How to access Apple WatchKit WKInterfaceController list - ios

Question

In my watch extension code I am trying to prevent the display of a second interface controller in certain scenarios. My solution requires looking through the list of active view controllers.
Does anyone know how to get a list of all active interface controllers? You can do this in iOS using self.navigationController.viewControllers but I could find no navigation controller in WatchKit.
I have read through the Apple Watch Programming Guide a number of times but they don't address this. Since you can push & pop interface controllers, there must be a list kept by the OS but I suspect there is no programming access to that list.

Answer 1

You could try to work around it by making your own list, and save it in NSUserDefaults for example:
You should clear it on the init of your initial ViewController:
- (instancetype)init {
self = [super init];
// get user defaults
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
// empty the array at application launch
[defaults setObject:[[NSMutableArray alloc] init] forKey:#"activeVCs"];
[defaults synchronize];
return self;
}
And then in every other ViewController, you add and remove to this list on activate/deactivate of the controllers:
- (void)willActivate {
// get list of VCs
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSMutableArray *listOfVCs = [defaults objectForKey:#"activeVCs"];
[listOfVCs addObject:#"VC1"];
// save array and sync
[defaults setObject:listOfVCs forKey:#"activeVCs"];
[defaults synchronize];
[super willActivate];
}
- (void)didDeactivate {
// get list of VCs
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSMutableArray *listOfVCs = [defaults objectForKey:#"activeVCs"];
// remove VC if exists
if ([listOfVCs containsObject:#"VC1"])
[listOfVCs removeObject:#"VC1"];
// save array and sync
[defaults setObject:listOfVCs forKey:#"activeVCs"];
[defaults synchronize];
[super didDeactivate];
}

Answer 2

Because you can pass any valid context and access it in awakeWithContext:, I've used the technique of bundling a reference to the presenting view controller along with additional context in my WatchKit app. Not only does this allow you to build-up a list of presented interface controllers, but it also allows you to do things like assign delegates, inform controllers of interesting events, etc. I've published my JBInterfaceController project on GitHub: https://github.com/mikeswanson/JBInterfaceController