Angular PrimeNG Table Lazy

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 Table Lazy in Angular PrimeNG.

Angular PrimeNG Table Lazy is used to lazy load the data of the Table component. It loads the data when required and makes the Table more interactive and user-friendly.

Syntax:

// In app.component.html
<p-table
    [columns]="cols"
    [value]="tableData"
    [lazy]="true"
    (onLazyLoad)="loadNodes($event)"
    [loading]="loading">
</p-table>

// In app.component.ts 
loadNodes(event) {
    // lazy function
}

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 Table Lazy.

• app.component.html

HTML

<h2 style="color: green">
    GeeksforGeeks
</h2>
<h4>Angular PrimeNG Table Lazy</h4>

<p-table [value]="tableData"
         [lazy]="true"
         (onLazyLoad)="loadNodes($event)"
         [loading]="loading">
    <ng-template pTemplate="header">
        <tr>
            <th>First Name</th>
            <th>Last Name</th>
            <th>Age</th>
        </tr>
    </ng-template>

    <ng-template pTemplate="body" let-people>
        <tr>
            <td>{{ people.firstname }}</td>
            <td>{{ people.lastname }}</td>
            <td>{{ people.age }}</td>
        </tr>
    </ng-template>
</p-table>

• app.component.ts

Javascript

import { Component } from '@angular/core';
import { NodeService } from './nodeservice';

interface People {
    firstname?: string;
    lastname?: string;
    age?: string;
}

@Component({
    selector: 'app-root',
    templateUrl: './app.component.html',
})
export class AppComponent {
    tableData: People[] = [];
    cols: any[] = [];
    loading: boolean = false;
    constructor(private nodeService: NodeService) { }

    ngOnInit() {
        this.cols = [
            {
                field: 'firstname',
                header: 'First Name'
            },
            {
                field: 'lastname',
                header: 'Last Name'
            },
            {
                field: 'age',
                header: 'Age'
            },
        ];
        this.loading = true;
    }
    loadNodes(event: any) {
        this.loading = true;
        setTimeout(() => {
            this.loading = false;
            this.tableData = [
                {
                    firstname: 'David',
                    lastname: 'ace',
                    age: '40',
                },
                {
                    firstname: 'AJne',
                    lastname: 'west',
                    age: '40',
                },
                {
                    firstname: 'Mak',
                    lastname: 'Lame',
                    age: '40',
                },
                {
                    firstname: 'Peter',
                    lastname: 'raw',
                    age: '40',
                },
                {
                    firstname: 'Kane',
                    lastname: 'James',
                    age: '40',
                },
            ];
        }, 1000);
    }
}

• app.module.ts

Javascript

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { FormsModule } from '@angular/forms';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';

import { AppComponent } from './app.component';

import { TableModule } from 'primeng/table';

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

Output:

Example 2: Below is another example demonstrating the use of the Angular PrimeNG Table Lazy.  In this example, we lazy-loaded the data for 5 seconds.

• app.component.html

HTML

<h2 style="color: green">
    GeeksforGeeks
</h2>
<h4>Angular PrimeNG Table Lazy</h4>

<p-table [value]="tableData"
         [lazy]="true"
         (onLazyLoad)="loadNodes($event)"
         [loading]="loading">
    <ng-template pTemplate="header">
        <tr>
            <th>First Name</th>
            <th>Last Name</th>
            <th>Age</th>
        </tr>
    </ng-template>

    <ng-template pTemplate="body" let-people>
        <tr>
            <td>{{ people.firstname }}</td>
            <td>{{ people.lastname }}</td>
            <td>{{ people.age }}</td>
        </tr>
    </ng-template>
</p-table>

• app.component.ts

Javascript

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

interface People {
    firstname?: string;
    lastname?: string;
    age?: string;
}

@Component({
    selector: 'app-root',
    templateUrl: './app.component.html',
})
export class AppComponent {
    tableData: People[] = [];
    cols: any[] = [];
    loading: boolean = false;
    constructor() { }

    ngOnInit() {
        this.cols = [
            {
                field: 'firstname',
                header: 'First Name'
            },
            {
                field: 'lastname',
                header: 'Last Name'
            },
            {
                field: 'age',
                header: 'Age'
            },
        ];
        this.loading = true;
    }
    loadNodes(event: any) {
        this.loading = true;
        setTimeout(() => {
            this.loading = false;
            this.tableData = [
                {
                    firstname: 'David',
                    lastname: 'ace',
                    age: '40',
                },
                {
                    firstname: 'AJne',
                    lastname: 'west',
                    age: '40',
                },
                {
                    firstname: 'Mak',
                    lastname: 'Lame',
                    age: '40',
                },
                {
                    firstname: 'Peter',
                    lastname: 'raw',
                    age: '40',
                },
                {
                    firstname: 'Kane',
                    lastname: 'James',
                    age: '40',
                },
            ];
        }, 5000);
    }
}

• app.module.ts

Javascript

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { FormsModule } from '@angular/forms';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';

import { AppComponent } from './app.component';

import { TableModule } from 'primeng/table';

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

Output:

Reference: https://primefaces.org/primeng/table/lazy