As far as I know there is no way of doing this however what we do is give them a mandatory check box field which they must tick to confirm they have attached the document. Usually this is enough of a reminder.
You could probably create an external approval task with ServiceLink that would use the db adapter to call that query Emir suggested and the transformation could hold the logic to approve or reject the request automatically depending upon the query result. Quite a bit of effort though. You would probably need to create a custom rejection email template that would explain why the request was rejected.
This document explains the logic to develop Tidal Enterprise
Orchestrator workflow to automate the process of creating vCenter
Resource Pool* vSphere Power CLI must be installed either on the TEO
server or vCenter* vMA can also be used to achieve the same...
IntorductionCisco Process Orcehstrator (CPO) ships with the webservices
adapter that can be used to make Web Service API call to REST or SOAP
based applications. Before a sample workflow to make SOAP API calls
using CPO, lets understand some of the fundam...