validate method

Implementation

NiceValidationResult validate() {
  final errors = <String, String?>{};
  bool isValid = true;

  for (final entry in _fields.entries) {
    final error = entry.value.currentState?.validate();
    if (error != null) {
      errors[entry.key] = error;
      isValid = false;
    }
  }

  _notifyListeners();
  return NiceValidationResult(
    isValid: isValid,
    fieldErrors: errors,
    errors: errors.values.whereType<String>().toList(),
  );
}