When is a GKGameCenterViewController released?

Question

The following documentation has the sample code below:

https://developer.apple.com/library/ios/documentation/NetworkingInternet/Conceptual/GameKit_Guide/LeaderBoards/LeaderBoards.html#//apple_ref/doc/uid/TP40008304-CH6-SW9

Listing 4-9 Displaying the leaderboard page of the Game Center user interface

- (void) showLeaderboard: (NSString*) leaderboardID
{
    GKGameCenterViewController *gameCenterController = [[GKGameCenterViewController alloc] init];
    if (gameCenterController != nil)
    {
       gameCenterController.gameCenterDelegate = self;
       gameCenterController.viewState = GKGameCenterViewControllerStateLeaderboards;
       gameCenterController.leaderboardTimeScope = GKLeaderboardTimeScopeToday;
       gameCenterController.leaderboardCategory = leaderboardID;
       [self presentViewController: gameCenterController animated: YES completion:nil];
    }
}

When do you call "release" on the GKGameCenterViewController ? Should it be only after the view controller is dismissed, or can you call it at the end of this method ? Or should one just call autorelease ?

Answer 1

The project uses Automatic Reference Counting, therefore you do not need to explicitly declare release or dealloc. For reference, it is deallocated after the view leaves the view hierarchy.

Answer 2

I can't find any documentation to back this up (because all of Apple's documentation now assumes ARC), but my recollection from the pre-ARC days is that you release a modal view controller once you present it. I'm reasonably sure the presenting view controller will take a strong reference to the presented view controller. So:

- (void) showLeaderboard: (NSString*) leaderboardID
{
    GKGameCenterViewController *gameCenterController = [[GKGameCenterViewController alloc] init];
    if (gameCenterController != nil)
    {
       gameCenterController.gameCenterDelegate = self;
       gameCenterController.viewState = GKGameCenterViewControllerStateLeaderboards;
       gameCenterController.leaderboardTimeScope = GKLeaderboardTimeScopeToday;
       gameCenterController.leaderboardCategory = leaderboardID;
       [self presentViewController: gameCenterController animated: YES completion:nil];
       [gameCenterController release];
    }
}

A better answer might be, "use ARC". :) Seriously, ARC rules.