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# vim: tabstop=4 shiftwidth=4 softtabstop=4
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# Copyright 2012 OpenStack LLC
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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# http://www.apache.org/licenses/LICENSE-2.0
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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Dict <--> XML de/serializer.
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The identity API prefers attributes over elements, so we serialize that way
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by convention, with a few hardcoded exceptions.
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from lxml import etree
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DOCTYPE = '<?xml version="1.0" encoding="UTF-8"?>'
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XMLNS = 'http://docs.openstack.org/identity/api/v2.0'
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"""Deserialize XML to a dictionary."""
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deserializer = XmlDeserializer()
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return deserializer(xml)
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def to_xml(d, xmlns=None):
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"""Serialize a dictionary to XML."""
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serialize = XmlSerializer()
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return serialize(d, xmlns)
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class XmlDeserializer(object):
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def __call__(self, xml_str):
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"""Returns a dictionary populated by decoding the given xml string."""
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dom = etree.fromstring(xml_str.strip())
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return self.walk_element(dom)
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"""Remove the namespace from the tagname.
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TODO(dolph): We might care about the namespace at some point.
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>>> XmlDeserializer._tag_name('{xmlNamespace}tagName')
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m = re.search('[^}]+$', tag)
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return m.string[m.start():]
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def walk_element(self, element):
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"""Populates a dictionary by walking an etree element."""
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for k, v in element.attrib.iteritems():
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# boolean-looking attributes become booleans in JSON
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if element.text is not None:
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text = element.text.strip()
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# current spec does not have attributes on an element with text
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values = values or text or {}
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for child in [self.walk_element(x) for x in element]:
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values = dict(values.items() + child.items())
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return {XmlDeserializer._tag_name(element.tag): values}
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class XmlSerializer(object):
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def __call__(self, d, xmlns=None):
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"""Returns an xml etree populated by the given dictionary.
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Optionally, namespace the etree by specifying an ``xmlns``.
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# FIXME(dolph): skipping links for now
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assert len(d.keys()) == 1, ('Cannot encode more than one root '
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'element: %s' % d.keys())
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# name the root dom element
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# only the root dom element gets an xlmns
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root = etree.Element(name, xmlns=(xmlns or XMLNS))
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self.populate_element(root, d[name])
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# TODO(dolph): you can get a doctype from lxml, using ElementTrees
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return '%s\n%s' % (DOCTYPE, etree.tostring(root, pretty_print=True))
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def _populate_list(self, element, k, v):
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"""Populates an element with a key & list value."""
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# spec has a lot of inconsistency here!
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if k == 'media-types':
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# xsd compliance: <media-types> contains <media-type>s
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# find an existing <media-types> element or make one
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container = element.find('media-types')
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if container is None:
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container = etree.Element(k)
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element.append(container)
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elif k == 'serviceCatalog':
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# xsd compliance: <serviceCatalog> contains <service>s
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container = etree.Element(k)
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element.append(container)
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elif k == 'values' and element.tag[-1] == 's':
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# OS convention is to contain lists in a 'values' element,
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# so the list itself can have attributes, which is
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name = element.tag[:-1]
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child = etree.Element(name)
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self.populate_element(child, item)
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container.append(child)
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def _populate_dict(self, element, k, v):
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"""Populates an element with a key & dictionary value."""
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child = etree.Element(k)
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self.populate_element(child, v)
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element.append(child)
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def _populate_bool(self, element, k, v):
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"""Populates an element with a key & boolean value."""
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# booleans are 'true' and 'false'
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element.set(k, unicode(v).lower())
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def _populate_str(self, element, k, v):
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"""Populates an element with a key & string value."""
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if k in ['description']:
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# always becomes an element
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child = etree.Element(k)
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child.text = unicode(v)
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element.append(child)
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# add attributes to the current element
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element.set(k, unicode(v))
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def _populate_number(self, element, k, v):
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"""Populates an element with a key & numeric value."""
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# numbers can be handled as strings
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self._populate_str(element, k, v)
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def populate_element(self, element, value):
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"""Populates an etree with the given value."""
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if isinstance(value, list):
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self._populate_sequence(element, value)
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elif isinstance(value, dict):
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self._populate_tree(element, value)
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def _populate_sequence(self, element, l):
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"""Populates an etree with a sequence of elements, given a list."""
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# xsd compliance: child elements are singular: <users> has <user>s
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if element.tag[-1] == 's':
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name = element.tag[:-1]
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child = etree.Element(name)
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self.populate_element(child, item)
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element.append(child)
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def _populate_tree(self, element, d):
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"""Populates an etree with attributes & elements, given a dict."""
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for k, v in d.iteritems():
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if isinstance(v, dict):
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self._populate_dict(element, k, v)
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elif isinstance(v, list):
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self._populate_list(element, k, v)
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elif isinstance(v, bool):
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self._populate_bool(element, k, v)
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elif isinstance(v, basestring):
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self._populate_str(element, k, v)
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elif type(v) in [int, float, long, complex]:
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self._populate_number(element, k, v)
added
removed
.pc/CVE-2013-0280_Information-leak-and-Denial-of-Service-using-XML-entities.patch/keystone/common/serializer.py
