# Copyright 2013 OpenStack Foundation.
# 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.
import logging
from xml.etree import ElementTree as etree
from xml.parsers import expat
from oslo_serialization import jsonutils
import six
from tackerclient.common import constants
from tackerclient.common import exceptions as exception
from tackerclient.i18n import _
LOG = logging.getLogger(__name__)
if six.PY3:
long = int
class ActionDispatcher(object):
"""Maps method name to local methods through action name."""
def dispatch(self, *args, **kwargs):
"""Find and call local method."""
action = kwargs.pop('action', 'default')
action_method = getattr(self, str(action), self.default)
return action_method(*args, **kwargs)
def default(self, data):
raise NotImplementedError()
class DictSerializer(ActionDispatcher):
"""Default request body serialization."""
def serialize(self, data, action='default'):
return self.dispatch(data, action=action)
def default(self, data):
return ""
class JSONDictSerializer(DictSerializer):
"""Default JSON request body serialization."""
def default(self, data):
def sanitizer(obj):
return six.text_type(obj)
return jsonutils.dumps(data, default=sanitizer)
class XMLDictSerializer(DictSerializer):
def __init__(self, metadata=None, xmlns=None):
"""XMLDictSerializer constructor.
:param metadata: information needed to deserialize XML into
a dictionary.
:param xmlns: XML namespace to include with serialized XML
"""
super(XMLDictSerializer, self).__init__()
self.metadata = metadata or {}
if not xmlns:
xmlns = self.metadata.get('xmlns')
if not xmlns:
xmlns = constants.XML_NS_V10
self.xmlns = xmlns
def default(self, data):
"""Default serializer of XMLDictSerializer.
:param data: expect data to contain a single key as XML root, or
contain another '*_links' key as atom links. Other
case will use 'VIRTUAL_ROOT_KEY' as XML root.
"""
try:
links = None
has_atom = False
if data is None:
root_key = constants.VIRTUAL_ROOT_KEY
root_value = None
else:
link_keys = [k for k in six.iterkeys(data) or []
if k.endswith('_links')]
if link_keys:
links = data.pop(link_keys[0], None)
has_atom = True
root_key = (len(data) == 1 and
list(data.keys())[0] or constants.VIRTUAL_ROOT_KEY)
root_value = data.get(root_key, data)
doc = etree.Element("_temp_root")
used_prefixes = []
self._to_xml_node(doc, self.metadata, root_key,
root_value, used_prefixes)
if links:
self._create_link_nodes(list(doc)[0], links)
return self.to_xml_string(list(doc)[0], used_prefixes, has_atom)
except AttributeError as e:
LOG.exception(str(e))
return ''
def __call__(self, data):
# Provides a migration path to a cleaner WSGI layer, this
# "default" stuff and extreme extensibility isn't being used
# like originally intended
return self.default(data)
def to_xml_string(self, node, used_prefixes, has_atom=False):
self._add_xmlns(node, used_prefixes, has_atom)
return etree.tostring(node, encoding='UTF-8')
# NOTE(ameade): the has_atom should be removed after all of the
# XML serializers and view builders have been updated to the current
# spec that required all responses include the xmlns:atom, the has_atom
# flag is to prevent current tests from breaking
def _add_xmlns(self, node, used_prefixes, has_atom=False):
node.set('xmlns', self.xmlns)
node.set(constants.TYPE_XMLNS, self.xmlns)
if has_atom:
node.set(constants.ATOM_XMLNS, constants.ATOM_NAMESPACE)
node.set(constants.XSI_NIL_ATTR, constants.XSI_NAMESPACE)
ext_ns = self.metadata.get(constants.EXT_NS, {})
for prefix in used_prefixes:
if prefix in ext_ns:
node.set('xmlns:' + prefix, ext_ns[prefix])
def _to_xml_node(self, parent, metadata, nodename, data, used_prefixes):
"""Recursive method to convert data members to XML nodes."""
result = etree.SubElement(parent, nodename)
if ":" in nodename:
used_prefixes.append(nodename.split(":", 1)[0])
# TODO(bcwaldon): accomplish this without a type-check
if isinstance(data, list):
if not data:
result.set(
constants.TYPE_ATTR,
constants.TYPE_LIST)
return result
singular = metadata.get('plurals', {}).get(nodename, None)
if singular is None:
if nodename.endswith('s'):
singular = nodename[:-1]
else:
singular = 'item'
for item in data:
self._to_xml_node(result, metadata, singular, item,
used_prefixes)
# TODO(bcwaldon): accomplish this without a type-check
elif isinstance(data, dict):
if not data:
result.set(
constants.TYPE_ATTR,
constants.TYPE_DICT)
return result
attrs = metadata.get('attributes', {}).get(nodename, {})
for k, v in sorted(data.items()):
if k in attrs:
result.set(k, str(v))
else:
self._to_xml_node(result, metadata, k, v,
used_prefixes)
elif data is None:
result.set(constants.XSI_ATTR, 'true')
else:
if isinstance(data, bool):
result.set(
constants.TYPE_ATTR,
constants.TYPE_BOOL)
elif isinstance(data, int):
result.set(
constants.TYPE_ATTR,
constants.TYPE_INT)
elif isinstance(data, long):
result.set(
constants.TYPE_ATTR,
constants.TYPE_LONG)
elif isinstance(data, float):
result.set(
constants.TYPE_ATTR,
constants.TYPE_FLOAT)
LOG.debug("Data %(data)s type is %(type)s",
{'data': data,
'type': type(data)})
result.text = six.text_type(data)
return result
def _create_link_nodes(self, xml_doc, links):
for link in links:
link_node = etree.SubElement(xml_doc, 'atom:link')
link_node.set('rel', link['rel'])
link_node.set('href', link['href'])
class TextDeserializer(ActionDispatcher):
"""Default request body deserialization."""
def deserialize(self, datastring, action='default'):
return self.dispatch(datastring, action=action)
def default(self, datastring):
return {}
class JSONDeserializer(TextDeserializer):
def _from_json(self, datastring):
try:
return jsonutils.loads(datastring)
except ValueError:
msg = _("Cannot understand JSON")
raise exception.MalformedResponseBody(reason=msg)
def default(self, datastring):
return {'body': self._from_json(datastring)}
class XMLDeserializer(TextDeserializer):
def __init__(self, metadata=None):
"""XMLDeserializer constructor.
