"""\
A library of useful helper classes to the SAX classes, for the
convenience of application and driver writers.
"""

import os, urlparse, urllib, types
import handler
import xmlreader

try:
_StringTypes = [types.StringType, types.UnicodeType]
except AttributeError:
_StringTypes = [types.StringType]

# See whether the xmlcharrefreplace error handler is
# supported
try:
from codecs import xmlcharrefreplace_errors
_error_handling = "xmlcharrefreplace"
del xmlcharrefreplace_errors
except ImportError:
_error_handling = "strict"

def __dict_replace(s, d):
"""Replace substrings of a string using a dictionary."""
for key, value in d.items():
s = s.replace(key, value)
return s

def escape(data, entities={}):
"""Escape &, <, and > in a string of data.

You can escape other strings of data by passing a dictionary as
the optional entities parameter. The keys and values must all be
strings; each key will be replaced with its corresponding value.
"""

# must do ampersand first
data = data.replace("&", "&amp;")
data = data.replace(">", "&gt;")
data = data.replace("<", "&lt;")
if entities:
data = __dict_replace(data, entities)
return data

def unescape(data, entities={}):
"""Unescape &amp;, &lt;, and &gt; in a string of data.

You can unescape other strings of data by passing a dictionary as
the optional entities parameter. The keys and values must all be
strings; each key will be replaced with its corresponding value.
"""
data = data.replace("&lt;", "<")
data = data.replace("&gt;", ">")
if entities:
data = __dict_replace(data, entities)
# must do ampersand last
return data.replace("&amp;", "&")

def quoteattr(data, entities={}):
"""Escape and quote an attribute value.

Escape &, <, and > in a string of data, then quote it for use as
an attribute value. The \" character will be escaped as well, if
necessary.

You can escape other strings of data by passing a dictionary as
the optional entities parameter. The keys and values must all be
strings; each key will be replaced with its corresponding value.
"""
entities = entities.copy()
entities.update({'\n': '&#10;', '\r': '&#13;', '\t':'&#9;'})
data = escape(data, entities)
if '"' in data:
if "'" in data:
data = '"%s"' % data.replace('"', "&quot;")
else:
data = "'%s'" % data
else:
data = '"%s"' % data
return data


class XMLGenerator(handler.ContentHandler):

def __init__(self, out=None, encoding="iso-8859-1"):
if out is None:
import sys
out = sys.stdout
handler.ContentHandler.__init__(self)
self._out = out
self._ns_contexts = [{}] # contains uri -> prefix dicts
self._current_context = self._ns_contexts[-1]
self._undeclared_ns_maps = []
self._encoding = encoding

def _write(self, text):
if isinstance(text, str):
self._out.write(text)
else:
self._out.write(text.encode(self._encoding, _error_handling))

def _qname(self, name):
"""Builds a qualified name from a (ns_url, localname) pair"""
if name[0]:
# The name is in a non-empty namespace
prefix = self._current_context[name[0]]
if prefix:
# If it is not the default namespace, prepend the prefix
return prefix + ":" + name[1]
# Return the unqualified name
return name[1]

# ContentHandler methods

def startDocument(self):
self._write('<?xml version="1.0" encoding="%s"?>\n' %
self._encoding)

def startPrefixMapping(self, prefix, uri):
self._ns_contexts.append(self._current_context.copy())
self._current_context[uri] = prefix
self._undeclared_ns_maps.append((prefix, uri))

def endPrefixMapping(self, prefix):
self._current_context = self._ns_contexts[-1]
del self._ns_contexts[-1]

def startElement(self, name, attrs):
self._write('<' + name)
for (name, value) in attrs.items():
self._write(' %s=%s' % (name, quoteattr(value)))
self._write('>')

def endElement(self, name):
self._write('</%s>' % name)

def startElementNS(self, name, qname, attrs):
self._write('<' + self._qname(name))

for prefix, uri in self._undeclared_ns_maps:
if prefix:
self._out.write(' xmlns:%s="%s"' % (prefix, uri))
else:
self._out.write(' xmlns="%s"' % uri)
self._undeclared_ns_maps = []

