Customize Node Appearance

For minor customization of nodes, you can use the default item template. This template defines the appearance of a node depending on whether specific fields are present or absent from the node's data object. For example, the following code adds an icon to each node.

JavaScript
var hierarchicalData = [{
    id: '1',
    text: 'Fruits',
    icon: '/pics/fruits.ico',
    items: [
        { id: '1_1', text: 'Apples', icon: '/pics/fruits/apple.ico' },
        { id: '1_2', text: 'Oranges', icon: '/pics/fruits/orange.ico' }
    ]
}, {
    id: '2',
    text: 'Vegetables',
    icon: '/pics/vegetables.ico',
    items: [
        { id: '2_1', text: 'Cucumbers', icon: '/pics/vegetables/cucumber.ico' },
        { id: '2_2', text: 'Tomatoes', icon: '/pics/vegetables/tomato.ico' }
    ]
}];

$(function() {
    $("#treeViewContainer").dxTreeView({
        dataSource: hierarchicalData
    });
});

Using the default item template is the easiest way to customize an item, but it lacks flexibility. Instead, you can define a custom template. For AngularJS and Knockout apps, DevExtreme provides a markup component called dxTemplate. The following code gives a simple example of how you can use dxTemplate to customize nodes.

AngularJS

JavaScript
angular.module('DemoApp', ['dx'])
    .controller('DemoController', function DemoController($scope) {
        $scope.hierarchicalData = [{
            id: '1',
            text: 'Fruits',
            items: [
                { id: '1_1', text: 'Apples' },
                { id: '1_2', text: 'Oranges' }
            ]
        }, {
            id: '2',
            text: 'Vegetables',
            items: [
                { id: '2_1', text: 'Cucumbers' },
                { id: '2_2', text: 'Tomatoes' }
            ]
        }];
    });
HTML
<div ng-controller="DemoController">
    <div dx-tree-view="{
        dataSource: hierarchicalData,
        itemTemplate: 'itemTemplate'
    }" dx-item-alias="itemObj">
        <div data-options="dxTemplate: { name: 'itemTemplate' }">
            <i>{{ itemObj.text }}</i>
        </div>
    </div>
</div>

NOTE: The dx-item-alias directive specifies the variable that is used to access the item object.

Knockout

JavaScript
var viewModel = {
    hierarchicalData: [{
        id: '1',
        text: 'Fruits',
        items: [
            { id: '1_1', text: 'Apples' },
            { id: '1_2', text: 'Oranges' }
        ]
    }, {
        id: '2',
        text: 'Vegetables',
        items: [
            { id: '2_1', text: 'Cucumbers' },
            { id: '2_2', text: 'Tomatoes' }
        ]
    }]
};

ko.applyBindings(viewModel);
HTML
<div data-bind="dxTreeView: {
    dataSource: hierarchicalData,
    itemTemplate: 'itemTemplate'
}">
    <div data-options="dxTemplate: { name: 'itemTemplate' } ">
        <i data-bind="text: text"></i>
    </div>
</div>

If you use jQuery alone, combine the HTML markup manually with jQuery DOM manipulation methods. To apply the markup to the TreeView nodes, use the itemTemplate callback function.

JavaScript
$(function() {
    $("#treeViewContainer").dxTreeView({
        dataSource: treeViewData,
        itemTemplate: function (itemData, itemIndex, itemElement) {
            itemElement.append("<i>" + itemData.text + "</i>");
        }
    });
});

You can also customize an individual node. For this purpose, declare a template for this node as a script and pass its id to the template option.

HTML
<script id="individualTemplate" type="text/html">
    <!-- ... -->
</script>
JavaScript
var treeViewData = [{
    id: '1',
    text: 'Fruits',
    items: [
        { id: '1_1', text: 'Apples', template: $("#individualItemTemplate") },
        { id: '1_2', text: 'Oranges' }
    ]
},
// ...
];

In addition, you can use a 3rd-party template engine to customize widget appearance. For more information, see the Use an Alternative Template Engine article.

See Also