userDownloader method

Future<User> userDownloader ({User user, String uid })

Downloads a user from Firestore. If the uid field is given, it takes the gets the user with the given UID, otherwise it will look for the Firebase current user instance. If the given User is null or is not inserted, the method creates a new instance of User. The methos will save the user's data using the fromFirestore method.

Implementation 

static Future<User> userDownloader({User user, String uid}) async {
  // ... continuation of the method ...
  user ??= new User();
  if (uid == null) {
    FirebaseUser firebaseUser = await FirebaseAuth.instance.currentUser();
    if (firebaseUser == null) {
      return user;
    }
    uid = firebaseUser.uid;
  }
  DocumentReference userReference =
      Firestore.instance.collection(User.usersDbPath).document(uid);
  // TODO: catch exceptions
  DocumentSnapshot userOnDb = await userReference.get();
  user.fromFirestore(userOnDb);
  return user;
}