DevExtreme Angular - Use Plain Data

If you use plain data in the TreeView, set the dataStructure option to "plain". For an example of plain data, see the following code snippet.

HTML
TypeScript
  • <dx-tree-view
  • [dataSource]="plainData"
  • dataStructure="plain">
  • </dx-tree-view>
  • import { DxTreeViewModule } from "devextreme-angular";
  • // ...
  • export class AppComponent {
  • plainData = [
  • { id: '1', text: 'Fruits' },
  • { id: '1_1', text: 'Apples', parentId: '1' },
  • { id: '1_2', text: 'Oranges', parentId: '1' },
  • { id: '2', text: 'Vegetables' },
  • { id: '2_1', text: 'Cucumbers', parentId: '2' },
  • { id: '2_2', text: 'Tomatoes', parentId: '2' }
  • ];
  • }
  • @NgModule({
  • imports: [
  • // ...
  • DxTreeViewModule
  • ],
  • // ...
  • })

As you can see, all items in a plain data source have the id and text fields, and items that have a parent, have the parentId field. Those are conventional field names defined by the Default Item Template pattern. To use other names, change the keyExpr, displayExpr and parentIdExpr options, respectively.

HTML
TypeScript
  • <dx-tree-view
  • [dataSource]="plainData"
  • dataStructure="plain"
  • keyExpr="key"
  • displayExpr="name"
  • parentIdExpr="parent">
  • </dx-tree-view>
  • import { DxTreeViewModule } from "devextreme-angular";
  • // ...
  • export class AppComponent {
  • plainData = [
  • { key: '1', name: 'Fruits' },
  • { key: '1_1', name: 'Apples', parent: '1' },
  • { key: '1_2', name: 'Oranges', parent: '1' },
  • { key: '2', name: 'Vegetables' },
  • { key: '2_1', name: 'Cucumbers', parent: '2' },
  • { key: '2_2', name: 'Tomatoes', parent: '2' }
  • ];
  • }
  • @NgModule({
  • imports: [
  • // ...
  • DxTreeViewModule
  • ],
  • // ...
  • })

Frequently, the id of an item is also its text. In this case, set both the keyExpr and displayExpr options to a single value.

HTML
TypeScript
  • <dx-tree-view
  • [dataSource]="plainData"
  • dataStructure="plain"
  • keyExpr="name"
  • displayExpr="name">
  • </dx-tree-view>
  • import { DxTreeViewModule } from "devextreme-angular";
  • // ...
  • export class AppComponent {
  • plainData = [
  • { name: 'Fruits' },
  • { name: 'Apples', parentId: 'Fruits' },
  • { name: 'Oranges', parentId: 'Fruits' },
  • { name: 'Vegetables' },
  • { name: 'Cucumbers', parentId: 'Vegetables' },
  • { name: 'Tomatoes', parentId: 'Vegetables' }
  • ];
  • }
  • @NgModule({
  • imports: [
  • // ...
  • DxTreeViewModule
  • ],
  • // ...
  • })

View Demo

See Also