KVO Swift3 bind to object in array

🎤 General Discussion macOS
1

Hi,

First of all I hope I am posting this in the right forum, if not, please excuse.

I am probably doing this the wrong way, but I am stuck and don’t know how to solve this problem.
To be able to display a number of core data entities in a outline view I wrote a proxy class that translates between the multiple array controllers connected to the different entities and one tree controller that handles the data to be displayed in the outline view.

I can do something like:

 let arrayController = NSArrayController()
 childItemsController.bind("contentArray", to: Any, withKeyPath: "arrayController.arrangedObjects", options: nil)

this works,

but what if I have an array of Array Controllers? What should the KeyPath look like?

 let arrayController = NSArrayController()
 arrayControllerArray.append(arrayController)

 childItemsController.bind("contentArray", to: Any, withKeyPath: "arrayControllers[0].arrangedObjects", options: nil)

does not work.

I hope someone can give me a hint what to do here.

Thanks,

Andreas