Can I find out if an AppleScript object has a certain property?

Question

I'm attempting to script BBEdit to make me feel more at home in coming from TextMate. One thing I need to be able to do is see if an object I have a reference to has a particular property.

For instance:

tell application "BBEdit"
    tell front window
        get selected items
    end tell
end tell

This will succeed on a project window, but not on a disk browser window, because the latter does not have a 'selected items' property. How do I see if there is such a property in the object?

Please note: I know how to inspect an object in Script Editor (get properties) to see what properties it has, but I need to know at runtime what they are.

Answer 1

What about the class?

tell application "BBEdit"
  if class of window 1 is disk browser window then
    # ...
  else
    # ...
  end if
end tell