public override bool Validate(RuleValidation validation) { if (validation == null) { throw new ArgumentNullException("validation"); } bool valid = true; if (_expression == null) { valid = false; string message = string.Format(CultureInfo.CurrentCulture, Messages.ConditionExpressionNull, typeof(CodePrimitiveExpression).ToString()); ValidationError error = new ValidationError(message, ErrorNumbers.Error_EmptyExpression); error.UserData[RuleUserDataKeys.ErrorObject] = this; validation.AddError(error); } else { valid = validation.ValidateConditionExpression(_expression); } return(valid); }