Get all child nodes in EJ2 TypeScript TreeView control

28 Jan 20259 minutes to read

This section demonstrates how to retrieve child nodes from a corresponding parent ID within the TreeView control. By using the getNode method, you can obtain the node details of the TreeView. Please refer to the following example.

import { enableRipple } from '@syncfusion/ej2-base';
import { TreeView } from '@syncfusion/ej2-navigations';
enableRipple(true);

/**
 * TreeView get child nodes from parent id sample
 */

// List data source for TreeView control
let data: { [key: string]: Object }[] = [
    {
        code: "AF", name: "Africa", countries: [
            { code: "NGA", name: "Nigeria" },
            { code: "EGY", name: "Egypt" },
            { code: "ZAF", name: "South Africa" }
        ]
    },
    {
        code: "AS", name: "Asia", countries: [
            { code: "CHN", name: "China" },
            {
                code: "IND", name: "India", countries: [
                    { code: "TN", name: "TamilNadu" }
                ]
            },
            { code: "JPN", name: "Japan" }
        ]
    },
    {
        code: "EU", name: "Europe", countries: [
            { code: "DNK", name: "Denmark" },
            { code: "FIN", name: "Finland" },
            { code: "AUT", name: "Austria" }
        ]
    },
    {
        code: "NA", name: "North America", countries: [
            { code: "USA", name: "United States of America" },
            { code: "CUB", name: "Cuba" },
            { code: "MEX", name: "Mexico" }
        ]
    },
    {
        code: "SA", name: "South America", countries: [
            { code: "BR", name: "Brazil" },
            { code: "COL", name: "Colombia" },
            { code: "ARG", name: "Argentina" }
        ]
    },
];

let tree1: TreeView = new TreeView({
    fields: { dataSource: data, id: 'code', text: 'name', child: 'countries' },
    loadOnDemand: false,
    created: onCreate
});
tree1.appendTo('#tree');

function onCreate() {
    let proxy = this;
    (document.getElementById("btn") as HTMLElement).addEventListener("click", (event) => {
        let id = (document.getElementById('Nodes') as HTMLInputElement).value;
        let element = proxy.element.querySelector('[data-uid="' + id + '"]');
        // Gets the child Element
        let liElements = element.querySelectorAll('ul li');
        let arr: any = [];
        for (let i = 0; i < liElements.length; i++) {
            let nodeData = proxy.getNode(liElements[i]);
            arr.push(nodeData);
        }
        alert(JSON.stringify(arr));
    });
}
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 for TreeView </title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Essential JS 2 for TreeView UI Control" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/31.1.17/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/31.1.17/ej2-inputs/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/31.1.17/ej2-navigations/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='treeparent'>
            <div id="tree"></div>
        </div>
        <br />
        <input type="text" class="e-input" id="Nodes" style="margin-left: 300px; width: 175px;"
            placeholder="Enter the parent ID( Ex: AS)" />
        <input type="button" class="btn btn-primary" value="Submit" id="btn" />
        <br />
    </div>
    <style>
        #treeparent {
            display: block;
            max-width: 350px;
            max-height: 350px;
            margin: auto;
            overflow: auto;
            border: 1px solid #dddddd;
            border-radius: 3px;
        }
    </style>
</body>

</html>
#container {
  visibility: hidden;
}

#loader {
  color: #008cff;
  height: 40px;
  width: 30%;
  position: absolute;
  font-family: 'Helvetica Neue', 'calibiri';
  font-size: 14px;
  top: 45%;
  left: 45%;
}