Angular 12 CRUD Application example with Web API

In this tutorial, I will show you how to build an Angular 12 CRUD Application to consume Web APIs, display, modify & search data.

Other versions:
Angular 8 CRUD Application example with Web API
Angular 10 CRUD Application example with Web API
Angular 11 CRUD Application example with Web API

Fullstack CRUD Application:
Angular + Node.js Express + MySQL example
Angular + Node.js Express + PostgreSQL example
Angular + Node.js Express + MongoDB example
Angular + Spring Boot + MySQL example
Angular + Spring Boot + PostgreSQL example
Angular + Spring Boot + MongoDB example
Angular + Django example
Angular + Django + MySQL example
Angular + Django + PostgreSQL example
Angular + Django + MongoDB example

Authentication: Angular JWT Authentication example with Web Api

More Practice:
Angular Form Validation example (Reactive Forms)
Angular File upload example with Progress bar
Angular Multiple Files upload example with Progress Bar

Overview of Angular 12 CRUD Application

We will build an Angular 12 front-end Tutorial Application in that:

  • Each Tutorial has id, title, description, published status.
  • We can create, retrieve, update, delete Tutorials.
  • There is a Search bar for finding Tutorials by title.

Here are screenshots of our Angular CRUD Application.

– Create an object:

angular-12-crud-application-example-web-api-create-tutorial

– Retrieve all objects:

angular-12-crud-application-example-web-api-retrieve-all-tutorial

– Click on Edit button to update an object:

angular-12-crud-application-example-web-api-retrieve-one-tutorial

On this Page, you can:

  • change status to Published using Publish button
  • delete the Tutorial using Delete button
  • update the Tutorial details with Update button

angular-12-crud-application-example-web-api-update-tutorial

If you want to add form validation, please visit:
Angular Form Validation example (Reactive Forms)

– Search Tutorials by title:

angular-12-crud-application-example-web-api-search-tutorial

Web API

The introduction above is for Angular Client with assumption that we have a Server exporting REST APIs:

MethodsUrlsActions
POST/api/tutorialscreate new Tutorial
GET/api/tutorialsretrieve all Tutorials
GET/api/tutorials/:idretrieve a Tutorial by :id
PUT/api/tutorials/:idupdate a Tutorial by :id
DELETE/api/tutorials/:iddelete a Tutorial by :id
DELETE/api/tutorialsdelete all Tutorials
GET/api/tutorials?title=[keyword]find all Tutorials which title contains keyword

You can find step by step to build a Server like this in one of these posts:
Express, Sequelize & MySQL
Express, Sequelize & PostgreSQL
Express, Sequelize & SQL Server
Express & MongoDb
Spring Boot & MySQL
Spring Boot & PostgreSQL
Spring Boot & MongoDB
Spring Boot & SQL Server
Spring Boot & H2
Spring Boot & Cassandra
Spring Boot & Oracle
Django & MySQL
Django & PostgreSQL
Django & MongoDB

All of them can work well with this Angular App.

Angular 12 CRUD App Component Diagram

angular-12-crud-example-app-components-diagram

– The App component is a container with router-outlet. It has navbar that links to routes paths via routerLink.

TutorialsList component gets and displays Tutorials.
Tutorial component has form for editing Tutorial’s details based on :id.
AddTutorial component has form for submission new Tutorial.

– These Components call TutorialService methods which use Angular HTTPClient to make HTTP requests and receive responses.

Setup Angular 12 Project

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

ng new Angular12Crud
? 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

ng g class models/tutorial --type=model

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

Project Structure

angular-12-crud-application-example-web-api-project-structure

Let me explain it briefly.

tutorial.model.ts exports the main class model: Tutorial.
– There are 3 components: tutorials-list, tutorial-details, add-tutorial.
tutorial.service has methods for sending HTTP requests to the Apis.
app-routing.module.ts defines routes for each component.
app component contains router view and navigation bar.
app.module.ts declares Angular components and import necessary modules.

