Angular PrimeNG Tree Flex Scroll

Last Updated : 26 Apr, 2025

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 Flex Scroll in Angular PrimeNG.

Angular PrimeNG Tree Flex Scroll is used in cases where viewport should adjust itself according to the table parent’s height instead of a fixed viewport height. For that, we set the scrollHeight option as ‘flex’.

Syntax:

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

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 Flex Scroll.

app.component.html

HTML

<h2 style="color: green">GeeksforGeeks</h2> 
<h4>Angular PrimeNG Tree Flex Scroll</h4> 
  
<div [style]="{ height: '50vw' }"> 
    <p-tree [value]="files1" scrollHeight="flex"> </p-tree> 
</div>

app.component.ts

Javascript

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

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 { NodeService } from './nodeservice'; 
import { TreeModule } from 'primeng/tree'; 
import { ButtonModule } from 'primeng/button'; 
import { InputTextModule } from 'primeng/inputtext'; 
import { VirtualScrollerModule } 
    from 'primeng/virtualscroller'; 
import { DialogModule } from 'primeng/dialog'; 
  
@NgModule({ 
    imports: [ 
        BrowserModule, 
        BrowserAnimationsModule, 
        TreeModule, 
        ButtonModule, 
        InputTextModule, 
        HttpClientModule, 
        FormsModule, 
        VirtualScrollerModule, 
        DialogModule 
    ], 
    declarations: [AppComponent], 
    bootstrap: [AppComponent], 
    providers: [NodeService], 
}) 
export class AppModule { }

Output:

Example 2: Below is another example demonstrating the use of the Angular PrimeNG Tree Flex Scroll.

app.component.html

HTML

<h2 style="color: green">GeeksforGeeks</h2> 
<h4>Angular PrimeNG Tree Flex Scroll</h4> 
  
<div [style]="{ height: '200px' }"> 
    <p-tree [value]="files1" scrollHeight="flex"> </p-tree> 
</div>

app.component.ts

Javascript

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

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 { NodeService } from './nodeservice'; 
import { TreeModule } from 'primeng/tree'; 
import { ButtonModule } from 'primeng/button'; 
import { InputTextModule } from 'primeng/inputtext'; 
import { VirtualScrollerModule } 
    from 'primeng/virtualscroller'; 
import { DialogModule } from 'primeng/dialog'; 
  
@NgModule({ 
    imports: [ 
        BrowserModule, 
        BrowserAnimationsModule, 
        TreeModule, 
        ButtonModule, 
        InputTextModule, 
        HttpClientModule, 
        FormsModule, 
        VirtualScrollerModule, 
        DialogModule 
    ], 
    declarations: [AppComponent], 
    bootstrap: [AppComponent], 
    providers: [NodeService], 
}) 
export class AppModule { }