>Except for #5, I don't think this approach truly relies on VFP cursors. It seems like it would work as well if the business rules table were in DB2, etc.
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>With your modification (only instantiating oBiz when necessary), and perhaps the use of MTS, Alex could set this up so that instances of oBiz are not truly created each time they're needed, and are instead just hibernating until something in the UI requests them.
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>Also, I think you're right, that in a multi-tier system you'd want to pass THIS.ControlSource instead of THIS ... I don't know if COM can handle passing an object reference up the chain, but even if it can, it doesn't sound like good modular design. So I think you'd have to pass two parameters: THIS.ControlSource and THIS.Value.
>

COM definately handles passing objects around, and in fact, that's the preferred way to do things (like passing an ADO recordset), but the reason I was objecting to passing "This" was that it assumes the receiver knows this is in VFP, and it knows to read what's in the ControlSource property. As Erik points out, what if the front end is something else? You really need to tell the business object what field you want it to validate, not what object is calling it.