DEV Community

Cover image for Angular 16 Pagination example
Tien Nguyen
Tien Nguyen

Posted on • Originally published at bezkoder.com

Angular 16 Pagination example

In this tutorial, I will show you how to make Angular 16 Pagination example with existing API (server-side pagination) using ngx-pagination.

Related Posts:

Fullstack with Node.js Express:
Server side Pagination with Node.js and Angular

Fullstack with Spring Boot:
Spring Boot + Angular: Server side Pagination example

Overview of Angular 16 Pagination example

One of the most important things to make a website friendly is the response time, and pagination comes for this reason. For example, this bezkoder.com website has hundreds of tutorials, and we don’t want to see all of them at once. Paging means displaying a small number of all, by a page.

Assume that we have tutorials table in database like this:

angular-16-pagination-example-database

Our Angular 16 app will display the result with pagination:

angular-16-pagination-example-ngx-pagination

You can change to a page with larger index:

angular-16-pagination-example-change-page

Or change quantity of items per page:

angular-16-pagination-example-items-per-page

Or paging with filter:

angular-16-pagination-example-ngx-pagination-filter

The API for this Angular client can be found at one of following posts:

These Servers will exports API for pagination (with/without filter), here are some url samples:

  • /api/tutorials?page=1&size=5
  • /api/tutorials?size=5: using default value for page
  • /api/tutorials?page=1: using default value for size
  • /api/tutorials?title=data&page=1&size=3: pagination & filter by title containing 'data'

This is structure of the response (server-side pagination) for the HTTP GET request:

{
    "totalItems": 8,
    "tutorials": [...],
    "totalPages": 3,
    "currentPage": 1
}
Enter fullscreen mode Exit fullscreen mode

This is a kind of server-side paging, where the server sends just a single page at a time. ngx-pagination supports this scenario, so We actually only need to use tutorials and totalItems when working with this library.

ngx-pagination with Angular 16

ngx-pagination provides NgxPaginationModule for displaying pagination with numbers and responsive style.

There are 2 main things that we're gonna use:

  • PaginatePipe: placed at the end of an ngFor expression
<your-element *ngFor="let item of collection | paginate: { id: 'foo',
                                                      itemsPerPage: pageSize,
                                                      currentPage: page,
                                                      totalItems: total }">...</your-element>
Enter fullscreen mode Exit fullscreen mode

Use the id if you need to support more than one instance of pagination at a time.

  • PaginationControlsComponent: a default component for displaying pagination controls
<pagination-controls></pagination-controls>
Enter fullscreen mode Exit fullscreen mode

For example, this is the default display for simple pagination-controls above:

ngx-pagination-example-angular-16-pagination-controls

We can customize the label displayed on the "previous"/"next" link using previousLabel/nextLabel, and enable "responsive" to hide individual page links on small screens.

<pagination-controls
  previousLabel="Prev"
  nextLabel="Next"
  responsive="true"
></pagination-controls>
Enter fullscreen mode Exit fullscreen mode

ngx-pagination-example-angular-16-customize-pagination-controls

For handling page changes, we pass handlePageChange to pageChange.
Notice that count is totalItems in the API response, and page is the current page.

<pagination-controls
  (pageChange)="handlePageChange($event)"
></pagination-controls>

<ul>
  <li
    *ngFor="let tutorial of tutorials | paginate: {
              itemsPerPage: pageSize,
              currentPage: page,
              totalItems: count
            }"
  >
    {{ tutorial.title }}
  </li>
</ul>
Enter fullscreen mode Exit fullscreen mode
@Component(...)
export class TutorialsListComponent {
  ...
  page = 1;

  handlePageChange(event) {
    this.page = event;
  }

}
Enter fullscreen mode Exit fullscreen mode

pageChange is the expression invoked whenever the page changes via a click on the pagination controls. The $event argument will be the number of the new page.

There are more attributes that ngx-pagination supports:

<pagination-controls  id="some_id"
                      (pageChange)="pageChanged($event)"
                      (pageBoundsCorrection)="pageChanged($event)"
                      maxSize="9"
                      directionLinks="true"
                      autoHide="true"
                      responsive="true"
                      previousLabel="Previous"
                      nextLabel="Next"
                      screenReaderPaginationLabel="Pagination"
                      screenReaderPageLabel="page"
                      screenReaderCurrentLabel="You're on page">
</pagination-controls>
Enter fullscreen mode Exit fullscreen mode

You can find the details at: https://www.npmjs.com/package/ngx-pagination.

Technology

  • Angular 16
  • RxJS 7
  • ngx-pagination 6

Setup Angular 16 Pagination Project

Let's open cmd and use Angular CLI to create a new Angular Project as following command:

ng new angular-16-pagination-example
? Would you like to add Angular routing? Yes
? Which stylesheet format would you like to use? CSS
Enter fullscreen mode Exit fullscreen mode

You can follow step by step, or get source code in this post:
Angular 16 CRUD example with Web API

The Angular 16 Project contains structure that we only need to add some changes (in tutorials-list component and tutorial.service.ts) to make the pagination work well.

angular-16-pagination-example-project

Or you can get the new Github source code at the end of this tutorial.

Setup ngx-pagination for Angular 16 Pagination example

We need to install ngx-pagination with command:
npm install ngx-pagination

Then open app.module.ts and import it:

...
import { HttpClientModule } from '@angular/common/http';
import { NgxPaginationModule } from 'ngx-pagination';

@NgModule({
  declarations: [ ... ],
  imports: [
    ...
    NgxPaginationModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }
Enter fullscreen mode Exit fullscreen mode

Create Data Service

This service will use Angular HttpClient to send HTTP requests.

services/tutorial.service.ts

import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { Observable } from 'rxjs';
import { Tutorial } from '../models/tutorial.model';

const baseUrl = 'http://localhost:8080/api/tutorials';

@Injectable({
  providedIn: 'root'
})
export class TutorialService {

  constructor(private http: HttpClient) { }

  getAll(params: any): Observable<any> {
    return this.http.get<any>(baseUrl, { params });
  }

  // other CRUD operations
}
Enter fullscreen mode Exit fullscreen mode

In the code above, you can see that we pass params object to GET method.
The params object will have one, two or all fields: title, page, size.

