A frustrating problem I came across today when I tried binding an
NSPopUpButton's selection key to an
NSArrayController's selection was that the
NSPopUpButton would always display a 'ghost' object -one of the opaque classes internal to Cocoa/Core-Data Bindings(
_NSControllerObjectProxy... or similar).
It turns out that
NSPopUpButton does not record the user's selection, so even if I had been able to get rid of the ghost object, I wouldn't have been able to access the selected object.
The solution is to manually maintain a currently selected object in the window controller -
File's Owner in Interface Builder; in this case,
In Interface Builder, the NSPopUpButton should be bound to the NSArrayController (Packages) and the File's Owner as:
*Content Values: *Packages.arrangedObjects;modelPath=packageName
Selection: File's Owner.selectedPackage
A default selection can then be provided by calling the