""
                   name="Name"
                   id="cufc1"
                   class="required"
                   aria-required="true">
          </p>
          <p>
            <label for="cufc2">
              Email
              <span aria-hidden="true">
                *
              </span>
              :
            </label>
            <input type="text"
                   value=""
                   name="Email"
                   id="cufc2"
                   aria-required="true">
          </p>
          <p>
            <label for="cufc3">
              Phone:
            </label>
            <input type="text"
                   value=""
                   name="Phone"
                   id="cufc3">
          </p>
          <p>
            <label for="cufc4">
              Extension:
            </label>
            <input type="text"
                   value=""
                   name="Ext"
                   id="cufc4">
          </p>
          <p>
            <label for="cufc5">
              Country:
            </label>
            <input type="text"
                   value=""
                   name="Country"
                   id="cufc5">
          </p>
          <p>
            <label for="cufc6">
              City/Province:
            </label>
            <input type="text"
                   value=""
                   name="City_Province"
                   id="cufc6">
          </p>
        </fieldset>
      </div>
    </div>
    <h3>
      <button type="button"
              aria-expanded="false"
              class="Accordion-trigger"
              aria-controls="sect2"
              id="accordion2id">
        <span class="Accordion-title">
          Billing Address
          <span class="Accordion-icon"></span>
        </span>
      </button>
    </h3>
    <div id="sect2"
         role="region"
         aria-labelledby="accordion2id"
         class="Accordion-panel"
         hidden="">
      <div>
        <fieldset>
          <p>
            <label for="b-add1">
              Address 1:
            </label>
            <input type="text"
                   name="b-add1"
                   id="b-add1">
          </p>
          <p>
            <label for="b-add2">
              Address 2:
            </label>
            <input type="text"
                   name="b-add2"
                   id="b-add2">
          </p>
          <p>
            <label for="b-city">
              City:
            </label>
            <input type="text"
                   name="b-city"
                   id="b-city">
          </p>
          <p>
            <label for="b-state">
              State:
            </label>
            <input type="text"
                   name="b-state"
                   id="b-state">
          </p>
          <p>
            <label for="b-zip">
              Zip Code:
            </label>
            <input type="text"
                   name="b-zip"
                   id="b-zip">
          </p>
        </fieldset>
      </div>
    </div>
    <h3>
      <button type="button"
              aria-expanded="false"
              class="Accordion-trigger"
              aria-controls="sect3"
              id="accordion3id">
        <span class="Accordion-title">
          Shipping Address
          <span class="Accordion-icon"></span>
        </span>
      </button>
    </h3>
    <div id="sect3"
         role="region"
         aria-labelledby="accordion3id"
         class="Accordion-panel"
         hidden="">
      <div>
        <fieldset>
          <p>
            <label for="m-add1">
              Address 1:
            </label>
            <input type="text"
                   name="m-add1"
                   id="m-add1">
          </p>
          <p>
            <label for="m-add2">
              Address 2:
            </label>
            <input type="text"
                   name="m-add2"
                   id="m-add2">
          </p>
          <p>
            <label for="m-city">
              City:
            </label>
            <input type="text"
                   name="m-city"
                   id="m-city">
          </p>
          <p>
            <label for="m-state">
              State:
            </label>
            <input type="text"
                   name="m-state"
                   id="m-state">
          </p>
          <p>
            <label for="m-zip">
              Zip Code:
            </label>
            <input type="text"
                   name="m-zip"
                   id="m-zip">
          </p>
        </fieldset>
      </div>
    </div>
  </div>
</div>