def substitute_namespaces(element, element_dict, attribute_dict=None, deep=True):
# NB: You probably need to call normalize_namespaces after using this.
assert element.nodeType == element.ELEMENT_NODE
# The default attribute_dict is the same as the element_dict, but with the
# entry for EMPTY_NAMESPACE removed.
if attribute_dict is None:
attribute_dict = element_dict.copy()
if EMPTY_NAMESPACE in attribute_dict:
del attribute_dict[EMPTY_NAMESPACE]
# Replace attribute namespaces
for attrNode in list(getAttributeNodes(element)):
if attrNode.namespaceURI in attribute_dict:
attrNode = change_attribute_namespace(attrNode, attribute_dict[attrNode.namespaceURI])
# Set element namespace
if element.namespaceURI in element_dict:
element.namespaceURI = element_dict[element.namespaceURI]
# Iterate over child elements
if deep:
for node in element.childNodes:
if node.nodeType != node.ELEMENT_NODE:
continue
substitute_namespaces(node, element_dict, attribute_dict, deep)
def normalize_namespaces(element, strip_dups=False, parent_prefixes=None):
assert element.nodeType == element.ELEMENT_NODE
if parent_prefixes is None:
# Walk up the document tree to find the list of elements that might
# declare namespaces.
top_element = element.ownerDocument.documentElement
ancestry = []
e = element
while not top_element.isSameNode(e):
e = e.parentNode
if e is None:
raise ValueError("element %r not connected to document" % (element,))
ancestry.append(e)
# Walk down the tree to determine the current scope
ancestry.reverse()
parent_prefixes = NamespaceScope()
for e in ancestry:
parent_prefixes.update(get_namespace_declarations(e))
# Build list of local namespace declarations
new_prefixes = get_namespace_declarations(element)
# Merge the parent and new prefixes
current_prefixes = parent_prefixes.copy()
if strip_dups:
duplicate_prefixes = current_prefixes.update(new_prefixes)
for prefix in duplicate_prefixes:
del new_prefixes[prefix]
else:
current_prefixes.update(new_prefixes)
# Fix the element's namespace declarations
if element.prefix in current_prefixes and current_prefixes[element.prefix] == element.namespaceURI:
# Elements prefix and namespaceURI are in-scope. Do nothing
pass
elif element.namespaceURI == EMPTY_NAMESPACE and element.prefix is not None:
# You can't have a non-empty prefix with an empty namespace with
# XML Namespaces 1.0
raise ValueError("Cannot undeclare non-default namespace prefix")
else:
# Create a local namespace declaration attribute for this
# namespace. Don't care if a conflicting prefix existed before.
new_prefixes[element.prefix] = element.namespaceURI
current_prefixes[element.prefix] = element.namespaceURI
# Fix the attributes' namespace declarations
for attrNode in list(getAttributeNodes(element)):
# Skip xmlns attributes
if attrNode.namespaceURI == XMLNS_NAMESPACE:
continue
# Skip attributes with no namespace URI
if attrNode.namespaceURI == EMPTY_NAMESPACE:
assert hasattr(attrNode, 'localName') # Require at least DOM level 2 for now
continue # Do nothing, because attributes don't have namespaces by default.
# Skip attributes whose prefixes and namespace URIs match the current in-scope prefixes.
if attrNode.prefix and attrNode.prefix in current_prefixes and current_prefixes[attrNode.prefix] == attrNode.namespaceURI:
# Attribute and prefix are matched. Do nothing.
continue
# If the attribute's namespace has a declared prefix in the current
# scope, change the attribute's prefix to that prefix. If there is
# more than one such prefix, pick one that has the "most local" binding.
if current_prefixes.has_namespace(attrNode.namespaceURI):
prefix = current_prefix.prefix_from_namespace(attrNode.namespaceURI)
change_attribute_prefix(attrNode, prefix)
continue
# The attribute's namespace has no associated prefix yet. We need to
# declare one. If we can use the existing prefix (i.e. it's not
# already defined), do so.
if attrNode.prefix not in current_prefixes:
new_prefixes[attrNode.prefix] = attrNode.namespaceURI
current_prefixes[attrNode.prefix] = attrNode.namespaceURI
continue
# The attribute's namespace has no associated prefix, and the
# attribute's current prefix is already taken. Generate one.
j = 1
while True:
generated_prefix = "NS%d" % (j,)
if generated_prefix not in current_prefixes:
break
j += 1
# Declare the new prefix
new_prefixes[generated_prefix] = attrNode.namespaceURI
current_prefixes[generated_prefix] = attrNode.namespaceURI
# Change attribute's prefix
change_attribute_prefix(attrNode, generated_prefix)
# Update the namespace declarations on the element.
replace_namespace_declarations(element, new_prefixes)
# HACK - Remove xmlns='' attribute if it doesn't need to be there.
if (new_prefixes.get(None, object()) == EMPTY_NAMESPACE and
parent_prefixes.get(None, object()) == EMPTY_NAMESPACE and
element.hasAttributeNS(XMLNS_NAMESPACE, 'xmlns') and
not element.getAttributeNS(XMLNS_NAMESPACE, 'xmlns')):
element.removeAttributeNS(XMLNS_NAMESPACE, 'xmlns')
# Recurse over child elements
for e in element.childNodes:
if e.nodeType == element.ELEMENT_NODE:
normalize_namespaces(e, strip_dups=strip_dups, parent_prefixes=current_prefixes)
