Question
Answer and Explanation
The message "aria-selected is not supported on role button" indicates that you are attempting to use the aria-selected attribute on an HTML element that has been assigned the role="button". This is an accessibility issue because the aria-selected attribute is specifically designed for elements that represent selectable items within a set, such as tabs or list items in a multi-select list, not for buttons.
Here's a breakdown of why this is a problem and how to address it:
Understanding ARIA Attributes and Roles
- ARIA (Accessible Rich Internet Applications): ARIA attributes are used to enhance the accessibility of web content, especially for users who rely on assistive technologies like screen readers.
- Roles: ARIA roles define the type of element and its purpose. For example, role="button" indicates that an element should behave like a button.
- `aria-selected`: This attribute is used to indicate whether an element within a set of selectable items is currently selected. It's typically used with roles like tab, option, or menuitemradio.
Why `aria-selected` Doesn't Work with `role="button"`
- Buttons are designed to perform actions, not to represent selectable states within a group. A button is either active (clickable) or inactive (disabled), but it doesn't have a "selected" state in the same way a tab or a list item does.
- Using aria-selected on a button confuses assistive technologies because it implies a selection behavior that buttons don't have.
How to Fix the Issue
1. Review Your UI: Determine if the element you've marked as a button is actually behaving like a button or if it's part of a selectable group. If it's part of a group, it should have a different role.
2. Use the Correct Role: If the element is part of a selectable group, use roles like tab, option, or menuitemradio, and then use aria-selected to indicate the selected state.
3. For Buttons, Use `aria-pressed`: If the button toggles a state (like a play/pause button), use aria-pressed="true" or aria-pressed="false" to indicate the toggle state. This is the correct ARIA attribute for toggle buttons.
4. Avoid Misusing ARIA: Only use ARIA attributes when necessary to enhance accessibility. If a standard HTML element (like a <button>) already provides the correct semantics, avoid adding ARIA attributes that might conflict.
Example of Correct Usage
- Incorrect:
<button role="button" aria-selected="true">Button</button>
- Correct (Toggle Button):
<button role="button" aria-pressed="true">Pause</button>
<button role="button" aria-pressed="false">Play</button>
- Correct (Tab):
<div role="tablist">
<button role="tab" aria-selected="true">Tab 1</button>
<button role="tab" aria-selected="false">Tab 2</button>
</div>
In summary, the error message "aria-selected is not supported on role button" is a reminder to use ARIA attributes correctly and to ensure that the roles and attributes you use match the intended behavior of the element. Using aria-pressed for toggle buttons and aria-selected for selectable items within a set will improve the accessibility of your web content.