---
title: "Row Grouping - Expanding Groups"
enterprise: true
framework: javascript
version: "36.1.0"
---

# Row Grouping - Expanding Groups

Configure the initial expanded group row state when using Tree Data.

## Expanding by Group Level

When providing a hierarchy, all levels will default to a collapsed state. This can be configured by setting the `groupDefaultExpanded` grid option. Providing a number will expand all groups down to that level, or providing -1 will expand all groups.

#### Group Default Expanded

```ts
import {
  ClientSideRowModelModule,
  GridApi,
  GridOptions,
  ModuleRegistry,
  createGrid,
  enableDevValidations,
} from "ag-grid-community";
import { RowGroupingModule } from "ag-grid-enterprise";
import { IOlympicData } from "./interfaces";

// Enable extended validations only for development
if (process.env.NODE_ENV !== "production") {
  enableDevValidations();
}

ModuleRegistry.registerModules([ClientSideRowModelModule, RowGroupingModule]);

let gridApi: GridApi<IOlympicData>;

const gridOptions: GridOptions<IOlympicData> = {
  columnDefs: [
    { field: "country", rowGroup: true, hide: true },
    { field: "year", rowGroup: true, hide: true },
    { field: "athlete" },
    { field: "sport" },
    { field: "gold" },
    { field: "silver" },
    { field: "bronze" },
  ],
  defaultColDef: {
    flex: 1,
    minWidth: 100,
  },
  autoGroupColumnDef: {
    minWidth: 200,
  },
  // all 'country' row groups will be open by default
  groupDefaultExpanded: 1,
};

const gridDiv = document.querySelector<HTMLElement>("#myGrid")!;
gridApi = createGrid(gridDiv, gridOptions);

fetch("https://www.ag-grid.com/example-assets/olympic-winners.json")
  .then((response) => response.json())
  .then((data: IOlympicData[]) => gridApi!.setGridOption("rowData", data));
```

[Live example: Group Default Expanded](https://www.ag-grid.com/examples/grouping-opening-groups/group-default-expanded/typescript)

The example above uses the following configuration to expand the first level of groups, but no others:

```js
const gridOptions = {
    groupDefaultExpanded: 1,

    // other grid options ...
}
```

## Expanding via Callback

To granularly determine which groups should be expanded by default, use the `isGroupOpenByDefault` grid callback.

| Property | Type | Required | Default | Description |
| --- | --- | --- | --- | --- |
| `isGroupOpenByDefault` | `IsGroupOpenByDefault` |  |  | (Client-side Row Model only) Allows group rows to be open by default. For master rows use `isMasterOpenByDefault`. Modules (any of): [`RowGroupingModule`](https://www.ag-grid.com/javascript-data-grid/modules/), [`TreeDataModule`](https://www.ag-grid.com/javascript-data-grid/modules/). |

#### Open by Default

```ts
import {
  ClientSideRowModelModule,
  GridApi,
  GridOptions,
  IsGroupOpenByDefaultParams,
  ModuleRegistry,
  NumberFilterModule,
  TextFilterModule,
  createGrid,
  enableDevValidations,
} from "ag-grid-community";
import { RowGroupingModule } from "ag-grid-enterprise";
import { IOlympicData } from "./interfaces";

// Enable extended validations only for development
if (process.env.NODE_ENV !== "production") {
  enableDevValidations();
}

ModuleRegistry.registerModules([
  TextFilterModule,
  NumberFilterModule,
  ClientSideRowModelModule,
  RowGroupingModule,
]);

let gridApi: GridApi<IOlympicData>;

const gridOptions: GridOptions<IOlympicData> = {
  columnDefs: [
    { field: "country", rowGroup: true },
    { field: "year", rowGroup: true },
    { field: "sport" },
    { field: "athlete" },
    { field: "total" },
  ],
  defaultColDef: {
    flex: 1,
    minWidth: 100,
    filter: true,
  },
  autoGroupColumnDef: {
    minWidth: 200,
  },
  isGroupOpenByDefault: (params: IsGroupOpenByDefaultParams) => {
    const route = params.rowNode.getRoute();
    const destPath = ["Australia", "2004"];
    return !!route?.every((item, idx) => destPath[idx] === item);
  },
};

const gridDiv = document.querySelector<HTMLElement>("#myGrid")!;
gridApi = createGrid(gridDiv, gridOptions);

fetch("https://www.ag-grid.com/example-assets/olympic-winners.json")
  .then((response) => response.json())
  .then((data: IOlympicData[]) => gridApi!.setGridOption("rowData", data));
```

