# Slixmpp: The Slick XMPP Library
# Copyright (C) 2010 Nathanael C. Fritz
# This file is part of Slixmpp.
# See the file LICENSE for copying permission.
import logging
from xml.parsers.expat import ExpatError
from xml.etree.ElementTree import Element
from slixmpp.xmlstream.stanzabase import ET, StanzaBase
from slixmpp.xmlstream.matcher.base import MatcherBase
log = logging.getLogger(__name__)
[docs]
class MatchXMLMask(MatcherBase):
"""
The XMLMask matcher selects stanzas whose XML matches a given
XML pattern, or mask. For example, message stanzas with body elements
could be matched using the mask:
.. code-block:: xml
<message xmlns="jabber:client"><body /></message>
Use of XMLMask is discouraged, and
:class:`~slixmpp.xmlstream.matcher.xpath.MatchXPath` or
:class:`~slixmpp.xmlstream.matcher.stanzapath.StanzaPath`
should be used instead.
:param criteria: Either an :class:`~xml.etree.ElementTree.Element` XML
object or XML string to use as a mask.
"""
_criteria: Element
def __init__(self, criteria: str, default_ns: str = 'jabber:client'):
MatcherBase.__init__(self, criteria)
if isinstance(criteria, str):
self._criteria = ET.fromstring(criteria)
self.default_ns = default_ns
[docs]
def setDefaultNS(self, ns: str) -> None:
"""Set the default namespace to use during comparisons.
:param ns: The new namespace to use as the default.
"""
self.default_ns = ns
[docs]
def match(self, xml: StanzaBase) -> bool:
"""Compare a stanza object or XML object against the stored XML mask.
Overrides MatcherBase.match.
:param xml: The stanza object or XML object to compare against.
"""
real_xml = xml.xml
return self._mask_cmp(real_xml, self._criteria, True)
def _mask_cmp(self, source: Element, mask: Element, use_ns: bool = False,
default_ns: str = '__no_ns__') -> bool:
"""Compare an XML object against an XML mask.
:param source: The :class:`~xml.etree.ElementTree.Element` XML object
to compare against the mask.
:param mask: The :class:`~xml.etree.ElementTree.Element` XML object
serving as the mask.
:param use_ns: Indicates if namespaces should be respected during
the comparison.
:default_ns: The default namespace to apply to elements that
do not have a specified namespace.
Defaults to ``"__no_ns__"``.
"""
if source is None:
# If the element was not found. May happen during recursive calls.
return False
mask_ns_tag = "{%s}%s" % (self.default_ns, mask.tag)
if source.tag not in [mask.tag, mask_ns_tag]:
return False
# If the mask includes text, compare it.
if mask.text and source.text and \
source.text.strip() != mask.text.strip():
return False
# Compare attributes. The stanza must include the attributes
# defined by the mask, but may include others.
for name, value in mask.attrib.items():
if source.attrib.get(name, "__None__") != value:
return False
# Recursively check subelements.
matched_elements = {}
for subelement in mask:
matched = False
for other in source.findall(subelement.tag):
matched_elements[other] = False
if self._mask_cmp(other, subelement, use_ns):
if not matched_elements.get(other, False):
matched_elements[other] = True
matched = True
if not matched:
return False
# Everything matches.
return True