Tree data

Strata’s defining capability is the indented, multi-level tree grid. This guide covers the two input shapes, the tree column, and expand/collapse behavior.

The two shapes

Input shape	Config field	Use when
Nested children	`getChildren(row)`	Your rows already form a tree, such as JSON imports.
Flat parent ids	`getParentId(row)`	Your rows come from a flat table with `parentId`.

Strata internally normalizes both shapes to the same row model, so sorting and filtering behave consistently.

The tree column

Mark exactly one column as the tree column with isTreeColumn: true. That column renders indentation and the expand/collapse chevron. Other columns render normally.

Expand and collapse

Click the chevron in the tree column to toggle a row.
defaultExpanded expands every row on first render.
Expansion state is keyed by row id, so stable ids matter.

Examples

Nested data:

Name

Kind

Size

Flat parent-pointer data:

Name

Kind