Using validation rule

kids_pro posted on Friday, February 16, 2007

Dear Rocky,

I have had a problem when I tried to use business rule as follow:
    protected override void AddBusinessRules() {
            ValidationRules.AddRule(ValidatePaymentDate, "PayDate");
    }
   
    private bool ValidatePaymentDate(object target, Csla.Validation.RuleArgs e) {
            /* prevent payment in future date */
            if (_payDate.Date > DateTime.Today) {
                e.Description = "Please do not make payment in the future date.";
                return false;
            }

            return true;
     }

Here is the factory method:

       public static Payment GetPayment(Int32 payment_id) {
            if (!CanGetObject())
                throw new System.Security.SecurityException(
                    "You are not authorized to view payment information.");

            return DataPortal.Fetch<Payment>(new Criteria(payment_id)); // error raised here ...
        }

Error:
DataPortal.Fetch failed (System.InvalidOperationException: Invalid rule method (instance methods of the target object not allowed): ValidatePaymentDate

How is that happen?

RRorije replied on Friday, February 16, 2007

Hi,

Your problem is that you are trying to add an instance rule as a type rule.

If you have the 2.1 csla e-book you might check that because it explains why this is not possible.

In short there are 2 options to solve this.
1. Add this rule as an instance rule (using ValidationRules.AddInstanceRule).
2. Make this rule static.

Number 2 is preferred, because this rule then will be loaded once per AppDomain, I.e. it will be loaded once for all businessobjects. But check the book for a more in-depth discussion.