Set up App Module

Open app.module.ts and import FormsModule, HttpClientModule:

...
import { FormsModule } from '@angular/forms';
import { HttpClientModule } from '@angular/common/http';

@NgModule({
  declarations: [ ... ],
  imports: [
    ...
    FormsModule,
    HttpClientModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

Define Routes for Angular 12 AppRoutingModule

There are 3 main routes:
/tutorials for tutorials-list component
/tutorials/:id for tutorial-details component
/add for add-tutorial component

app-routing.module.ts

import { NgModule } from '@angular/core';
import { RouterModule, Routes } from '@angular/router';
import { TutorialsListComponent } from './components/tutorials-list/tutorials-list.component';
import { TutorialDetailsComponent } from './components/tutorial-details/tutorial-details.component';
import { AddTutorialComponent } from './components/add-tutorial/add-tutorial.component';

const routes: Routes = [
  { path: '', redirectTo: 'tutorials', pathMatch: 'full' },
  { path: 'tutorials', component: TutorialsListComponent },
  { path: 'tutorials/:id', component: TutorialDetailsComponent },
  { path: 'add', component: AddTutorialComponent }
];

@NgModule({
  imports: [RouterModule.forRoot(routes)],
  exports: [RouterModule]
})
export class AppRoutingModule { }

Import Bootstrap into Angular 12 Project

Open index.html, we only need to add one line of code for Bootstrap 4.

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>Angular12Crud</title>
  ...
  <link type="text/css" rel="stylesheet" href="//unpkg.com/[email protected]/dist/css/bootstrap.min.css" />
</head>
<body>
  <app-root></app-root>
</body>
</html>

Add Navbar and Router View to Angular 12 CRUD App

Let’s open src/app.component.html, this App component is the root container for our application, it will contain a nav element.

<div>
  <nav class="navbar navbar-expand navbar-dark bg-dark">
    <a href="#" class="navbar-brand">bezKoder</a>
    <div class="navbar-nav mr-auto">
      <li class="nav-item">
        <a routerLink="tutorials" class="nav-link">Tutorials</a>
      </li>
      <li class="nav-item">
        <a routerLink="add" class="nav-link">Add</a>
      </li>
    </div>
  </nav>

  <div class="container mt-3">
    <router-outlet></router-outlet>
  </div>
</div>

Define Model Class

Our main model class Tutorial will be exported in tutorial.model.ts with 4 fields:

  • id
  • title
  • description
  • published

models/tutorial.model.ts

export class Tutorial {
  id?: any;
  title?: string;
  description?: string;
  published?: boolean;
}

Create Data Service

This service will use Angular HTTPClient to send HTTP requests.
You can see that its functions includes CRUD operations and finder method.

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(): Observable<Tutorial[]> {
    return this.http.get<Tutorial[]>(baseUrl);
  }

  get(id: any): Observable<Tutorial> {
    return this.http.get(`${baseUrl}/${id}`);
  }

  create(data: any): Observable<any> {
    return this.http.post(baseUrl, data);
  }

  update(id: any, data: any): Observable<any> {
    return this.http.put(`${baseUrl}/${id}`, data);
  }

  delete(id: any): Observable<any> {
    return this.http.delete(`${baseUrl}/${id}`);
  }

  deleteAll(): Observable<any> {
    return this.http.delete(baseUrl);
  }

  findByTitle(title: any): Observable<Tutorial[]> {
    return this.http.get<Tutorial[]>(`${baseUrl}?title=${title}`);
  }
}

Create Angular 12 Components

As you’ve known before, there are 3 components corresponding to 3 routes defined in AppRoutingModule.

Add new Item Component

This component has a Form to submit new Tutorial with 2 fields: title & description. It calls TutorialService.create() method.

components/add-tutorial/add-tutorial.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-add-tutorial',
  templateUrl: './add-tutorial.component.html',
  styleUrls: ['./add-tutorial.component.css']
})
export class AddTutorialComponent implements OnInit {

  tutorial: Tutorial = {
    title: '',
    description: '',
    published: false
  };
  submitted = false;

  constructor(private tutorialService: TutorialService) { }

  ngOnInit(): void {
  }

  saveTutorial(): void {
    const data = {
      title: this.tutorial.title,
      description: this.tutorial.description
    };

    this.tutorialService.create(data)
      .subscribe(
        response => {
          console.log(response);
          this.submitted = true;
        },
        error => {
          console.log(error);
        });
  }

  newTutorial(): void {
    this.submitted = false;
    this.tutorial = {
      title: '',
      description: '',
      published: false
    };
  }
}

components/add-tutorial/add-tutorial.component.html

<div>
  <div class="submit-form">
    <div *ngIf="!submitted">
      <div class="form-group">
        <label for="title">Title</label>
        <input
          type="text"
          class="form-control"
          id="title"
          required
          [(ngModel)]="tutorial.title"
          name="title"
        />
      </div>

