Angular PrimeNG Tree Scrolling

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 the Basic TreeTable in Angular PrimeNG.

Angular PrimeNG Tree Scrolling is used to enable scroll in the Tree Component. Scroller is an efficient approach to handling data effectively. We can easily add a scroller to show the data in a scrollable way.

Syntax:

<p-tree 
    [value]="..." 
    scrollHeight="...">
</p-tree>

Angular PrimeNG Tree Scrolling properties:

• scrollHeight: It is used to define the height of the scrollable viewport. It is a string type and its default value is null.
• value: It is used to define the array of all the tree nodes. It is an array type and its default value is null.

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 TreeTable Scrolling.

app.component.html

<h2 style="color: green">GeeksforGeeks</h2>
<h4>Angular PrimeNG Tree Scrolling</h4>
<p-tree
    [value]="files1"
    scrollHeight="300px">
</p-tree>

app.component.ts

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

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

    constructor(private nodeService: NodeService) { }

    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

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 { NodeService } from './nodeservice';
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: [NodeService],
})
export class AppModule { }

Output:

Example 2: Below is another example demonstrating the use of the Angular PrimeNG TreeTable Scrolling.

app.component.html

<h2 style="color: green">GeeksforGeeks</h2>
<h4>Angular PrimeNG Tree Scrolling</h4>
<p-tree
    [value]="files1"
    scrollHeight="200px">
</p-tree>

app.component.ts

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

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

    constructor(private nodeService: NodeService) { }

    ngOnInit() {
        this.files1 = [
            {
                label: 'Z',
                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: '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: 'D',
                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: 'C',
                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: 'W',
                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: 'B',
                        icon: 'pi pi-folder',

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

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 { NodeService } from './nodeservice';
import { TreeModule } from 'primeng/tree';
import { ButtonModule } from 'primeng/button';
import { InputTextModule } from 'primeng/inputtext';
import { VirtualScroller, VirtualScrollerModule }
    from 'primeng/virtualscroller';

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

Output:

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