Liew,

When you create your Com object I assume it would be created in dot net and consumed by VFP. This would set me on a path to create a business object project in MM and put all my rules in the the business rules including retrieving any data driven rule information. The business object project (dll) is used in the dot net Com object you would create. A save would be called on the com object which would intern use the business classes to validate the rules.

You might even consider retrieving all the business rule info at startup depending on how many records we are talking about. I would suspect they don't change during the life of the application runtime. This would make for a speedier application of the rules especially if many are applied to the same record.

A generic rule functionality could be placed in the ABusinessRule class which all your rule classes inherit from. This would be a bit tricky however as everything would be generic and access to individual fields would be very tricky.

You mention passing the BO to the VFP Com object for validation. I am not sure I understand this and maybe my assumption above is not correct. Is the application an MM application or is the application a VFP application? My assumption was the application was VFP and needed to work through a dot net Com object to get to the WCF service. In this case, the business objects will already be part of the com object and would not need to be passed to it.

Can you clarify that for me?
Tim

>Hi Tim,
>
>Basically we need a data validation engine for document submission in our web app. Kindly refer to the following exmaples.
>
>(i) If Control A.value > 10, then Control B must be filled up.
>(ii) If Control A.selected value = X, then Control B can't enter certain values.
>(iiI) If Control A.value is empty, then Control B can't be selected.
>
>We would like to design the validation engine to be data driven as the rules of the validation may differ for each client. At the moment, we plan to write a generic function which will be executed before the MM.Save() method and pass the BO to our VFP COM for validation.
>
>Appreciate if you could provide any valuable advise, thanks.