Customize the tree nodes based on levels in EJ2 JavaScript TreeView control

28 Jan 202515 minutes to read

You can customize the tree node levels by adding a custom cssClass to the control and applying styles accordingly.

ej.base.enableRipple(true);

/**
 * TreeView node editing sample with validation
 */

// Hierarchical data source for TreeView control
var hierarchicalData = [
    {
        id: '01', name: 'Local Disk (C:)', expanded: true,
        subChild: [
            {
                id: '01-01', name: 'Program Files',
                subChild: [
                    { id: '01-01-01', name: 'Windows NT' },
                    { id: '01-01-02', name: 'Windows Mail' },
                    { id: '01-01-03', name: 'Windows Photo Viewer' },
                ]
            },
            {
                id: '01-02', name: 'Users', expanded: true,
                subChild: [
                    { id: '01-02-01', name: 'Smith' },
                    { id: '01-02-02', name: 'Public' },
                    { id: '01-02-03', name: 'Admin' },
                ]
            },
            {
                id: '01-03', name: 'Windows',
                subChild: [
                    { id: '01-03-01', name: 'Boot' },
                    { id: '01-03-02', name: 'FileManager' },
                    { id: '01-03-03', name: 'System32' },
                ]
            },
        ]
    },
    {
        id: '02', name: 'Local Disk (D:)',
        subChild: [
            {
                id: '02-01', name: 'Personals',
                subChild: [
                    { id: '02-01-01', name: 'My photo.png' },
                    { id: '02-01-02', name: 'Rental document.docx' },
                    { id: '02-01-03', name: 'Pay slip.pdf' },
                ]
            },
            {
                id: '02-02', name: 'Projects',
                subChild: [
                    { id: '02-02-01', name: 'ASP Application' },
                    { id: '02-02-02', name: 'TypeScript Application' },
                    { id: '02-02-03', name: 'React Application' },
                ]
            },
            {
                id: '02-03', name: 'Office',
                subChild: [
                    { id: '02-03-01', name: 'Work details.docx' },
                    { id: '02-03-02', name: 'Weekly report.docx' },
                    { id: '02-03-03', name: 'Wish list.csv' },
                ]
            },
        ]
    },
    {
        id: '03', name: 'Local Disk (E:)', icon: 'folder',
        subChild: [
            {
                id: '03-01', name: 'Pictures',
                subChild: [
                    { id: '03-01-01', name: 'Wind.jpg' },
                    { id: '03-01-02', name: 'Stone.jpg' },
                    { id: '03-01-03', name: 'Home.jpg' },
                ]
            },
            {
                id: '03-02', name: 'Documents',
                subChild: [
                    { id: '03-02-01', name: 'Environment Pollution.docx' },
                    { id: '03-02-02', name: 'Global Warming.ppt' },
                    { id: '03-02-03', name: 'Social Network.pdf' },
                ]
            },
            {
                id: '03-03', name: 'Study Materials',
                subChild: [
                    { id: '03-03-01', name: 'UI-Guide.pdf' },
                    { id: '03-03-02', name: 'Tutorials.zip' },
                    { id: '03-03-03', name: 'TypeScript.7z' },
                ]
            },
        ]
    }
];

var treeObj = new ej.navigations.TreeView({
    fields: { dataSource: hierarchicalData, id: 'id', text: 'name', child: 'subChild' },
    cssClass: ("mytree")
});
treeObj.appendTo('#tree');
<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/ej2/29.1.33/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-navigations/styles/material.css" rel="stylesheet">
    <script src="https://cdn.syncfusion.com/ej2/29.1.33/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id="container">
        <div id="treeparent">
            <div id="tree"></div>
        </div>
        <div class="details">
            <label>Note:</label>
            <div><b>1. The font-weight "Bold" is applied for all the leaf nodes</b></div>
            <div><i>2. The font-weight "Italic" is applied for first level nodes</i></div>
            <div style="color: darkmagenta">3. The color "darkmagenta" is applied for second level nodes</div>
        </div>
    </div>

    <script>
        var ele = document.getElementById('container');
        if (ele) {
            ele.style.visibility = "visible";
        }   
    </script>
    <script src="index.js" type="text/javascript"></script>
    <style>
        #container {
            display: flex;
        }

        #treeparent,
        .details {
            width: 300px;
            display: block;
            max-width: 350px;
            max-height: 350px;
            margin: auto;
            overflow: auto;
            border: 1px solid #dddddd;
            border-radius: 3px;
        }

        .details {
            padding-left: 10px;
        }

        /*apply custom css to first level*/
        .mytree .e-level-1>.e-text-content .e-list-text {
            font-style: italic;
        }

        /*apply custom css to second level*/
        .mytree .e-level-2>.e-text-content .e-list-text {
            color: darkmagenta;
        }

        /*apply custom css to all the leaf nodes*/
        .mytree .e-level-3>.e-text-content .e-list-text {
            font-weight: bold;
        }
    </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%;
}