# A simple XML-generator# Originally Lars Marius Garshol, September 1998
# http://mail.python.org/pipermail/xml-sig/1998-September/000347.html
# Changes by Uche Ogbuji April 2003
# * unicode support: accept encoding argument and use Python codecs
# for correct character output
# * switch from deprecated string module to string methods
# * use PEP 8 style

import sys
import codecs

class XMLWriter:

def __init__(self, out=sys.stdout, encoding="utf-8", indent=u" "):
"""
out - a stream for the output
encoding - an encoding used to wrap the output for unicode
indent - white space used for indentation
"""
wrapper = codecs.lookup(encoding)[3]
self.out = wrapper(out)
self.stack = []
self.indent = indent
self.out.write(u'\n' \
% encoding)

def doctype(self, root, pubid, sysid):
"""
Create a document type declaration (no internal subset)
"""
if pubid == None:
self.out.write(
u"\n" % (root, sysid))
else:
self.out.write(
u"\n" \
% (root, pubid, sysid))

def push(self, elem, attrs={}):
"""
Create an element which will have child elements
"""
self.__indent()
self.out.write("<" + elem)
for (a, v) in attrs.items():
self.out.write(u" %s='%s'" % (a, self.__escape_attr(v)))
self.out.write(u">\n")
self.stack.append(elem)

def elem(self, elem, content, attrs={}):
"""
Create an element with text content only
"""
self.__indent()
self.out.write(u"<" + elem)
for (a, v) in attrs.items():
self.out.write(u" %s='%s'" % (a, self.__escape_attr(v)))
self.out.write(u">%s\n" \
% (self.__escape_cont(content), elem))

def empty(self, elem, attrs={}):
"""
Create an empty element
"""
self.__indent()
self.out.write(u"<"+elem)
for a in attrs.items():
self.out.write(u" %s='%s'" % a)
self.out.write(u"/>\n")

def pop(self):
"""
Close an element started with the push() method
"""
elem=self.stack[-1]
del self.stack[-1]
self.__indent()
self.out.write(u"\n" % elem)

def __indent(self):
self.out.write(self.indent * (len(self.stack) * 2))

def __escape_cont(self, text):
return text.replace(u"&", u"&")\
.replace(u"<", u"<")

def __escape_attr(self, text):
return text.replace(u"&", u"&") \
.replace(u"'", u"'").replace(u"<", u"<")