How to work with activedocumentnode

I try to use a few existing GUI items and encountered the command: "activedocumentnode()" But when I put it at the top of my code it always returns a NILL. What is the trick with using this command?
And what is a document? Is that a GUI?

Hi Steven!

I've also tried activedocumentnode() without a result. With nodefromwindow(activeview()) it works for me. Maybe this might help you...

Hi Carsten,

Thanks for your answer, but it means that I have to go through 16 objects and change the code, so I wait a little till I have more information.

A document is a GUI with a documentwindow attribute.

activedocumentnode() only works in GUIs with a palettewindow attribute, such as the Modeling Utilities.

It returns a reference to the currently active window that has a documentwindow attribute, such as the ortho, perspective, and tree views. If those windows are tabbed together, it returns a reference to the selected tab.

Palette windows are designed as tool windows that affect the currently active document window. They are specially designed to allow document windows to remain active when the palette window is clicked. If your gui isn't a "palettewindow", then it will become the active window when clicked so there is no active document window.