How To Create Pagination In Angular 6

In this tutorial, I will show you how to make Pagination example in an Angular 10 Application with existing API (server-side pagination) using ngx-pagination.

Related Posts:
– Angular 10 CRUD Application example with Web API
– Angular 10 JWT Authentication example with Web Api
– Angular 10 Form Validation example (Reactive Forms)

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

Fullstack with Spring Boot:
Server side Pagination with Angular 10 + Spring Boot example

Newer versions:
– Angular 11 Pagination example | ngx-pagination
– Angular 12 Pagination example | ngx-pagination
– Angular 13 Pagination example | ngx-pagination

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-10-pagination-example-ngx-database

Our Angular 10 app will display the result with pagination:

angular-10-pagination-example-ngx-default-paging

You can change to a page with larger index:

angular-10-pagination-example-ngx-change-page

Or change quantity of items per page:

angular-10-pagination-example-ngx-change-items-per-page

Or paging with filter:

angular-10-pagination-example-ngx-paging-filter

The API for this Angular client can be found at one of following posts:
– Node.js Express Pagination with MySQL
– Node.js Express Pagination with PostgreSQL
– Node.js Express Pagination with MongoDB
– Spring Boot Pagination & Filter example | Spring JPA, Pageable
– Spring Boot MongoDB Pagination example with Spring Data

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 }

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 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>

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>

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

angular-10-pagination-example-ngx-default-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>

angular-10-pagination-example-ngx-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>

          @Component(...) export class TutorialsListComponent {   ...   page = 1;    handlePageChange(event) {     this.page = event;   }  }

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>

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

Technology

Angular 10
RxJS 6
ngx-pagination 5

Setup Angular 10 Application

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

          ng new Angular10PaginationExample ? Would you like to add Angular routing? Yes ? Which stylesheet format would you like to use? CSS

We also need to generate some Components and Services:

          ng g s services/tutorial  ng g c components/add-tutorial ng g c components/tutorial-details ng g c components/tutorials-list

Now you can see that our project directory structure looks like this.

src

app

components

add-tutorial

tutorial-details

tutorials-list

services

tutorial.service.ts

app.routing.module

app.component.html

app.component.ts

index.html

package.json

You can follow step by step, or get source code in this post:
Angular 10 CRUD Application example with Web API

The Angular 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-10-pagination-example-ngx-project-structure

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

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

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 { }

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';  const baseUrl = 'http://localhost:8080/api/tutorials';  @Injectable({   providedIn: 'root' }) export class TutorialService {    constructor(private http: HttpClient) { }    getAll(params): Observable<any> {     return this.http.get(baseUrl, { params });   }    // other CRUD operations }

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.

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-10-pagination-example-ngx-default-paging

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)="retrieveTutorials()"         >           Search         </button>       </div>     </div>   </div>    <div class="col-md-12">     <pagination-controls       previousLabel="Prev"       nextLabel="Next"       responsive="true"       (pageChange)="handlePageChange($event)"     ></pagination-controls>   </div>    <div class="col-md-6">     <h4>Tutorials List</h4>      <ul class="list-group">       <li         class="list-group-item"         *ngFor="           let tutorial of tutorials | paginate : {                   itemsPerPage: pageSize,                   currentPage: page,                   totalItems: count                 };           let i = index         "         [class.active]="i == currentIndex"         (click)="setActiveTutorial(tutorial, i)"       >         {{ tutorial.title }}       </li>     </ul>   </div>   ...    <div class="mt-3">     ...      Items per Page:     <select (change)="handlePageSizeChange($event)">       <option *ngFor="let size of pageSizes" [ngValue]="size">         {{ size }}       </option>     </select>   </div> </div>

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 { 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: any;   currentTutorial = null;   currentIndex = -1;   title = '';    page = 1;   count = 0;   pageSize = 3;   pageSizes = [3, 6, 9];    constructor(private tutorialService: TutorialService) { }    ngOnInit(): void {     this.retrieveTutorials();   }    getRequestParams(searchTitle, page, pageSize): any {     // tslint:disable-next-line:prefer-const     let params = {};      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): void {     this.page = event;     this.retrieveTutorials();   }    handlePageSizeChange(event): void {     this.pageSize = event.target.value;     this.page = 1;     this.retrieveTutorials();   }    ... }

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 }

– We use tutorials and totalItems as count value from the response data:

          {     "totalItems": 8,     "tutorials": [...],     "totalPages": 3,     "currentPage": 1 }

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

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

Node.js Express Pagination with MySQL
Node.js Express Pagination with PostgreSQL
Node.js Express Pagination with MongoDB
Spring Boot Pagination & Filter example | Spring JPA, Pageable
Spring Boot MongoDB Pagination example with Spring Data

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 10 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!