[Live example: Open by Default](https://www.ag-grid.com/examples/grouping-opening-groups/open-by-default/typescript)

The example above uses the following configuration to expand the `Australia` and its child `2004` groups by default:

```js
const gridOptions = {
    isGroupOpenByDefault: (params) => {
        const route = params.rowNode.getRoute();
        const destPath = ['Australia', '2004'];
        return route.every((item, idx) => destPath[idx] === item);
    },

    // other grid options ...
}
```

> **Note**
>
> Row keys are only unique within their groups, so it is recommended to instead use the entire [Row Route](https://www.ag-grid.com/javascript-data-grid/row-object/#reference-serverSide-getRoute) to identify the row.

## Prevent Sticky Groups

When scrolling through an expanded group, the group row will stick to the top of the grid. To prevent this behaviour, set the `suppressGroupRowsSticky` property to `true`.

#### Sticky Groups

```ts
import {
  ClientSideRowModelModule,
  GridApi,
  GridOptions,
  ModuleRegistry,
  createGrid,
  enableDevValidations,
} from "ag-grid-community";
import { RowGroupingModule } from "ag-grid-enterprise";
import { IOlympicData } from "./interfaces";

// Enable extended validations only for development
if (process.env.NODE_ENV !== "production") {
  enableDevValidations();
}

ModuleRegistry.registerModules([ClientSideRowModelModule, RowGroupingModule]);

let gridApi: GridApi<IOlympicData>;

const gridOptions: GridOptions<IOlympicData> = {
  columnDefs: [
    { field: "country", rowGroup: true },
    { field: "year", rowGroup: true },
    { field: "sport" },
    { field: "athlete" },
    { field: "total" },
  ],
  defaultColDef: {
    flex: 1,
    minWidth: 100,
  },
  autoGroupColumnDef: {
    minWidth: 200,
  },
  suppressGroupRowsSticky: true,
  groupDefaultExpanded: 1,
};

const gridDiv = document.querySelector<HTMLElement>("#myGrid")!;
gridApi = createGrid(gridDiv, gridOptions);

fetch("https://www.ag-grid.com/example-assets/olympic-winners.json")
  .then((response) => response.json())
  .then((data: IOlympicData[]) => gridApi!.setGridOption("rowData", data));
```

[Live example: Sticky Groups](https://www.ag-grid.com/examples/grouping-opening-groups/suppress-sticky-groups/typescript)

The example above uses the following configuration to prevent groups from sticking:

```js
const gridOptions = {
    suppressGroupRowsSticky: true,

    // other grid options ...
}
```

## Scrolling Child Rows into View

When expanding a group the vertical scroll does not change, which can result in the child rows not being visible. You can use the `ensureIndexVisible()` function on the API to ensure the index is visible, scrolling the table if needed.

In the example below, if you expand a group at the bottom, the grid will scroll so that all of the children of the group are visible.

