##############################################################################
#
# Copyright (c) 2001, 2002 Zope Foundation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL). A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.
#
##############################################################################
"""Traversal components for containers
"""
__docformat__ = 'restructuredtext'
from zope.component import ComponentLookupError
from zope.component import getSiteManager
from zope.component import queryMultiAdapter
from zope.interface import implementer
from zope.interface import providedBy
from zope.publisher.interfaces import IDefaultViewName
from zope.publisher.interfaces import NotFound
from zope.publisher.interfaces.browser import IBrowserPublisher
from zope.publisher.interfaces.xmlrpc import IXMLRPCPublisher
from zope.traversing.interfaces import ITraversable
from zope.traversing.interfaces import TraversalError
from zope.container.interfaces import IItemContainer
from zope.container.interfaces import IReadContainer
from zope.container.interfaces import ISimpleReadContainer
# Note that the next two classes are included here because they
# can be used for multiple view types.
[docs]
@implementer(IBrowserPublisher, IXMLRPCPublisher)
class ContainerTraverser:
"""A traverser that knows how to look up objects by name in a container."""
__used_for__ = ISimpleReadContainer
def __init__(self, container, request):
self.context = container
self.request = request
[docs]
def publishTraverse(self, request, name):
"""See zope.publisher.interfaces.IPublishTraverse"""
subob = self.context.get(name, None)
if subob is None:
view = queryMultiAdapter((self.context, request), name=name)
if view is not None:
return view
raise NotFound(self.context, name, request)
return subob
[docs]
def browserDefault(self, request):
"""See zope.publisher.browser.interfaces.IBrowserPublisher"""
# XXX this re-implements
# zope.app.publisher.browser.getDefaultViewName()
# to break our only dependency on it.
view_name = getSiteManager(None).adapters.lookup(
map(providedBy, (self.context, request)), IDefaultViewName)
if view_name is None:
raise ComponentLookupError("Couldn't find default view name",
self.context, request)
view_uri = "@@%s" % view_name
return self.context, (view_uri,)
[docs]
class ItemTraverser(ContainerTraverser):
"""A traverser that knows how to look up objects by name in an item
container."""
__used_for__ = IItemContainer
[docs]
def publishTraverse(self, request, name):
"""See zope.publisher.interfaces.IPublishTraverse"""
try:
return self.context[name]
except KeyError:
view = queryMultiAdapter((self.context, request), name=name)
if view is not None:
return view
raise NotFound(self.context, name, request)
_marker = object()
[docs]
@implementer(ITraversable)
class ContainerTraversable:
"""Traverses containers via `getattr` and `get`."""
__used_for__ = IReadContainer
def __init__(self, container):
self._container = container
def traverse(self, name, furtherPath):
container = self._container
v = container.get(name, _marker)
if v is _marker:
try:
# Note that if name is a unicode string, getattr will
# implicitly try to encode it using the system
# encoding (usually ascii). Failure to encode means
# invalid attribute name.
v = getattr(container, name, _marker)
except UnicodeEncodeError:
raise TraversalError(container, name)
if v is _marker:
raise TraversalError(container, name)
return v