CRUD Operations in Angular

In this tutorial, we will be developing an angular application and perform CRUD operations in angular. CRUD operations include POST, GET, UPDATE and DELETE requests respectively. In this tutorial, you will learn how to implement CRUD operations in an angular step by step.

Creating angular application:

Create an angular application by using the following command.

ng new crud-app-in-angular

Your angular application will get created with this command.
Now put the following code in the app.component.ts file.

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

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent implements OnInit {
  constructor() { }
  title = 'CRUD operations in angular';

  ngOnInit() {
  }
}

Put the following code in the app.component.html file.

<div style="text-align:center; margin-bottom: 24px">
  <h1>
    {{ title }}!
  </h1>
</div>

By changing the code from the above file, we have changed the title to “CRUD operations in angular”.

Adding Bootstrap CSS framework:

Add Bootstrap CSS framework into the angular application for easily applying styles. Adding bootstrap is optional. You can learn how to add bootstrap in angular with this article: Install Bootstrap in angular.

Adding FontAwesome in angular:

To add icons in these crud operations in the angular project, let’s add FontAwesome to the project. To add FontAwesome in angular simply add the following link tag in the index.html file.

<link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.7.0/css/all.css"
    integrity="sha384-lZN37f5QGtY3VHgisS14W3ExzMWZxybE1SJSEsQp9S+oqd12jhcu+A56Ebc1zFSJ" crossorigin="anonymous">

You can also learn how to install it with this article: Installing FontAwesome in Angular

Creating User Component:

Create a new component named as a user with the following command.

ng generate component user

OR using a short command like the following.

ng g c user

We will implement all crud operations using this newly created user component.

Put the following code in the app.component.html file. Here I have called the selector of the user component which will load into the app component.

<div style="text-align:center; margin-bottom: 24px">
  <h1>
    {{ title }}!
  </h1>
</div>
<app-user></app-user>

Creating userdata service:

Create userdata service with the following command.

ng generate service userdata

OR using a short command like the following.

ng g s userdata

We will use this service to send requests such as GET, POST, PUT, and DELETE to perform CRUD operations on user data.

CRUD operations in angular:

For implementing CRUD operations in angular, put the following code into respective files as suggested. After this, you can learn the code explanation.
Here, you will learn how to use the service to make requests to the server. In the following code, I made a call to the JSONPlaceholder website which provides fake online REST API for testing and prototyping purposes. I created functions in service and made calls to perform CRUD operations on data.

Put the following code in the userdata.service.ts file.

import { Injectable } from '@angular/core';
import { HttpClient, HttpHeaders } from '@angular/common/http';

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

  constructor(private http: HttpClient) { }

  getUserData() {
    const url = 'https://jsonplaceholder.typicode.com/users';
    return this.http.get(url);
  }

  createUser(userData) {
    const url = 'https://jsonplaceholder.typicode.com/users';
    const httpOptions = {
      headers: new HttpHeaders({
        'Content-Type': 'application/json; charset=UTF-8'
      })
    };

    return this.http.post(url, userData, httpOptions);
  }

  deleteUser(userData) {
    const url = `https://jsonplaceholder.typicode.com/users/${userData.id}`;
    const httpOptions = {
      headers: new HttpHeaders({
        'Content-Type': 'application/json; charset=UTF-8'
      })
    };
    return this.http.delete(url, httpOptions);
  }

  editUser(userData) {
    const url = `https://jsonplaceholder.typicode.com/users/${userData.id}`;
    const httpOptions = {
      headers: new HttpHeaders({
        'Content-Type': 'application/json; charset=UTF-8'
      })
    };

    return this.http.put(url, userData, httpOptions);
  }
}

Put the following code in the user.component.ts file

import { Component, OnInit } from '@angular/core';
import { FormGroup, FormControl, FormBuilder } from '@angular/forms';

import { UserdataService } from './userdata.service';

@Component({
  selector: 'app-user',
  templateUrl: './user.component.html',
  styleUrls: ['./user.component.css']
})
export class UserComponent implements OnInit {
  userData;
  userForm: FormGroup;
  editUserForm: FormGroup;
  showEditUserForm = false;
  editFormId;

  // variables to status of request;
  userCreated = false;
  userEdited = false;
  userDeleted = false;
  userDeletedId;
  constructor(private userDataService: UserdataService, private fb: FormBuilder) { }

  ngOnInit() {
    this.userDataService.getUserData().subscribe((data) => {
      console.log('data', data);
      this.userData = data;
    });

    this.initForm();
  }

  initForm() {
    this.userForm = this.fb.group({
      name: [],
      username: [],
      email: []
    });
  }

  createUser(event, userform) {
    const userData = userform.value;
    this.userDataService.createUser(userData).subscribe((data) => {
      console.log('user created', data);
      this.userCreated = true;
      setTimeout(() => {
        this.userCreated = false;
      }, 2000);
    });
  }

