Accordion tree in EJ2 JavaScript TreeView control

28 Jan 202510 minutes to read

An Accordion is an interface in which a list of items can be collapsed or expanded, but only one list can be expanded at a time. You can customize the TreeView to make it behave like an accordion. Refer to the following code sample to create an accordion tree.

/**
* Accordion tree sample
*/

// Hierarchical data source for TreeView control
var continents = [
    {
        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", selected: true },
            { 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: "OC", name: "Oceania", countries: [
            { code: "AUS", name: "Australia" },
            { code: "NZL", name: "New Zealand" },
            { code: "WSM", name: "Samoa" }
        ]
    },

];

// Render TreeView with cssClass
var tree1 = new ej.navigations.TreeView({
    fields: { dataSource: continents, id: "code", text: "name", child: "countries" },
    nodeSelected: nodeSelect,
    cssClass: ("accordiontree")
});
tree1.appendTo('#tree');

function nodeSelect(args) {
    if (args.node.classList.contains('e-level-1')) {
        this.collapseAll();
        this.expandAll([args.node]);
    }
}
<!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/ej2/29.1.33/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-inputs/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>

    <script>
        var ele = document.getElementById('container');
        if (ele) {
            ele.style.visibility = "visible";
        }   
    </script>
    <script src="index.js" type="text/javascript"></script>
    <style>
        #treeparent {
            display: block;
            max-width: 350px;
            max-height: 350px;
            margin: auto;
            overflow: auto;
            padding-top: 50px;
        }

        .accordiontree .e-list-item.e-level-1>.e-fullrow,
        .accordiontree .e-list-item.e-level-1.e-active>.e-fullrow,
        .accordiontree .e-list-item.e-level-1.e-hover>.e-fullrow,
        .accordiontree .e-list-item.e-level-1>.e-fullrow,
        .accordiontree .e-list-item.e-level-1.e-active.e-hover>.e-fullrow {
            background-color: darkslateblue;
            border-color: darkslateblue;
        }

        .accordiontree .e-list-item.e-level-1>.e-text-content .e-list-text,
        .accordiontree .e-list-item.e-level-1.e-active>.e-text-content .e-list-text,
        .accordiontree .e-list-item.e-level-1.e-hover>.e-text-content .e-list-text,
        .accordiontree .e-list-item.e-level-1.e-active.e-hover>.e-text-content .e-list-text {
            color: white;
            font-size: 16px;
        }

        .accordiontree .e-list-item.e-level- .e-icons.e-icon-collapsible,
        .accordiontree .e-list-item.e-level-1 .e-icons.e-icon-collapsible,
        .accordiontree .e-list-item.e-level-1 .e-icon-expandable {
            display: none
        }

        .accordiontree .e-list-item.e-level-2>.e-fullrow,
        .accordiontree .e-list-item.e-level-2.e-active>.e-fullrow,
        .accordiontree .e-list-item.e-level-2.e-hover>.e-fullrow,
        .accordiontree .e-list-item.e-level-2>.e-fullrow,
        .accordiontree .e-list-item.e-level-2.e-active.e-hover>.e-fullrow {
            background-color: white;
            border-color: white;
        }

        .accordiontree .e-list-item.e-level-2>.e-text-content .e-list-text,
        .accordiontree .e-list-item.e-level-2.e-active>.e-text-content .e-list-text,
        .accordiontree .e-list-item.e-level-2.e-hover>.e-text-content .e-list-text,
        .accordiontree .e-list-item.e-level-2.e-active.e-hover>.e-text-content .e-list-text {
            color: blue;
            font-size: 14px;
        }
    </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%;
}