for (name, value) in attrs.items():
self._write(' %s=%s' % (self._qname(name), quoteattr(value)))
self._write('>')

def endElementNS(self, name, qname):
self._write('</%s>' % self._qname(name))

def characters(self, content):
self._write(escape(content))

def ignorableWhitespace(self, content):
self._write(content)

def processingInstruction(self, target, data):
self._write('<?%s %s?>' % (target, data))


class XMLFilterBase(xmlreader.XMLReader):
"""This class is designed to sit between an XMLReader and the
client application's event handlers. By default, it does nothing
but pass requests up to the reader and events on to the handlers
unmodified, but subclasses can override specific methods to modify
the event stream or the configuration requests as they pass
through."""

def __init__(self, parent = None):
xmlreader.XMLReader.__init__(self)
self._parent = parent

# ErrorHandler methods

def error(self, exception):
self._err_handler.error(exception)

def fatalError(self, exception):
self._err_handler.fatalError(exception)

def warning(self, exception):
self._err_handler.warning(exception)

# ContentHandler methods

def setDocumentLocator(self, locator):
self._cont_handler.setDocumentLocator(locator)

def startDocument(self):
self._cont_handler.startDocument()

def endDocument(self):
self._cont_handler.endDocument()

def startPrefixMapping(self, prefix, uri):
self._cont_handler.startPrefixMapping(prefix, uri)

def endPrefixMapping(self, prefix):
self._cont_handler.endPrefixMapping(prefix)

def startElement(self, name, attrs):
self._cont_handler.startElement(name, attrs)

def endElement(self, name):
self._cont_handler.endElement(name)

def startElementNS(self, name, qname, attrs):
self._cont_handler.startElementNS(name, qname, attrs)

def endElementNS(self, name, qname):
self._cont_handler.endElementNS(name, qname)

def characters(self, content):
self._cont_handler.characters(content)

def ignorableWhitespace(self, chars):
self._cont_handler.ignorableWhitespace(chars)

def processingInstruction(self, target, data):
self._cont_handler.processingInstruction(target, data)

def skippedEntity(self, name):
self._cont_handler.skippedEntity(name)

# DTDHandler methods

def notationDecl(self, name, publicId, systemId):
self._dtd_handler.notationDecl(name, publicId, systemId)

def unparsedEntityDecl(self, name, publicId, systemId, ndata):
self._dtd_handler.unparsedEntityDecl(name, publicId, systemId, ndata)

# EntityResolver methods

def resolveEntity(self, publicId, systemId):
return self._ent_handler.resolveEntity(publicId, systemId)

# XMLReader methods

def parse(self, source):
self._parent.setContentHandler(self)
self._parent.setErrorHandler(self)
self._parent.setEntityResolver(self)
self._parent.setDTDHandler(self)
self._parent.parse(source)

def setLocale(self, locale):
self._parent.setLocale(locale)

def getFeature(self, name):
return self._parent.getFeature(name)

def setFeature(self, name, state):
self._parent.setFeature(name, state)

def getProperty(self, name):
return self._parent.getProperty(name)

def setProperty(self, name, value):
self._parent.setProperty(name, value)

# XMLFilter methods

def getParent(self):
return self._parent

def setParent(self, parent):
self._parent = parent

# --- Utility functions

def prepare_input_source(source, base = ""):
"""This function takes an InputSource and an optional base URL and
returns a fully resolved InputSource object ready for reading."""

if type(source) in _StringTypes:
source = xmlreader.InputSource(source)
elif hasattr(source, "read"):
f = source
source = xmlreader.InputSource()
source.setByteStream(f)
if hasattr(f, "name"):
source.setSystemId(f.name)

if source.getByteStream() is None:
sysid = source.getSystemId()
basehead = os.path.dirname(os.path.normpath(base))
sysidfilename = os.path.join(basehead, sysid)
if os.path.isfile(sysidfilename):
source.setSystemId(sysidfilename)
f = open(sysidfilename, "rb")
else:
source.setSystemId(urlparse.urljoin(base, sysid))
f = urllib.urlopen(source.getSystemId())

source.setByteStream(f)

return source