Proper way to structure classes in Xcode framework

Question

I'm building a custom Xcode framework, and I have a class called AXController that has a class method called showActivationWindow. showActivationWindow initializes and shows a window using AXWindowController which is a subclass of NSWindowController. Then, AXWindowController calls activate which is a class method in AXController on a button press in the window it displays.

I included AXWindowController.h in AXController.h and included AXController.h in AXWindowController.h so each could access the other's methods, but this is throwing a lot of Xcode warnings. It also seems like a very inelegant solution.

What is the correct way to solve this problem?

Answer 1

It's not a good idea to import header files recursively. There's a directive @class (link to Apple doc) which tells that there is a class named as such. In practice the usage is something like A.h

@class B;
@interface A:NSObject {
   B* anInstanceOfB;
} 
...
@end

and B.h

#import "A.h"
@interface B:NSObject {
  A* anInstanceOfA;
}
...
@end

Then you can import A.h and B.h as you like from your .m file! But be careful not to make a retain cycle, if you don't use garbage collection.