JavaScript Data GridRow Grouping - Opening GroupsEnterprise

This section covers different ways to control how row groups are expanded and collapsed.

Opening Group Levels by Default

To open all groups down to a given group level use the groupDefaultExpanded grid option as shown below:

const gridOptions = {
    columnDefs: [
        { field: 'country', hide: true, rowGroup: true },
        { field: 'year', hide: true, rowGroup: true },
        { field: 'sport' },
        { field: 'total' }
    // all 'country' row groups will be open by default
    groupDefaultExpanded: 1,

    // other grid options ...

In the snippet above, all country row groups will be expanded by default as groupDefaultExpanded = 1.

By default groupDefaultExpanded = 0 which means no groups are expanded by default. To expand all row groups set groupDefaultExpanded = -1.

The example below demonstrates the groupDefaultExpanded behaviour. Note the following:

  • There are two active row groups as the supplied country and year column definitions have rowGroup=true declared.
  • All country row groups are expanded by default as groupDefaultExpanded = 1.

Open Groups by Default

To have groups open by default, implement the grid callback isGroupOpenByDefault. This callback is invoked each time a group is created.

const gridOptions = {
    // expand when year is '2004' or when country is 'United States'
    isGroupOpenByDefault: params => {
        return (params.field == 'year' && params.key == '2004') ||
            (params.field == 'country' && params.key == 'United States');

    // other grid options ...

The params passed to the callback have the IsGroupOpenByDefaultParams interface:

Properties available on the IsGroupOpenByDefaultParams<TData = any, TContext = any> interface.

The row node being considered.
The Column for which this row is grouping.
Same as rowNode.level - what level the group is at, e.g. 0 for top level, 1 for second etc
Same as rowNode.field - the field we are grouping on, e.g. 'country'
Same as rowNode.key, the value of this group, e.g. 'Ireland'
The grid api.
The column api.
Application context as set on gridOptions.context.

In the example below, the country 'United States' and year '2004' are expanded by default. Note that year '2004' is expanded for all countries, not just 'United States'.

Expand / Collapse Groups via API

It is possible to expand and collapse all group rows using the expandAll() and collapseAll() grid API's as shown below:

Expand all groups.
expandAll = () => void;
Collapse all groups.
collapseAll = () => void;

When more custom behaviour is required, obtain a reference to the rowNode and then call api.setRowNodeExpanded(rowNode, boolean).

Expand or collapse a specific row node, optionally expanding/collapsing all of its parent nodes.
setRowNodeExpanded = (
    rowNode: IRowNode,
    expanded: boolean,
    expandParents?: boolean
) => void;

For example, to expand a group with the name 'United States' would be done as follows:

gridOptions.api.forEachNode(node => {
     if (node.key === 'United States') {
         gridOptions.api.setRowNodeExpanded(node, true);

The following example demonstrates different ways to expand / collapse row groups via the grid API.

Next Up

Continue to the next section to learn about grouping with Complex Objects.