Source code for zope.container.traversal

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#
# 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.
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"""Traversal components for containers
"""
__docformat__ = 'restructuredtext'

from zope.interface import implementer, providedBy
from zope.component import queryMultiAdapter, getSiteManager
from zope.component import ComponentLookupError
from zope.traversing.interfaces import TraversalError, ITraversable
from zope.publisher.interfaces.browser import IBrowserPublisher
from zope.publisher.interfaces.xmlrpc import IXMLRPCPublisher
from zope.publisher.interfaces import IDefaultViewName, NotFound

from zope.container.interfaces import ISimpleReadContainer, IItemContainer
from zope.container.interfaces import IReadContainer
from six.moves import map


# Note that the next two classes are included here because they
# can be used for multiple view types.

@implementer(IBrowserPublisher, IXMLRPCPublisher)
[docs]class ContainerTraverser(object): """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() @implementer(ITraversable)
[docs]class ContainerTraversable(object): """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