Local data in EJ2 TypeScript Treegrid control

16 Sep 202310 minutes to read

In Local Data binding, data source for rendering the TreeGrid control is retrieved from the same application locally.

Two types of Data binding are possible with the TreeGrid control.

Hierarchical Datasource binding
Self-Referential Data binding (Flat Data)

To bind local data to the treegrid, you can assign a JavaScript object array to the dataSource property. The local data source can also be provided as an instance of the DataManager.

By default, DataManager uses JsonAdaptor for local data-binding.

Hierarchy data source binding

The childMapping property is used to map the child records in hierarchy data source.

The following code example shows you how to bind the hierarchical local data into the TreeGrid control.

index.ts
index.html
import { TreeGrid, Page } from '@syncfusion/ej2-treegrid';
import { sampleData } from './datasource.ts';
TreeGrid.Inject(Page);

let treeGridObj: TreeGrid = new TreeGrid({
    dataSource: sampleData,
    childMapping: 'subtasks',
    allowPaging: true,
    pageSettings: {pageSize: 7},
    treeColumnIndex: 1,
    columns: [
                { field: 'taskID', headerText: 'Task ID', width: 90, textAlign: 'Right' },
                { field: 'taskName', headerText: 'Task Name', width: 180 },
                {
                    field: 'startDate', headerText: 'Start Date', width: 90, textAlign: 'Right', type: 'date',format: 'yMd'
                },
                { field: 'duration', headerText: 'Duration', width: 80, textAlign: 'Right' }
    ]
});

treeGridObj.appendTo('#TreeGrid');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 Grid</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript Grid Control" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-grids/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-treegrid/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-popups/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-navigations/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-dropdowns/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-lists/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-inputs/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-calendars/styles/material.css" rel="stylesheet" />
    
    
    
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-splitbuttons/styles/material.css" rel="stylesheet" />
    
    
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>
<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <div id='TreeGrid'></div>        
    </div>
</body>
</html>

Remote data binding is not supported for Hierarchy Data.

Self-Referential data binding (Flat data)

TreeGrid is rendered from Self-Referential data structures by providing two fields, ID field and parent ID field.

ID Field: This field contains unique values used to identify nodes. Its name is assigned to the idMapping property.
Parent ID Field: This field contains values that indicate parent nodes. Its name is assigned to the parentIdMapping property.

index.ts
index.html
import { TreeGrid, Page } from '@syncfusion/ej2-treegrid';
import { projectData } from './datasource.ts';
TreeGrid.Inject(Page);

let treeGridObj: TreeGrid = new TreeGrid({
    dataSource: projectData,
    idMapping: 'TaskID',
    parentIdMapping: 'parentID',
    allowPaging: true,
    treeColumnIndex: 1,
    pageSettings: {pageSize: 7},
    columns: [
                { field: 'TaskID', headerText: 'Task ID', width: 90, textAlign: 'Right' },
                { field: 'TaskName', headerText: 'Task Name', width: 180 },
                {
                    field: 'StartDate', headerText: 'Start Date', width: 90, textAlign: 'Right', type: 'date',format: 'yMd'
                },
                { field: 'Duration', headerText: 'Duration', width: 80, textAlign: 'Right' }
    ]
});

treeGridObj.appendTo('#TreeGrid');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 Grid</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript Grid Control" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-grids/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-treegrid/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-popups/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-navigations/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-dropdowns/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-lists/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-inputs/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-calendars/styles/material.css" rel="stylesheet" />
    
    
    
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-splitbuttons/styles/material.css" rel="stylesheet" />
    
    
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>
<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <div id='TreeGrid'></div>        
    </div>
</body>
</html>

Herewith we have provided list of reserved properties and the purpose we used internally in TreeGrid. We recommend to avoid these reserved properties in your dataSource(To get rid of conflicts).

Reserved keywords	Purpose
childRecords	Specifies the childRecords of a parentData
hasChildRecords	Specifies whether the record contains child records
hasFilteredChildRecords	Specifies whether the record contains filtered child records
expanded	Specifies whether the child records are expanded
parentItem	Specifies the parentItem of childRecords
index	Specifies the index of current record
level	Specifies the hierarchy level of record
filterLevel	Specifies the hierarchy level of filtered record
parentIdMapping	Specifies the parentID
uniqueID	Specifies the unique ID of a record
parentUniqueID	Specifies the parent Unique ID of a record
checkboxState	Specifies the checkbox state of a record
isSummaryRow	Specifies the summary of a record
taskData	Specifies the main data
primaryParent	Specifies the Primary data