# HeaderContentDefinition

> _Since v0.1.1_

Header content definition for plugins contributing to shell header center section.

Register via the shell plugin's `registerHeaderContent()` to add content between
the title and toolbar buttons.

#### Example

```typescript
grid.getPluginByName('shell')?.registerHeaderContent({
  id: 'row-count',
  order: 10,
  render: (container) => {
    const span = document.createElement('span');
    span.className = 'row-count';
    span.textContent = `${grid.rows.length} rows`;
    container.appendChild(span);

    // Update on data changes
    const unsub = grid.on('data-change', () => {
      span.textContent = `${grid.rows.length} rows`;
    });

    return () => {
      unsub();
    };
  },
});
```

## Properties

| Property | Type | Description |
| -------- | ---- | ----------- |
| `id` | <code>string</code> | Unique content ID |
| `render` | <code>(container: HTMLElement) =&gt; void &#124; () =&gt; void</code> | Content factory - called once when shell header renders |
| `onDestroy?` | <code>() =&gt; void</code> | Called when content is removed (for cleanup) |
| `order?` | <code>number</code> | Order priority (lower = first, default: 100) |

## See Also

- [`ShellConfig`](/grid/plugins/shell/interfaces/shellconfig.md) for shell configuration