Accessibility in Angular Dropdown Tree component
24 Jan 20246 minutes to read
The Dropdown Tree component followed the accessibility guidelines and standards, including ADA, Section 508, WCAG 2.2 standards, and WCAG roles that are commonly used to evaluate accessibility.
The accessibility compliance for the Dropdown Tree component is outlined below.
| Accessibility Criteria | Compatibility |
|---|---|
| WCAG 2.2 Support |  |
| Section 508 Support | |
| Screen Reader Support |  |
| Right-To-Left Support | |
| Color Contrast | |
| Mobile Device Support | |
| Keyboard Navigation Support | |
| Accessibility Checker Validation | |
| Axe-core Accessibility Validation | |
- All features of the component meet the requirement. - Some features of the component do not meet the requirement.
- The component does not meet the requirement.WAI-ARIA attributes
The Dropdown Tree component followed the WAI-ARIA patterns to meet the accessibility. The following ARIA attributes are used in the Dropdown Tree component:
| Attributes | Purpose |
|---|---|
role=listbox |
All list items are contained within the element. |
aria-disabled |
Indicates element is perceivable but disabled. |
aria-owns |
This attribute contains the ID of the popup list to indicate popup as a child element. |
aria-haspopup |
Indicates whether the Dropdown Tree input element has a popup list or not. |
aria-expanded |
Indicates the state of the popup list for Dropdown Tree and the parent node’s expansion status for TreeView. |
aria-activedescendent |
This attribute holds the ID of the active list item to focus its descendant child element. |
aria-labelledby |
This attribute points to the element(s) labeling the element it’s applied to. |
aria-decribedby |
This attribute points to the element(s) describing the one it’s set on. |
role=tree |
All tree nodes are contained within the element. |
role=treeitem |
Specifies the role of each tree node in a selectable TreeView and its containment within the tree. |
role=group |
Specifies the role of each parent node container in the TreeView. |
role=checkbox |
Indicates checkbox control along with treeitem element. |
aria-multiselectable |
Indicates whether the TreeView enables multiple selection or not. |
aria-selected |
Indicates the selected node. |
aria-level |
Indicates the level of node in TreeView. |
aria-checked |
Indicates the current checked state of TreeView checkbox. |
aria-label |
Indicates the contextual message for the TreeView checkbox and Dropdown Tree. |
aria-activedescendant |
Identifies the currently active element when focusing on the TreeView. |
Keyboard interaction
The Dropdown Tree component followed the keyboard interaction guideline, making it easy for people who use assistive technologies (AT) and those who completely rely on keyboard navigation. The following keyboard shortcuts are supported by the Dropdown Tree component.
| Interaction Keys | Description |
|---|---|
| Alt + Down | Opens the popup. |
| Alt + Up | Closes the popup. |
| Esc(Escape) | Closes the popup when it is in an open state. |
| Arrow Up | Goes to the previous item in the popup. |
| Arrow Down | Goes to the next item in the popup. |
| Arrow Right | Expands the current item in the popup. |
| Arrow Left | Collapses the current item in the popup. |
| Home | Goes to the first item in the popup. |
| End | Goes to the last item in the popup. |
| Enter | Selects the focused item in the popup. |
| Space | Checks the current item in the popup. |
Ensuring accessibility
The Dropdown Tree component’s accessibility levels are ensured through an accessibility-checker and axe-core software tools during automated testing.
The accessibility compliance of the Dropdown Tree component is shown in the following sample. Open the sample in a new window to evaluate the accessibility of the Dropdown Tree component with accessibility tools.