Detect successful facebook post using FBDialogs

Detect successful facebook post using FBDialogs

I'm trying to present the facebook share dialog from my iOS app.
This code opens the facebook app and shows the dialog:
FBShareDialogParams* params = [[FBShareDialogParams alloc] init];
params.link = urlToShare;
params.name = @"Test";
params.description = @"Description";
params.picture = [NSURL URLWithString:FB_IMG_URL];
BOOL canPresentShareDialog = [FBDialogs
canPresentShareDialogWithParams:params];
if (canPresentShareDialog) {
[FBDialogs presentShareDialogWithParams:params clientState:nil
handler:^(FBAppCall *call, NSDictionary *results, NSError *error) {
if (error) {
if ([FBErrorUtility shouldNotifyUserForError:error]) {
UIAlertView* alert = [[UIAlertView alloc]
initWithTitle:@"Facebook-Error!" message:[FBErrorUtility
userMessageForError:error] delegate:nil
cancelButtonTitle:@"OK" otherButtonTitles:nil];
[alert show];
}
} else {
NSLog(@"SUCCESS");
}
}];
}
In the completion handler I want to know if the user canceled the action.
The results dictionary should tell me that. However I only get
didComplete=YES in the dictionary but not a completionGesture. The NSError
object is always nil.
The results dictionary is explained here:
https://developers.facebook.com/ios/share-dialog/
So the problem is I can't tell if the post was successful or not.
Is something wrong with my code?