paula.grouputil/src/paula/grouputil/subscribers.py

   1 # Copyright (c) 2008 by Florian Friesdorf
   2 #
   3 # GNU Affero General Public License (AGPL)
   4 #
   5 # This program is free software; you can redistribute it and/or modify
   6 # it under the terms of the GNU Affero General Public License as
   7 # published by the Free Software Foundation; either version 3 of the
   8 # License, or (at your option) any later version.
   9 #
  10 # This program is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13 # GNU Affero General Public License for more details.
  14 #
  15 # You should have received a copy of the GNU Affero General Public
  16 # License along with this program.  If not, see
  17 # <http://www.gnu.org/licenses/>.
  18 """
  19 """
  20 __author__ = "Florian Friesdorf <flo@chaoflow.net>"
  21 __docformat__ = "plaintext"
  22
  23 from zope.app.container.interfaces import IObjectAddedEvent
  24 from zope.app.container.interfaces import IObjectRemovedEvent
  25
  26 from zope.component import adapter, queryUtility
  27
  28 from zope.location.interfaces import ILocation
  29
  30 from paula.grouputil.interfaces import IMembershipProvider
  31 from paula.grouputil.interfaces import IMembershipProviderAdaptable
  32 from paula.grouputil.interfaces import IRWMemberships
  33
  34
  35 @adapter(ILocation, IObjectAddedEvent)
  36 def checkRegister(obj, event):
  37     """A subscriber to ObjectAddedEvent
  38     """
  39     if not IMembershipProviderAdaptable.providedBy(obj) and \
  40             not IMembershipProvider.providedBy(obj):
  41         return
  42
  43     # we are registered globally and might run in a context without
  44     # IRWMemberships
  45     util = queryUtility(IRWMemberships) #, context=event.newParent)
  46     # XXX: not working, util is False?!
  47     #if util:
  48     if util is not None:
  49         util.register(obj)
  50
  51
  52 @adapter(ILocation, IObjectRemovedEvent)
  53 def checkUnregister(obj, event):
  54     """A subscriber to ObjectRemovedEvent
  55     """
  56     if not IMembershipProviderAdaptable.providedBy(obj) and \
  57             not IMembershipProvider.providedBy(obj):
  58         return
  59
  60     # we are registered globally and might run in a context without
  61     # IRWMemberships
  62     util = queryUtility(IRWMemberships) #, context=event.newParent)
  63     # XXX: not working, util is False?!
  64     #if util:
  65     if util is not None:
  66         try:
  67             util.unregister(obj)
  68         except KeyError:
  69             pass