Question

I am trying to learn Objective-C for iOS. i am currently following the “coding together” on iTunesU. Although i have got stuck since i can’t get my controller to call on a method from another class. Can’t find what i am doing wrong and thought that StackOverflow might have the solution to it!

The method “flipCardAtIndex” is the one that isn’t working. I have debugged using nslog and from the method “flipCard” i get an output. But when i put in the implementation for flipCardAtIndex i don’t get anything.. So my guess is that it never calls it…
I have made the code a bit shorter so it is only the parts i think is important, this is controller:

#import "ViewController.h"
#import "PlayingCardDeck.h"
#import "CardMatchingGame.h"

@interface ViewController ()

@property (weak, nonatomic) IBOutlet UILabel *flipsLabel;
@property (nonatomic) int flipCount;
@property (weak, nonatomic) IBOutlet UILabel *scoreLabel;
@property (strong, nonatomic) IBOutletCollection(UIButton) NSArray *cardButtons;
@property (strong, nonatomic) CardMatchingGame *game;

@end

@implementation ViewController

- (CardMatchingGame *) game{
    if (_game) _game = [[CardMatchingGame alloc] initWithCardCount:[self.cardButtons     count]
                                                     usingDeck:[[PlayingCardDeck alloc] init]];
    return _game;
}

- (IBAction)flipCard:(UIButton *)sender {

[self.game flipCardAtIndex:[self.cardButtons indexOfObject:sender]];
self.flipCount++;
[self updateUI];

}

And implementation:

- (void)flipCardAtIndex:(NSUInteger)index
{
    NSLog(@"ALL YOUR BASE ARE BELONG TO US");
    Card *card = [self cardAtIndex:index];
}

Answer 1

Fix?

- (CardMatchingGame *) game{
    if (!_game) _game = [[CardMatchingGame alloc] initWithCardCount:[self.cardButtons        count] usingDeck:[[PlayingCardDeck alloc] init]];
    return _game;
}