I have a service with a subject:

@Injectable() export class UserService() {

    private currentUserSubject = new BehaviorSubject<User>(null);

    public currentUser = this.currentUserSubject.asObservable().distinctUntilChanged(); 



    ... // emitting new User    

}

Have a component I inject this service into and subscribing on updates:

@Component() export class UserComponent {

    constructor(private userService: UserService) {

        this.userService.currentUser

            .subscribe((user) => {

                // I want to see not null value here

            })

    }

}

I want to apply something to Observable<User> to filter all null values and get into subscribe only when User is actually loaded.