# FlattenedTreeRow

> _Since v0.1.1_

A flattened tree row with hierarchy metadata *

## Properties

| Property | Type | Description |
| -------- | ---- | ----------- |
| `key` | <code>string</code> | Unique key identifying this row |
| `data` | <code>T</code> | Original row data |
| `depth` | <code>number</code> | Depth level in the tree (0 = root) |
| `hasChildren` | <code>boolean</code> | Whether this row has children |
| `isExpanded` | <code>boolean</code> | Whether this row is currently expanded |
| `parentKey` | <code>string &#124; unknown</code> | Key of the parent row, or null for root level |
| `posInSet` | <code>number</code> | 1-based position among siblings at the same level (for `aria-posinset`). |
| `setSize` | <code>number</code> | Total number of siblings at this level under the same parent (for `aria-setsize`). |