# -*- coding: utf-8 -*-
from __future__ import unicode_literals
import logging
import re
import html5lib
from html5lib.sanitizer import HTMLSanitizer
from html5lib.serializer.htmlserializer import HTMLSerializer
from . import callbacks as linkify_callbacks
from .encoding import force_unicode
from .sanitizer import BleachSanitizer
VERSION = (1, 4, 2)
__version__ = '.'.join([str(n) for n in VERSION])
__all__ = ['clean', 'linkify']
log = logging.getLogger('bleach')
ALLOWED_TAGS = [
'a',
'abbr',
'acronym',
'b',
'blockquote',
'code',
'em',
'i',
'li',
'ol',
'strong',
'ul',
]
ALLOWED_ATTRIBUTES = {
'a': ['href', 'title'],
'abbr': ['title'],
'acronym': ['title'],
}
ALLOWED_STYLES = []
ALLOWED_PROTOCOLS = ['http', 'https', 'mailto']
TLDS = """ac ad ae aero af ag ai al am an ao aq ar arpa as asia at au aw ax az
ba bb bd be bf bg bh bi biz bj bm bn bo br bs bt bv bw by bz ca cat
cc cd cf cg ch ci ck cl cm cn co com coop cr cu cv cx cy cz de dj dk
dm do dz ec edu ee eg er es et eu fi fj fk fm fo fr ga gb gd ge gf gg
gh gi gl gm gn gov gp gq gr gs gt gu gw gy hk hm hn hr ht hu id ie il
im in info int io iq ir is it je jm jo jobs jp ke kg kh ki km kn kp
kr kw ky kz la lb lc li lk lr ls lt lu lv ly ma mc md me mg mh mil mk
ml mm mn mo mobi mp mq mr ms mt mu museum mv mw mx my mz na name nc ne
net nf ng ni nl no np nr nu nz om org pa pe pf pg ph pk pl pm pn post
pr pro ps pt pw py qa re ro rs ru rw sa sb sc sd se sg sh si sj sk sl
sm sn so sr ss st su sv sx sy sz tc td tel tf tg th tj tk tl tm tn to
tp tr travel tt tv tw tz ua ug uk us uy uz va vc ve vg vi vn vu wf ws
xn xxx ye yt yu za zm zw""".split()
# Make sure that .com doesn't get matched by .co first
TLDS.reverse()
PROTOCOLS = HTMLSanitizer.acceptable_protocols
url_re = re.compile(
r"""\(* # Match any opening parentheses.
\b(?<![@.])(?:(?:{0}):/{{0,3}}(?:(?:\w+:)?\[email protected])?)? # http://
([\w-]+\.)+(?:{1})(?:\:\d+)?(?!\.\w)\b # xx.yy.tld(:##)?
(?:[/?][^\s\{{\}}\|\\\^\[\]`<>"]*)?
# /path/zz (excluding "unsafe" chars from RFC 1738,
# except for # and ~, which happen in practice)
""".format('|'.join(PROTOCOLS), '|'.join(TLDS)),
re.IGNORECASE | re.VERBOSE | re.UNICODE)
proto_re = re.compile(r'^[\w-]+:/{0,3}', re.IGNORECASE)
punct_re = re.compile(r'([\.,]+)$')
email_re = re.compile(
r"""(?<!//)
(([-!#$%&'*+/=?^_`{0!s}|~0-9A-Z]+
(\.[-!#$%&'*+/=?^_`{1!s}|~0-9A-Z]+)* # dot-atom
|^"([\001-\010\013\014\016-\037!#-\[\]-\177]
|\\[\001-011\013\014\016-\177])*" # quoted-string
)@(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+[A-Z]{2,6})\.? # domain
""",
re.IGNORECASE | re.MULTILINE | re.VERBOSE)
NODE_TEXT = 4 # The numeric ID of a text node in simpletree.
