Angular Data GridSSRM Tree Data

This section shows how Tree Data can be used with the Server-Side Row Model.

Tree Data

Tree Data is defined as data that has parent / child relationships where the parent / child relationships are provided as part of the data. This is in contrast to Row Grouping where the parent / child relationships are the result of grouping. When working with Tree Data, there are no columns getting grouped.

An example of a Tree Data JSON structure is shown below:

[{
    "employeeId": 101,
    "employeeName": "Erica Rogers",
    "jobTitle": "CEO",
    "employmentType": "Permanent",
    "children": [{
        "employeeId": 102,
        "employeeName": "Malcolm Barrett",
        "jobTitle": "Exec. Vice President",
        "employmentType": "Permanent",
        "children": [
            {
                "employeeId": 103,
                "employeeName": "Leah Flowers",
                "jobTitle": "Parts Technician",
                "employmentType": "Contract"
            },
            {
                "employeeId": 104,
                "employeeName": "Tammy Sutton",
                "jobTitle": "Service Technician",
                "employmentType": "Contract"
            }
        ]
    }]
}]

It is expected that the data set will be too large to send over the network, hence the SSRM is used to lazy-load child row as the parent rows are expanded.

Tree Data Mode

In order to set the grid to work with Tree Data, simply enable Tree Data mode via the Grid Options using: gridOptions.treeData = true.

Supplying Tree Data

Tree Data is supplied via the Server-Side Datasource just like flat data, however there are two additional gridOptions callbacks: isServerSideGroup(dataItem) and getServerSideGroupKey(dataItem).

The following code snippet shows the relevant gridOptions entries for configuring tree data with the server-side row model:

<ag-grid-angular
    [rowModelType]="rowModelType"
    [treeData]="treeData"
    [isServerSideGroup]="isServerSideGroup"
    [getServerSideGroupKey]="getServerSideGroupKey"
    /* other grid options ... */ />

// choose Server-Side Row Model
this.rowModelType = 'serverSide';

// enable Tree Data
this.treeData = true;

// indicate if row is a group node
this.isServerSideGroup = dataItem => {
    return dataItem.group;
};

// specify which group key to use
this.getServerSideGroupKey = dataItem => {
    return dataItem.employeeId;
};

The example below shows this in action where the following can be noted:

• Tree Data is enabled with the Server-Side Row Model using gridOptions.treeData = true.
• Group nodes are determined using the callback gridOptions.isServerSideGroup(dataItem).
• Group keys are returned from the callback gridOptions.getServerSideGroupKey(dataItem).

Refreshing Tree Data

Tree Data can be refreshed in the same way as groups are refreshed when not using Tree Data. This is explained in the SSRM Refresh.

The example below shows this in action where the following can be noted:

• Click Refresh Everything to clear all caches by calling api.refreshServerSide({ route: [], purge: true }).
• Click Refresh ['Kathryn Powers','Mabel Ward'] to clear a single cache by calling api.refreshServerSide({ route: ['Kathryn Powers','Mabel Ward'], purge: true }).

Transactions with Tree Data

Tree Data can have transactions applied in the same way as row groups. This is explained in the SSRM Transactions section.

The example below demonstrates transactions with Tree Data. Note the following:

• Add Child to Selected adds a child under the selected row, even if it wasn't originally a group.
• Update Selected changes the selected row's Employment Type.
• Delete Selected removes the selected row, and all of its child rows.
• Move Selected to Robert Peterson moves the selected row and its children directly under Robert Peterson.

Selection with Tree Data

Tree Data can have row selection applied in the same way as row groups. This is explained in the SSRM Row Selection section.

The example below demonstrates row selection with Tree Data where the grid has been configured with rowSelection.groupSelects = 'descendants'. This means that selecting a row with descendants selects all of its descendants. Selecting some, but not all, of the descendants of a row places that row in the indeterminate state.

Filtering Tree Data

Server-Side Tree Data Filtering should behave the same as Client-Side Tree Data Filtering. A group will be included if:

1. it has any children that pass the filter, or

2. it has a parent that passes the filter, or

3. its own data passes the filter

The following example demonstrates Server-Side Tree Data Filtering using the Set Filter Tree List, which replicates the Tree Data structure in the filter.

• The Group column has the Set Filter Tree List enabled via filterParams.treeList = true. A Key Creator is specified to convert the path into a string.
• The Group column has the filter values supplied asynchronously as a nested array of strings that matches the data paths. The supplied values are at the child level only.
• The Date column has the Set Filter Tree List enabled via filterParams.treeList = true, and is grouped by year -> month -> day.
• The Date column has the filter values supplied asynchronously as an array of Date objects.
• The Date column has a filterParams.keyCreator provided to convert the Date values into the (string) format the server is expecting in the Filter Model.
• The Group and Date columns both have filterParams.excelMode = 'windows', which allows changes to the tree filter to be applied in batches.

Providing Hierarchical Data via API

Below is an example of utilising api.applyServerSideRowData to populate data. The datasource is only used to provide root level rows, and when these are loaded the grid is provided the child row data via the API.