Vaadin WC API reference

Description

The accordion heading element.

vaadin-accordion-heading is the element for the headings in the accordion. As recommended by the WAI ARIA Best Practices, each heading needs to wrap a <button>. This element puts that button in the Shadow DOM, as it is more convenient to use and doesn't make styling of the heading more problematic.

The WAI ARIA Best Practices also recommend setting aria-level depending on what level the headings are. It is hard to determine the level of a heading algorithmically, and setting it is not strictly required to have an accessible accordion. To keep things easier to use, this element does not set aria-level attribute but leaves that to the developer creating an accordion.

Styling

The following shadow DOM parts are exposed for styling:

Part name Description
toggle The icon element
content The content wrapper

The following state attributes are available for styling:

Attribute Description
active Set when the element is pressed down, either with mouse, touch or the keyboard.
opened Set when the collapsible content is expanded and visible.
disabled Set when the element is disabled.

See Styling Components documentation.

Properties

disabled

Type: boolean

If true, the user cannot interact with this element.

opened

Type: boolean

When true, the element is opened.