  editUser(event, data) {
    this.showEditUserForm = true;
    this.editFormId = data.Id;
    this.editUserForm = this.fb.group({
      id: [data.id],
      name: [data.name],
      username: [data.username],
      email: [data.email]
    });
  }

  editUserData(event, userform) {
    const userData = userform.value;
    this.userDataService.editUser(userData).subscribe((data) => {
      console.log('user edited', data);
      this.userEdited = true;
      setTimeout(() => {
        this.userEdited = false;
        this.showEditUserForm = false;
      }, 2000);
    });
  }

  deleteUser(event, userData) {
    this.userDataService.deleteUser(userData).subscribe((data) => {
      console.log('user deleted', data);
      this.userDeletedId = userData.id;
      this.userDeleted = true;
      setTimeout(() => {
        this.userDeleted = false;
      }, 2000);
    });
  }
}

Put the following code in the user.component.html file.

<div *ngIf="!showEditUserForm" class="container">
  <div class="create-block">
    <div>
      <h3>Create User:</h3>
    </div>
    <form [formGroup]="userForm" (submit)="createUser($event, userForm)">
      <div class="form-group row">
        <label class="col-sm-3" for="name">Name:</label>
        <input class="col-sm-9" type="text" placeholder="Enter name" id="email" formControlName="name">
      </div>
      <div class="form-group row">
        <label class="col-sm-3" for="username">Username:</label>
        <input class="col-sm-9" type="text" placeholder="Enter username" id="username" formControlName="username">
      </div>
      <div class="form-group row">
        <label class="col-sm-3" for="email">Email address:</label>
        <input class="col-sm-9" type="email" placeholder="Enter email" id="email" formControlName="email">
      </div>

      <button class="btn btn-primary" type="submit">
        <i class="fas fa-plus"></i> Create User
      </button>
    </form>

    <div class="status" *ngIf="userCreated">
      User Created Sucessfully.
    </div>
  </div>
</div>

<div *ngIf="userData">
  <h3 class="text-center">User Data</h3>
  <div class="container" *ngFor="let data of userData">
    <div *ngIf="!showEditUserForm" class="user-data card">
      <div>
        <div>
          <h4> Name: {{data.name}}</h4>
        </div>
        <div>
          <h4> Username: {{data.username}}</h4>
        </div>
        <div>
          <h4> Email: {{data.email}}</h4>
        </div>
      </div>
      <div>
        <button style="margin: 4px;" class="btn btn-primary" (click)="editUser($event, data)">
          <i class="fas fa-edit"></i> Edit User
        </button>
        <button style="margin: 4px;" class="btn btn-danger" (click)="deleteUser($event, data)">
          <i class="fas fa-trash"></i> Delete User
        </button>
      </div>

      <div>
        <div class="status" *ngIf="userDeleted && data.id === userDeletedId">
          User Deleted Sucessfully.
        </div>
      </div>
    </div>
  </div>

  <div class="container" *ngIf="showEditUserForm">
    <div class="create-block">
      <div>
        <h3>Edit User:</h3>
      </div>
      <form [formGroup]="editUserForm" (submit)="editUserData($event, editUserForm)">
        <div class="form-group row">
          <label class="col-sm-3" for="name">Name:</label>
          <input class="col-sm-9" type="text" placeholder="Enter name" id="email" formControlName="name">
        </div>
        <div class="form-group row">
          <label class="col-sm-3" for="username">Username:</label>
          <input class="col-sm-9" type="text" placeholder="Enter username" id="username" formControlName="username">
        </div>
        <div class="form-group row">
          <label class="col-sm-3" for="email">Email address:</label>
          <input class="col-sm-9" type="email" placeholder="Enter email" id="email" formControlName="email">
        </div>

        <button class="btn btn-primary" type="submit">Edit User</button>
      </form>

      <div class="status" *ngIf="userEdited">
        User Edited Sucessfully.
      </div>
    </div>
  </div>
</div>

Put the following code in the user.component.css file for style purposes.

.user-data {
  width: 100%;
  padding: 24px;
  margin-bottom: 24px;
  box-shadow: 0 2px 1px -1px rgba(0,0,0,.2), 0 1px 1px 0 rgba(0,0,0,.14), 0 1px 3px 0 rgba(0,0,0,.12);
}

.info-block {
  display: flex;
}

.create-block {
  padding: 24px;
  border: 1px solid grey;
  border-radius: 5px;
  margin-bottom: 24px;
}

.status {
  padding: 8px;
  background: #0b990b;
  color: white;
  margin-top: 8px;
  border: 1px solid black;
  border-radius: 5px;
}

Put following code into app.module.ts file.

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';

import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';
import { HttpClientModule } from '@angular/common/http';
import { UserComponent } from './user/user.component';
import { ReactiveFormsModule, FormsModule } from '@angular/forms';

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

Output:

Run your project and you can perform CRUD operations on data that we fetched from the JSONPlaceholder website. See the following images of the output of CRUD operations.

GET operation output:

CREATE operation output:

Update operation output:

DELETE operation output:

Code Explanation:

From the following points, you will learn how operations of CREATE, READ, UPDATE, and DELETE are done in the above code with an explanation.

