Show / hide panels
- Core HTML base.
- ARIA roles, states and properties.
- Keyboard interactions.
- Expected behavior.
Expand/collapse panels are dynamic components designed to optimize the display of content in limited spaces by means of an “expand/collapse” system.
They can be controlled by the user, usually by activating a button at the top of the panel.
This sheet is based on the “Disclosure” design pattern detailed in W3C’s WAI-ARIA 1.1 Authoring Practices.
Core HTML base
ARIA roles, states and properties
aria-expanded attribute must be added to the button which controls the panel. Its value is must be dynamically set based upon the status of the associated expanded panel:
aria-expanded="true"when the associated panel is open.
aria-expanded="false"when the associated panel is closed.
Enter and Spacebar
When the keyboard focus is on the button, either of these keys will toggle the associated panel open or closed.
- When the focus is on the button, the panel can be opened or closed using the Spacebar and Enter keys. To do so, listen to the
- When the panel is closed, it must be hidden with
- The value of the
aria-expandedattribute must be modified dynamically each time the state of the associated panel is updated.
If the action button is not located immediately before the HTML code of the associated expanded panel, it is important to programmatically associate the panel with the button that controls it..
This association should be made explicit using the
- The show / hide panel must have an
idattribute set to a unique value.
- The button that controls it must have the
aria-controlsattribute set to the value of the show / hide panel
The “Expandable panel” components are shown here because their level of accessibility is considered good or very good.
However, before using it in your project, it is important to check for compliancy with the specifications presented above. Depending on the version used, the components may need some adjustments before they can be used in your project.