[TYPO3-english] Formhandler: Validating via JSON?

[Benjamin Mack]

Hey all,

I'm currently implementing a form with this amazingly new extension 
"formhandler". However, since my HTML form is built in a way to send the 
form via AJAX that expects JSON with either the missing fields or a 
success flag (already predefined, not by me ;-)), I was wondering if 
anybody knows where to hook in the Formhandler process to change the 
output of the sent form to return JSON of something I want instead of 
the HTML form again. This ain't a "Validator" but also not a "Finisher", 
right?

Could anybody point me in the right direction?

Thanks a ton!

Benni.