diff options
Diffstat (limited to 'bs4/builder/_lxml.py')
| -rw-r--r-- | bs4/builder/_lxml.py | 43 |
1 files changed, 38 insertions, 5 deletions
diff --git a/bs4/builder/_lxml.py b/bs4/builder/_lxml.py index d8251b2..971c81e 100644 --- a/bs4/builder/_lxml.py +++ b/bs4/builder/_lxml.py @@ -80,15 +80,24 @@ class LXMLTreeBuilderForXML(TreeBuilder): This might be useful later on when creating CSS selectors. + This will track (almost) all namespaces, even ones that were + only in scope for part of the document. If two namespaces have + the same prefix, only the first one encountered will be + tracked. Un-prefixed namespaces are not tracked. + :param mapping: A dictionary mapping namespace prefixes to URIs. """ for key, value in list(mapping.items()): + # This is 'if key' and not 'if key is not None' because we + # don't track un-prefixed namespaces. Soupselect will + # treat an un-prefixed namespace as the default, which + # causes confusion in some cases. if key and key not in self.soup._namespaces: # Let the BeautifulSoup object know about a new namespace. # If there are multiple namespaces defined with the same # prefix, the first one in the document takes precedence. self.soup._namespaces[key] = value - + def default_parser(self, encoding): """Find the default parser for the given encoding. @@ -126,6 +135,7 @@ class LXMLTreeBuilderForXML(TreeBuilder): self.empty_element_tags = set(empty_element_tags) self.soup = None self.nsmaps = [self.DEFAULT_NSMAPS_INVERTED] + self.active_namespace_prefixes = [dict(self.DEFAULT_NSMAPS)] super(LXMLTreeBuilderForXML, self).__init__(**kwargs) def _getNsTag(self, tag): @@ -250,6 +260,20 @@ class LXMLTreeBuilderForXML(TreeBuilder): # mappings. self.nsmaps.append(_invert(nsmap)) + # The currently active namespace prefixes have + # changed. Calculate the new mapping so it can be stored + # with all Tag objects created while these prefixes are in + # scope. + current_mapping = dict(self.active_namespace_prefixes[-1]) + current_mapping.update(nsmap) + + # We should not track un-prefixed namespaces as we can only hold one + # and it will be recognized as the default namespace by soupsieve, + # which may be confusing in some situations. + if '' in current_mapping: + del current_mapping[''] + self.active_namespace_prefixes.append(current_mapping) + # Also treat the namespace mapping as a set of attributes on the # tag, so we can recreate it later. attrs = attrs.copy() @@ -274,8 +298,11 @@ class LXMLTreeBuilderForXML(TreeBuilder): namespace, name = self._getNsTag(name) nsprefix = self._prefix_for_namespace(namespace) - self.soup.handle_starttag(name, namespace, nsprefix, attrs) - + self.soup.handle_starttag( + name, namespace, nsprefix, attrs, + namespaces=self.active_namespace_prefixes[-1] + ) + def _prefix_for_namespace(self, namespace): """Find the currently active prefix for the given namespace.""" if namespace is None: @@ -299,8 +326,14 @@ class LXMLTreeBuilderForXML(TreeBuilder): if len(self.nsmaps) > 1: # This tag, or one of its parents, introduced a namespace # mapping, so pop it off the stack. - self.nsmaps.pop() - + out_of_scope_nsmap = self.nsmaps.pop() + + if out_of_scope_nsmap is not None: + # This tag introduced a namespace mapping which is no + # longer in scope. Recalculate the currently active + # namespace prefixes. + self.active_namespace_prefixes.pop() + def pi(self, target, data): self.soup.endData() data = target + ' ' + data |