If the ProjectWise client install included some form of limited sandboxed PowerShell runtime environment that allowed the manipulation of the current document record Attributes from the client-side buffer and the ability to read from other tables as an alternative to passing SQL statements back to the database engine for processing. The script could be stored/maintained in the ProjectWise Datasource and passed to this runtime environment for performing the required pre save processing of the Attribute record.
David Humpherson
An alternative to PowerShell would be an imbedded JavaScript runtime environment. Allowing an administrator to write the body for a trigger. This could be inserted into a template function that has a JSON encoded object containing the current attribute record data passed in by reference and is required to return a Boolean value and has some other basic date, math and string functions along with ProjectWise specific functions available to it.
This would provide a scripting environment for client-side processing/logic without the need to interact with the server unless required.