Viewing file:  SimpleXMLWriter.py (8.69 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
#
# SimpleXMLWriter
# $Id: SimpleXMLWriter.py 2312 2005-03-02 18:13:39Z fredrik $
#
# a simple XML writer
#
# history:
# 2001-12-28 fl created
# 2002-11-25 fl fixed attribute encoding
# 2002-12-02 fl minor fixes for 1.5.2
# 2004-06-17 fl added pythondoc markup
# 2004-07-23 fl added flush method (from Jay Graves)
# 2004-10-03 fl added declaration method
#
# Copyright (c) 2001-2004 by Fredrik Lundh
#
# fredrik@pythonware.com
# http://www.pythonware.com
#
# --------------------------------------------------------------------
# The SimpleXMLWriter module is
#
# Copyright (c) 2001-2004 by Fredrik Lundh
#
# By obtaining, using, and/or copying this software and/or its
# associated documentation, you agree that you have read, understood,
# and will comply with the following terms and conditions:
#
# Permission to use, copy, modify, and distribute this software and
# its associated documentation for any purpose and without fee is
# hereby granted, provided that the above copyright notice appears in
# all copies, and that both that copyright notice and this permission
# notice appear in supporting documentation, and that the name of
# Secret Labs AB or the author not be used in advertising or publicity
# pertaining to distribution of the software without specific, written
# prior permission.
#
# SECRET LABS AB AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
# TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANT-
# ABILITY AND FITNESS. IN NO EVENT SHALL SECRET LABS AB OR THE AUTHOR
# BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY
# DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
# WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
# ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
# OF THIS SOFTWARE.
# --------------------------------------------------------------------
##
# Tools to write XML files, without having to deal with encoding
# issues, well-formedness, etc.
# <p>
# The current version does not provide built-in support for
# namespaces. To create files using namespaces, you have to provide
# "xmlns" attributes and explicitly add prefixes to tags and
# attributes.
#
# <h3>Patterns</h3>
#
# The following example generates a small XHTML document.
# <pre>
#
# from elementtree.SimpleXMLWriter import XMLWriter
# import sys
#
# w = XMLWriter(sys.stdout)
#
# html = w.start("html")
#
# w.start("head")
# w.element("title", "my document")
# w.element("meta", name="generator", value="my application 1.0")
# w.end()
#
# w.start("body")
# w.element("h1", "this is a heading")
# w.element("p", "this is a paragraph")
#
# w.start("p")
# w.data("this is ")
# w.element("b", "bold")
# w.data(" and ")
# w.element("i", "italic")
# w.data(".")
# w.end("p")
#
# w.close(html)
# </pre>
##
import re, sys, string
try:
unicode("")
except NameError:
def encode(s, encoding):
# 1.5.2: application must use the right encoding
return s
_escape = re.compile(r"[&<>\"\x80-\xff]+") # 1.5.2
else:
def encode(s, encoding):
return s.encode(encoding)
_escape = re.compile(eval(r'u"[&<>\"\u0080-\uffff]+"'))
def encode_entity(text, pattern=_escape):
# map reserved and non-ascii characters to numerical entities
def escape_entities(m):
out = []
for char in m.group():
out.append("&#%d;" % ord(char))
return string.join(out, "")
return encode(pattern.sub(escape_entities, text), "ascii")
del _escape
#
# the following functions assume an ascii-compatible encoding
# (or "utf-16")
def escape_cdata(s, encoding=None, replace=string.replace):
s = replace(s, "&", "&")
s = replace(s, "<", "<")
s = replace(s, ">", ">")
if encoding:
try:
return encode(s, encoding)
except UnicodeError:
return encode_entity(s)
return s
def escape_attrib(s, encoding=None, replace=string.replace):
s = replace(s, "&", "&")
s = replace(s, "'", "'")
s = replace(s, "\"", """)
s = replace(s, "<", "<")
s = replace(s, ">", ">")
if encoding:
try:
return encode(s, encoding)
except UnicodeError:
return encode_entity(s)
return s
##
# XML writer class.
#
# @param file A file or file-like object. This object must implement
# a <b>write</b> method that takes an 8-bit string.
# @param encoding Optional encoding.
class XMLWriter:
def __init__(self, file, encoding="us-ascii"):
if not hasattr(file, "write"):
file = open(file, "w")
self.__write = file.write
if hasattr(file, "flush"):
self.flush = file.flush
self.__open = 0 # true if start tag is open
self.__tags = []
self.__data = []
self.__encoding = encoding
def __flush(self):
# flush internal buffers
if self.__open:
self.__write(">")
self.__open = 0
if self.__data:
data = string.join(self.__data, "")
self.__write(escape_cdata(data, self.__encoding))
self.__data = []
##
# Writes an XML declaration.
def declaration(self):
encoding = self.__encoding
if encoding == "us-ascii" or encoding == "utf-8":
self.__write("<?xml version='1.0'?>\n")
else:
self.__write("<?xml version='1.0' encoding='%s'?>\n" % encoding)
##
# Opens a new element. Attributes can be given as keyword
# arguments, or as a string/string dictionary. You can pass in
# 8-bit strings or Unicode strings; the former are assumed to use
# the encoding passed to the constructor. The method returns an
# opaque identifier that can be passed to the <b>close</b> method,
# to close all open elements up to and including this one.
#
# @param tag Element tag.
# @param attrib Attribute dictionary. Alternatively, attributes
# can be given as keyword arguments.
# @return An element identifier.
def start(self, tag, attrib={}, **extra):
self.__flush()
tag = escape_cdata(tag, self.__encoding)
self.__data = []
self.__tags.append(tag)
self.__write("<%s" % tag)
if attrib or extra:
attrib = attrib.copy()
attrib.update(extra)
attrib = attrib.items()
attrib.sort()
for k, v in attrib:
k = escape_cdata(k, self.__encoding)
v = escape_attrib(v, self.__encoding)
self.__write(" %s=\"%s\"" % (k, v))
self.__open = 1
return len(self.__tags)-1
##
# Adds a comment to the output stream.
#
# @param comment Comment text, as an 8-bit string or Unicode string.
def comment(self, comment):
self.__flush()
self.__write("<!-- %s -->\n" % escape_cdata(comment, self.__encoding))
##
# Adds character data to the output stream.
#
# @param text Character data, as an 8-bit string or Unicode string.
def data(self, text):
self.__data.append(text)
##
# Closes the current element (opened by the most recent call to
# <b>start</b>).
#
# @param tag Element tag. If given, the tag must match the start
# tag. If omitted, the current element is closed.
def end(self, tag=None):
if tag:
assert self.__tags, "unbalanced end(%s)" % tag
assert escape_cdata(tag, self.__encoding) == self.__tags[-1],\
"expected end(%s), got %s" % (self.__tags[-1], tag)
else:
assert self.__tags, "unbalanced end()"
tag = self.__tags.pop()
if self.__data:
self.__flush()
elif self.__open:
self.__open = 0
self.__write(" />")
return
self.__write("</%s>" % tag)
##
# Closes open elements, up to (and including) the element identified
# by the given identifier.
#
# @param id Element identifier, as returned by the <b>start</b> method.
def close(self, id):
while len(self.__tags) > id:
self.end()
##
# Adds an entire element. This is the same as calling <b>start</b>,
# <b>data</b>, and <b>end</b> in sequence. The <b>text</b> argument
# can be omitted.
def element(self, tag, text=None, attrib={}, **extra):
apply(self.start, (tag, attrib), extra)
if text:
self.data(text)
self.end()
##
# Flushes the output stream.
def flush(self):
pass # replaced by the constructor
|