Level A
Changing the setting of any user interface component does not automatically cause a change of context unless the user has been advised of the behavior before using the component.>
Explanation
When changing an interface component like selecting a radio button, it must not trigger a change of context unless the user has been warned it will happen. This makes sure that people who cannot see the change in context are aware of the change and not caught by surprise when it happens.
Roles
- Design
- Development
- QA
Requirements
- Interface components that trigger a change of context or content warn the user what will happen.
Common mistakes
- A button causes a menu or additional content to be revealed, but the user is not warned what will happen;
- Selecting a radio button or checkbox causes additional fields to be displayed, but the user is not warned what will happen;
- A disclosure widget does not use the
<details>and<summary>elements (which include a native warning of the intended action); - A custom disclosure component does not use
aria-expanded, to notify the user of the intended action; - A button that causes a menu to appear does not use the
aria-haspopupattribute to notify the user what will happen; - A link opens a new window or tab, and the user is not warned what will happen.