Revision: 840 http://trac.macosforge.org/projects/calendarserver/changeset/840 Author: wsanchez@apple.com Date: 2006-12-15 11:53:12 -0800 (Fri, 15 Dec 2006) Log Message: ----------- Don't forget resource.py Added Paths: ----------- CalendarServer/trunk/twistedcaldav/directory/resource.py Added: CalendarServer/trunk/twistedcaldav/directory/resource.py =================================================================== --- CalendarServer/trunk/twistedcaldav/directory/resource.py (rev 0) +++ CalendarServer/trunk/twistedcaldav/directory/resource.py 2006-12-15 19:53:12 UTC (rev 840) @@ -0,0 +1,55 @@ +## +# Copyright (c) 2006 Apple Computer, Inc. All rights reserved. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +# +# DRI: Wilfredo Sanchez, wsanchez@apple.com +## + +""" +Implements a directory-backed principal hierarchy. +""" + +__all__ = ["AutoProvisioningResourceMixIn"] + +class AutoProvisioningResourceMixIn (object): + """ + Adds auto-provisioning to a Resource implementation. + """ + def provision(self): + """ + Provision this resource by creating any required backing store, etc. that + must be set up before the resource can be accessed normally. + FIXME: More description of what that means would be helpful here. Basically, + RenderMixIn methods should work (perhaps returning None) without having to + call this first, so that dirlist can happen, but it is expected that this will + have been called before anything that involves I/O happens. + This method may be called multiple times; provisioning code should ensure that + it handles this properly, typically by returning immediately if the resource is + already provisioned (eg. the backing store exists). + @return: a deferred or None. + """ + return None + + def locateChild(self, *args): + """ + This implementation calls L{provision}, then super's L{locateChild}, thereby + ensuring that looked-up resources are provisioned. + """ + super_method = super(AutoProvisioningResourceMixIn, self).locateChild + d = self.provision() + if d is None: + return super_method(*args) + else: + d.addCallback(lambda _: super_method(*args)) + return d