diff options
Diffstat (limited to '.venv/lib/python3.12/site-packages/lxml/sax.py')
| -rw-r--r-- | .venv/lib/python3.12/site-packages/lxml/sax.py | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/lxml/sax.py b/.venv/lib/python3.12/site-packages/lxml/sax.py new file mode 100644 index 00000000..eee44226 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/lxml/sax.py @@ -0,0 +1,275 @@ +# cython: language_level=2 + +""" +SAX-based adapter to copy trees from/to the Python standard library. + +Use the `ElementTreeContentHandler` class to build an ElementTree from +SAX events. + +Use the `ElementTreeProducer` class or the `saxify()` function to fire +the SAX events of an ElementTree against a SAX ContentHandler. + +See https://lxml.de/sax.html +""" + + +from xml.sax.handler import ContentHandler +from lxml import etree +from lxml.etree import ElementTree, SubElement +from lxml.etree import Comment, ProcessingInstruction + + +class SaxError(etree.LxmlError): + """General SAX error. + """ + + +def _getNsTag(tag): + if tag[0] == '{': + return tuple(tag[1:].split('}', 1)) + else: + return None, tag + + +class ElementTreeContentHandler(ContentHandler): + """Build an lxml ElementTree from SAX events. + """ + def __init__(self, makeelement=None): + ContentHandler.__init__(self) + self._root = None + self._root_siblings = [] + self._element_stack = [] + self._default_ns = None + self._ns_mapping = { None : [None] } + self._new_mappings = {} + if makeelement is None: + makeelement = etree.Element + self._makeelement = makeelement + + def _get_etree(self): + "Contains the generated ElementTree after parsing is finished." + return ElementTree(self._root) + + etree = property(_get_etree, doc=_get_etree.__doc__) + + def setDocumentLocator(self, locator): + pass + + def startDocument(self): + pass + + def endDocument(self): + pass + + def startPrefixMapping(self, prefix, uri): + self._new_mappings[prefix] = uri + try: + self._ns_mapping[prefix].append(uri) + except KeyError: + self._ns_mapping[prefix] = [uri] + if prefix is None: + self._default_ns = uri + + def endPrefixMapping(self, prefix): + ns_uri_list = self._ns_mapping[prefix] + ns_uri_list.pop() + if prefix is None: + self._default_ns = ns_uri_list[-1] + + def _buildTag(self, ns_name_tuple): + ns_uri, local_name = ns_name_tuple + if ns_uri: + el_tag = "{%s}%s" % ns_name_tuple + elif self._default_ns: + el_tag = "{%s}%s" % (self._default_ns, local_name) + else: + el_tag = local_name + return el_tag + + def startElementNS(self, ns_name, qname, attributes=None): + el_name = self._buildTag(ns_name) + if attributes: + attrs = {} + try: + iter_attributes = attributes.iteritems() + except AttributeError: + iter_attributes = attributes.items() + + for name_tuple, value in iter_attributes: + if name_tuple[0]: + attr_name = "{%s}%s" % name_tuple + else: + attr_name = name_tuple[1] + attrs[attr_name] = value + else: + attrs = None + + element_stack = self._element_stack + if self._root is None: + element = self._root = \ + self._makeelement(el_name, attrs, self._new_mappings) + if self._root_siblings and hasattr(element, 'addprevious'): + for sibling in self._root_siblings: + element.addprevious(sibling) + del self._root_siblings[:] + else: + element = SubElement(element_stack[-1], el_name, + attrs, self._new_mappings) + element_stack.append(element) + + self._new_mappings.clear() + + def processingInstruction(self, target, data): + pi = ProcessingInstruction(target, data) + if self._root is None: + self._root_siblings.append(pi) + else: + self._element_stack[-1].append(pi) + + def endElementNS(self, ns_name, qname): + element = self._element_stack.pop() + el_tag = self._buildTag(ns_name) + if el_tag != element.tag: + raise SaxError("Unexpected element closed: " + el_tag) + + def startElement(self, name, attributes=None): + if attributes: + attributes = {(None, k): v for k, v in attributes.items()} + self.startElementNS((None, name), name, attributes) + + def endElement(self, name): + self.endElementNS((None, name), name) + + def