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101 lines
3.1 KiB
101 lines
3.1 KiB
# -*- encoding: utf-8 -*-
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from __future__ import unicode_literals
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import bleach
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import misaka
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try:
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from backports.configparser import NoOptionError
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except ImportError:
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from configparser import NoOptionError
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class Sanitizer(object):
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def __init__(self, elements, attributes):
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# attributes found in Sundown's HTML serializer [1]
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# except for <img> tag,
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# because images are not generated anyways.
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#
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# [1] https://github.com/vmg/sundown/blob/master/html/html.c
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self.elements = ["a", "p", "hr", "br", "ol", "ul", "li",
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"pre", "code", "blockquote",
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"del", "ins", "strong", "em",
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"h1", "h2", "h3", "h4", "h5", "h6",
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"table", "thead", "tbody", "th", "td"] + elements
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# href for <a> and align for <table>
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self.attributes = ["align", "href"] + attributes
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def sanitize(self, text):
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clean_html = bleach.clean(text, tags=self.elements, attributes=self.attributes, strip=True)
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def set_links(attrs, new=False):
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href_key = (None, u'href')
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if href_key not in attrs:
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return attrs
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if attrs[href_key].startswith(u'mailto:'):
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return attrs
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rel_key = (None, u'rel')
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rel_values = [val for val in attrs.get(rel_key, u'').split(u' ') if val]
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for value in [u'nofollow', u'noopener']:
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if value not in [rel_val.lower() for rel_val in rel_values]:
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rel_values.append(value)
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attrs[rel_key] = u' '.join(rel_values)
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return attrs
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linker = bleach.linkifier.Linker(callbacks=[set_links])
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return linker.linkify(clean_html)
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def Markdown(extensions=("strikethrough", "superscript", "autolink",
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"fenced-code"), flags=[]):
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renderer = Unofficial(flags=flags)
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md = misaka.Markdown(renderer, extensions=extensions)
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def inner(text):
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rv = md(text).rstrip("\n")
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if rv.startswith("<p>") or rv.endswith("</p>"):
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return rv
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return "<p>" + rv + "</p>"
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return inner
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class Unofficial(misaka.HtmlRenderer):
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"""A few modifications to process "common" Markdown.
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For instance, fenced code blocks (~~~ or ```) are just wrapped in <code>
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which does not preserve line breaks. If a language is given, it is added
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to <code class="$lang">, compatible with Highlight.js.
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"""
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def blockcode(self, text, lang):
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lang = ' class="{0}"'.format(lang) if lang else ''
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return "<pre><code{1}>{0}</code></pre>\n".format(text, lang)
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class Markup(object):
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def __init__(self, conf):
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try:
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conf_flags = conf.getlist("flags")
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except NoOptionError:
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conf_flags = []
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parser = Markdown(extensions=conf.getlist("options"), flags=conf_flags)
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sanitizer = Sanitizer(
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conf.getlist("allowed-elements"),
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conf.getlist("allowed-attributes"))
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self._render = lambda text: sanitizer.sanitize(parser(text))
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def render(self, text):
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return self._render(text)
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