**Note:-

As the JSONPlaceholder website provides fake online REST API for testing and prototyping purposes, the requests we made like POST, PUT, DELETE will not actually insert, modify or delete data into the server. But as you can see that from the above images of dev tools and console logs, the requests get performed successfully.

READ operation:

To read data from the server, you have to perform a GET request to the server. To make HTTP requests, you have to import angular’s built-in HttpClientModule into AppModule. This module will be helpful for making HTTP requests.
I have made a function that makes a GET request to the server for fetching data.

getUserData() {
    const url = 'https://jsonplaceholder.typicode.com/users';
    return this.http.get(url);
  }

This function return data fetched from the server. To access data from this function, I have made call to this function from the user component.

 this.userDataService.getUserData().subscribe((data) => {
    console.log('data', data);
    this.userData = data;
  });

I stored data received from the server into the userData variable. To display data from the server I have performed for loop on userData and displayed the userData like name, username, and email.

<div class="container" *ngFor="let data of userData">
  <div class="user-data card">
    <div>
      <div>
        <h4> Name: {{data.name}}</h4>
      </div>
      <div>
        <h4> Username: {{data.username}}</h4>
      </div>
      <div>
        <h4> Email: {{data.email}}</h4>
      </div>
    </div>
  </div>
</div>

CREATE operation:

For CREATE operation, we have to send a POST request to the server. Here, to create a user into the server, I have made a POST request to the server. To create a user, I made the createUser function which gets required data from the user component when a user fills a form. Then createUser function sends a POST request to the server.

I have created a userForm where information has to be filled to create a user into the server. When the user fills that form and clicks on Create User button, it sends data to the following function.

createUser(event, userform) {
  const userData = userform.value;
  this.userDataService.createUser(userData).subscribe((data) => {
    console.log('user created', data);
  });
}

This createUser function from the user component makes a call to the createUser function from the userData service. This createUser function from the userData service makes a POST request to the server.

createUser(userData) {
  const url = 'https://jsonplaceholder.typicode.com/users';
  const httpOptions = {
    headers: new HttpHeaders({
      'Content-Type': 'application/json; charset=UTF-8'
    })
  };

  return this.http.post(url, userData, httpOptions);
}

UPDATE operation:

To update or modify certain data, we have to make a PUT request to the server. I have created an editUserForm where information has to be filled in to edit a user from the server. For UPDATE operation, editUserData function from the user component gets data when a user fills a form and clicks on the Edit User button.

editUserData(event, userform) {
  const userData = userform.value;
  this.userDataService.editUser(userData).subscribe((data) => {
    console.log('user edited', data);
  });
}

This editUserData function sends data to editUser function from the userData service. editUser function from userData service makes PUT request to the server. To make a PUT request for particular user data, you have to send a PUT request to that particular user data only. Like in the below editUser function, I have passed the id of the user data which is being edited into a URL.

editUser(userData) {
  const url = `https://jsonplaceholder.typicode.com/users/${userData.id}`;
  const httpOptions = {
    headers: new HttpHeaders({
      'Content-Type': 'application/json; charset=UTF-8'
    })
  };

  return this.http.put(url, userData, httpOptions);
}

For a good user interface, I have only shown the edit user form when the user clicks on the Edit User button. Also, I hide that edit form when the PUT request gets successfully performed. For this, I have made the showEditUserForm variable true when the user clicks the Edit User button. To hide the edit user form I have set the showEditUserForm variable to false when the PUT request gets successfully performed.

Delete operation:

For the DELETE operation, we have to make a DELETE request to the server. When the user clicks the Delete user button, data gets passed to deleteUser function from the user component.

deleteUser(event, userData) {
  this.userDataService.deleteUser(userData).subscribe((data) => {
    console.log('user deleted', data);
    this.userDeletedId = userData.id;
    this.userDeleted = true;
    setTimeout(() => {
      this.userDeleted = false;
    }, 2000);
  });
}

deleteUser function from user component makes a call to deleteUser from userData service which then makes DELETE request to the server. To make a DELETE request, I have sent the id of user data which is to be deleted into the URL.

deleteUser(userData) {
  const url = `https://jsonplaceholder.typicode.com/users/${userData.id}`;
  const httpOptions = {
    headers: new HttpHeaders({
      'Content-Type': 'application/json; charset=UTF-8'
    })
  };
  return this.http.delete(url, httpOptions);
}

Request Status:

To indicate when the request gets successfully performed, I have used variables userCreated, userEdited, userDeleted, userDeletedId; After the request gets successfully performed, I have set appropriate messages regarding that operation.

Conclusion:

From this tutorial, you learned how to perform CRUD operations in angular in detail. As this tutorial might get difficult for beginners to learn, post comments if you have any difficulty implementing this application.

See Also:

Components in angular
Services in Angular
Routing in Angular
template vs templateUrl
*ngFor in angular
Angular Material: Getting Started

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