I have an Angular Service that checks if my client has a valid http-only JWT Cookie. Since I cannot access this cookie from the client I need to call the service method in my Guard to send a call to the server and see if my user is authenticated. The only problem is that I have no idea how I should get an instance of the service inside the Guard
The code I have written so far:
My guard (or at least what it should do):
export class AuthGuard implements CanActivate {
  canActivate(
    route: ActivatedRouteSnapshot,
    state: RouterStateSnapshot): boolean {
      let isAuthenticated : boolean = false;
      
      auth: AuthService = new AuthService()
      this.auth.getAuthStatus()
      .subscribe({
        res => {
          if(res.status == 200){
            isAuthenticated = true;
          }
        }
      });
      return isAuthenticated;
  }
}
My service:
export class AuthService{
  constructor(private http: HttpClient) { }
  getAuthStatus(): Observable<HttpResponse<any>>{
    return this.http.post(environment.server + environment.routes.authRoutes.status, "", {
      withCredentials: true,
      observe: 'response'
    })
  }
}
I know that I somehow need to get an instance of the http service but I dont think getting a new instance every time is a good idea. I would like to create an instance of the service once and then use it, or make it static so i dont need instances at all. What would be the best solution to this?
You can simply just inject it using the constructor
@Injectable()
export class AuthGuard implements CanActivate {
  constructor(
    private authService: AuthService,
  ) {}
  canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot) {
     
    // use 'this.authService.whatever()'
  }
}
If you want a single instance of any service that will be available everywhere in your app.
Otherwise known as a Singleton service.
You can simply add this to the services class:
@Injectable({
    providedIn: 'root'
})
export class MyServiceClass...
A singleton service is a service for which only one instance exists in an application.