private string GetErrorIfInvalid(User user, bool shouldCheckUsername) { var error = string.Empty; if (string.IsNullOrWhiteSpace(user.UserName)) { error = "user name cant be empty or null"; } if (shouldCheckUsername && _userBl.IsUserExist(user.UserName)) { error = "user name already exist"; } if (user.Gender.ToString().Length < 1) { error = "Please Select Gender"; } return(error); }