powermail (flexform) limitation

Question

I am trying to extend powermail with an own extension.

I created a form for events and there is a field, where that can be filled with the number of the members, who want to join. In TYPO3 backend I added a plugin setting field "Max Limit". I want to count all members and compare with "Max Limit". And the form should not show itself or show a page with information, as soon as the total number of members are more than Max Limit.

I searched in internet for while and I found a documentation about Finisher and Dataprocessor, but I don't know how exactly I should use them?

Can someone give me any tipp for that?

Answer 1

I would simply overwrite the template file for the formular output and add a custom viewhelper which checks for your contraint. If the contraint is active, render your custom html, else render the powermail formular.