How to expand the first group level in ag-grid-angular

Question

I have an ag-grid where rows are grouped by two columns by default, but the groups are collapsed.

colDefs = 
[
  {
    field: 'colA',
    rowGroupIndex: 0,
  },
  {
    field: 'colB',
    rowGroupIndex: 1
  },
  …
];

I would like to have the first group level expanded like this:

- ColA 1
  + COlB 1 (5)
  + ColB 2 (3)
- ColA 2
  + COlB 3 (1)
  + COlB 4 (9)
  + COlB 5 (11)

Where is the best place to expand the first level groups?

Answer 1

Have a look at the plunk I've created: ag-grid: expand groups in ag-grid-angular

this.gridApi.expandAll();

For more reference, have a look at the documentation: Built In Menu Items

expandAll: Expand all groups. Only shown if grouping by at least one column.

---

Update:

The above point expands nodes at all levels. Below solution is to achieve as per what you need.

Have a look at the another plunk I've created: ag-grid: expand the first group level in ag-grid-angular

I am simply programmatically expanding the nodes which are at 0 level.

this.gridApi.forEachNode((node, b) => {
  if (node.level === 0) {
    node.setExpanded(true);
  }
});