Accessing script run handler from NSAppleScript

FROM : jonathan@mugginsoft.com
DATE : Fri Jan 04 21:56:27 2008

Hi

I am trying to call as wide as possible a variety of AppleScripts from 
cocoa using NSAppleScript and am having trouble
finding a way of calling a script with a parameterised run handler.

eg: a script called beepn.scpt and containing

on run (n, interval)
   repeat n times
       beep
       delay interval
   end repeat
end run

can be executed from the terminal as:

osascript beepn.scpt 2 1

As yet I have been unable to call such a script from NSAppleScript.

So far my approach has been.

1. If the script has no specified run handler or a run handler without 
parameters then
    use the NSAppleScript - executeAndReturnError method.

    This works for scripts such as:

   beep
    or

        on run
          beep
      end run

2. if the script contains a specified handler then I construct an 
NSAppleEventDescriptor
    specifying the handler and parameters  and call the NSAppleScript 
- executeAppleEvent method.

    This works for scripts such as:

    on beep(n, interval)
        repeat n times
          beep
          delay interval
      end repeat
    end beep


Unfortunately neither of these methods can handle a script with run 
handler parameters.

Calling NSAppleScript -executeAndReturnError gives no output - as may 
be expected.

Calling the run handler explicitly by name with NSAppleScript - 
executeAppleEvent results in:

Error -1708 occured the run(Hello) call: (null)

  which evaluates to errAEEventNotHandled    -1708    Event wasnt handled 
by an Apple event handler.
Passing an empty or nil handler name also does not work.

Of course I can change the run handler name but that means editing the 
script, which I would like to avoid if at all possible.

Any thoughts would be welcome.