Angular 16 JWT User Authentication Example Tutorial

Set up Angular Project

Let’s get started by installing the basic Angular app, enter the following command in your terminal:

ng new angular-meanstack-authentication

Next, head over to the Angular user authentication project folder:

cd angular-meanstack-authentication

To make things simpler create a separate front-end and backend (server) in Angular app. Our Angular user auth app will have signin, signup and user-profile pages.

Create specific components folder in src/app/components in Angular app and create the following components in it.

ng g c components/signin

ng g c components/signup

ng g c components/user-profile

Next, install Bootstrap.

npm install bootstrap

Add the Bootstrap stylesheet path in angular.json file.

"styles": [
          "node_modules/bootstrap/dist/css/bootstrap.min.css",
          "src/styles.scss"
         ]

No Property Access From Index Signature

To resolve error:

Property ‘xxxName’ comes from an index signature, so it must be accessed with [‘xxxName’]

This setting makes sure profound consistency between accessing a field via the “dot” (obj.key) syntax, and “indexed” (obj["key"]) and the way which the property is declared in the type.

Without this flag, TypeScript will allow you to use the dot syntax to access fields which are not defined:

Make sure to set noPropertyAccessFromIndexSignature property to false under compilerOptions in tsconfig.json file:

"compilerOptions": {
// ...
// ...
   "noPropertyAccessFromIndexSignature": false,
// ...
// ...
}

Clone Node Js Token-Based Auth REST API from GitHub

Run the following command to clone Node.js token-based auth REST API from GitHub in your Angular’s root folder.

git clone https://github.com/SinghDigamber/node-token-based-authentication.git

Please read the guide on:

How to build Node Js Token-Based Auth REST API using Express and MongoDB.

Get inside the server folder:

cd node-token-based-authentication

Next, install npm packages to set up and start the Node server:

Run `npm install` to install required packages.

Next, install the nodemon NPM package for development purpose with --save-dev attribute, it helps in starting the node server when any change occurs in the server files.

npm install nodemon --save-dev

Also, run command to start the Node server:

npx nodemon server

Make sure to start the MongoDB in another tab.

Go through the guide for MongoDB setup:

Start the MongoDB community and MongoDB Compass GUI database in your local macOS system.

Following auth APIs we are going to use in this tutorial.

Open API URL on http://localhost:4000/api

Setting up HttpClient

To handle REST APIs via HTTP requests in our Angular user authentication app. We need to import Angular HttpClient service in the auth module.

Import HttpClientModule service in app.module.ts file.

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

@NgModule({
  imports: [
    HttpClientModule
   ]
})

Creating User Authentication Service in Angular

Now create Angular auth service and user class, these files will handle all the JWT user authentication related APIs in our project.

Inside the shared folder create shared/user.ts file and include the following code inside of it.

export class User {
  _id?: String;
  name?: String;
  email?: String;
  password?: String;
}

Next, run below command to create user auth service.

ng g s shared/auth

Add the following code in the shared/auth.service.ts file.

import { Injectable } from '@angular/core';
import { User } from './user';
import { Observable, throwError } from 'rxjs';
import { catchError, map } from 'rxjs/operators';
import {
  HttpClient,
  HttpHeaders,
  HttpErrorResponse,
} from '@angular/common/http';
import { Router } from '@angular/router';

@Injectable({
  providedIn: 'root',
})

export class AuthService {
  endpoint: string = 'http://localhost:4000/api';
  headers = new HttpHeaders().set('Content-Type', 'application/json');
  currentUser = {};

  constructor(private http: HttpClient, public router: Router) {}

  // Sign-up
  signUp(user: User): Observable<any> {
    let api = `${this.endpoint}/register-user`;
    return this.http.post(api, user).pipe(catchError(this.handleError));
  }

