blob: cc0a069495c1c15425b37a56b63553748be23089 [file] [log] [blame]
import sys
from os.path import dirname, join
from collections import OrderedDict
from xml.parsers import expat
import xml.etree.ElementTree as etree # noqa: N813
MYPY = False
if MYPY:
# MYPY is set to True when run under Mypy.
from typing import Dict
from typing import List
from typing import Optional
from typing import Text
from typing import Union
_catalog = join(dirname(__file__), "catalog")
def _wrap_error(e):
# type: (expat.error) -> etree.ParseError
err = etree.ParseError(e)
err.code = e.code # type: ignore
err.position = e.lineno, e.offset # type: ignore
raise err
_names = {} # type: Dict[str, str]
def _fixname(key):
# type: (str) -> str
try:
name = _names[key]
except KeyError:
name = key
if "}" in name:
name = "{" + name
_names[key] = name
return name
if sys.version_info[0:2] >= (3, 2):
_undefined_entity_code = expat.errors.codes[expat.errors.XML_ERROR_UNDEFINED_ENTITY] # type: int
else:
_codes = {expat.ErrorString(i): i for i in range(0x100)} # type: Dict[str, int]
_undefined_entity_code = _codes[expat.errors.XML_ERROR_UNDEFINED_ENTITY]
class XMLParser(object):
"""
An XML parser with support for XHTML DTDs and all Python-supported encodings
This implements the API defined by
xml.etree.ElementTree.XMLParser, but supports XHTML DTDs
(therefore allowing XHTML entities) and supports all encodings
Python does, rather than just those supported by expat.
"""
def __init__(self, encoding=None):
# type: (Optional[str]) -> None
self._parser = expat.ParserCreate(encoding, "}")
self._target = etree.TreeBuilder()
# parser settings
self._parser.buffer_text = True
self._parser.ordered_attributes = True
self._parser.SetParamEntityParsing(expat.XML_PARAM_ENTITY_PARSING_UNLESS_STANDALONE)
# parser callbacks
self._parser.XmlDeclHandler = self._xml_decl
self._parser.StartElementHandler = self._start
self._parser.EndElementHandler = self._end
self._parser.CharacterDataHandler = self._data
self._parser.ExternalEntityRefHandler = self._external
self._parser.SkippedEntityHandler = self._skipped # type: ignore
# used for our horrible re-encoding hack
self._fed_data = [] # type: Optional[List[bytes]]
self._read_encoding = None # type: Optional[str]
def _xml_decl(self, version, encoding, standalone):
# type: (str, Optional[str], int) -> None
self._read_encoding = encoding
def _start(self, tag, attrib_in):
# type: (str, List[str]) -> etree.Element
self._fed_data = None
tag = _fixname(tag)
attrib = OrderedDict() # type: Dict[Union[str, Text], Union[str, Text]]
if attrib_in:
for i in range(0, len(attrib_in), 2):
attrib[_fixname(attrib_in[i])] = attrib_in[i+1]
return self._target.start(tag, attrib)
def _data(self, text):
# type: (str) -> None
self._target.data(text)
def _end(self, tag):
# type: (str) -> etree.Element
return self._target.end(_fixname(tag))
def _external(self, context, base, system_id, public_id):
# type: (str, Optional[str], Optional[str], Optional[str]) -> bool
if public_id in {
"-//W3C//DTD XHTML 1.0 Transitional//EN",
"-//W3C//DTD XHTML 1.1//EN",
"-//W3C//DTD XHTML 1.0 Strict//EN",
"-//W3C//DTD XHTML 1.0 Frameset//EN",
"-//W3C//DTD XHTML Basic 1.0//EN",
"-//W3C//DTD XHTML 1.1 plus MathML 2.0//EN",
"-//W3C//DTD XHTML 1.1 plus MathML 2.0 plus SVG 1.1//EN",
"-//W3C//DTD MathML 2.0//EN",
"-//WAPFORUM//DTD XHTML Mobile 1.0//EN"
}:
parser = self._parser.ExternalEntityParserCreate(context)
with open(join(_catalog, "xhtml.dtd"), "rb") as fp:
try:
parser.ParseFile(fp)
except expat.error:
return False
return True
def _skipped(self, name, is_parameter_entity):
# type: (str, bool) -> None
err = expat.error("undefined entity %s: line %d, column %d" %
(name, self._parser.ErrorLineNumber,
self._parser.ErrorColumnNumber))
err.code = _undefined_entity_code
err.lineno = self._parser.ErrorLineNumber
err.offset = self._parser.ErrorColumnNumber
raise err
def feed(self, data):
# type: (str) -> None
if self._fed_data is not None:
self._fed_data.append(data)
try:
self._parser.Parse(data, False)
except expat.error as v:
_wrap_error(v)
except ValueError as e:
if e.args[0] == 'multi-byte encodings are not supported':
assert self._read_encoding is not None
assert self._fed_data is not None
xml = b"".join(self._fed_data).decode(self._read_encoding).encode("utf-8")
new_parser = XMLParser("utf-8")
self._parser = new_parser._parser
self._target = new_parser._target
self._fed_data = None
self.feed(xml)
def close(self):
# type: () -> etree.Element
try:
self._parser.Parse("", True)
except expat.error as v:
_wrap_error(v)
tree = self._target.close()
return tree