Evaluate a Cocoa Scripting object from NSAppleEventDescriptor

Question

In my sdef, I have a command that accepts a parameter of type "Any".

In the script, I pass the reference to a scriptable object:

tell application "myApp"
  set theArg to first subItem of appElement -- appElement is an element of the app object
  myCommand theArg
end

In my command handler code, when fetching the parameter, I get back an object like this:

<NSAppleEventDescriptor: 'obj '{ 'form':'ID ', 'want':'Subi', 'seld':10900, 'from':'obj '{ 'form':'ID ', 'want':'Elem', 'seld':10900, 'from':null() } }>

Now, I like to resolve that back into an NSObject that represents the actual scripting object of "theArg". How do I do that? I can't find any evaluation functions in NSAppleEventDescriptor, other than for simple types such as text, numbers and file references.

Answer 1

Turns out I need again a private function that's been mentioned here as well.

@interface NSScriptObjectSpecifier (NSPrivate)
+ (id) _scriptingSpecifierWithDescriptor:(NSAppleEventDescriptor*) descriptor;
@end

With that, I'll get an NSScriptObjectSpecifier, on which I then invoke objectsByEvaluatingSpecifier to get my object.