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Diffstat (limited to 'sleekxmpp/xmlstream/matcher/xmlmask.py')
-rw-r--r-- | sleekxmpp/xmlstream/matcher/xmlmask.py | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/sleekxmpp/xmlstream/matcher/xmlmask.py b/sleekxmpp/xmlstream/matcher/xmlmask.py new file mode 100644 index 00000000..7977e767 --- /dev/null +++ b/sleekxmpp/xmlstream/matcher/xmlmask.py @@ -0,0 +1,158 @@ +""" + 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. +IGNORE_NS = False + + +log = logging.getLogger(__name__) + + +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' + + 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 + + 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] |