Facebook iframe tab signed request always empty
I'm working on a Facebook app tab and would like to use the signed request bundle as documented here: http://developers.facebook.com/blog/post/462/
I'm trying to use their example code to unpackage the signed request which is supposedly passed to the tab, however, $_POST, $_GET, and $_REQUEST are always all empty.
The exact code works on the canvas page and I am able to parse the signed request.
Is there something that I'm missing in their recent announcement?
By the way, the app is not published to the marketplace, and the fanpage my tab is installed on is private. Will that make a difference?
-Seth
Answer
Okay, figured it out! When configuring the app, I had filled in the "Tab URL" to be "tab/" This made the full url to the tab page "http://www.example.com/myfacebookapp/tab/" This made sense to me.
Apparently, Facebook doesn't like this. After changing my "Tab URL" to 'tab/index.php", the signed request started to show up in the app tab!