Top Level Document

Issue:

Is there a need for a top level Document for all objects to reference as thier ownerDocument?

Notes:

Mike

Further investigation shows a class called Root defined in ZDOM.py. This class is a base class for the Application.

Jim

Which is wrong, as Amos has pointed out to us several times. Sigh.

Of course, this doen't really have anything to do with whether there should be a top-level document.

Mike

Having a Document as the "Parent" class will not work well in Zope. A document is only allowed one element child, the document element. what we really neeed to say is that the application is trhe document element.

Jim

Right.

Resolution:

Jim

You need to tell us whether Zope needs to have a top-level Document.

If the answer is yes, then it should be provided as a sub-object defined in (a base class of) the Aplication class. Something like:

In ZDOM.py or some such:

       class ZopeDocument(Acquisition.Implicit, ...):
          """Implement the document interface

          For the document that is Zope. :)
          """

          # Note that we get at our top-level element
          # and the rest of the object system though
          # aq_parent, which we get because we acquire.

          ...

       class ZopeTopLevelElement(...):

          OwnerDocument=ZopeDocument()

          ....

In Application.py:

       class Application(..., ZDOM.ZopeTopLevelElement, ...):
          ...

Mike

This is the way I have implemented it. A super class of element called RootElement? is a base class for application. The root element needs to be a special case, not for owner document support, but because it is the acuisition parent of all other nodes hence its parentNode attribute functions differently. I create a singleton Document for the Application when it is first created.

Jim

The singleton should be defined in the class.

There's no reason to store it in the application object.

Mike

It is not. It is defined in RootElement?.py as a singleton.