Auth service

Create the Auth service

Inside src/app create a new folder _services. (The underscore is just a trick to keep the folder up).

Right click and select Create Service, name it auth.

Register the service in app.module.ts in the providers section.

import { AuthService } from './_services/auth.service';
providers: [

Edit auth.service.ts

Add a prop baseUrl with the auth controller address and add a prop userToken.

Inject the Http service in the constructor. Check the import from ‘@angular/http’.

Implement the login method. Note that when the result is returned succesfully the JWT token is also stored in localStorage. This implementation is very rough but it will work for now.

export class AuthService {
  baseUrl = 'https://localhost:5001/api/auth/';
  userToken: any;

  constructor(private http: Http) {}

  login(model: any) {
    const header = new Headers({ 'Content-type': 'application/json' });
    const options = new RequestOptions({ headers: header });

    return + 'login', model, options).pipe(
      map(response => {
        const user = response.json();
        if (user) {
          localStorage.setItem('token', user.tokenString);
          this.userToken = user.tokenString;

Use the login service

Back in nav.component.ts inject the AuthService in the constructor and use it from the login function.

login() {
  this.authService.login(this.model).subscribe(data => {
    console.log('Sucessfully logged in');
  }, error => {
    console.log('Login unsuccesful');

Hide the form for logged Users

Copy from the templates at

  • switch to bootstrap 3.3.7
  • navigate to Components
  • click on the Navbar
  • inspect the code
  • select all the code from the ul tag for the dropdown

In nav.component.html paste the code below the loginForm

Change the text to “Welcome user”, remove a couple links and fix the text for the items in the dropdown. Also add icons.

The dropdown is temporarly not working, so we duplicate the logout functionality in the Link just before the dropdown.

Now we add the structural directive ngIf to the ul of the dropdown (snippet a-ngIf) and we bind it to a new function loggedIn().

<ul *ngIf="loggedIn()" class="nav navbar-nav navbar-right">
  <li><a (click)="logout()"><i class="fa fa-sign-out"></i> Logout</a></li>
  <li class="dropdown">
    <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button"
    aria-haspopup="true" aria-expanded="false">Welcome user <span class="caret"></span></a>
    <ul class="dropdown-menu">
      <li><a href="#"><i class="fa fa-user"></i> Edit profile</a></li>
      <li role="separator" class="divider"></li>
      <li><a (click)="logout()"><i class="fa fa-sign-out"></i> Logout</a></li>

Add a similar ngIf to loginForm binding it to !loggedin()

<form *ngIf="!loggedIn()" #loginForm="ngForm" class="navbar-form navbar-right" (ngSubmit)="login()">

loggedIn and logout

In nav.component.ts implement a rough version of logout by directly removing the token, and a loggedIn that checks if the token is present.

logout() {
  this.authService.userToken = null;

loggedIn() {
  const token = localStorage.getItem('token');
  return !!token;

Now we can test the login functionality and see that if we succesfully log in the form disappears and the user combo shows up on the page. And when we log out the login form comes back.