Angular PrimeNG Tree Sections

Angular PrimeNG is an open-source framework with a rich set of native Angular UI components that are used for great styling and this framework is used to make responsive websites with very much ease. This article will show us how to use Tree Sections in Angular PrimeNG.

Angular PrimeNG Tree Sections offer various templates to display additional information about the data such as a header, footer and empty message.

Syntax:

<ng-template pTemplate="header">
       Header Content
</ng-template>
<ng-template pTemplate="empty">
       No records found
</ng-template>
<ng-template pTemplate="footer">
       Footer Content
</ng-template>

Creating Angular application & Module Installation:

Step 1: Create an Angular application using the following command.

ng new appname

Step 2:  After creating your project folder i.e. appname, move to it using the following command.

cd appname

Step 3: Install PrimeNG in your given directory.

npm install primeng --save
npm install primeicons --save

Project Structure: It will look like the following:

Example 1: Below is a simple example demonstrating the use of the Angular PrimeNG Tree Sections. In this example, we are header and footer section.

• app.component.html

HTML

<h2 style="color: green;">
    GeeksforGeeks
</h2>

<h4>Angular PrimeNG Tree Sections</h4>

<p-tree [value]="files1" scrollHeight="300px">
    <ng-template pTemplate="header">
        My Folder Directory
    </ng-template>
    <ng-template pTemplate="footer">
        The End
    </ng-template>
</p-tree>

• app.component.ts

Javascript

import { Component, OnInit } from '@angular/core';
import { TreeNode } from 'primeng/api';

@Component({
    selector: 'app-root',
    templateUrl: './app.component.html',
})
export class AppComponent {
    files1: TreeNode[] = [];

    constructor() { }

    ngOnInit() {
        this.files1 = [
            { label: 'Z', icon: 'pi pi-folder' },
            { label: 'A', icon: 'pi pi-folder' },
            { label: 'D', icon: 'pi pi-folder' },
            { label: 'C', icon: 'pi pi-folder' },
            { label: 'W', icon: 'pi pi-folder' },
            { label: 'E', icon: 'pi pi-folder' },
            { label: 'R', icon: 'pi pi-folder' },
            { label: 'G', icon: 'pi pi-folder' },
            { label: 'K', icon: 'pi pi-folder' },

            {
                label: 'A',
                icon: 'pi pi-folder',

                children: [
                    {
                        label: 'B',
                        icon: 'pi pi-folder',

                        children: [
                            {
                                label: 'C',
                                icon: 'pi pi-folder',
                            },
                            {
                                label: 'D',
                                icon: 'pi pi-folder',
                            },
                        ],
                    },
                    {
                        label: 'E',
                        icon: 'pi pi-folder',

                        children: [
                            {
                                label: 'F',
                                icon: 'pi pi-folder',
                            },
                        ],
                    },
                ],
            },
            {
                label: 'G',
                icon: 'pi pi-folder',

                children: [
                    {
                        label: 'H',
                        icon: 'pi pi-folder',
                    },
                    {
                        label: 'I',
                        icon: 'pi pi-folder',
                    },
                    {
                        label: 'J',
                        icon: 'pi pi-folder',
                    },
                ],
            },
        ];
    }
}

• app.module.ts

Javascript

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { FormsModule } from '@angular/forms';
import { HttpClientModule } from '@angular/common/http';
import { BrowserAnimationsModule }
    from '@angular/platform-browser/animations';
import { AppComponent } from './app.component';
import { TreeModule } from 'primeng/tree';
import { ButtonModule } from 'primeng/button';
import { InputTextModule } from 'primeng/inputtext';
import { VirtualScrollerModule }
    from 'primeng/virtualscroller';

@NgModule({
    imports: [
        BrowserModule,
        BrowserAnimationsModule,
        TreeModule,
        ButtonModule,
        InputTextModule,
        HttpClientModule,
        FormsModule,
        VirtualScrollerModule
    ],
    declarations: [AppComponent],
    bootstrap: [AppComponent],
    providers: [],
})
export class AppModule { }

Output:

Example 2: Below is another example demonstrating the use of the Angular PrimeNG Tree Sections. In this example, we are using empty template.

• app.component.html

HTML

<h2 style="color: green;">
    GeeksforGeeks
</h2>

<h4>Angular PrimeNG Tree Sections</h4>

<p-tree [value]="files1" scrollHeight="300px">
    <ng-template pTemplate="empty">
        No records found
    </ng-template>
</p-tree>

• app.component.ts

Javascript

import { Component, OnInit } from '@angular/core';
import { TreeNode } from 'primeng/api';

@Component({
    selector: 'app-root',
    templateUrl: './app.component.html',
})
export class AppComponent {
    files1: TreeNode[] = [];

    constructor() { }

    ngOnInit() {
        this.files1 = [];
    }
}

• app.module.ts

Javascript

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { FormsModule } from '@angular/forms';
import { HttpClientModule } from '@angular/common/http';
import { BrowserAnimationsModule }
    from '@angular/platform-browser/animations';
import { AppComponent } from './app.component';
import { TreeModule } from 'primeng/tree';
import { ButtonModule } from 'primeng/button';
import { InputTextModule } from 'primeng/inputtext';
import { VirtualScrollerModule }
    from 'primeng/virtualscroller';

@NgModule({
    imports: [
        BrowserModule,
        BrowserAnimationsModule,
        TreeModule,
        ButtonModule,
        InputTextModule,
        HttpClientModule,
        FormsModule,
        VirtualScrollerModule
    ],
    declarations: [AppComponent],
    bootstrap: [AppComponent],
    providers: [],
})
export class AppModule { }

Output:

Reference: https://primefaces.org/primeng/tree