Blazor MultiSelect Accessibility
Out of the box, the Telerik UI for Blazor MultiSelect provides extensive accessibility support and enables users with disabilities to acquire complete control over its features.
The MultiSelect is compliant with the Web Content Accessibility Guidelines (WCAG) 2.2 AA standards](https://www.w3.org/TR/WCAG22/) and Section 508 requirements, follows the Web Accessibility Initiative - Accessible Rich Internet Applications (WAI-ARIA) best practices for implementing the keyboard navigation for its component role, provides options for managing its focus and is tested against the most popular screen readers.
WAI-ARIA
This section lists the selectors, attributes, and behavior patterns supported by the component and its composite elements, if any.
MultiSelect Wrapping Element
The following table summarizes the selectors and attributes supported by the MultiSelect wrapper element:
| Selector | Attribute | Usage |
|---|---|---|
.k-input-inner |
role=combobox |
Announces the presence of a combobox as the inner element of the MultiSelect used for filtering. |
label for or aria-label or aria-labelledby
|
The input needs an accessible name that will be assigned to it. | |
aria-haspopup=listbox |
Indicates the presence of a listbox popup. | |
aria-expanded=true/false |
Announces the state of the popup visibility. | |
aria-controls=.k-list-ul id |
Points to the listbox element. Signifies that the combobox element controls the listbox one. |
|
aria-autocomplete=list |
When the filtering feature is enabled, the attribute is rendered and the value is set to the list. | |
aria-describedby=.k-chip-list id |
Points to the taglist element that contains the selected items. |
|
aria-activedescendant=.k-list-item.k-focus id |
Points to the focused item,which is either an item from the popup or a tag item from the selected items. The focused item is changed through keyboard navigation. If the focus is not currently on a tag item and the popup is not visible, the attribute must not point to any element or must be removed. | |
aria-readonly=true |
The attribute is rendered only when the MultiSelect is read-only. | |
aria-invalid=true |
The attribute is rendered only when the MultiSelect is in a form and announces the valid state of the component. | |
aria-busy=true |
The attribute is rendered only when the MultiSelect is loading data. | |
tabindex=0 |
The element must be focusable. | |
.k-disabled .k-input-inner |
aria-disabled=true |
The attribute is rendered only when the MultiSelect is disabled. |
.k-input-button |
role=button or nodeName=button
|
The element must either be a <button> element or have the role="button" assigned. |
aria-label |
The button needs an accessible name that will be assigned to it. | |
tabindex=-1 |
The button element must not be focusable. |
Popup Listbox
The popup element of the MultiSelect must implement the WAI-ARIA specification for a Popup List component. The following table summarizes the selectors and attributes supported by the listbox popup of the MultiSelect:
| Selector | Attribute | Usage |
|---|---|---|
.k-list-ul |
aria-multiselectable=true |
Announces multiselection of the listbox popup. |
| Selector | Attribute | Usage |
|---|---|---|
.k-animation-container |
role=region |
When the component container is appended to the <body> element of the document, it requires you to assing a landmark role to it. Otherwise, append it to an element with an appropriate landmark role. |
aria-label or aria-labelledby
|
When the container has a region role assigned, povides a label. |
|
.k-list-ul |
role=listbox |
Identifies the ul element as a listbox. |
aria-label or aria-labelledby
|
Provides a label for the listbox of the ComboBox. | |
.k-list-item |
role=option |
Identifies the li element as a listbox option. |
id |
When grouped, the list items must have an id attribute specified, so that the aria-owns attribute of their group header elements (with role=group) point to that ids. |
|
aria-describedby |
When grouped, the list items must have an aria-describedby attribute pointing to the id of the k-list-item-text element in their k-list-group-item. |
|
.k-list-item.k-selected |
aria-selected=true |
Indicates the selected state of the item. |
.k-list-group-item |
role=group |
The group elements in the popup list must be have role=group. |
aria-owns |
The group elements in the popup list must own the list items belonging to their group. | |
.k-list-group-item>.k-list-item-text |
id |
The k-list-item-text elements of the k-list-group-item must have an id specified. The aria-labelledby attribute of the list items in the group must point to that id. |
Resources
WAI-ARIA Authoring Practices: Select-Only Combobox Example
WAI-ARIA Authoring Practices: Scrollable Listbox Example
Section 508
The MultiSelect is fully compliant with the Section 508 requirements.
Testing
The MultiSelect has been extensively tested automatically with axe-core and manually with the most popular screen readers.
To report any accessibility issues, contact the team through the Telerik Support System.
Screen Readers
The MultiSelect has been tested with the following screen readers and browsers combinations:
| Environment | Tool |
|---|---|
| Firefox | NVDA |
| Chrome | JAWS |
| Microsoft Edge | JAWS |