Create a new folder src/app/_guards.

There is no template for Guards so we use Angular cli.

ng g guard /_guards/auth

Open auth.guard.ts and remove the parameters from canActivate() because we don’t need them.

Add a new constructor and inject AuthService, Router and AlertifyService.

Inside the canActivate method we check to see if the user is logged in. If not we send a message and redirect to home.

constructor(private authService: AuthService, private router: Router, private alertify: AlertifyService) {}

canActivate(): Observable<boolean> | Promise<boolean> | boolean {
  if (this.authService.loggedIn()) {
    return true;
  } else {
    this.alertify.error('You need to be logged in to acces this area');
    return false;

Register the guard in app.module.ts providers.

providers: [

Open the routes configuration file routes.ts and add a dummy route protected by our guard.

export const ROUTES: Routes = [
  { path: 'home', component: HomeComponent },
    path: '',
    runGuardsAndResolvers: 'always',
    canActivate: [AuthGuard],
    children: [
      { path: 'members', component: MemberListComponent },
      { path: 'lists', component: ListsComponent },
      { path: 'messages', component: MessagesComponent }
  { path: '**', redirectTo: 'home', pathMatch: 'full' }

Test the application. If the user is logged out and we manually enter the url http://localhost:4200/messages then we are redirected to home with an error message.