Angular Data GridTree Data - Nested Records

Configure the grid to display structured data by providing nested records.

Providing Hierarchy

Each row in the data can contain a field containing an array of child rows. The treeDataChildrenField property is used to specify the field containing the child rows.

The below structure demonstrates a simple hierarchy, wherein the treeDataChildrenField grid option would specify "children" as the field containing child rows:

const data = [
    {
        id: 'A',
        children: [
            { id: 'B' },
            { id: 'C' },
        ]
    },
    {
        id: 'D',
        children: [
            {
                id: 'E',
                children: [
                    { id: 'F' },
                ]
            }
        ]
    }
]

In the above hierarchy, the 'A' row is the parent of 'B' and 'C'. The 'D' row is the parent of 'E' which is the parent of 'F'.

Providing Group Values

When providing a nested hierarchy, the grid will use the row ID as the group value by default. To provide a custom value, the autoGroupColumnDef grid options field can be used.

The example below demonstrates a case where the autoGroupColumnDef field is set to name to display a group value:

The following snippet demonstrates how to provide nested siblings with a custom group value:

<ag-grid-angular
    [treeData]="treeData"
    [treeDataChildrenField]="treeDataChildrenField"
    [autoGroupColumnDef]="autoGroupColumnDef"
    /* other grid options ... */ />

this.treeData = true;
this.treeDataChildrenField = 'children';
this.autoGroupColumnDef = {
    field: 'name',
};

Supplied vs Aggregated

When using Tree Data, columns defined with an aggregation function will always perform aggregations on the group nodes. This means any supplied group data will be ignored in favour of the aggregated values.

The example above uses the configuration below to demonstrate the Desktop row is being aggregated to show the sum of its children (4), rather than the provided value (1), despite both columns showing the same field:

const gridOptions = {
    treeData: true,
    columnDefs: [
        {
            headerName: 'Aggregated (Sum)',
            aggFunc: 'sum',
            field: 'items',
        },
        {
            headerName: 'Provided',
            field: 'items',
        },
    ],
};

Refer to the Aggregation page for more details.

Next Up

Continue to the next section to learn how to configure the Group Column.