How to get a pointer to a viewController inside the appDelegate when using storyboards

Question

I'm trying to save the data from a viewController. I'm doing this by using the delegate methods in the appDelegate: - (void)applicationDidEnterBackground:(UIApplication *)application

The problem is when using storyboards, the viewControllers automatically get set up for you and I'm not sure how to get a pointer to them so that I can access their data for saving.

How can I get a pointer to them in appDelegate while using storyboards?

Answer 1

You can register to receive going to and from background notification inside your UIViewController and manage the saving there.

//Going into background
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(saveData) name:@"UIApplicationDidEnterBackgroundNotification" object:nil];

//Waking up
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(doSomethingOnWakeup) name:@"UIApplicationWillEnterForegroundNotification" object:nil];