1.0 Documentation


Source code for sleekxmpp.xmlstream.matcher.xmlmask

    SleekXMPP: The Sleek XMPP Library
    Copyright (C) 2010  Nathanael C. Fritz
    This file is part of SleekXMPP.

    See the file LICENSE for copying permission.

import logging

from xml.parsers.expat import ExpatError

from sleekxmpp.xmlstream.stanzabase import ET
from sleekxmpp.xmlstream.matcher.base import MatcherBase

# Flag indicating if the builtin XPath matcher should be used, which
# uses namespaces, or a custom matcher that ignores namespaces.
# Changing this will affect ALL XMLMask matchers.

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:`~sleekxmpp.xmlstream.matcher.xpath.MatchXPath` or :class:`~sleekxmpp.xmlstream.matcher.stanzapath.StanzaPath` should be used instead. The use of namespaces in the mask comparison is controlled by ``IGNORE_NS``. Setting ``IGNORE_NS`` to ``True`` will disable namespace based matching for ALL XMLMask matchers. :param criteria: Either an :class:`~xml.etree.ElementTree.Element` XML object or XML string to use as a mask. """ def __init__(self, criteria): MatcherBase.__init__(self, criteria) if isinstance(criteria, str): self._criteria = ET.fromstring(self._criteria) self.default_ns = 'jabber:client'
[docs] def setDefaultNS(self, ns): """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): """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. """ if hasattr(xml, 'xml'): xml = xml.xml return self._mask_cmp(xml, self._criteria, True)
def _mask_cmp(self, source, mask, use_ns=False, default_ns='__no_ns__'): """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__"``. """ use_ns = not IGNORE_NS if source is None: # If the element was not found. May happend during recursive calls. return False # Convert the mask to an XML object if it is a string. if not hasattr(mask, 'attrib'): try: mask = ET.fromstring(mask) except ExpatError: log.warning("Expat error: %s\nIn parsing: %s", '', mask) if not use_ns: # Compare the element without using namespaces. source_tag = source.tag.split('}', 1)[-1] mask_tag = mask.tag.split('}', 1)[-1] if source_tag != mask_tag: return False else: # Compare the element using namespaces 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: if use_ns: 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 else: if not self._mask_cmp(self._get_child(source, subelement.tag), subelement, use_ns): return False # Everything matches. return True def _get_child(self, xml, tag): """Return a child element given its tag, ignoring namespace values. Returns ``None`` if the child was not found. :param xml: The :class:`~xml.etree.ElementTree.Element` XML object to search for the given child tag. :param tag: The name of the subelement to find. """ tag = tag.split('}')[-1] try: children = [c.tag.split('}')[-1] for c in xml.getchildren()] index = children.index(tag) except ValueError: return None return xml.getchildren()[index]


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