      <div class="form-group">
        <label for="description">Description</label>
        <input
          class="form-control"
          id="description"
          required
          [(ngModel)]="tutorial.description"
          name="description"
        />
      </div>

      <button (click)="saveTutorial()" class="btn btn-success">Submit</button>
    </div>

    <div *ngIf="submitted">
      <h4>Tutorial was submitted successfully!</h4>
      <button class="btn btn-success" (click)="newTutorial()">Add</button>
    </div>
  </div>
</div>

components/add-tutorial/add-tutorial.component.css

.submit-form {
  max-width: 400px;
  margin: auto;
}

List of items Component

This component calls 3 TutorialService methods:

  • getAll()
  • deleteAll()
  • findByTitle()

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 = '';

  constructor(private tutorialService: TutorialService) { }

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

  retrieveTutorials(): void {
    this.tutorialService.getAll()
      .subscribe(
        data => {
          this.tutorials = data;
          console.log(data);
        },
        error => {
          console.log(error);
        });
  }

  refreshList(): void {
    this.retrieveTutorials();
    this.currentTutorial = {};
    this.currentIndex = -1;
  }

  setActiveTutorial(tutorial: Tutorial, index: number): void {
    this.currentTutorial = tutorial;
    this.currentIndex = index;
  }

  removeAllTutorials(): void {
    this.tutorialService.deleteAll()
      .subscribe(
        response => {
          console.log(response);
          this.refreshList();
        },
        error => {
          console.log(error);
        });
  }

  searchTitle(): void {
    this.currentTutorial = {};
    this.currentIndex = -1;

    this.tutorialService.findByTitle(this.title)
      .subscribe(
        data => {
          this.tutorials = data;
          console.log(data);
        },
        error => {
          console.log(error);
        });
  }
}

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-6">
    <h4>Tutorials List</h4>
    <ul class="list-group">
      <li
        class="list-group-item"
        *ngFor="let tutorial of tutorials; let i = index"
        [class.active]="i == currentIndex"
        (click)="setActiveTutorial(tutorial, i)"
      >
        {{ tutorial.title }}
      </li>
    </ul>

    <button class="m-3 btn btn-sm btn-danger" (click)="removeAllTutorials()">
      Remove All
    </button>
  </div>
  <div class="col-md-6">
    <div *ngIf="currentTutorial.id">
      <h4>Tutorial</h4>
      <div>
        <label><strong>Title:</strong></label> {{ currentTutorial.title }}
      </div>
      <div>
        <label><strong>Description:</strong></label>
        {{ currentTutorial.description }}
      </div>
      <div>
        <label><strong>Status:</strong></label>
        {{ currentTutorial.published ? "Published" : "Pending" }}
      </div>

      <a class="badge badge-warning" routerLink="/tutorials/{{ currentTutorial.id }}">
        Edit
      </a>
    </div>

    <div *ngIf="!currentTutorial">
      <br />
      <p>Please click on a Tutorial...</p>
    </div>
  </div>
</div>

If you click on Edit button of any Tutorial, You will be directed to Tutorial page with url: /tutorials/:id.

components/tutorials-list/tutorials-list.component.css

.list {
  text-align: left;
  max-width: 750px;
  margin: auto;
}

You can add Pagination to this Component, just follow instruction in the post:
Angular Pagination example with ngx-pagination

Item details Component

For getting data & update, delete the Tutorial, this component will use 3 TutorialService methods:

