Game Center can't find existing turn-based matches - iphone

Question

I'm writing a turn-based iPhone game and I can't seem to find my own games.
I have three accounts trying to matchmake in my game - one on my iPhone 5, and two different Game Center test accounts created in the iPhone simulator which I switch between all playing my game through the Game Center sandbox. Unfortunately, they never find eachother and always create new games on their own. How can I fix it so they will ALWAYS find an existing match, if there is one available, and only create a new game if there are NO open games?

Answer 1

I'm assuming you are using GKTurnBasedMatchmakerViewController to find matches and doing something similar to this:
GKMatchRequest *request = [[GKMatchRequest alloc] init];
request.minPlayers = 2;
request.maxPlayers = 2;
GKTurnBasedMatchmakerViewController *mmvc = [[GKTurnBasedMatchmakerViewController alloc] initWithMatchRequest:request];
mmvc.turnBasedMatchmakerDelegate = self;
[self presentViewController:mmvc animated:YES completion:nil];
In your delegate method you can do this to figure out if this was a brand new game or if you're joining an existing game:
- (void)turnBasedMatchmakerViewController:(GKTurnBasedMatchmakerViewController *)viewController didFindMatch:(GKTurnBasedMatch *)match {
int numberOfParticipants = [match.participants count];
// check the number of valid participant ids to find out if you need to know if this is a "new" game or not.
....
For match making to pair up a user with an existing game, the opponent player must have "completed" their turn by calling this method on GKTurnedBasedMatch:
- (void)endTurnWithNextParticipants:(NSArray *)nextParticipants turnTimeout:(NSTimeInterval)timeout matchData:(NSData*)matchData completionHandler:(void(^)(NSError *error))completionHandler;