Re: [Zope] Need some help to get rid of an InvalidObjectReference exception

20 Aug 2008

      --- On Tue, 8/19/08, Dieter Maurer <dieter@handshake.de> wrote:
...
From: Dieter Maurer <dieter@handshake.de>
Subject: Re: [Zope] Need some help to get rid of an InvalidObjectReference exception
To: yacinechaouche@yahoo.com
Cc: zope@zope.org
Date: Tuesday, August 19, 2008, 11:16 AM
chaouche yacine wrote at 2008-8-18 09:50 -0700:
...
Need some help to get rid of an InvalidObjectReference
exception
In my zope product, when I try to put some specific
object in the session, I get this :
2008-08-18T14:51:02 ERROR(200) SiteError
http://www.afdas.com:8091/noyauafdas/tests/testAdresses
Traceback (most recent call last):
 File
"/opt/Zope-2.7/lib/python/ZPublisher/Publish.py",
line 107, in publish
   transactions_manager.commit()
 File
"/opt/Zope-2.7/lib/python/Zope/App/startup.py",
line 222, in commit
   get_transaction().commit()
 File
"/opt/Zope-2.7/lib/python/ZODB/Transaction.py",
line 241, in commit
   ncommitted += self._commit_objects(objects)
 File
"/opt/Zope-2.7/lib/python/ZODB/Transaction.py",
line 356, in _commit_objects
   jar.commit(o, self)
 File
"/opt/Zope-2.7/lib/python/ZODB/Connection.py",
line 452, in commit
   dump(state)
InvalidObjectReference: Attempt to store an object from
a foreign database connection
A given persistent object can only be in one (ZODB-)
database, not in several
databases at the same time.
You must copy the persistent object, when you want it to be
stored
(also) in another (ZODB-) database.
You can use the "_getCopy(destination)" method to
create such
a copy. "_getCopy" is defined by
"OFS.CopySupport.CopySource" inherited
by most Zope objects.
-- 
Dieter
I narrowed the code to what is necessary to fire this exception, and here is the tarball for those who want to test it live http://yacinechaouche.googlepages.com/InvalidObjectReferenceExample.tgz

This is the directory contents :

+ InvalidObjectReferenceExample 
\_ __init__.py
\_ NonZODBObject.py
\_+ zmi
  \_ ZODBLivingObjectAddForm.pt
\_ ZODBLivingObject.py

================
NonZODBObject.py
================
class NonZODBObject:
    """
    Hello, i do not live in the ZODB
    """

    def __init__(self,p_context):
        """
        """
	# This is the evil line. 
        self.context = p_context

===================
ZODBLivingObject.py
===================
from OFS.SimpleItem import SimpleItem
from NonZODBObject import NonZODBObject

class ZODBLivingObject(SimpleItem) :
    """
    Hello, I live in the ZODB.
    """
    meta_type = "ZODBish"
    def __init__(self):
        """
        """
        self.id = "ZODBish"
        self.title = "ZODBish"

    def breakEverything(self):
        """
        """
        nonZODBish = NonZODBObject(self)
        # This line breaks everything.
        self.REQUEST.SESSION.set('breakish',nonZODBish)
        # This can be seen in the console if runzope
        print "it's me",nonZODBish.context
        return nonZODBish.context

__init__.py contains the code necessary to create a ZODBish in the ZODB through the ZMI
zmi contains the form that adds a ZODBish through the ZMI

As you see, I do not intentionally copy objects from one ZODB to another... Except maybe if the session has a separate storage and that this breaks everything. But then, I could not even use the _getCopy method because nonZODBish do not have a _p_jar attribute.

Any help or comment would be appreciated .