import urllib.parse
from typing import Mapping, Optional, Tuple, Union
import bleach
ALLOWED_TAGS = ["a", "abbr", "acronym", "b", "br", "blockquote", "code", "em", "hr", "i", "li", "ol", "strong", "ul", "iframe", "img", "div", "p"]
ALLOWED_ATTRIBUTES = {
"acronym": ["title"],
"a": ["href", "title"],
"abbr": ["title"],
"iframe": ["src", "height", "width", "allowfullscreen", "frameborder"],
"img": ["src", "alt", "title", "style"],
}
ALLOWED_STYLES = [
"width",
"height",
"float",
"margin-left",
"margin-right",
"margin-top",
"margin-bottom",
"margin",
"border",
"border-style",
"border-width",
]
[docs]def safe_html(txt):
return bleach.linkify(bleach.clean(txt, tags=ALLOWED_TAGS, attributes=ALLOWED_ATTRIBUTES, styles=ALLOWED_STYLES))
[docs]def link_removal_callback( # pylint: disable=unused-argument
attrs: Mapping[Union[str, Tuple[Optional[str]]], str], new: bool = False
) -> Optional[Mapping[Union[str, Tuple[Optional[str]]], str]]:
"""Internal callback for ``nullify_links()``."""
for key in tuple(attrs.keys()):
if isinstance(key, tuple) and "href" in key:
attrs[key] = "javascript:void(0)"
return attrs
[docs]def nullify_links(text: str) -> str:
"""Given a string containing HTML, changes the ``href`` attribute of any links to "javascript:void(0)" to render
the link useless.
Args:
text: The HTML string in which links should be nullified.
Returns:
The HTML string with all links nullified.
"""
return bleach.linkify(text, [link_removal_callback])
[docs]def safe_fcps_emerg_html(text: str, base_url: str) -> str:
def translate_link_attr( # pylint: disable=unused-argument
attrs: Mapping[Union[str, Tuple[Optional[str]]], str], new: bool = False
) -> Optional[Mapping[Union[str, Tuple[Optional[str]]], str]]:
for key in tuple(attrs.keys()):
if isinstance(key, tuple) and "href" in key:
# Translate links that don't specify a protocol/host
# For example, /a/b will be translated to (something like) https://fcps.edu/a/b
attrs[key] = urllib.parse.urljoin(base_url, attrs[key])
return attrs
return bleach.linkify(
bleach.clean(text, strip=True, tags=ALLOWED_TAGS, attributes=ALLOWED_ATTRIBUTES, styles=ALLOWED_STYLES), [translate_link_attr]
)