:param metadata: information needed to deserialize XML into
a dictionary.
"""
super(XMLDeserializer, self).__init__()
self.metadata = metadata or {}
xmlns = self.metadata.get('xmlns')
if not xmlns:
xmlns = constants.XML_NS_V10
self.xmlns = xmlns
def _get_key(self, tag):
tags = tag.split("}", 1)
if len(tags) == 2:
ns = tags[0][1:]
bare_tag = tags[1]
ext_ns = self.metadata.get(constants.EXT_NS, {})
if ns == self.xmlns:
return bare_tag
for prefix, _ns in ext_ns.items():
if ns == _ns:
return prefix + ":" + bare_tag
else:
return tag
def _get_links(self, root_tag, node):
link_nodes = node.findall(constants.ATOM_LINK_NOTATION)
root_tag = self._get_key(node.tag)
link_key = "%s_links" % root_tag
link_list = []
for link in link_nodes:
link_list.append({'rel': link.get('rel'),
'href': link.get('href')})
# Remove link node in order to avoid link node being
# processed as an item in _from_xml_node
node.remove(link)
return link_list and {link_key: link_list} or {}
def _from_xml(self, datastring):
if datastring is None:
return None
plurals = set(self.metadata.get('plurals', {}))
try:
node = etree.fromstring(datastring)
root_tag = self._get_key(node.tag)
links = self._get_links(root_tag, node)
result = self._from_xml_node(node, plurals)
# There is no case where root_tag = constants.VIRTUAL_ROOT_KEY
# and links is not None because of the way data are serialized
if root_tag == constants.VIRTUAL_ROOT_KEY:
return result
return dict({root_tag: result}, **links)
except Exception as e:
parseError = False
# Python2.7
if (hasattr(etree, 'ParseError') and
isinstance(e, getattr(etree, 'ParseError'))):
parseError = True
# Python2.6
elif isinstance(e, expat.ExpatError):
parseError = True
if parseError:
msg = _("Cannot understand XML")
raise exception.MalformedResponseBody(reason=msg)
else:
raise
def _from_xml_node(self, node, listnames):
"""Convert a minidom node to a simple Python type.
:param node: minidom node name
:param listnames: list of XML node names whose subnodes should
be considered list items.
"""
attrNil = node.get(str(etree.QName(constants.XSI_NAMESPACE, "nil")))
attrType = node.get(str(etree.QName(
self.metadata.get('xmlns'), "type")))
if (attrNil and attrNil.lower() == 'true'):
return None
elif not len(node) and not node.text:
if (attrType and attrType == constants.TYPE_DICT):
return {}
elif (attrType and attrType == constants.TYPE_LIST):
return []
else:
return ''
elif (len(node) == 0 and node.text):
converters = {constants.TYPE_BOOL:
lambda x: x.lower() == 'true',
constants.TYPE_INT:
lambda x: int(x),
constants.TYPE_LONG:
lambda x: long(x),
constants.TYPE_FLOAT:
lambda x: float(x)}
if attrType and attrType in converters:
return converters[attrType](node.text)
else:
return node.text
elif self._get_key(node.tag) in listnames:
return [self._from_xml_node(n, listnames) for n in node]
else:
result = dict()
for attr in node.keys():
if (attr == 'xmlns' or
attr.startswith('xmlns:') or
attr == constants.XSI_ATTR or
attr == constants.TYPE_ATTR):
continue
result[self._get_key(attr)] = node.get(attr)
children = list(node)
for child in children:
result[self._get_key(child.tag)] = self._from_xml_node(
child, listnames)
return result
def default(self, datastring):
return {'body': self._from_xml(datastring)}
def __call__(self, datastring):
# Adding a migration path to allow us to remove unncessary classes
return self.default(datastring)
# NOTE(maru): this class is duplicated from tacker.wsgi
class Serializer(object):
"""Serializes and deserializes dictionaries to certain MIME types."""
def __init__(self, metadata=None, default_xmlns=None):
"""Create a serializer based on the given WSGI environment.
'metadata' is an optional dict mapping MIME types to information
needed to serialize a dictionary to that type.
"""
self.metadata = metadata or {}
self.default_xmlns = default_xmlns
def _get_serialize_handler(self, content_type):
handlers = {
'application/json': JSONDictSerializer(),
'application/xml': XMLDictSerializer(self.metadata),
}
try:
return handlers[content_type]
except Exception:
raise exception.InvalidContentType(content_type=content_type)
def serialize(self, data, content_type):
"""Serialize a dictionary into the specified content type."""
return self._get_serialize_handler(content_type).serialize(data)
def deserialize(self, datastring, content_type):
"""Deserialize a string to a dictionary.
The string must be in the format of a supported MIME type.
"""
return self.get_deserialize_handler(content_type).deserialize(
datastring)
def get_deserialize_handler(self, content_type):
handlers = {
'application/json': JSONDeserializer(),
'application/xml': XMLDeserializer(self.metadata),
}
try:
return handlers[content_type]
except Exception:
raise exception.InvalidContentType(content_type=content_type)