Getting Started with Angular TreeView Component

27 Aug 202510 minutes to read

This section explains the steps required to create a simple Angular TreeView component and configure its available functionalities in your Angular application.

Setup Angular Environment

You can use Angular CLI to set up your Angular applications. To install Angular CLI, use the following command.

npm install -g @angular/cli

Create an Angular Application

Start a new Angular application using the Angular CLI command below.

ng new my-app
cd my-app

Installing Syncfusion® TreeView Package

Syncfusion® packages are distributed in npm as @syncfusion scoped packages. You can get all the Angular Syncfusion® packages from npm link.

Currently, Syncfusion® provides two types of package structures for Angular components:

  1. Ivy library distribution package format
  2. Angular compatibility compiler (Angular’s legacy compilation and rendering pipeline) package

Ivy library distribution package

Syncfusion® Angular packages(>=20.2.36) have been moved to the Ivy distribution to support the Angular Ivy rendering engine. The packages are compatible with Angular version 12 and above. To download the package, use the command below.

Add @syncfusion/ej2-angular-navigations package to the application.

npm install @syncfusion/ej2-angular-navigations --save

Angular compatibility compiled package (ngcc)

For Angular versions below 12, you can use the legacy (ngcc) package of the Syncfusion® Angular components. To download the ngcc package, use the command below.

Add @syncfusion/ej2-angular-navigations@ngcc package to the application.

npm install @syncfusion/ej2-angular-navigations@ngcc --save

To specify the ngcc package in the package.json file, add the suffix -ngcc with the package version as shown below.

@syncfusion/ej2-angular-navigations:"20.2.38-ngcc"

Note: If the ngcc tag is not specified while installing the package, the Ivy Library Package will be installed and this package will display a warning.

Adding CSS Reference

Add the TreeView component’s styles as given below in styles.css.

@import "../node_modules/@syncfusion/ej2-base/styles/material.css";
@import "../node_modules/@syncfusion/ej2-angular-navigations/styles/material.css";
@import "../node_modules/@syncfusion/ej2-inputs/styles/material.css";
@import "../node_modules/@syncfusion/ej2-buttons/styles/material.css";

Alternatively, based on the location of your CSS file, you can import the styles as shown below:

@import "node_modules/@syncfusion/ej2-base/styles/material.css";
@import "node_modules/@syncfusion/ej2-angular-navigations/styles/material.css";
@import "node_modules/@syncfusion/ej2-inputs/styles/material.css";
@import "node_modules/@syncfusion/ej2-buttons/styles/material.css";

Note: If you want to refer to the combined component styles, make use of the CRG (Custom Resource Generator) in your application.

Add TreeView component

Modify the template in the src/app/app.component.ts file to render the TreeView component. Add the Angular TreeView by using the <ejs-treeview> selector in the template section of the app.component.ts file.

import { TreeViewModule } from '@syncfusion/ej2-angular-navigations'
import { Component } from '@angular/core';

@Component({
imports: [
  TreeViewModule
],
standalone: true,
selector: 'app-root',
template: `<ejs-treeview id='treeelement'></ejs-treeview>`
})
export class AppComponent { }

Binding data source

The TreeView can load data from either local data sources or remote data services. This is accomplished using the dataSource property that is a member of the fields property. The dataSource property supports array of JavaScript objects and DataManager. In this example, an array of JavaScript objects is passed to the TreeView component.

The fields property defines the mapping between your data source and the TreeView display. The key properties include id for unique identification, text for the display text, and child for nested hierarchical data structure.

import { TreeViewModule } from '@syncfusion/ej2-angular-navigations'
import { Component, ViewEncapsulation } from '@angular/core';

@Component({
imports: [
  TreeViewModule
],
standalone: true,
selector: 'app-root',
template: `<ejs-treeview id='treeelement' [fields]='field'></ejs-treeview>`,
encapsulation: ViewEncapsulation.None
})
export class AppComponent {
    constructor() {
    }
    // defined the array of data
    public hierarchicalData: Object[] = [
        { id: '01', name: 'Music', expanded: true,
            subChild: [
                {id: '01-01', name: 'Gouttes.mp3'}
            ]
        },
        {
            id: '02', name: 'Videos',
            subChild: [
                {id: '02-01', name: 'Naturals.mp4'},
                {id: '02-02', name: 'Wild.mpeg'}
            ]
        },
        {
            id: '03', name: 'Documents',
            subChild: [
                {id: '03-01', name: 'Environment Pollution.docx'},
                {id: '03-02', name: 'Global Water, Sanitation, & Hygiene.docx'},
                {id: '03-03', name: 'Global Warming.ppt'},
                {id: '03-04', name: 'Social Network.pdf'},
                {id: '03-05', name: 'Youth Empowerment.pdf'}
            ]
        }
    ];
    public field: Object = { dataSource: this.hierarchicalData, id: 'id', text: 'name', child: 'subChild' };
}

Run the application

Use the following command to run the application in the browser.

ng serve --open

The output will appear as follows.

import { NgModule } from '@angular/core'
import { BrowserModule } from '@angular/platform-browser'
import { FormsModule } from '@angular/forms'
import { TreeViewModule } from '@syncfusion/ej2-angular-navigations'
import { Component } from '@angular/core';

@Component({
    imports: [
        FormsModule, TreeViewModule
    ],
    standalone: true,
    selector: 'app-root',
    styleUrls: ['./app.component.css'],
    template: `<div id='treeparent'><ejs-treeview id='treeelement' [fields]='field'></ejs-treeview></div>`
})
export class AppComponent {
    constructor() {
    }
    // defined the array of data
    public hierarchicalData: Object[] = [
        {
            id: '01', name: 'Music', expanded: true,
            subChild: [
                { id: '01-01', name: 'Gouttes.mp3' },
            ]
        },
        {
            id: '02', name: 'Videos',
            subChild: [
                { id: '02-01', name: 'Naturals.mp4' },
                { id: '02-02', name: 'Wild.mpeg' }
            ]
        },
        {
            id: '03', name: 'Documents',
            subChild: [
                { id: '03-01', name: 'Environment Pollution.docx' },
                { id: '03-02', name: 'Global Water, Sanitation, & Hygiene.docx' },
                { id: '03-03', name: 'Global Warming.ppt' },
                { id: '03-02', name: 'Social Network.pdf' },
                { id: '03-03', name: 'Youth Empowerment.pdf' },
            ]
        }
    ];
    public field: Object = { dataSource: this.hierarchicalData, id: 'id', text: 'name', child: 'subChild' };
}
@import 'node_modules/@syncfusion/ej2-base/styles/material.css';
@import 'node_modules/@syncfusion/ej2-inputs/styles/material.css';
@import 'node_modules/@syncfusion/ej2-buttons/styles/material.css';
@import 'node_modules/@syncfusion/ej2-angular-base/styles/material.css';
@import 'node_modules/@syncfusion/ej2-angular-navigations/styles/material.css';
@import 'node_modules/@syncfusion/ej2-angular-inputs/styles/material.css';
import { bootstrapApplication } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import 'zone.js';
bootstrapApplication(AppComponent).catch((err) => console.error(err));

You can also explore the Angular TreeView example to learn how to present and manipulate data.

See Also