JavaScript/jQuery TreeView - items

The TreeView works with object collections that can have a plain or hierarchical structure. Depending on the structure, the objects should provide different data fields. Specify the dataStructure property to notify the TreeView of the used structure and refer to the property's description for information on the required fields.

If you need to update the UI component items, reassign the entire items array as shown in the following example:

treeViewInstance.option('items', newItems);

As an alternative to items, you can use the dataSource property. It accepts the DataSource object, whose underlying stores provide an API that allows you to update individual items without reassigning the entire item collection.

This field makes sense no matter whether a custom template or the default one is used.

See Also

• Expand and Collapse Nodes
• expandedExpr

This field is used when the virtual mode is enabled. It can hold a Boolean value or a function that returns a Boolean value.

The TreeView component evaluates the html property's value. This evaluation, however, makes the TreeView potentially vulnerable to XSS attacks. To guard against these attacks, encode the HTML markup before you assign it to the html property. Refer to the following help topic for more information: Potentially Vulnerable API - html.

You can use the text property as a safe alternative.

This property accepts one of the following:

• The icon's URL
• The icon's name if the icon is from the DevExtreme icon library
• The icon's CSS class if the icon is from an external icon library (see External Icon Libraries)
• The icon in the Base64 format
• The icon in the SVG format. Ensure that the source is reliable.

Nested items should have the same structure as the first-level items.

See Also

• Use Hierarchical Data
• Customize Node Appearance

This field makes sense no matter whether a custom template or the default one is used.

See Also

• selectedExpr

The following types of the specified value are available.

• Assign a string containing the name of the required template.
• Assign a jQuery object of the template's container.
• Assign a DOM Node of the template's container.
• Assign a function that returns the jQuery object or a DOM Node of the template's container.

The following example adds a custom item to the component. Note that Angular and Vue use custom templates instead of the template property. In React, specify the render property.

$(function() {
    $("#treeViewContainer").dxTreeView({
        // ...
        items: [
            {
                // ...
                template: '<div>Custom Item</div>'
            }
        ]
    });
});

<dx-tree-view ... >
    <dxi-item ... >
        <div *dxTemplate>
            <div>Custom Item</div>
        </div>
    </dxi-item>
</dx-tree-view>

import { Component } from '@angular/core';

@Component({
    selector: 'app-root',
    templateUrl: './app.component.html',
    styleUrls: ['./app.component.css']
})
export class AppComponent {
    // ...
}

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { AppComponent } from './app.component';

import { DxTreeViewModule } from 'devextreme-angular';

@NgModule({
    declarations: [
        AppComponent
    ],
    imports: [
        BrowserModule,
        DxTreeViewModule
    ],
    providers: [ ],
    bootstrap: [AppComponent]
})
export class AppModule { }

<template>
    <DxTreeView ... >
        <dxItem ... >
            <div>Custom Item</div>
        </dxItem>
    </DxTreeView>
</template>

<script>

import DxTreeView, {
    DxItem
} from 'devextreme-vue/tree-view';

export default {
    components: {
        DxTreeView,
        DxItem
    },
    // ...
}
</script>

import React from 'react';

import TreeView, {
    Item
} from 'devextreme-react/tree-view';

const renderCustomItem = () => {
    return <div>Custom Item</div>;
}

class App extends React.Component {
    render() {
        return (
            <TreeView ... >
                <Item ...
                    render={renderCustomItem}
                >
                </Item>
            </TreeView>
        );
    }
}
export default App;

See Also

• Custom Templates