public function postFavourite()
 {
     $fbUserId = \Session::get('fb_user_id');
     $confessionId = \Input::get('confession_id');
     if ($fbUserId && $confessionId) {
         $fbUser = FbUser::find($fbUserId);
         if (!Confession::find($confessionId)) {
             return \Response::json(['success' => false, 'errors' => ['Confession does not exist.']]);
         }
         if ($fbUser->favourites->contains($confessionId)) {
             return \Response::json(['success' => false, 'errors' => ['Confession already favourited.']]);
         }
         $fbUser->favourites()->attach($confessionId);
         return \Response::json(['success' => true]);
     }
     return \Response::json(['success' => false, 'errors' => ['User not logged in.']]);
 }