##############################################################################
#
# Copyright (c) 2001, 2002 Zope Foundation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL). A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.
#
##############################################################################
"""Generic Expat-based XML parser base class.
This creates a parser with namespace processing enabled.
"""
import logging
try:
# Python 2.x
from urllib import urlopen
except ImportError:
# Python 3.x
from urllib.request import urlopen
try:
unicode
except NameError:
unicode = str # Python 3.x
[docs]class XMLParser(object):
"""
Parse XML using :mod:`xml.parsers.expat`.
"""
ordered_attributes = 0
handler_names = [
"StartElementHandler",
"EndElementHandler",
"ProcessingInstructionHandler",
"CharacterDataHandler",
"UnparsedEntityDeclHandler",
"NotationDeclHandler",
"StartNamespaceDeclHandler",
"EndNamespaceDeclHandler",
"CommentHandler",
"StartCdataSectionHandler",
"EndCdataSectionHandler",
"DefaultHandler",
"DefaultHandlerExpand",
"NotStandaloneHandler",
"ExternalEntityRefHandler",
"XmlDeclHandler",
"StartDoctypeDeclHandler",
"EndDoctypeDeclHandler",
"ElementDeclHandler",
"AttlistDeclHandler"
]
def __init__(self, encoding=None):
self.parser = p = self.createParser(encoding)
if self.ordered_attributes:
try:
self.parser.ordered_attributes = self.ordered_attributes
except AttributeError:
logging.warn("TAL.XMLParser: Can't set ordered_attributes")
self.ordered_attributes = 0
for name in self.handler_names:
method = getattr(self, name, None)
if method is not None:
try:
setattr(p, name, method)
except AttributeError:
logging.error("TAL.XMLParser: Can't set "
"expat handler %s" % name)
def createParser(self, encoding=None):
global XMLParseError
from xml.parsers import expat
XMLParseError = expat.ExpatError
return expat.ParserCreate(encoding, ' ')
[docs] def parseFile(self, filename):
"""Parse from the given filename."""
with open(filename, 'rb') as f:
self.parseStream(f)
[docs] def parseString(self, s):
"""Parse the given string."""
if isinstance(s, unicode):
# Expat cannot deal with unicode strings, only with
# encoded ones. Also, its range of encodings is rather
# limited, UTF-8 is the safest bet here.
s = s.encode('utf-8')
self.parser.Parse(s, 1)
[docs] def parseURL(self, url):
"""Parse the given URL."""
self.parseStream(urlopen(url))
[docs] def parseStream(self, stream):
"""Parse the given stream (open file)."""
self.parser.ParseFile(stream)
def parseFragment(self, s, end=0):
self.parser.Parse(s, end)
def getpos(self):
# Apparently ErrorLineNumber and ErrorLineNumber contain the current
# position even when there was no error. This contradicts the official
# documentation[1], but expat.h[2] contains the following definition:
#
# /* For backwards compatibility with previous versions. */
# #define XML_GetErrorLineNumber XML_GetCurrentLineNumber
#
# [1] http://python.org/doc/current/lib/xmlparser-objects.html
# [2] http://cvs.sourceforge.net/viewcvs.py/expat/expat/lib/expat.h
return (self.parser.ErrorLineNumber, self.parser.ErrorColumnNumber)