Binding NSMenuItem state in Document-based app

FROM : Steve Nicholson
DATE : Mon Jun 09 20:07:49 2008

I have a document-based app in which I'm trying to bind the state of 
NSMenuItems to values in my document's window controller. For 
example, in the window's nib file, I have a checkbox bound to File's 
Owner/autoscaleX. I'd like the menu item to have the same 
functionality as that check box and to display the status for 
whichever window is currently selected.

Since File's Owner is NSApplication in MainMenu.nib I get an 
exception when I try to bind to autoscaleX. I tried adding an 
autoscaleX action to FirstResponder and binding to that, but I still 
get the exception.

I also tried not binding the menu item and just setting its action to 
FirstResponder's autoscaleX action, but the menu item remains disabled.

I'm sure there's an easy Cocoa way to do this, but I haven't been 
able to dig it up in the docs or my searches.