Getting the turn based games in which a player is participating - iphone

Question

I am trying to pull the turn based games in which a player is participating in order to populate my tableView.
This is my function to pull their games:
- (void) loadMatchDataWithArray:(NSMutableArray*)currentGames Flag:(bool*)returned
{
NSMutableArray* __block blockGames = currentGames;
bool* __block blockReturn = returned;
[GKTurnBasedMatch loadMatchesWithCompletionHandler:^(NSArray *matches, NSError *error)
{
if (matches)
{
for (int i = 0; i < matches.count; i++)
{
[(GKTurnBasedMatch*)matches[i] loadMatchDataWithCompletionHandler: ^(NSData *matchData, NSError *error)
{
int size = [matchData length];
if (size != 0)
{
Game* game = [NSKeyedUnarchiver unarchiveObjectWithData:matchData];
[blockGames addObject:game];
}
else
{
Game* game = [[Game alloc] init];
[blockGames addObject:game];
game.activePlayer = [GKLocalPlayer localPlayer];
}
*blockReturn = true;
}];
}
}
else
{
*blockReturn = true;
}
}];
}
And this is where I call it:
- (void)viewDidLoad
{
[super viewDidLoad];
[[self tableView]
setBackgroundView:[[UIImageView alloc]
initWithImage:[UIImage imageNamed:#"iPhoneBackground-568h"]]];
bool* returned = false;
[[GKMatchHelper sharedInstance] loadMatchDataWithArray:currentGames Flag:returned];
while (!returned);
[self.tableView reloadData];
// Uncomment the following line to preserve selection between presentations.
// self.clearsSelectionOnViewWillAppear = NO;
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem;
}
Sadly, this is just giving me a blank black screen and never returns. Is there a way that I can detect when my block comes back and display a loading spinner until then, at which point I would reload the table?
EDIT:
I have revised my code and brought the function inside my MainMenuViewController, and now it builds but never displays the data.
- (void) loadMatchData
{
NSMutableArray* __block blockGames = currentGames;
MainMenuViewController* __weakSelf = self;
[GKTurnBasedMatch loadMatchesWithCompletionHandler:^(NSArray *matches, NSError *error)
{
if (matches)
{
for (int i = 0; i < matches.count; i++)
{
[(GKTurnBasedMatch*)matches[i] loadMatchDataWithCompletionHandler: ^(NSData *matchData, NSError *error)
{
int size = [matchData length];
if (size != 0)
{
Game* game = [NSKeyedUnarchiver unarchiveObjectWithData:matchData];
[blockGames addObject:game];
}
else
{
Game* game = [[Game alloc] init];
[blockGames addObject:game];
game.activePlayer = [GKLocalPlayer localPlayer];
}
[__weakSelf.tableView reloadData];
}];
}
}
[__weakSelf.tableView reloadData];
}];
[__weakSelf.tableView reloadData];
}
And now in my ViewDidLoad I just call:
[self loadMatchData];

Answer 1

Oh dear. Do NOT halt the program execution with "while" loops!
Why not simply call [self.tableView reloadData] at the end of your block?
So,
Remove the last 2 lines in the viewDidLoad method
Replace *blockReturn = true; with [self.tableView reloadData] (you might need to keep a weak reference to 'self' to avoid retain cycles)
Never ever use while (this and that) to wait for an operation to complete. A non-responsive UI is bad and it will cause the users to abandon your app.