ETREE_TAG = lambda x: "".join(['{http://www.w3.org/1999/xhtml}', x])
# a simple routine that returns the tag name with the namespace prefix
# as returned by etree's Element.tag attribute
DEFAULT_CALLBACKS = [linkify_callbacks.nofollow]
def clean(text, tags=ALLOWED_TAGS, attributes=ALLOWED_ATTRIBUTES,
styles=ALLOWED_STYLES, protocols=ALLOWED_PROTOCOLS, strip=False,
strip_comments=True):
"""Clean an HTML fragment and return it
:arg text: the text to clean
:arg tags: whitelist of allowed tags; defaults to
``bleach.ALLOWED_TAGS``
:arg attributes: whitelist of allowed attributes; defaults to
``bleach.ALLOWED_ATTRIBUTES``
:arg styles: whitelist of allowed css; defaults to
``bleach.ALLOWED_STYLES``
:arg protocols: whitelist of allowed protocols for links; defaults
to ``bleach.ALLOWED_PROTOCOLS``
:arg strip: whether or not to strip disallowed elements
:arg strip_comments: whether or not to strip HTML comments
"""
if not text:
return ''
text = force_unicode(text)
class s(BleachSanitizer):
allowed_elements = tags
allowed_attributes = attributes
allowed_css_properties = styles
allowed_protocols = protocols
strip_disallowed_elements = strip
strip_html_comments = strip_comments
parser = html5lib.HTMLParser(tokenizer=s)
return _render(parser.parseFragment(text))
def linkify(text, callbacks=DEFAULT_CALLBACKS, skip_pre=False,
parse_email=False, tokenizer=HTMLSanitizer):
"""Convert URL-like strings in an HTML fragment to links.
linkify() converts strings that look like URLs or domain names in a
blob of text that may be an HTML fragment to links, while preserving
(a) links already in the string, (b) urls found in attributes, and
(c) email addresses.
"""
text = force_unicode(text)
if not text:
return ''
parser = html5lib.HTMLParser(tokenizer=tokenizer)
forest = parser.parseFragment(text)
_seen = set([])
def replace_nodes(tree, new_frag, node, index=0):
"""
Doesn't really replace nodes, but inserts the nodes contained in
new_frag into the treee at position index and returns the number
of nodes inserted.
If node is passed in, it is removed from the tree
"""
count = 0
new_tree = parser.parseFragment(new_frag)
# capture any non-tag text at the start of the fragment
if new_tree.text:
if index == 0:
tree.text = tree.text or ''
tree.text += new_tree.text
else:
tree[index - 1].tail = tree[index - 1].tail or ''
tree[index - 1].tail += new_tree.text
# the put in the tagged elements into the old tree
for n in new_tree:
if n.tag == ETREE_TAG('a'):
_seen.add(n)
tree.insert(index + count, n)
count += 1
# if we got a node to remove...
if node is not None:
tree.remove(node)
return count
def strip_wrapping_parentheses(fragment):
"""Strips wrapping parentheses.
Returns a tuple of the following format::
(string stripped from wrapping parentheses,
count of stripped opening parentheses,
count of stripped closing parentheses)
"""
opening_parentheses = closing_parentheses = 0
# Count consecutive opening parentheses
# at the beginning of the fragment (string).
for char in fragment:
if char == '(':
opening_parentheses += 1
else:
break
if opening_parentheses:
newer_frag = ''
# Cut the consecutive opening brackets from the fragment.
fragment = fragment[opening_parentheses:]
# Reverse the fragment for easier detection of parentheses
# inside the URL.
reverse_fragment = fragment[::-1]
skip = False
for char in reverse_fragment:
# Remove the closing parentheses if it has a matching
# opening parentheses (they are balanced).
if (char == ')' and
closing_parentheses < opening_parentheses and
not skip):
