Passing Data from VC to VC and Model - ios

Question

I have a levelViewController:
.m
- (void)viewDidLoad {
[super viewDidLoad];
double delayTimeInSeconds = 2;
dispatch_time_t popTimeDelay = dispatch_time(DISPATCH_TIME_NOW, delayTimeInSeconds * NSEC_PER_SEC);
dispatch_after(popTimeDelay, dispatch_get_main_queue(), ^(void){
//code to be executed after delay
GameViewController *level1 = [self.storyboard instantiateViewControllerWithIdentifier:#"gameViewController"];
level1.CARDS_PER_ROW = 6;
level1.gameModel.NUMBER_OF_PAIRS = 3;
[self presentViewController:level1 animated:NO completion:nil];
});//code to be executed after delay end
}
ok, he presents now the GameViewController with level1. The CARDS_PER_ROW is declared in GameViewController.h
.h
#import <UIKit/UIKit.h>
#import "GameModel.h"
#interface GameViewController : UIViewController
#property (nonatomic) GameModel *gameModel;
#property (nonatomic) int CARDS_PER_ROW;
#property (nonatomic) NSInteger newGame;
#end
.m
in my ViewDidLoad i have
self.gameModel = [[GameModel alloc] initWithNewGame:self.newGame];
And for my GameViewController i have my GameModel:
.h
#import <Foundation/Foundation.h>
#interface GameModel : NSObject
#property (nonatomic) int NUMBER_OF_PAIRS;
-(id) initWithNewGame: (NSInteger)newGame;
#end
.m
-(NSMutableArray *) createNewDeck {
NSMutableArray *cardDeck = [NSMutableArray array];
for (int i = 0; i < _NUMBER_OF_PAIRS; i++) {
[cardDeck addObject:[[CardModel alloc] initWithValue:i]];
[cardDeck addObject:[[CardModel alloc] initWithValue:i]];
}
return cardDeck;
}
Ok. My Problem is:
I CAN passing CARDS_PER_ROW. If i define NUMBER_OF_PAIRS ( #define NUMBER_OF_PAIRS = x; ) it works. But i CANT passing my NUMBER_OF_PAIRS data, and i don't know why. The Screen is empty with this Code I've posted.

Answer 1

The problem is that gameModel is nil at that point. The fact that you have instantiated a controller doesn't mean that its view is also loaded, the view will be lazy-loaded at first access. So, what you can do is to move the gameModel initializer to the controller's initializer (-initWithCoder in case of a nib/storyboard instantiation)