In App Purchase - No purchase to restore - ios

Question

I'm trying to figure out if I get a message back when a user tries to restore an In App Purchase but there was no purchase ever made.
Right now, as soon as a user taps the restoreButton, I disable the restoreButton.
- (IBAction)purchaseRestore:(id)sender {
NSLog(#"4 IBAction Purchase Restore Method: start");
[[SKPaymentQueue defaultQueue] addTransactionObserver:self];
[[SKPaymentQueue defaultQueue]restoreCompletedTransactions];
NSLog(#"4 Purchase Restore: SKPayment Queue two lines... log in user");
restoreButton.enabled = NO;
NSLog(#"4 Restore button enabled: No");
}
So if they click the restoreButton, and have nothing to restore then the restoreButton just stays grayed out.
I would like to do something like a UIAlert or change the restoreButton text if that happens to say "You don't have any items to Restore", but I assume I need to get some message back from Apple saying "no items to restore" so I can fire off that code.
Here's my updatedTransactions code if needed:
case SKPaymentTransactionStateRestored:
[[SKPaymentQueue defaultQueue] finishTransaction:transaction];
NSLog(#"5 Finish Transaction");
restoreButton.hidden = YES;
NSLog(#"5 restore button hidden: Yes");
[self showButtonThree];
NSLog(#"5 Show Button Three");
NSLog(#"5 Restored: End");
break;
Any ideas? Thanks!
Update
Tried this:
- (void)paymentQueueRestoreCompletedTransactionsFinished:(SKPaymentQueue *)queue {
NSLog(#"Completed Transactions Finished");
UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:
#"Restored succesfully" message:nil delegate:
self cancelButtonTitle:#"Ok" otherButtonTitles: nil];
[alertView show];
}
But that was popping up whether there was a transaction to restore or not. I had assumed this would get called if there was no transaction to restore maybe, but makes sense that it wouldn't:
-(void)paymentQueue:(SKPaymentQueue *)queue restoreCompletedTransactionsFailedWithError:(NSError *)error {
NSLog(#"Completed Transactions Failed with Error");
UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:
#"Not restored succesfully" message:nil delegate:
self cancelButtonTitle:#"Ok" otherButtonTitles: nil];
[alertView show];
}

Answer 1

From the official Apple documentation for restoreCompletedTransactions
After the transactions are delivered, the payment queue calls the
observer’s paymentQueueRestoreCompletedTransactionsFinished: method.
If an error occurred while restoring transactions, the observer will
be notified through its
paymentQueue:restoreCompletedTransactionsFailedWithError: method.