characters(self, data): + last_element = self._element_stack[-1] + try: + # if there already is a child element, we must append to its tail + last_element = last_element[-1] + last_element.tail = (last_element.tail or '') + data + except IndexError: + # otherwise: append to the text + last_element.text = (last_element.text or '') + data + + ignorableWhitespace = characters + + +class ElementTreeProducer: + """Produces SAX events for an element and children. + """ + def __init__(self, element_or_tree, content_handler): + try: + element = element_or_tree.getroot() + except AttributeError: + element = element_or_tree + self._element = element + self._content_handler = content_handler + from xml.sax.xmlreader import AttributesNSImpl as attr_class + self._attr_class = attr_class + self._empty_attributes = attr_class({}, {}) + + def saxify(self): + self._content_handler.startDocument() + + element = self._element + if hasattr(element, 'getprevious'): + siblings = [] + sibling = element.getprevious() + while getattr(sibling, 'tag', None) is ProcessingInstruction: + siblings.append(sibling) + sibling = sibling.getprevious() + for sibling in siblings[::-1]: + self._recursive_saxify(sibling, {}) + + self._recursive_saxify(element, {}) + + if hasattr(element, 'getnext'): + sibling = element.getnext() + while getattr(sibling, 'tag', None) is ProcessingInstruction: + self._recursive_saxify(sibling, {}) + sibling = sibling.getnext() + + self._content_handler.endDocument() + + def _recursive_saxify(self, element, parent_nsmap): + content_handler = self._content_handler + tag = element.tag + if tag is Comment or tag is ProcessingInstruction: + if tag is ProcessingInstruction: + content_handler.processingInstruction( + element.target, element.text) + tail = element.tail + if tail: + content_handler.characters(tail) + return + + element_nsmap = element.nsmap + new_prefixes = [] + if element_nsmap != parent_nsmap: + # There have been updates to the namespace + for prefix, ns_uri in element_nsmap.items(): + if parent_nsmap.get(prefix) != ns_uri: + new_prefixes.append( (prefix, ns_uri) ) + + attribs = element.items() + if attribs: + attr_values = {} + attr_qnames = {} + for attr_ns_name, value in attribs: + attr_ns_tuple = _getNsTag(attr_ns_name) + attr_values[attr_ns_tuple] = value + attr_qnames[attr_ns_tuple] = self._build_qname( + attr_ns_tuple[0], attr_ns_tuple[1], element_nsmap, + preferred_prefix=None, is_attribute=True) + sax_attributes = self._attr_class(attr_values, attr_qnames) + else: + sax_attributes = self._empty_attributes + + ns_uri, local_name = _getNsTag(tag) + qname = self._build_qname( + ns_uri, local_name, element_nsmap, element.prefix, is_attribute=False) + + for prefix, uri in new_prefixes: + content_handler.startPrefixMapping(prefix, uri) + content_handler.startElementNS( + (ns_uri, local_name), qname, sax_attributes) + text = element.text + if text: + content_handler.characters(text) + for child in element: + self._recursive_saxify(child, element_nsmap) + content_handler.endElementNS((ns_uri, local_name), qname) + for prefix, uri in new_prefixes: + content_handler.endPrefixMapping(prefix) + tail = element.tail + if tail: + content_handler.characters(tail) + + def _build_qname(self, ns_uri, local_name, nsmap, preferred_prefix, is_attribute): + if ns_uri is None: + return local_name + + if not is_attribute and nsmap.get(preferred_prefix) == ns_uri: + prefix = preferred_prefix + else: + # Pick the first matching prefix, in alphabetical order. + candidates = [ + pfx for (pfx, uri) in nsmap.items() + if pfx is not None and uri == ns_uri + ] + prefix = ( + candidates[0] if len(candidates) == 1 + else min(candidates) if candidates + else None + ) + + if prefix is None: + # Default namespace + return local_name + return prefix + ':' + local_name + + +def saxify(element_or_tree, content_handler): + """One-shot helper to generate SAX events from an XML tree and fire + them against a SAX ContentHandler. + """ + return ElementTreeProducer(element_or_tree, content_handler).saxify() |