My customer would like to restrict case attachments to Excel spreadsheets only.
There is an extension activity Data-WorkAttachFile.CallVirusCheck that is intended to be saved into the application ruleset and extended with custom checks e.g. checking for viruses. We could implement the customer requirement by placing a check on the file extension in this activity - simple.
However CallVirusCheck is called in many contexts: including uploading image files to profile, uploading files to Pega Pulse, etc. It is very general. The customer only wants to restrict to Excel in situation of case attachments.
How can CallVirusCheck know from where it was called?
CallVirusCheck might not be the correct place for this requirement.
If you are only looking to restrict for case level attachments and not in other contexts. Then you can just override the pyAttachContent flow action to have a custom validation which does this check. This flow action is very specific to Case attachments and is actually meant for requirements like these.
Let us know if this helps or you need more information.