You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
isso/isso/utils/html.py

104 lines
3.0 KiB

# -*- encoding: utf-8 -*-
from __future__ import unicode_literals
import operator
import pkg_resources
from distutils.version import LooseVersion as Version
HTML5LIB_VERSION = Version(pkg_resources.get_distribution("html5lib").version)
HTML5LIB_SIMPLETREE = Version("0.95")
from isso.compat import reduce
import html5lib
from html5lib.sanitizer import HTMLSanitizer
from html5lib.serializer import HTMLSerializer
import misaka
def Sanitizer(elements, attributes):
class Inner(HTMLSanitizer):
# attributes found in Sundown's HTML serializer [1] except for <img> tag,
# because images are not generated anyways.
#
# [1] https://github.com/vmg/sundown/blob/master/html/html.c
allowed_elements = ["a", "p", "hr", "br", "ol", "ul", "li",
"pre", "code", "blockquote",
"del", "ins", "strong", "em",
"h1", "h2", "h3", "h4", "h5", "h6",
"table", "thead", "tbody", "th", "td"] + elements
# href for <a> and align for <table>
allowed_attributes = ["align", "href"] + attributes
# remove disallowed tokens from the output
def disallowed_token(self, token, token_type):
return None
return Inner
def sanitize(tokenizer, document):
parser = html5lib.HTMLParser(tokenizer=tokenizer)
domtree = parser.parseFragment(document)
if HTML5LIB_VERSION > HTML5LIB_SIMPLETREE:
builder = "etree"
else:
builder = "simpletree"
stream = html5lib.treewalkers.getTreeWalker(builder)(domtree)
serializer = HTMLSerializer(
quote_attr_values=True, omit_optional_tags=False)
return serializer.render(stream)
def Markdown(extensions=("strikethrough", "superscript", "autolink")):
flags = reduce(operator.xor, map(
lambda ext: getattr(misaka, 'EXT_' + ext.upper()), extensions), 0)
md = misaka.Markdown(Unofficial(), extensions=flags)
def inner(text):
rv = md.render(text).rstrip("\n")
if rv.startswith("<p>") or rv.endswith("</p>"):
return rv
return "<p>" + rv + "</p>"
return inner
class Unofficial(misaka.HtmlRenderer):
"""A few modifications to process "common" Markdown.
For instance, fenced code blocks (~~~ or ```) are just wrapped in <code>
which does not preserve line breaks. If a language is given, it is added
to <code class="$lang">, compatible with Highlight.js.
"""
def block_code(self, text, lang):
lang = ' class="{0}"'.format(lang) if lang else ''
return "<pre><code{1}>{0}</code></pre>\n".format(text, lang)
class Markup(object):
def __init__(self, conf):
parser = Markdown(conf.getlist("options"))
sanitizer = Sanitizer(
conf.getlist("allowed-elements"),
conf.getlist("allowed-attributes"))
self._render = lambda text: sanitize(sanitizer, parser(text))
def render(self, text):
return self._render(text)