Question

I am using Parse.com to store data for an iOS app. The code below successfully retrieves all values in a nested array belonging to a PFObject “game”. However, if I need to query for another array (at the same level as “winners” (say “losers”) i cannot get it to work, and not all the values in the array losers gets populated. I suppose i could do them all on the main thread and not try to nest the fetches (nested blocks) but i’m wondering if:

1) Is the way i’m storing my data prohibiting me from using Parse’s built in query/fetch functionality properly? Data stored as:

PFObject * newGame = [PFObject objectWithClassName:@"Game"];
NSArray * winner = [NSArray arrayWithObjects:[_allPlayersPFDictionary objectForKey:[playerData objectAtIndex:0]], [playerData objectAtIndex:1], nil];
[_gamePF addObject:winner forKey:@"winners"];

2) Is there a better, cleaner way to do the query and get ALL the values of all nested arrays of data in a query? Again, winners is not a PFObject, but is an array of array of PFObject of 2 different types ([PFObject fetchAll:(NSArray *)winnersArray] does not work, because all objects in the Array must be of the same ‘type’ of PFObject). I store it this way because each winning player has another PFObject (1 to many) “powers” associated with them.

Here is the query that works but i can’t figure out how to add “losers” to it and properly populate all data in the background.

PFQuery * gamesQuery = [PFQuery queryWithClassName:@"Game"];
[gamesQuery orderByDescending:@"createdAt"];
gamesQuery.limit = 30;
[gamesQuery findObjectsInBackgroundWithBlock:^(NSArray * theGames, NSError * error) {
    if (error) {
        NSLog(@"ERROR: There was an error with the Query to get Games!");
    } else {
        for (PFObject * aGame in theGames) {
            for (NSArray * aWinner in [aGame objectForKey:@"winners"]) {
                [[aWinner objectAtIndex:0] fetchIfNeededInBackgroundWithBlock:^(PFObject *object, NSError *error) {
                    if (error) {
                        NSLog(@"ERROR: There was an error with the Query to get Player in winnersArray!");
                    } else {
                        [PFObject fetchAllIfNeededInBackground:[aWinner objectAtIndex:1] block:^(NSArray *objects, NSError *error) {
                            if (error) {
                                NSLog(@"ERROR: There was an error with the Query to get Powers in winnersArray!");
                            } else {
                             [_gamesPF addObject:aGame];
                                NSLog(@"Games from viewDidLoad %@", _gamesPF);
                                [_tableView reloadData];
                            }
                        }];
                    }
                }];
            }
        }
    }
}];

Answer 1

Well… i feel kinda stupid. Definitely much easier to use Parse in an object oriented manner for the data model. Was able to easily solve it by remodeling the data to be:

Game (PFObject *) has:

--> winners { (PFObject *), (PFObject *), ..., nil }
--> losers  { (PFObject *), (PFObject *), ..., nil }

where a winner is created as:

[testWinner1 addObject:power1 forKey:@"power"];
[testWinner1 addObject:power2 forKey:@"power"];
[testWinner1 addObject:[_playerPFDictionary objectForKey:@"Tom"] forKey:@"player"];

Which then makes the query much easier and involves only one background block like so:

PFQuery * gameQuery = [PFQuery queryWithClassName:@"TestGame"];
[gameQuery includeKey:@"winners.player"];
[gameQuery includeKey:@"winners.power"];
[gameQuery includeKey:@"losers.player"];
[gameQuery includeKey:@"losers.power"];
[gameQuery findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
    if (error) {
        NSLog(@"failed");
    } else {
        NSLog(@"testGame: %@", [objects objectAtIndex:0]);
    }
}];