  // Sign-in
  signIn(user: User) {
    return this.http
      .post<any>(`${this.endpoint}/signin`, user)
      .subscribe((res: any) => {
        localStorage.setItem('access_token', res.token);
        this.getUserProfile(res._id).subscribe((res) => {
          this.currentUser = res;
          this.router.navigate(['user-profile/' + res.msg._id]);
        });
      });
  }

  getToken() {
    return localStorage.getItem('access_token');
  }

  get isLoggedIn(): boolean {
    let authToken = localStorage.getItem('access_token');
    return authToken !== null ? true : false;
  }

  doLogout() {
    let removeToken = localStorage.removeItem('access_token');
    if (removeToken == null) {
      this.router.navigate(['log-in']);
    }
  }

  // User profile
  getUserProfile(id: any): Observable<any> {
    let api = `${this.endpoint}/user-profile/${id}`;
    return this.http.get(api, { headers: this.headers }).pipe(
      map((res) => {
        return res || {};
      }),
      catchError(this.handleError)
    );
  }

  // Error
  handleError(error: HttpErrorResponse) {
    let msg = '';
    if (error.error instanceof ErrorEvent) {
      // client-side error
      msg = error.error.message;
    } else {
      // server-side error
      msg = `Error Code: ${error.status}\nMessage: ${error.message}`;
    }
    return throwError(msg);
  }
}

• The signUp() method stores the user name, email and password in mongoDB database.
• By taking the help of bcryptjs, we are storing the password securely in the database.
• The signin() method allows the user to access in the app using JSON web token generated by node server.
• We are getting JWT token from the API response and storing in the local storage, then in the getToken() method, we are accessing the token via local storage getItem() method.
• The isLoggedIn method returns true if the user is logged in else returns false.

Set JWT Token with Angular HttpInterceptor

In this part of the tutorial, we are going to set the JSON web token in the header using Angular HttpInterceptor.

To set the authorization header, first create the authconfig.interceptor.ts file in the shared/ folder.

import { Injectable } from "@angular/core";
import { HttpInterceptor, HttpRequest, HttpHandler } from "@angular/common/http";
import { AuthService } from "./auth.service";

@Injectable()

export class AuthInterceptor implements HttpInterceptor {
    constructor(private authService: AuthService) { }

    intercept(req: HttpRequest<any>, next: HttpHandler) {
        const authToken = this.authService.getToken();
        req = req.clone({
            setHeaders: {
                Authorization: "Bearer " + authToken
            }
        });
        return next.handle(req);
    }
}

Import the AuthService in and inject inside the constructor. In the intercept(){…} method call the getToken() method to get the JWT token then within the req.clone method set the Authorization header and call teh next.handle() method.

import { HttpClientModule, HTTP_INTERCEPTORS } from '@angular/common/http';
import { AuthInterceptor } from './shared/authconfig.interceptor';

@NgModule({
  declarations: [...],
  imports: [HttpClientModule],
  providers: [
    {
      provide: HTTP_INTERCEPTORS,
      useClass: AuthInterceptor,
      multi: true
    }
  ],
  bootstrap: [...]
})

export class AppModule { }

Next, import the HTTP_INTERCEPTORS in the app.module.ts file and set the HTTP_INTERCEPTORS along with AuthInterceptor in providers:[...] array.

Protect Routes with CanActivate

The CanActivate offers route guard service in Angular, It stops visitors to access certain urls in the Angular app.

In our case we only want logged-in users to access the /user-profile/:id URL.

ng g guard shared/auth

Next, add the following code in the auth.guard.ts file.

import { Injectable } from '@angular/core';
import {
  ActivatedRouteSnapshot,
  RouterStateSnapshot,
  UrlTree,
  Router,
} from '@angular/router';
import { Observable } from 'rxjs';
import { AuthService } from './../shared/auth.service';

@Injectable({
  providedIn: 'root',
})
export class AuthGuard {
  constructor(public authService: AuthService, public router: Router) {}

  canActivate(
    next: ActivatedRouteSnapshot,
    state: RouterStateSnapshot
  ):
    | Observable<boolean | UrlTree>
    | Promise<boolean | UrlTree>
    | boolean
    | UrlTree {
    if (this.authService.isLoggedIn !== true) {
      window.alert('Access not allowed!');
      this.router.navigate(['log-in']);
    }
    return true;
  }
}

