Blazor Grid Accessibility
The Telerik UI for Blazor Grid component is WCAG 2.1 AA and Section 508 compliant. The component also follows the WAI-ARIA best practices for implementing the keyboard navigation for its component role, and is tested against the popular screen readers.
Wai-Aria
The Grid is a composite component that consists of 4 logically separated structural elements:
- Toolbar (
role=toolbar); - Group header (
role=toolbar); - Data Grid (
role=grid); - Pager (
role=application);
Grid Toolbar
Grid Toolbar follows the specification of the ToolBar component.
ToolBar accessibility specification
| Selector | Attribute | Usage |
|---|---|---|
| .k-grid-toolbar | role=toolbar |
The toolbar is a collection of command buttons and inputs. |
aria-label |
Clarifies the purpose of the toolbar. | |
aria-controls=.k-grid-aria-root id |
Pointing to the id of the element with role=grid. |
Grid Grouping Header
Grid Grouping Header follows the specification of the ToolBar component.
ToolBar accessibility specification
| Selector | Attribute | Usage |
|---|---|---|
| .k-grouping-header | role=toolbar |
The Grouping header is a ToolBar (collection of buttons). |
aria-label |
Clarifies the purpose of the header. | |
aria-controls=.k-grid-aria-root id |
Pointing to the id of the element with role=grid. |
|
| .k-group-indicator |
role=button or nodeName=button
|
If the element used is not <button>, then the role must be specified. |
title |
Present on the element or its child if sorting is enabled for that field. | |
| .k-group-indicator .k-icon-button |
role=button or nodeName=button
|
If the element used is not <button>, then the role must be specified. |
aria-label |
Specifies the purpose of the button. | |
tabindex=-1 |
The indicator delete button must not be part of the page tab sequence. |
Data Grid (excluding Toolbars and Pager)
The element with role=grid must not include the ToolBar and the Pager elements as those do not belong to the role=grid element itself.
Grid element
| Selector | Attribute | Usage |
|---|---|---|
| .k-grid-aria-root | role=grid |
The role specifies the element is a Data Grid. |
aria-colcount |
The total number of columns in the Grid. Needed only for Virtual columns and Hidden columns scenarios, when not all columns are rendered in the DOM. If the total number of columns is unknown, the value of aria-colcount must be set to -1. |
|
aria-rowcount |
The total number of rows in the table (header rows + master rows + detail rows + data rows + footer rows + aggregates rows). Needed only when Paging (and more that 1 page is present in the component), Virtual rows, or Master/Detail rows (Hierarchical Grid, Detail Template Grid) are enabled. If data is also Grouped, the proper number of all rows could not be calculated. In that case the value must be set to -1. |
In scenarios when master and detail rows are present in the Grid (Hierarchical Grid, Detail Template Grid), the aria-rowcount (the total number of rows) must be calculated: 2 * (total number of items) + header rows + footer rows. That is because for each item in the Grid there is a master row and a detail row duplicating this way the number of rows.
If the Grid is composed of a single table (there is no separate <table> element for its header), no role attributes should be set on its inner elements(<thead>, <body>, <tr>, <th>, and <td>). Their semantic meaning will be used instead.
Grid header
| Selector | Attribute | Usage |
|---|---|---|
| .k-grid-header-wrap>table | role=presentation/none |
Negates the default semantic role of the <table> element. |
| .k-grid-header-wrap>table>thead | role=rowgroup |
Required as the owner <table> element has its semantic role removed. |
| .k-grid-header-wrap>table>thead>tr | role=row |
Required as the owner <table> element has its semantic role removed. |
aria-rowindex |
Row number including all headers, data (including master and detail) rows, and footers starting from 1. Needed only when Paging (and more that 1 page is present in the component), Virtual rows, or Master/Detail rows (Hierarchical Grid, Detail Template Grid) are enabled. If data is also Grouped, the proper indexing could not be calculated. Hence, the attribute must not be set. | |
| .k-grid-header-wrap>table>thead>tr>th | role=columnheader |
Required as the owner <table> element has its semantic role removed. |
aria-sort=none/ascending/descending |
Present if sorting is enabled for that column. | |
title or aria-label
|
Present on the element or its child if sorting is enabled for that field. | |
aria-colindex |
Col number, based on leaf columns, starting from 1. Needed only for Virtual columns and Hidden columns scenarios, when not all columns are rendered in the DOM. Otherwise, can be interpreted from the DOM structure. Can be calculated by summing previous columns colspans. | |
aria-haspopup=menu |
The attribute must be present if the column has a ColumnMenu. | |
aria-haspopup=dialog |
The attribute must be present if the column has a FilterMenu and no ColumnMenu. |
Grid filter row
Even if part of the <thead>, the Filter row must be composed of <td> elements.
| Selector | Attribute | Usage |
|---|---|---|
| .k-grid-header-wrap>table>thead>tr.k-filter-row>td | role=gridcell |
Required as the owner <table> element has its semantic role removed. |
aria-label |
Has a label indicating that the cell is part of a filter row. |
Grid filter menu
Implements the Form specification in a Popup.