  • get()
  • update()
  • delete()

components/tutorial-details/tutorial-details.component.ts

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

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

  currentTutorial: Tutorial = {
    title: '',
    description: '',
    published: false
  };
  message = '';

  constructor(
    private tutorialService: TutorialService,
    private route: ActivatedRoute,
    private router: Router) { }

  ngOnInit(): void {
    this.message = '';
    this.getTutorial(this.route.snapshot.params.id);
  }

  getTutorial(id: string): void {
    this.tutorialService.get(id)
      .subscribe(
        data => {
          this.currentTutorial = data;
          console.log(data);
        },
        error => {
          console.log(error);
        });
  }

  updatePublished(status: boolean): void {
    const data = {
      title: this.currentTutorial.title,
      description: this.currentTutorial.description,
      published: status
    };

    this.message = '';

    this.tutorialService.update(this.currentTutorial.id, data)
      .subscribe(
        response => {
          this.currentTutorial.published = status;
          console.log(response);
          this.message = response.message ? response.message : 'The status was updated successfully!';
        },
        error => {
          console.log(error);
        });
  }

  updateTutorial(): void {
    this.message = '';

    this.tutorialService.update(this.currentTutorial.id, this.currentTutorial)
      .subscribe(
        response => {
          console.log(response);
          this.message = response.message ? response.message : 'This tutorial was updated successfully!';
        },
        error => {
          console.log(error);
        });
  }

  deleteTutorial(): void {
    this.tutorialService.delete(this.currentTutorial.id)
      .subscribe(
        response => {
          console.log(response);
          this.router.navigate(['/tutorials']);
        },
        error => {
          console.log(error);
        });
  }
}

components/tutorial-details/tutorial-details.component.html

<div>
  <div *ngIf="currentTutorial.id" class="edit-form">
    <h4>Tutorial</h4>
    <form>
      <div class="form-group">
        <label for="title">Title</label>
        <input
          type="text"
          class="form-control"
          id="title"
          [(ngModel)]="currentTutorial.title"
          name="title"
        />
      </div>
      <div class="form-group">
        <label for="description">Description</label>
        <input
          type="text"
          class="form-control"
          id="description"
          [(ngModel)]="currentTutorial.description"
          name="description"
        />
      </div>

      <div class="form-group">
        <label><strong>Status:</strong></label>
        {{ currentTutorial.published ? "Published" : "Pending" }}
      </div>
    </form>

    <button
      class="badge badge-primary mr-2"
      *ngIf="currentTutorial.published"
      (click)="updatePublished(false)"
    >
      UnPublish
    </button>
    <button
      *ngIf="!currentTutorial.published"
      class="badge badge-primary mr-2"
      (click)="updatePublished(true)"
    >
      Publish
    </button>

    <button class="badge badge-danger mr-2" (click)="deleteTutorial()">
      Delete
    </button>

    <button
      type="submit"
      class="badge badge-success mb-2"
      (click)="updateTutorial()"
    >
      Update
    </button>
    <p>{{ message }}</p>
  </div>

  <div *ngIf="!currentTutorial.id">
    <br />
    <p>Cannot access this Tutorial...</p>
  </div>
</div>

components/tutorial-details/tutorial-details.component.css

.edit-form {
  max-width: 400px;
  margin: auto;
}

Run the Angular 12 CRUD App

You can run this App with command: ng serve.

If you use this front-end app for one of these back-end Rest APIs:
Express, Sequelize & MySQL
Express, Sequelize & PostgreSQL
Express, Sequelize & SQL Server
Express & MongoDb
Spring Boot & MySQL
Spring Boot & PostgreSQL
Spring Boot & MongoDB
Spring Boot & SQL Server
Spring Boot & H2
Spring Boot & Cassandra
Spring Boot & Oracle
Django & MySQL
Django & PostgreSQL
Django & MongoDB

It configures CORS for port 8081, so you have to run command: ng serve --port 8081 instead.

Conclusion

Today we’ve built an Angular 12 CRUD Application successfully working with Web API. Now we can, display, modify, delete or search data in a clean way. I hope you apply it in your project at ease.

For adding Form Validation, please visit:
Angular Form Validation example (Reactive Forms)

You can also find how to implement Authentication with the post:
Angular JWT Authentication example with Web Api

Or you can add Pagination Component:
Angular Pagination example with ngx-pagination

spring-boot-angular-12-pagination-example-change-page

Or implement File Upload Component:
Angular File upload example with Progress bar

Happy learning, see you again!

Further Reading

Serverless with Firebase:
Angular 12 Firebase CRUD with Realtime Database example
Angular Firestore CRUD example
Angular Firebase Storage: File Upload/Display/Delete Files example

Integration:
How to Integrate Angular with Node.js Restful Services
How to Integrate Angular with Spring Boot Rest API

Source Code

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

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