Then, go to app-routing.module.ts file and import the AuthGuard interface class and inject the AuthGuard in the route as given below.

import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';

import { SigninComponent } from './components/signin/signin.component';
import { SignupComponent } from './components/signup/signup.component';
import { UserProfileComponent } from './components/user-profile/user-profile.component';

import { AuthGuard } from "./shared/auth.guard";


const routes: Routes = [
  { path: '', redirectTo: '/log-in', pathMatch: 'full' },
  { path: 'log-in', component: SigninComponent },
  { path: 'sign-up', component: SignupComponent },
  { path: 'user-profile/:id', component: UserProfileComponent, canActivate: [AuthGuard] }
];

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

export class AppRoutingModule { }

Implement Reactive Forms

Import ReactiveFormsModule and FormsModule in app.module.ts file and also declare in imports: […] array.

Check out more about Reactive forms in Angular

import { FormsModule, ReactiveFormsModule } from '@angular/forms';

@NgModule({
  imports: [
    FormsModule,
    ReactiveFormsModule
  ],
})

export class AppModule { }

Implementing User Registration in MEAN Stack App

Now, implement user registration in MEAN stack auth app using Node API. Go to components/signup.component.ts file and add the following code.

import { Component, OnInit } from '@angular/core';
import { FormBuilder, FormGroup } from '@angular/forms';
import { AuthService } from './../../shared/auth.service';
import { Router } from '@angular/router';

@Component({
  selector: 'app-signup',
  templateUrl: './signup.component.html',
  styleUrls: ['./signup.component.scss'],
})

export class SignupComponent implements OnInit {
  signupForm: FormGroup;

  constructor(
    public fb: FormBuilder,
    public authService: AuthService,
    public router: Router
  ) {
    this.signupForm = this.fb.group({
      name: [''],
      email: [''],
      mobile: [''],
      password: [''],
    });
  }

  ngOnInit() {}

  registerUser() {
    this.authService.signUp(this.signupForm.value).subscribe((res) => {
      if (res.result) {
        this.signupForm.reset();
        this.router.navigate(['log-in']);
      }
    });
  }
}

Go to components/signup.component.html file and add the following code inside of it.

<div class="form-signin w-100 m-auto">
  <form
    [formGroup]="signupForm"
    (ngSubmit)="registerUser()"
  >
    <h3 class="h3 mb-3 font-weight-normal text-center">Please sign up</h3>
    <div class="mb-3">
      <label>Name</label>
      <input
        type="text"
        class="form-control"
        formControlName="name"
        placeholder="Enter name"
        required
      />
    </div>
    <div class="mb-3">
      <label>Email address</label>
      <input
        type="email"
        class="form-control"
        formControlName="email"
        placeholder="Enter email"
        required
      />
    </div>
    <div class="mb-3">
      <label>Password</label>
      <input
        type="password"
        class="form-control"
        formControlName="password"
        placeholder="Password"
        required
      />
    </div>
    <div class="d-grid">
      <button type="submit" class="btn btn-block btn-primary">Sign up</button>
    </div>
  </form>
</div>

Call the signUp() method to register the user via the registerUser() method. On successful user registration redirect user to the log-in page.

Handling MEAN Stack Login with Angular

In this step, we will implement MEAN stack login in an Angular app. Go to components/signin.component.ts file and add the following code.

import { Component, OnInit } from '@angular/core';
import { FormBuilder, FormGroup } from '@angular/forms';
import { AuthService } from './../../shared/auth.service';
import { Router } from '@angular/router';

@Component({
  selector: 'app-signin',
  templateUrl: './signin.component.html',
  styleUrls: ['./signin.component.scss'],
})

export class SigninComponent implements OnInit {
  signinForm: FormGroup;

  constructor(
    public fb: FormBuilder,
    public authService: AuthService,
    public router: Router
  ) {
    this.signinForm = this.fb.group({
      email: [''],
      password: [''],
    });
  }

  ngOnInit() {}

  loginUser() {
    this.authService.signIn(this.signinForm.value);
  }
}

Head over to components/signin.component.html file and add the following code inside of it.

