Is it possible to create messages to the user telling them why they have not met the Entry Criteria just as you would for a Validation Rule ?
ie : "You cannot Submit this for Approval because the Status is already Approved"
Thank you.
The answer is basically NO but you can simulate this by adding a formula field to the top of the standard layout that displays a message
This object is not ready for approval submission for reason xxx
The formula field generates that text via something like
"This Foo is not ready for approval submission for reason " &
IF (someConditionUseCase1,'reason1',
IF( someconditionUseCase2,'reason2',
...
))...)
More sophisticated strategies involve using jQuery + VF to hide the Submit for Approval button as well
Another possible option for this is create two layouts; one which includes the submit for approval button and one that doesn't. Create a field update which changes the record type based on the criteria for a complete form. You could also use the formula field idea to create a message that says the application is not yet complete, (if record type = incomplete, application is not yet complete etc) User will fill out the form, save, and if it is complete, they will have the submit option on the next screen.