Selection provides an interactive support and highlights the node that you select. Selection can be done through simple mouse down or keyboard interaction.
The TreeView also supports selection of multiple nodes by setting allowMultiSelection to true.
To multi-select, press and hold CTRL key and click the desired nodes. To select range of nodes, press and hold the SHIFT key and click the nodes.
In the following example, the allowMultiSelection property is enabled.
Multi selection is not applicable through touch interactions.
import { enableRipple } from '@syncfusion/ej2-base';
enableRipple(true);
import { TreeView } from '@syncfusion/ej2-navigations';
let countries: { [key: string]: Object }[] = [
{ id: 1, name: 'Australia', hasChild: true, expanded: true },
{ id: 2, pid: 1, name: 'New South Wales', isSelected: true },
{ id: 3, pid: 1, name: 'Victoria' },
{ id: 4, pid: 1, name: 'South Australia' },
{ id: 6, pid: 1, name: 'Western Australia', isSelected: true },
{ id: 7, name: 'Brazil', hasChild: true },
{ id: 8, pid: 7, name: 'Paraná' },
{ id: 9, pid: 7, name: 'Ceará' },
{ id: 10, pid: 7, name: 'Acre' },
{ id: 11, name: 'China', hasChild: true },
{ id: 12, pid: 11, name: 'Guangzhou' },
{ id: 13, pid: 11, name: 'Shanghai' },
{ id: 14, pid: 11, name: 'Beijing' },
{ id: 15, pid: 11, name: 'Shantou' },
{ id: 16, name: 'France', hasChild: true },
{ id: 17, pid: 16, name: 'Pays de la Loire' },
{ id: 18, pid: 16, name: 'Aquitaine' },
{ id: 19, pid: 16, name: 'Brittany' },
{ id: 20, pid: 16, name: 'Lorraine' },
{ id: 21, name: 'India', hasChild: true },
{ id: 22, pid: 21, name: 'Assam' },
{ id: 23, pid: 21, name: 'Bihar' },
{ id: 24, pid: 21, name: 'Tamil Nadu' },
{ id: 25, pid: 21, name: 'Punjab' }
];
let treeObj: TreeView = new TreeView({
fields: { dataSource: countries, id: 'id', parentID: 'pid', text: 'name', hasChildren: 'hasChild', selected: 'isSelected' },
allowMultiSelection: true,
});
treeObj.appendTo('#tree');<!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="//cdn.syncfusion.com/ej2/21.2.3/ej2-base/styles/material.css" rel="stylesheet" />
<link href="//cdn.syncfusion.com/ej2/21.2.3/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>
</head>
<body>
<div id='loader'>Loading....</div>
<div id='container'>
<div id='treeparent'>
<div id="tree"></div>
</div>
</div>
</body>
</html>You can get or set the selected nodes in TreeView at initial rendering and dynamically by using the selectedNodes property. It will return the selected node’s ID as an array.
nodeselecting event is triggered before a node is selected/unselected which can be used to prevent the selection.nodeSelected event is triggered once a node is successfully selected/unselected.In the following example, New South Wales and Western Australia nodes are selected at initial rendering. When a node is selected, the selected node’s ID is displayed in alert.
import { enableRipple } from '@syncfusion/ej2-base';
enableRipple(true);
import { TreeView, NodeSelectEventArgs } from '@syncfusion/ej2-navigations';
let countries: { [key: string]: Object }[] = [
{ id: 1, name: 'Australia', hasChild: true, expanded: true },
{ id: 2, pid: 1, name: 'New South Wales', isSelected: true },
{ id: 3, pid: 1, name: 'Victoria' },
{ id: 4, pid: 1, name: 'South Australia' },
{ id: 6, pid: 1, name: 'Western Australia', isSelected: true },
{ id: 7, name: 'Brazil', hasChild: true },
{ id: 8, pid: 7, name: 'Paraná' },
{ id: 9, pid: 7, name: 'Ceará' },
{ id: 10, pid: 7, name: 'Acre' },
{ id: 11, name: 'China', hasChild: true },
{ id: 12, pid: 11, name: 'Guangzhou' },
{ id: 13, pid: 11, name: 'Shanghai' },
{ id: 14, pid: 11, name: 'Beijing' },
{ id: 15, pid: 11, name: 'Shantou' },
{ id: 16, name: 'France', hasChild: true },
{ id: 17, pid: 16, name: 'Pays de la Loire' },
{ id: 18, pid: 16, name: 'Aquitaine' },
{ id: 19, pid: 16, name: 'Brittany' },
{ id: 20, pid: 16, name: 'Lorraine' },
{ id: 21, name: 'India', hasChild: true },
{ id: 22, pid: 21, name: 'Assam' },
{ id: 23, pid: 21, name: 'Bihar' },
{ id: 24, pid: 21, name: 'Tamil Nadu' },
{ id: 25, pid: 21, name: 'Punjab' }
];
let treeObj: TreeView = new TreeView({
fields: { dataSource: countries, id: 'id', parentID: 'pid', text: 'name', hasChildren: 'hasChild' },
allowMultiSelection: true,
selectedNodes: ['2','6'],
nodeSelected: nodeSelected
});
treeObj.appendTo('#tree');
function nodeSelected(args: NodeSelectEventArgs) {
alert("The selected node's id: " + treeObj.selectedNodes); // To alert the selected node's id.
}<!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="//cdn.syncfusion.com/ej2/21.2.3/ej2-base/styles/material.css" rel="stylesheet" />
<link href="//cdn.syncfusion.com/ej2/21.2.3/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>
</head>
<body>
<div id='loader'>Loading....</div>
<div id='container'>
<div id='treeparent'>
<div id="tree"></div>
</div>
</div>
</body>
</html>