How to clean up old interfaces on zc.relation catalog?

Question

I was using plone.directives.form version 1.0 with Plone 4.2.5 and after upgrading to 4.2.6 I started seeing the following traceback and I guess its due to plone.

Answer 1

Just for reference that's how I fixed it:

While still on plone.directives.form 1.0 update your objects so that they do no longer provide the plone.directives.form.schema.Schema interface.

Then re-create the relations:

from z3c.relationfield import RelationValue
from zc.relation.interfaces import ICatalog
from zope.app.intid.interfaces import IIntIds
from zope.component import getUtility
from zope.event import notify
from zope.lifecycleevent import ObjectModifiedEvent

logger = logging.getLogger(LOGGER)
relations_catalog = getUtility(ICatalog)
intids = getUtility(IIntIds)

relations = [rel for rel in relations_catalog.findRelations()]
len_relations = len(relations)
logger.info('Relations needed to update: {0}'.format(len_relations))

for relation in relations:
    # get the object link and the object linked
    object_with_link = relation.from_object
    object_linked_to = relation.to_object

    # remove the broken relation
    object_with_link.reference = None

    # let the catalog remove the old relation
    notify(ObjectModifiedEvent(object_with_link))

    # create a new relation
    object_linked_to_intid = intids.getId(object_linked_to)
    new_relation = RelationValue(object_linked_to_intid)
    object_with_link.reference = new_relation

    # let the catalog know about this new relation
    notify(ObjectModifiedEvent(object_with_link))

After this, stop the instance, run buildout again to update plone.directives.form to version 1.1 and voilà!