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Diffstat (limited to 'sleekxmpp/xmlstream/matcher/xpath.py')
-rw-r--r-- | sleekxmpp/xmlstream/matcher/xpath.py | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/sleekxmpp/xmlstream/matcher/xpath.py b/sleekxmpp/xmlstream/matcher/xpath.py new file mode 100644 index 00000000..b6af0609 --- /dev/null +++ b/sleekxmpp/xmlstream/matcher/xpath.py @@ -0,0 +1,86 @@ +# -*- coding: utf-8 -*- +""" + sleekxmpp.xmlstream.matcher.xpath + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + + Part of SleekXMPP: The Sleek XMPP Library + + :copyright: (c) 2011 Nathanael C. Fritz + :license: MIT, see LICENSE for more details +""" + +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 XPath matchers. +IGNORE_NS = False + + +class MatchXPath(MatcherBase): + + """ + The XPath matcher selects stanzas whose XML contents matches a given + XPath expression. + + .. warning:: + + Using this matcher may not produce expected behavior when using + attribute selectors. For Python 2.6 and 3.1, the ElementTree + :meth:`~xml.etree.ElementTree.Element.find()` method does + not support the use of attribute selectors. If you need to + support Python 2.6 or 3.1, it might be more useful to use a + :class:`~sleekxmpp.xmlstream.matcher.stanzapath.StanzaPath` matcher. + + If the value of :data:`IGNORE_NS` is set to ``True``, then XPath + expressions will be matched without using namespaces. + """ + + def match(self, xml): + """ + Compare a stanza's XML contents to an XPath expression. + + If the value of :data:`IGNORE_NS` is set to ``True``, then XPath + expressions will be matched without using namespaces. + + .. warning:: + + In Python 2.6 and 3.1 the ElementTree + :meth:`~xml.etree.ElementTree.Element.find()` method does not + support attribute selectors in the XPath expression. + + :param xml: The :class:`~sleekxmpp.xmlstream.stanzabase.ElementBase` + stanza to compare against. + """ + if hasattr(xml, 'xml'): + xml = xml.xml + x = ET.Element('x') + x.append(xml) + + if not IGNORE_NS: + # Use builtin, namespace respecting, XPath matcher. + if x.find(self._criteria) is not None: + return True + return False + else: + # Remove namespaces from the XPath expression. + criteria = [] + for ns_block in self._criteria.split('{'): + criteria.extend(ns_block.split('}')[-1].split('/')) + + # Walk the XPath expression. + xml = x + for tag in criteria: + if not tag: + # Skip empty tag name artifacts from the cleanup phase. + continue + + children = [c.tag.split('}')[-1] for c in xml.getchildren()] + try: + index = children.index(tag) + except ValueError: + return False + xml = xml.getchildren()[index] + return True |