Is there any way to assign a global value to a document (object)?

[i73]

I'll try and keep this short. I need to set a global in my photoshop application to tell my program if the document has been opened externally, I need this for a few reasons:

1. If it's opened externally I can't have the user change the canvas size (Lock the opened doc canvas size).

2. I need to provide a call back to my calling application to tell it whenever I save (That way it can update the UI with the new saved image) OR simply assign a global on the PS application to query if the doc was opened.

I was thinking of prefixing the Document name with a Character so I can just look up the document name and know if it's been opened by an external app.

     //Javascript

    var documentName = "!" + ActiveDocument.Name;

    //c++

    if(DocumentNameContainsBash(&documentName))

EDIT: I've just realized that the doc name is read only... I can't save over it with a new name either...

But I would love to be able to check if it's been opened though some kind of document object that I could return like:

    hasDocumentOpenedExternal(&document);

Is this possible in JS?

[i73 · Accepted solution]

I got it:

              //Set a global actionDesc

        app.DoJavascript("var desc = new ActionDescriptor(); desc.putString( 0 , \"yes\"); app.putCustomOptions('mmm', desc, true);");

                 //Return global actionDesc

        app.DoJavascript("var desc2 = app.getCustomOptions('mmm'); var s = desc2.getString(0);");