Angular TreeView - Customize Node Appearance

For minor customization of nodes, you can define specific fields in node data objects. For example, the following code adds an icon to each node.

App.vue
  • <template>
  • <DxTreeView
  • :items="hierarchicalData"
  • />
  • </template>
  • <script>
  • import 'devextreme/dist/css/dx.light.css';
  •  
  • import { DxTreeView } from 'devextreme-vue/tree-view';
  •  
  • const 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' }
  • ]
  • }];
  •  
  • export default {
  • components: {
  • DxTreeView
  • },
  • data() {
  • return {
  • hierarchicalData
  • };
  • },
  • };
  • </script>

If you need a more flexible solution, define an itemTemplate. In Angular and Vue, you can declare it in the markup. In React, you can use a rendering function (shown in the code below) or component:

App.vue
  • <template>
  • <DxTreeView
  • :items="hierarchicalData">
  • <template #item="item">
  • <i>{{ item.data.text }}</i>
  • </template>
  • </DxTreeView>
  • </template>
  • <script>
  • import 'devextreme/dist/css/dx.light.css';
  •  
  • import { DxTreeView } from 'devextreme-vue/tree-view';
  •  
  • const 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' }
  • ]
  • }];
  •  
  • export default {
  • components: {
  • DxTreeView
  • },
  • data() {
  • return {
  • hierarchicalData
  • };
  • },
  • };
  • </script>

If you use jQuery, use DOM manipulation methods to combine the HTML markup for nodes. To apply this markup, use the itemTemplate callback function as shown in the following code:

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

You can also customize individual nodes. In Angular, Vue, and React, declare them using the dxItem component. When using jQuery, you can declare the nodes as scripts and reference them in the template property or assign a customization function straight to this property.

App.vue
  • <template>
  • <DxTreeView>
  • <DxItem>
  • <template #default>
  • <i>Apples</i>
  • </template>
  • </DxItem>
  • <DxItem>
  • <template #default>
  • <p>Oranges</p>
  • </template>
  • </DxItem>
  • </DxTreeView>
  • </template>
  • <script>
  • import 'devextreme/dist/css/dx.light.css';
  •  
  • import { DxTreeView, DxItem } from 'devextreme-vue/tree-view';
  •  
  • export default {
  • components: {
  • DxTreeView,
  • DxItem
  • }
  • };
  • </script>

In addition, you can use a 3rd-party template engine to customize UI component appearance. For more information, see the 3rd-Party Template Engines article.

See Also