Question

Hopefully this is an easy one…

I have an NSObject with methods that is used in multiple UIViewControllers (the NSObject is imported in my .pch file).

The UIViewControllers then make calls to the NSObject like so;

[ThisNSObject doSomething];

This is all working to plan so there’s no issue there… however, I would love the method doSomething to be able to detect WHICH UIViewController made the call to that NSObject. Then, based on that information I can manipulate the UIViewController in any given way.

The reason I need this is because if I have a UITabBar with each Tab loading a different UIViewController, but all making a call to the global NSObject, I need to direct further action to that one specific UIViewController.

I know I have access to keyWindow, but I’m not sure this is exactly what I’m after.

Any suggestions would be great, thank you.

Roy

EDIT:
Actually, perhaps in the NSObject I can detect which tab is currently selected, then get the top View in the stack… and make a reference like that? Does anyone have thoughts on why this would be a bad idea?

Answer 1

Using runtime code you could probably drill back through the call stack, but it’s a rather complex solution to a simple problem. I would suggest that you look to the APIs for inspiration and modify your doSomething method to take a controller argument like this:

-(void) doSomethingWithViewController:(UIViewController *) viewController;

This way when you can the doSomething method you pass a reference to self like this:

[theObject doSomethingWithViewController:self];

And your problem is solved – simply.

P.S. if you have other parameters, an alternative signature style might be

-(void) viewController:(UIViewController *) viewController doSomethingWithX:(id) x;

It all depends on what makes the best sense to you.