z3c.form data manager for persistent dictionaries

configure.zcml

<configure
  xmlns="http://namespaces.zope.org/zope">

  <adapter
     factory=".datamanager.PersistentDictionaryField" />

</configure>

datamanger.py

from persistent.dict import PersistentDict
from z3c.form import datamanager
from z3c.form.interfaces import IDataManager
from zope.component import adapts
from zope.interface import implements
from zope.schema.interfaces import IField


class PersistentDictionaryField(datamanager.DictionaryField):
    adapts(PersistentDict, IField)
    implements(IDataManager)