Paging in EJ2 TypeScript Treegrid control

27 Apr 202320 minutes to read

Paging provides an option to display TreeGrid data in page segments. To enable paging, set the allowPaging to true. When paging is enabled, pager component renders at the bottom of the treegrid.
Paging options can be configured through the pageSettings.

To use paging, inject the Page module in the treegrid.

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: 160 },
        {
            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>

You can achieve better performance by using treegrid paging to fetch only a pre-defined number of records from the data source.

Page Size Mode

Two behaviors are available in TreeGrid paging to display certain number of records in a current page. Following are the two types of pageSizeMode.

All : This is the default mode. The number of records in a page is based on pageSize property.
Root : The number of root nodes or the 0th level records to be displayed per page is based on pageSize property.

With pageSizeMode property as Root, only the root level or the 0th level records are considered in records count.

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,
    height: 265,
    pageSettings: {pageSize: 2, pageSizeMode: 'Root'},
    treeColumnIndex: 1,
    columns: [
        { field: 'taskID', headerText: 'Task ID', width: 90, textAlign: 'Right' },
        { field: 'taskName', headerText: 'Task Name', width: 160 },
        {
            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>

Template

You can use custom elements inside the pager instead of default elements.
The custom elements can be defined by using the template property.
Inside this template, you can access the currentPage, pageSize, pageCount, totalPage and totalRecordCount values.

index.ts
index.html
import { TreeGrid, Page, PageEventArgs } from '@syncfusion/ej2-treegrid';
import { sampleData } from './datasource.ts';
import { NumericTextBox } from '@syncfusion/ej2-inputs';

TreeGrid.Inject(Page);

let flag: boolean = true;
let treeGridObj: TreeGrid = new TreeGrid({
    dataSource: sampleData,
    childMapping: 'subtasks',
    allowPaging: true,
    pageSettings: {pageSize: 6,  template: '#template'},
    treeColumnIndex: 1,
    columns: [
        { field: 'taskID', headerText: 'Task ID', width: 90, textAlign: 'Right' },
        { field: 'taskName', headerText: 'Task Name', width: 160 },
        {
            field: 'startDate', headerText: 'Start Date', width: 90, textAlign: 'Right', type: 'date',format: 'yMd'
        },
        { field: 'duration', headerText: 'Duration', width: 80, textAlign: 'Right' }
    ],
    dataBound: () => {
        if (flag) {
            flag = false;
            updateTemplate();
        }
    },
    actionComplete: (args: PageEventArgs) => {
        if (args.requestType === 'paging') {
            updateTemplate();
        }
    }
});

treeGridObj.appendTo('#TreeGrid');

let updateTemplate: Function = () => {
    let numeric: NumericTextBox;
    this.numeric = new NumericTextBox({
        min: 1,
        max: 3,
        step: 1,
        width: 75,
        format: '###.##',
        change: (args) => {
            let value: number = args.value;
            treeGridObj.goToPage(value);
        }
    });
    this.numeric.appendTo('#currentPage');
};
let flag: boolean = true;
<!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 id="template" type="text/x-template">
        <div class="e-pagertemplate">
        <div class="col-lg-12 control-section">
            <div class="content-wrapper">
                <input id="currentPage" type="text" value=${currentPage} style="padding-left: 10px; text-align: left">
            </div>                                   
        </div>
    
        <div id="totalPages" class="e-pagertemplatemessage" style="margin-top:5px;margin-left:30px;border: none; display: inline-block ">
            <span class ="e-pagenomsg">${currentPage} of ${totalPages} pages (${totalRecordsCount} items)</span>
        </div>
    </div>
    </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>

The pager Dropdown allows you to change the number of records in the TreeGrid dynamically. It can be enabled by defining the pageSettings.pageSizes property as true.

pageSettings: {pageSize: 7, pageSizes: true},

Page size dropdown

By default, Pager will be rendered at the bottom of the TreeGrid. You can also render the Pager at the top of the TreeGrid by using the dataBound event.

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

TreeGrid.Inject(Page);

let initialGridLoad: boolean = true;
let treeGridObj: TreeGrid = new TreeGrid({
    dataSource: sampleData,
    childMapping: 'subtasks',
    allowPaging: true,
    pageSettings: {pageSize: 7, pageSizes: true},
    treeColumnIndex: 1,
    columns: [
        { field: 'taskID', headerText: 'Task ID', width: 90, textAlign: 'Right' },
        { field: 'taskName', headerText: 'Task Name', width: 160 },
        {
            field: 'startDate', headerText: 'Start Date', width: 90, textAlign: 'Right', type: 'date',format: 'yMd'
        },
        { field: 'duration', headerText: 'Duration', width: 80, textAlign: 'Right' }
    ]
});

treeGridObj.appendTo('#TreeGrid');

treeGridObj.dataBound = () =>{
    if (initialGridLoad) {
        initialGridLoad = false;
        var pager = document.getElementsByClassName('e-gridpager');
        var topElement;
        if ( treeGridObj.toolbar) {
            topElement = document.getElementsByClassName('e-toolbar');
        } else {
            topElement = document.getElementsByClassName('e-gridheader');
        }
        topElement[0].before(pager[0]);
    }
};
<!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>

During the paging action, the pager component triggers the below three events.

The created event triggers when Pager is created.

The click event triggers when the numeric items in the pager is clicked.

The dropDownChanged event triggers when pageSize DropDownList value is selected.
You can refer to our JavaScript Tree Grid feature tour page for its groundbreaking feature representations. You can also explore our JavaScript Tree Grid example JavaScript Tree Grid example to knows how to present and manipulate data.

Paging in EJ2 TypeScript Treegrid control

Page Size Mode

Template

Pager with Page Size Dropdown

How to render Pager at the Top of the TreeGrid