<div class="form-signin w-100 m-auto">
  <form [formGroup]="signinForm" (ngSubmit)="loginUser()">
    <h3 class="h3 mb-3 font-weight-normal text-center">Please sign in</h3>
    <div class="mb-3">
      <label>Email</label>
      <input
        type="email"
        class="form-control"
        formControlName="email"
        placeholder="Enter email"
        required
      />
    </div>
    <div class="mb-3">
      <label>Password</label>
      <input
        type="password"
        class="form-control"
        formControlName="password"
        placeholder="Password"
      />
    </div>

    <div class="d-grid">
      <button type="submit" class="btn btn-primary">Sign in</button>
    </div>
  </form>
</div>

Enter the user email and password, we are setting up Authorization: Bearer token in the header when the user successfully logged-in.

Fetch User Profile in Angular Auth App

Now, we will fetch the user data when the user is successfully logged in.

In server/middlewares/auth.js file we have set the jwt.verify() method.

This method checks the API request and does not render the user data if found invalid token or JWT secret.

For example try to access the /user-profile/_id Angular URL without providing the invalid token. You will find out that server doesn’t render the user data.

Get into the components/user-profile.component.ts file and include the following code inside of it.

import { Component, OnInit } from '@angular/core';
import { ActivatedRoute } from '@angular/router';
import { AuthService } from './../../shared/auth.service';
import { User } from '../../shared/user';

@Component({
  selector: 'app-user-profile',
  templateUrl: './user-profile.component.html',
  styleUrls: ['./user-profile.component.scss'],
})
export class UserProfileComponent implements OnInit {
  currentUser: User = {};

  constructor(
    public authService: AuthService,
    private actRoute: ActivatedRoute
  ) {
    let id = this.actRoute.snapshot.paramMap.get('id');
    this.authService.getUserProfile(id).subscribe((res) => {
      this.currentUser = res.msg;
    });
  }

  ngOnInit() {}
}

Get into the components/user-profile.component.html file and include the following code inside of it.

<div class="container">
  <div class="row">
    <div class="inner-main">
      <h2 class="mb-4">User Profile</h2>
      <p><strong>Name:</strong> {{ this.currentUser.name }}</p>
      <p><strong>Email:</strong> {{ this.currentUser.email }}</p>
    </div>
  </div>
</div>

Adding Logout in MEAN App

In this step, we will add the logout, hiding and showing nav items in our MEAN stack user authentication app.

Go to app/app.component.ts file and add the following code inside of it.

import { Component } from '@angular/core';
import { AuthService } from './shared/auth.service';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.scss']
})

export class AppComponent {

  constructor(public authService: AuthService) { }

  logout() {
    this.authService.doLogout()
  }
}

Go to app/app.component.html file and add the following code inside of it.

<div class="container d-flex flex-wrap p-3 px-md-4 mb-3 bg-white border-bottom">
  <h5 class="nav me-auto">Angular JWT Mean Authentication Example</h5>
  <nav class="nav">
    <a *ngIf="this.authService.isLoggedIn" class="p-2 text-dark"
      >User Profile</a
    >
    <a
      *ngIf="!this.authService.isLoggedIn"
      class="btn btn-light text-dark me-2"
      routerLinkActive="active"
      routerLink="/log-in"
      >Sign in</a
    >
  </nav>
  <a
    *ngIf="!this.authService.isLoggedIn"
    class="btn btn-primary"
    routerLinkActive="active"
    routerLinkActive="active"
    routerLink="/sign-up"
    >Sign up</a
  >
  <button
    (click)="logout()"
    *ngIf="this.authService.isLoggedIn"
    type="button"
    class="btn btn-danger"
  >
    Logout
  </button>
</div>

<div class="container mt-5">
  <div class="mt-5">
    <router-outlet></router-outlet>
  </div>
</div>

Start your Angular app.

ng serve --open

Conclusion

Finally, we completed the Angular JWT User Authentication Tutorial. In this tutorial, we have learned how to implement JWT user authentication in Angular application.

Click below to get the full code of this tutorial on GitHub.

Git Repo