Create Angular 16 Component with Pagination

This component has:

  • a search bar for finding Tutorials by title.
  • a select element for quantity of items per page.
  • a PaginationControlsComponent component
  • a tutorials array displayed as a list on the left.
  • a selected Tutorial which is shown on the right.

angular-16-pagination-example-items-per-page

components/tutorials-list/tutorials-list.component.html

<div class="list row">
  <div class="col-md-8">
    <div class="input-group mb-3">
      <input
        type="text"
        class="form-control"
        placeholder="Search by title"
        [(ngModel)]="title"
      />
      <div class="input-group-append">
        <button
          class="btn btn-outline-secondary"
          type="button"
          (click)="searchTitle()"
        >
          Search
        </button>
      </div>
    </div>
  </div>

  <div class="col-md-12">
    <pagination-controls
      previousLabel="Prev"
      nextLabel="Next"
      [responsive]="true"
      (pageChange)="handlePageChange($event)"
    ></pagination-controls>
  </div>

  <div class="col-md-6">
    <h4>Tutorials List</h4>

    <ul class="list-group">
      <li
        class="list-group-item"
        *ngFor="
          let tutorial of tutorials | paginate : {
                  itemsPerPage: pageSize,
                  currentPage: page,
                  totalItems: count
                };
          let i = index
        "
        ...
      >
        {{ tutorial.title }}
      </li>
    </ul>
  </div>
  ...

  <div class="mt-3">
    ...

    Items per Page:
    <select (change)="handlePageSizeChange($event)">
      <option *ngFor="let size of pageSizes" [ngValue]="size">
        {{ size }}
      </option>
    </select>
  </div>
</div>
Enter fullscreen mode Exit fullscreen mode

We will have following variables:

  • search and display Tutorials:
    • title
    • tutorials
    • currentTutorial and currentIndex
  • pagination:
    • page: current page
    • count: total pages
    • pageSize: number of items in each page

For pagination, we're gonna use TutorialService.getAll() methods.

components/tutorials-list/tutorials-list.component.ts

import { Component, OnInit } from '@angular/core';
import { Tutorial } from 'src/app/models/tutorial.model';
import { TutorialService } from 'src/app/services/tutorial.service';

@Component({
  selector: 'app-tutorials-list',
  templateUrl: './tutorials-list.component.html',
  styleUrls: ['./tutorials-list.component.css']
})
export class TutorialsListComponent implements OnInit {

  tutorials: Tutorial[] = [];
  currentTutorial: Tutorial = {};
  currentIndex = -1;
  title = '';

  page = 1;
  count = 0;
  pageSize = 3;
  pageSizes = [3, 6, 9];

  constructor(private tutorialService: TutorialService) { }

  ngOnInit(): void {
    this.retrieveTutorials();
  }

  getRequestParams(searchTitle: string, page: number, pageSize: number): any {
    let params: any = {};

    if (searchTitle) {
      params[`title`] = searchTitle;
    }

    if (page) {
      params[`page`] = page - 1;
    }

    if (pageSize) {
      params[`size`] = pageSize;
    }

    return params;
  }

  retrieveTutorials(): void {
    const params = this.getRequestParams(this.title, this.page, this.pageSize);

    this.tutorialService.getAll(params)
    .subscribe(
      response => {
        const { tutorials, totalItems } = response;
        this.tutorials = tutorials;
        this.count = totalItems;
        console.log(response);
      },
      error => {
        console.log(error);
      });
  }

  handlePageChange(event: number): void {
    this.page = event;
    this.retrieveTutorials();
  }

  handlePageSizeChange(event: any): void {
    this.pageSize = event.target.value;
    this.page = 1;
    this.retrieveTutorials();
  }

  ...

  searchTitle(): void {
    this.page = 1;
    this.retrieveTutorials();
  }
}
Enter fullscreen mode Exit fullscreen mode

Let me explain some lines of code.

In the retrieveTutorials() method:

  • We get title, page, pageSize value and transform them into params object:
{
    "title": searchTitle,
    "page": page - 1,
    "size": pageSize
}
Enter fullscreen mode Exit fullscreen mode
  • We use tutorials and totalItems as count value from the response data:
{
    "totalItems": 8,
    "tutorials": [...],
    "totalPages": 3,
    "currentPage": 1
}
Enter fullscreen mode Exit fullscreen mode

handlePageChange() and handlePageSizeChange() methods are for setting new page and pageSize, then we invoke retrieveTutorials() that updates the tutorials List when pagination information changes.

Run Angular 16 Pagination example

First you need to run the Server at one of following posts:

Then you can run our App with command: ng serve --port 8081.
If the process is successful, open Browser with Url: http://localhost:8081/ and check it.

Conclusion

Today we've built a Angular 16 Pagination example that consume API (server-side pagination) successfully with ngx-pagination. I hope you apply it in your project at ease.

Happy learning, see you again!

Source Code

You can find the complete source code for this tutorial on Github.

Further Reading

Fullstack with Node.js Express:
Server side Pagination with Node.js and Angular

Fullstack with Spring Boot:
Spring Boot + Angular: Server side Pagination example

Top comments (1)

Collapse
 
rhythm08 profile image
Rhythm Sharma

great Blog