Facebook calling Google App Engine code using GET instead of POST

Question

I've been developing a Facebook app using Google App Engine in Python and the pyfacebook bindings. For weeks everything worked fine but suddenly it stopped.

At first I thought it was a code change so I rolled back the entire dev directory to a version I knew worked, but still it failed. It's possible a change I made to the application's settings caused the issue but, if so, I can't figure out what.

I've figured out that the problem is that instead of calling the post(self) method of my Main class, Facebook is calling using a GET.

Does anyone know why Facebook would use a GET method instead of a POST? It's an IFrame app.

Thanks,

Answer 1

Although I'm not completely sure this was the cause, it appears I changed from an FBML app to an IFrame app. FBML mode relies on POST calls but IFrame appears to use GET. I'm inferring this answer from what I read here as well as from the observations I'm seeing and this being the only answer that makes any sense.