closing_parentheses += 1
continue
# Do not remove ')' from the URL itself.
elif char != ')':
skip = True
newer_frag += char
fragment = newer_frag[::-1]
return fragment, opening_parentheses, closing_parentheses
def apply_callbacks(attrs, new):
for cb in callbacks:
attrs = cb(attrs, new)
if attrs is None:
return None
return attrs
def _render_inner(node):
out = ['' if node.text is None else node.text]
for subnode in node:
out.append(_render(subnode))
if subnode.tail:
out.append(subnode.tail)
return ''.join(out)
def linkify_nodes(tree, parse_text=True):
children = len(tree)
current_child = -1
# start at -1 to process the parent first
while current_child < len(tree):
if current_child < 0:
node = tree
if parse_text and node.text:
new_txt = old_txt = node.text
if parse_email:
new_txt = re.sub(email_re, email_repl, node.text)
if new_txt and new_txt != node.text:
node.text = ''
adj = replace_nodes(tree, new_txt, None, 0)
children += adj
current_child += adj
linkify_nodes(tree, True)
continue
new_txt = re.sub(url_re, link_repl, new_txt)
if new_txt != old_txt:
node.text = ''
adj = replace_nodes(tree, new_txt, None, 0)
children += adj
current_child += adj
continue
else:
node = tree[current_child]
if parse_text and node.tail:
new_tail = old_tail = node.tail
if parse_email:
new_tail = re.sub(email_re, email_repl, new_tail)
if new_tail != node.tail:
node.tail = ''
adj = replace_nodes(tree, new_tail, None,
current_child + 1)
# Insert the new nodes made from my tail into
# the tree right after me. current_child+1
children += adj
continue
new_tail = re.sub(url_re, link_repl, new_tail)
if new_tail != old_tail:
node.tail = ''
adj = replace_nodes(tree, new_tail, None,
current_child + 1)
children += adj
if node.tag == ETREE_TAG('a') and not (node in _seen):
if not node.get('href', None) is None:
attrs = dict(node.items())
_text = attrs['_text'] = _render_inner(node)
attrs = apply_callbacks(attrs, False)
if attrs is None:
# <a> tag replaced by the text within it
adj = replace_nodes(tree, _text, node,
current_child)
current_child -= 1
# pull back current_child by 1 to scan the
# new nodes again.
else:
text = force_unicode(attrs.pop('_text'))
for attr_key, attr_val in attrs.items():
node.set(attr_key, attr_val)
for n in reversed(list(node)):
node.remove(n)
text = parser.parseFragment(text)
node.text = text.text
for n in text:
node.append(n)
_seen.add(node)
elif current_child >= 0:
if node.tag == ETREE_TAG('pre') and skip_pre:
linkify_nodes(node, False)
elif not (node in _seen):
linkify_nodes(node, True)
current_child += 1
def email_repl(match):
addr = match.group(0).replace('"', '"')
link = {
'_text': addr,
'href': 'mailto:{0!s}'.format(addr),
}
link = apply_callbacks(link, True)
if link is None:
return addr
_href = link.pop('href')
_text = link.pop('_text')
repl = '<a href="{0!s}" {1!s}>{2!s}</a>'
attr = '{0!s}="{1!s}"'
attribs = ' '.join(attr.format(k, v) for k, v in link.items())
return repl.format(_href, attribs, _text)
def link_repl(match):
url = match.group(0)
open_brackets = close_brackets = 0
if url.startswith('('):
_wrapping = strip_wrapping_parentheses(url)
url, open_brackets, close_brackets = _wrapping
end = ''
m = re.search(punct_re, url)
if m:
end = m.group(0)
url = url[0:m.start()]
if re.search(proto_re, url):
href = url
else:
href = ''.join(['http://', url])
link = {
'_text': url,
'href': href,
}
link = apply_callbacks(link, True)
if link is None:
return '(' * open_brackets + url + ')' * close_brackets
_text = link.pop('_text')
_href = link.pop('href')
repl = '{0!s}<a href="{1!s}" {2!s}>{3!s}</a>{4!s}{5!s}'
attr = '{0!s}="{1!s}"'
attribs = ' '.join(attr.format(k, v) for k, v in link.items())
return repl.format('(' * open_brackets,
_href, attribs, _text, end,
')' * close_brackets)
try:
linkify_nodes(forest)
except RuntimeError as e:
# If we hit the max recursion depth, just return what we've got.
log.exception('Probable recursion error: {0!r}'.format(e))
return _render(forest)
def _render(tree):
"""Try rendering as HTML, then XML, then give up."""
return force_unicode(_serialize(tree))
def _serialize(domtree):
walker = html5lib.treewalkers.getTreeWalker('etree')
stream = walker(domtree)
serializer = HTMLSerializer(quote_attr_values=True,
alphabetical_attributes=True,
omit_optional_tags=False)
return serializer.render(stream)
