public ValidationMessages Validate(Saying saying) { var validations = new ValidationMessages(); // Probably will move this logic into sayingService - a Validate method if (saying.SageId == 0) { // eg "saying.sageId" var fieldName = ValidationHelpers.GetFieldName(saying, x => x.SageId); validations.AddError(fieldName, "Please select a sage."); } return(validations); }