Form accessibility specification
Grid column menu
Implements the ContextMenu specification. Has menuitemcheckbox instead of menuitems for Columns checkboxes.
ContextMenu accessibility specification
Grid content
| Selector | Attribute | Usage |
|---|---|---|
| .k-grid-content>table | role=none/presentation |
Negates the default semantic role of the <table> element. |
| .k-grid-content>table>tbody | role=rowgroup |
Required as the owner <table> element has its semantic role removed. |
| .k-grid-content>table>tbody>tr | role=row |
Required as the owner <table> element has its semantic role removed. |
aria-rowindex |
Row number including all headers, data (including master and detail) rows, and footers starting from 1. Needed only when Paging (and more that 1 page is present in the component), Virtual rows, or Master/Detail rows (Hierarchical Grid, Detail Template Grid) are enabled. If data is also Grouped, the proper indexing could not be calculated. Hence, the attribute must not be set. In scenarios when master and detail rows are present in the Grid (Hierarchical Grid, Detail Template Grid), both master and detail rows must always be indexed. For example, if the first master row has aria-rowindex=2, even if its detail row is not present in the DOM, the next master row must have aria-rowindex=4. When rendered, the detail row must receive the missing index between the two master rows. In this example it would be aria-rowindex=3. |
|
| .k-grid-content tr.k-state-selected | aria-selected=true |
Set on the currently selected row(s). Only used wen selection mode is set to row. |
| .k-grid-content>table>tbody>tr>td | role=gridcell |
Required as the owner <table> element has its semantic role removed. |
aria-colindex |
Col number, based on leaf columns, starting from 1. Needed only for Virtual columns and Hidden columns scenarios, when not all columns are rendered in the DOM. Otherwise, can be interpreted from the DOM structure. Can be calculated by summing previous columns colspans. | |
| td.k-state-selected | aria-selected=true |
Set on the currently selected cell(s). Only used when selection mode is set to cell. |
| .k-master-row .k-hierarchy-cell,.k-grouping-row>td | aria-expanded=true/false |
Optionally for cells holding grouping criteria values and for Master row cells in Detail template scenario. |
| .k-drag-cell | aria-label |
Must be present in a Drag Row scenario on the cell containing the drag handle. |
Grid footer
The Aggregates totals are placed within a <tfoot> element in the Content <table>.
| Selector | Attribute | Usage |
|---|---|---|
| tfoot | role=rowgroup |
Required as the owner <table> element has its semantic role removed. |
| tfoot>tr | role=row |
Required as the owner <table> element has its semantic role removed. |
aria-rowindex |
Row number including all headers, data (including master and detail) rows, and footers starting from 1. Footer rows are always the last ones in a Grid. Needed only when Paging (and more that 1 page is present in the component), Virtual rows, or Master/Detail rows (Hierarchical Grid, Detail Template Grid) are enabled. If data is also Grouped, the proper indexing could not be calculated. Hence, the attribute must not be set. | |
| tfoot>tr>td | role=gridcell |
Required as the owner <table> element has its semantic role removed. |
aria-colindex |
Col number, based on leaf columns, starting from 1. Needed only for Virtual columns and Hidden columns scenarios, when not all columns are rendered in the DOM. Otherwise, can be interpreted from the DOM structure. Can be calculated by summing previous columns colspans. |
Pager
For the Grid Pager WAI-ARIA spec, please review the Pager component.
Pager accessibility specification
Resources
WAI-ARIA specification for grid
Section 508
The Grid is compliant with the Section 508 requirements
Testing
The component has been extensively tested automatically with static code analyzers and manually with the most popular screen readers.
Any Accessibility Issues could be reported in Telerik Support System.
Screen Readers
| Environment | Tool |
|---|---|
| Firefox | NVDA |
| Chrome | JAWS |
| Microsoft Edge | JAWS |