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stackdump/python/packages/markdown/serializers.py
Samuel Lai 993bee4fc1 Added markdown parsing for comments so links in comments now appear properly.
Also rewrote part of the HTML rewriting code so it doesn't introduce an additional wrapping element in the output which was added due to a html5lib requirements on input.
2012-12-15 21:43:06 +11:00

276 lines
9.3 KiB
Python

# markdown/searializers.py
#
# Add x/html serialization to Elementree
# Taken from ElementTree 1.3 preview with slight modifications
#
# Copyright (c) 1999-2007 by Fredrik Lundh. All rights reserved.
#
# fredrik@pythonware.com
# http://www.pythonware.com
#
# --------------------------------------------------------------------
# The ElementTree toolkit is
#
# Copyright (c) 1999-2007 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.
# --------------------------------------------------------------------
import util
ElementTree = util.etree.ElementTree
QName = util.etree.QName
if hasattr(util.etree, 'test_comment'):
Comment = util.etree.test_comment
else:
Comment = util.etree.Comment
PI = util.etree.PI
ProcessingInstruction = util.etree.ProcessingInstruction
__all__ = ['to_html_string', 'to_xhtml_string']
HTML_EMPTY = ("area", "base", "basefont", "br", "col", "frame", "hr",
"img", "input", "isindex", "link", "meta" "param")
try:
HTML_EMPTY = set(HTML_EMPTY)
except NameError:
pass
_namespace_map = {
# "well-known" namespace prefixes
"http://www.w3.org/XML/1998/namespace": "xml",
"http://www.w3.org/1999/xhtml": "html",
"http://www.w3.org/1999/02/22-rdf-syntax-ns#": "rdf",
"http://schemas.xmlsoap.org/wsdl/": "wsdl",
# xml schema
"http://www.w3.org/2001/XMLSchema": "xs",
"http://www.w3.org/2001/XMLSchema-instance": "xsi",
# dublic core
"http://purl.org/dc/elements/1.1/": "dc",
}
def _raise_serialization_error(text):
raise TypeError(
"cannot serialize %r (type %s)" % (text, type(text).__name__)
)
def _encode(text, encoding):
try:
return text.encode(encoding, "xmlcharrefreplace")
except (TypeError, AttributeError):
_raise_serialization_error(text)
def _escape_cdata(text):
# escape character data
try:
# it's worth avoiding do-nothing calls for strings that are
# shorter than 500 character, or so. assume that's, by far,
# the most common case in most applications.
if "&" in text:
text = text.replace("&", "&")
if "<" in text:
text = text.replace("<", "&lt;")
if ">" in text:
text = text.replace(">", "&gt;")
return text
except (TypeError, AttributeError):
_raise_serialization_error(text)
def _escape_attrib(text):
# escape attribute value
try:
if "&" in text:
text = text.replace("&", "&amp;")
if "<" in text:
text = text.replace("<", "&lt;")
if ">" in text:
text = text.replace(">", "&gt;")
if "\"" in text:
text = text.replace("\"", "&quot;")
if "\n" in text:
text = text.replace("\n", "&#10;")
return text
except (TypeError, AttributeError):
_raise_serialization_error(text)
def _escape_attrib_html(text):
# escape attribute value
try:
if "&" in text:
text = text.replace("&", "&amp;")
if "<" in text:
text = text.replace("<", "&lt;")
if ">" in text:
text = text.replace(">", "&gt;")
if "\"" in text:
text = text.replace("\"", "&quot;")
return text
except (TypeError, AttributeError):
_raise_serialization_error(text)
def _serialize_html(write, elem, qnames, namespaces, format):
tag = elem.tag
text = elem.text
if tag is Comment:
write("<!--%s-->" % _escape_cdata(text))
elif tag is ProcessingInstruction:
write("<?%s?>" % _escape_cdata(text))
else:
tag = qnames[tag]
if tag is None:
if text:
write(_escape_cdata(text))
for e in elem:
_serialize_html(write, e, qnames, None, format)
else:
write("<" + tag)
items = elem.items()
if items or namespaces:
items.sort() # lexical order
for k, v in items:
if isinstance(k, QName):
k = k.text
if isinstance(v, QName):
v = qnames[v.text]
else:
v = _escape_attrib_html(v)
if qnames[k] == v and format == 'html':
# handle boolean attributes
write(" %s" % v)
else:
write(" %s=\"%s\"" % (qnames[k], v))
if namespaces:
items = namespaces.items()
items.sort(key=lambda x: x[1]) # sort on prefix
for v, k in items:
if k:
k = ":" + k
write(" xmlns%s=\"%s\"" % (k, _escape_attrib(v)))
if format == "xhtml" and tag in HTML_EMPTY:
write(" />")
else:
write(">")
tag = tag.lower()
if text:
if tag == "script" or tag == "style":
write(text)
else:
write(_escape_cdata(text))
for e in elem:
_serialize_html(write, e, qnames, None, format)
if tag not in HTML_EMPTY:
write("</" + tag + ">")
if elem.tail:
write(_escape_cdata(elem.tail))
def _write_html(root,
encoding=None,
default_namespace=None,
format="html"):
assert root is not None
data = []
write = data.append
qnames, namespaces = _namespaces(root, default_namespace)
_serialize_html(write, root, qnames, namespaces, format)
if encoding is None:
return "".join(data)
else:
return _encode("".join(data))
# --------------------------------------------------------------------
# serialization support
def _namespaces(elem, default_namespace=None):
# identify namespaces used in this tree
# maps qnames to *encoded* prefix:local names
qnames = {None: None}
# maps uri:s to prefixes
namespaces = {}
if default_namespace:
namespaces[default_namespace] = ""
def add_qname(qname):
# calculate serialized qname representation
try:
if qname[:1] == "{":
uri, tag = qname[1:].split("}", 1)
prefix = namespaces.get(uri)
if prefix is None:
prefix = _namespace_map.get(uri)
if prefix is None:
prefix = "ns%d" % len(namespaces)
if prefix != "xml":
namespaces[uri] = prefix
if prefix:
qnames[qname] = "%s:%s" % (prefix, tag)
else:
qnames[qname] = tag # default element
else:
if default_namespace:
raise ValueError(
"cannot use non-qualified names with "
"default_namespace option"
)
qnames[qname] = qname
except TypeError:
_raise_serialization_error(qname)
# populate qname and namespaces table
try:
iterate = elem.iter
except AttributeError:
iterate = elem.getiterator # cET compatibility
for elem in iterate():
tag = elem.tag
if isinstance(tag, QName) and tag.text not in qnames:
add_qname(tag.text)
elif isinstance(tag, basestring):
if tag not in qnames:
add_qname(tag)
elif tag is not None and tag is not Comment and tag is not PI:
_raise_serialization_error(tag)
for key, value in elem.items():
if isinstance(key, QName):
key = key.text
if key not in qnames:
add_qname(key)
if isinstance(value, QName) and value.text not in qnames:
add_qname(value.text)
text = elem.text
if isinstance(text, QName) and text.text not in qnames:
add_qname(text.text)
return qnames, namespaces
def to_html_string(element):
return _write_html(ElementTree(element).getroot(), format="html")
def to_xhtml_string(element):
return _write_html(ElementTree(element).getroot(), format="xhtml")