Accessibility in Blazor MultiColumn ComboBox Component
30 Apr 20256 minutes to read
The Blazor MultiColumn ComboBox component has been designed with the WAI-ARIA specifications in mind, and applies the WAI-ARIA roles, states, and properties along with keyboard support. This component is characterized
by complete keyboard interaction support and ARIA accessibility support that makes it easy for people who use assistive technologies (AT) or those who completely rely on keyboard navigation.
The Blazor ComboBox 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 Blazor ComboBox 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 | |
| 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 Blazor MultiColumn ComboBox component uses the combobox role, and each list item has an option role. The following ARIA attributes denotes the ComboBox state:
| Properties | Functionalities |
|---|---|
aria-haspopup |
Indicates whether the ComboBox input element has a popup list or not. |
aria-expanded |
Indicates whether the popup list has expanded or not. |
aria-selected |
Indicates the selected option. |
aria-readonly |
Indicates the readonly state of the ComboBox element. |
aria-disabled |
Indicates whether the ComboBox component is in a disabled state or not. |
aria-activedescendent |
This attribute holds the ID of the active list item to focus its descendant child element. |
aria-owns |
This attribute contains the ID of the popup list to indicate popup as a child element. |
aria-autocomplete |
This attribute contains the ‘both’ to a list of options shows and the currently selected suggestion also shows inline. |
Keyboard interaction
You can use the following key shortcuts to access the Blazor MultiColumn ComboBox without interruptions:
| Windows | Mac | Actions |
|---|---|---|
| Focus | ||
| Alt + J | ⌥ + J | Focuses on the first component of the sample. |
| Input Navigation | ||
| Alt + ↓ | ⌥ + ↓ | Opens the popup list. |
| Alt + ↑ | ⌥ + ↑ | Closes the popup list. |
| Home | Home | Cursor moves before the first character in the input. |
| End | End | Cursor moves before the last character in the input. |
| Shift + Tab | ⇧ + Tab | Focuses on the previous TabIndex element on the page when the popup is closed. Otherwise, closes the popup list and remains the focus of the component. |
| Selection | ||
| Enter | Enter | Selects the focused item, and when it is in open state, the popup list closes. Otherwise, toggles the popup list. |
| Popup Navigation | ||
| Esc(Escape) | Escape | Closes the popup list when it is in an open state and the currently selected item remains the same. |
Ensuring accessibility
The Blazor MultiColumn ComboBox component’s accessibility levels are ensured through an axe-core software tool during automated testing.
The accessibility compliance of the MultiColumn ComboBox component is shown in the following sample. Open the sample in a new window to evaluate the accessibility of the MultiColumn ComboBox component with accessibility tools.