#### Row Group Scroll

```ts
import {
  ClientSideRowModelModule,
  ColDef,
  GridApi,
  GridOptions,
  ModuleRegistry,
  NumberEditorModule,
  RowGroupOpenedEvent,
  ScrollApiModule,
  TextEditorModule,
  TextFilterModule,
  createGrid,
  enableDevValidations,
} from "ag-grid-community";
import { RowGroupingModule } from "ag-grid-enterprise";
import { IOlympicData } from "./interfaces";

// Enable extended validations only for development
if (process.env.NODE_ENV !== "production") {
  enableDevValidations();
}

ModuleRegistry.registerModules([
  ScrollApiModule,
  NumberEditorModule,
  TextEditorModule,
  TextFilterModule,
  ClientSideRowModelModule,
  RowGroupingModule,
]);

const columnDefs: ColDef[] = [
  { field: "athlete", width: 150, rowGroupIndex: 0 },
  { field: "age", width: 90, rowGroupIndex: 1 },
  { field: "country", width: 120, rowGroupIndex: 2 },
  { field: "year", width: 90 },
  { field: "date", width: 110, rowGroupIndex: 2 },
];

let gridApi: GridApi<IOlympicData>;

const gridOptions: GridOptions<IOlympicData> = {
  columnDefs: columnDefs,
  animateRows: false,
  groupDisplayType: "groupRows",
  onRowGroupOpened: onRowGroupOpened,
  defaultColDef: {
    editable: true,
    filter: true,
    flex: 1,
    minWidth: 100,
  },
};

function onRowGroupOpened(event: RowGroupOpenedEvent<IOlympicData>) {
  if (event.expanded) {
    const rowNodeIndex = event.node.rowIndex!;
    // factor in child nodes so we can scroll to correct position
    const childCount = event.node.childrenAfterSort
      ? event.node.childrenAfterSort.length
      : 0;
    const newIndex = rowNodeIndex + childCount;
    gridApi!.ensureIndexVisible(newIndex);
  }
}

const gridDiv = document.querySelector<HTMLElement>("#myGrid")!;
gridApi = createGrid(gridDiv, gridOptions);

fetch("https://www.ag-grid.com/example-assets/olympic-winners.json")
  .then((response) => response.json())
  .then((data: IOlympicData[]) => gridApi!.setGridOption("rowData", data));
```

[Live example: Row Group Scroll](https://www.ag-grid.com/examples/grouping-opening-groups/row-group-scroll/typescript)

## API

> **Note**
>
> The row group expansion state can be saved and restored as part of [Grid State](https://www.ag-grid.com/javascript-data-grid/grid-state/).

The grid exposes API methods to expand or collapse groups programmatically.

| Property | Type | Required | Default | Description |
| --- | --- | --- | --- | --- |
| `expandAll` | `Function` |  |  | Expand all groups. Modules (any of): [`ClientSideRowModelApiModule`](https://www.ag-grid.com/javascript-data-grid/modules/), [`ServerSideRowModelApiModule`](https://www.ag-grid.com/javascript-data-grid/modules/). |
| `collapseAll` | `Function` |  |  | Collapse all groups. Modules (any of): [`ClientSideRowModelApiModule`](https://www.ag-grid.com/javascript-data-grid/modules/), [`ServerSideRowModelApiModule`](https://www.ag-grid.com/javascript-data-grid/modules/). |
| `resetRowGroupExpansion` | `Function` |  |  | Reset all group expansion to defaults, as determined by `groupDefaultExpanded`, `isGroupOpenByDefault`, or `isServerSideGroupOpenByDefault`. Any user-initiated expand/collapse overrides are discarded. Modules (any of): [`ClientSideRowModelApiModule`](https://www.ag-grid.com/javascript-data-grid/modules/), [`ServerSideRowModelApiModule`](https://www.ag-grid.com/javascript-data-grid/modules/). |
| `setRowNodeExpanded` | `Function` |  |  | Expand or collapse a specific row node, optionally expanding/collapsing all of its parent nodes. By default rows are expanded asynchronously for best performance. Set `forceSync: true` if you need to interact with the expanded row immediately after this function. Module: [`RowApiModule`](https://www.ag-grid.com/javascript-data-grid/modules/). |

### Expand Row Ancestors

When expanding rows via the API, the `setRowNodeExpanded` function can be used to expand a specific row as well as all of its ancestors.

