How to Handle Firebase Auth exceptions on flutter

Issue

Please does anyone know how to catch firebase Auth exceptions on flutter and display them?

Note: I am not interested in the console (catcherror((e) print(e))

I need something that is more effective, e.g " user doesn't exist" So that I can then pass it to a string and display it.

Been dealing with this for months.

Thanks in advance.

I have tried replacing print(e) with // errorMessage=e.toString(); and then passing it to a function, all efforts have been futile.

    FirebaseAuth.instance
              .signInWithEmailAndPassword(email: emailController.text, password: passwordController.text)
              .then((FirebaseUser user) {
                _isInAsyncCall=false;
            Navigator.of(context).pushReplacementNamed("/TheNextPage");

          }).catchError((e) {
           // errorMessage=e.toString();
            print(e);
            _showDialog(errorMessage);

            //exceptionNotice();
            //print(e);

I want to be able to extract the exception message and pass the exception message to a dialog that I can then display to the user.

Solution

(21/02/20) EDIT: This answer is old and the other answers contains cross platform solutions so you should look at theirs first and treat this as a fallback solution.

The firebase auth plugin doesn't really have a proper cross-platform error code system yet so you have to handle errors for android and ios independently.

I'm currently using the temporary fix from this github issue: #20223

Do note since its a temp fix, don't expect it to be fully reliable as a permanent solution.

enum authProblems { UserNotFound, PasswordNotValid, NetworkError }

try {
  FirebaseUser user = await FirebaseAuth.instance.signInWithEmailAndPassword(
      email: email,
      password: password,
  );
} catch (e) {
  authProblems errorType;
  if (Platform.isAndroid) {
    switch (e.message) {
      case 'There is no user record corresponding to this identifier. The user may have been deleted.':
        errorType = authProblems.UserNotFound;
        break;
      case 'The password is invalid or the user does not have a password.':
        errorType = authProblems.PasswordNotValid;
        break;
      case 'A network error (such as timeout, interrupted connection or unreachable host) has occurred.':
        errorType = authProblems.NetworkError;
        break;
      // ...
      default:
        print('Case ${e.message} is not yet implemented');
    }
  } else if (Platform.isIOS) {
    switch (e.code) {
      case 'Error 17011':
        errorType = authProblems.UserNotFound;
        break;
      case 'Error 17009':
        errorType = authProblems.PasswordNotValid;
        break;
      case 'Error 17020':
        errorType = authProblems.NetworkError;
        break;
      // ...
      default:
        print('Case ${e.message} is not yet implemented');
    }
  }
  print('The error is $errorType');
}

Answered By - Swift