beforeAction and empty result


I’m currently building a REST service for an iPhone App. So far everything is fine, but I have a problem with using “beforeAction()”…

In "beforeAction()" I would like to check the headers of the request, and if anything is wrong, the action shold not be called and instead a valid error json response should be send…

But here I get the problems. Because, when "beforeAction()" return false the result is allways null and "afterAction()" is also not called…

This leads to my question:

How can I send a valid response, when the "beforeAction()" return false?



No one with an idea on this?