Question

I have been struggling with this problem for a while now, so any help would be greatly appreciated.

Here is the situation: My application has a UIViewController subclass called InitialViewController. This view controller has a UIButton, and when that button is pressed it creates a NSObject subclass called MyEngine. Something like this:

@interface InitialViewController : UIViewController <MyEngineDelegate>
...
@end

@implementation InitialViewController
...
-(IBAction)pressedButton:(id)sender {
    MyEngine *engine = [[MyEngine alloc] init];
    [engine start];
}

Inside start, I present a ViewController (ConflictViewController) modally to get the user’s choice:

@interface MyEngine : NSObject <ConflictViewControllerDelegate>
...
-(void) start;
@end

@implementation MyEngine
...
-(void) start {
        ConflictViewcontroller *cvc = [[ConflictViewController alloc] initWithNibName:@"ConflictViewController" bundle:nil];
        cvc.modalPresentationStyle = UIModalPresentationFormSheet;
        cvc.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
        cvc.delegate = self;
        UIWindow *window = [(MyAppDelegate *) [[UIApplication sharedApplication] delegate] window];
        [[window rootViewController] presentModalViewController:cvc animated:YES];
}
@end

ConflictViewController is really simple. It just waits for the user to decide, and when the user press the button, it send the message to the delegate, and dismiss itself.

-(IBAction)didSelectConflict:(id)sender {
    UISegmentedControl *seg = (UISegmentedControl*) sender;
    [self.delegate didResolveConflictChoice:seg.selectedSegmentIndex];
    [self dismissModalViewControllerAnimated:YES];
}

I’ve checked every connection, all the delegates are working properly.
What is going wrong is:
When MyEngine receives the user’s choice in it’s implementation of didSelectConflict: it cannot continue properly because all of it’s properties have gone null.

When the MyEngine presents the ConflictViewController, the program continues the execution and when start finishes, it goes back to pressedButton: and when this method is closed, the MyEngine object gets released.

What i want to know is if there is way around this ? Has anyone done something like this in another way ?
The question here is: How to get the user’s choice properly when the choice is too complex to use UIAlertView.

Sorry for the long question, I simplified it as much as I could. Thanks for your time, any links, comments, or any kind of help is greatly appreciated

Answer 1

Why are you initializing MyEngine *engine in the IBAction, if you wish to use a MyEngine object why don’t you make a global declaration in your InitialViewController and just call [engine start] in the IBaction. Then when the delegate method returns the selected index you can apply that to a global int in your initial view controller and continue on your way. Hope that makes sense