# TableHeaderCell

> A table header cell (<th>). scope=col (default) carries an optional three-state DS-Icon sort control and aria-sort; scope=row marks the identifying cell of a body row so screen readers announce the row context with every other cell.

- Status: stable
- Group: data-display
- Page: https://www.digitaltableteur.com/design-system/components/table-header-cell
- Contract: https://www.digitaltableteur.com/contracts/v1/TableHeaderCell.contract.json

## When to use

TableHeaderCell names a column or row with correct scope semantics, and hosts sortable column headers driven by useTableSortable; sort state is announced via aria-sort, never by caret colour alone.

## When not to use

- Do not render it outside a table.
- Do not make a scope=row header sortable; row headers are not sort controls.
- Do not convey sort state with the caret colour alone.

## Look-alikes

- TableCell: Do not use it for a header; use TableHeaderCell so column/row context is announced.

## Props

| Prop | Type | Default | Description | Required |
| --- | --- | --- | --- | --- |
| `align` | `"center" \| "end" \| "start"` | `start` | Cell content alignment. | No |
| `scope` | `"row" \| "col"` | `col` | Header scope. `col` (default) labels a column; `row` makes the cell the accessible name for its row; use it on the identifying cell of each body row so screen readers announce the row context with every other cell. | No |
| `sortable` | `boolean` | none | Renders the sort button, which calls onSort on click; the consumer owns sortDirection. Column headers only: with scope="row" it is silently ignored and no button renders. Without onSort the button does nothing. | No |
| `sortDirection` | `"none" \| "ascending" \| "descending"` | `none` | Current sort state; drives `aria-sort` and the caret icon. Column headers only; ignored with scope="row". | No |
| `onSort` | `() => void` | none | Called when a sortable header is activated. | No |

## Variants

- Allowed `align` values: `start`, `center`, `end` (default `start`).
- Allowed `scope` values: `col`, `row` (default `col`).
- Allowed `sortDirection` values: `none`, `ascending`, `descending` (default `none`).

## Invalid combinations

The contract records no invalid combinations.

## Keyboard

| Key | Behaviour |
| --- | --- |
| Tab | Moves focus to the control and on to the next focusable element. (standard) |
| Enter | Activates the focused control. (standard) |
| Space | Activates or toggles the focused control. (standard) |

Rows marked (standard) name a key the contract lists without a description; the behaviour shown is the usual one for that key.

## Rules

Every item under When not to use is a MUST NOT. MUST and SHOULD follow RFC 2119.

| Level | Rule | How it is checked |
| --- | --- | --- |
| MUST | ARIA: Native <th> with an explicit scope (col or row) | Not yet verified: no evidence record. WCAG 4.1.2. |
| MUST | ARIA: Sortable column headers expose aria-sort and toggle via an inner button. | Not yet verified: no evidence record. WCAG 4.1.2. |
| MUST | ARIA: The sort caret is decorative (aria-hidden); state is carried by aria-sort, never the icon alone. | Not yet verified: no evidence record. WCAG 4.1.2. |
| MUST | Required stories produce no axe violations at the configured severity. | Automated by `npm run test:stories:matrix:ci`. WCAG 2.5.8. |
| MUST | The accessibility tree (role, name, state) matches the committed snapshot for every required story. | Automated by `npm run test:stories:matrix:ci`. WCAG 1.3.1, 4.1.2. |
| MUST | The component remains legible and operable under a real browser forced-colors: active pass. | Automated by `npm run test:stories:hc`. |
| MUST | Every documented keyboard interaction works as specified. | Not yet verified: no evidence record. WCAG 2.1.1, 2.1.2. |
| MUST | A human completed an end-to-end accessibility review of this component. | Manual review, last on 2026-11-04. |

## Install and import

- Install: `npm install @digitaltableteur/react` (version 0.9.1, restricted access on npm).
- Import: `import { TableHeaderCell } from "@digitaltableteur/react";`
- Entry point: `@digitaltableteur/react/content` exports it too.
- Styles: import `@digitaltableteur/react/style.css` once at the app boundary.

## Links

- Machine-readable contract (Design System Contract 1.0): https://www.digitaltableteur.com/contracts/v1/TableHeaderCell.contract.json
- Markdown version of this page: https://www.digitaltableteur.com/design-system/components/table-header-cell.md
- Component index as JSON: https://www.digitaltableteur.com/design-system/components.json
- All components: https://www.digitaltableteur.com/design-system/components
- Source: The implementation lives in a private repository. This page, its Markdown twin and the contract are generated from it at build time and are the public source of truth.