#### Expand to Row

```ts
import {
  ClientSideRowModelModule,
  GridApi,
  GridOptions,
  ModuleRegistry,
  RowApiModule,
  createGrid,
  enableDevValidations,
} from "ag-grid-community";
import { RowGroupingModule } from "ag-grid-enterprise";

// Enable extended validations only for development
if (process.env.NODE_ENV !== "production") {
  enableDevValidations();
}

ModuleRegistry.registerModules([
  RowApiModule,
  ClientSideRowModelModule,
  RowGroupingModule,
]);

let gridApi: GridApi;

const gridOptions: GridOptions = {
  columnDefs: [
    { field: "country", rowGroup: true, hide: true },
    { field: "year", rowGroup: true, hide: true },
    { field: "athlete" },
    { field: "total" },
  ],
  defaultColDef: {
    flex: 1,
    minWidth: 150,
  },

  getRowId: (params) => params.data.id,
  onFirstDataRendered: () => {
    const node = gridApi.getRowNode("2");
    if (node) {
      gridApi.setRowNodeExpanded(node, true, true);
    }
  },
};

const gridDiv = document.querySelector<HTMLElement>("#myGrid")!;
gridApi = createGrid(gridDiv, gridOptions);

fetch("https://www.ag-grid.com/example-assets/olympic-winners.json")
  .then((response) => response.json())
  .then((data: IOlympicData[]) =>
    gridApi!.setGridOption(
      "rowData",
      data.map((d, i) => ({ ...d, id: String(i) })),
    ),
  );
```

[Live example: Expand to Row](https://www.ag-grid.com/examples/grouping-opening-groups/expand-collapse-api/typescript)

The example above uses [Row IDs](https://www.ag-grid.com/javascript-data-grid/row-ids/#row-ids) to demonstrate the following configuration to expand all of the ancestors of the row with the ID `"2"`:

```
const expandToRow = () => {
  const node = gridApi.getRowNode('2');
  if (node) {
      gridApi.setRowNodeExpanded(node, true, true);
  }
}
```

### Reset Group Expansion

After users have expanded or collapsed groups, `resetRowGroupExpansion()` discards all overrides and re-evaluates each group against the configured defaults (`groupDefaultExpanded` or `isGroupOpenByDefault`).

In the example below, the `isGroupOpenByDefault` callback expands the `Australia > 2004` path by default. Try expanding or collapsing groups, then click **Reset to Defaults** to restore the original expansion state.

#### Reset Group Expansion

```ts
import {
  ClientSideRowModelApiModule,
  ClientSideRowModelModule,
  GridApi,
  GridOptions,
  IsGroupOpenByDefaultParams,
  ModuleRegistry,
  RowApiModule,
  createGrid,
  enableDevValidations,
} from "ag-grid-community";
import { RowGroupingModule } from "ag-grid-enterprise";
import { IOlympicData } from "./interfaces";

// Enable extended validations only for development
if (process.env.NODE_ENV !== "production") {
  enableDevValidations();
}

ModuleRegistry.registerModules([
  RowApiModule,
  ClientSideRowModelModule,
  ClientSideRowModelApiModule,
  RowGroupingModule,
]);

let gridApi: GridApi<IOlympicData>;

const gridOptions: GridOptions<IOlympicData> = {
  columnDefs: [
    { field: "country", rowGroup: true },
    { field: "year", rowGroup: true },
    { field: "sport" },
    { field: "athlete" },
    { field: "total" },
  ],
  defaultColDef: {
    flex: 1,
    minWidth: 100,
  },
  autoGroupColumnDef: {
    minWidth: 200,
  },
  isGroupOpenByDefault: (params: IsGroupOpenByDefaultParams) => {
    const route = params.rowNode.getRoute();
    const destPath = ["Australia", "2004"];
    return !!route?.every((item, idx) => destPath[idx] === item);
  },
};

function onBtExpandAll() {
  gridApi!.expandAll();
}

function onBtCollapseAll() {
  gridApi!.collapseAll();
}

function onBtResetExpansion() {
  gridApi!.resetRowGroupExpansion();
}

const gridDiv = document.querySelector<HTMLElement>("#myGrid")!;
gridApi = createGrid(gridDiv, gridOptions);

fetch("https://www.ag-grid.com/example-assets/olympic-winners.json")
  .then((response) => response.json())
  .then((data: IOlympicData[]) => gridApi!.setGridOption("rowData", data));

if (typeof window !== "undefined") {
  // Attach external event handlers to window so they can be called from index.html
  (<any>window).onBtExpandAll = onBtExpandAll;
  (<any>window).onBtCollapseAll = onBtCollapseAll;
  (<any>window).onBtResetExpansion = onBtResetExpansion;
}
```

[Live example: Reset Group Expansion](https://www.ag-grid.com/examples/grouping-opening-groups/reset-group-expansion/typescript)