OpenSlides/openslides/utils/validate.py
2019-11-08 15:39:18 +01:00

92 lines
2.0 KiB
Python

from typing import Any
import bleach
from .rest_api import ValidationError
allowed_tags = [
"a",
"img", # links and images
"br",
"p",
"span",
"blockquote", # text layout
"strike",
"del",
"ins",
"strong",
"u",
"em",
"sup",
"sub",
"pre", # text formatting
"h1",
"h2",
"h3",
"h4",
"h5",
"h6", # headings
"ol",
"ul",
"li", # lists
"table",
"caption",
"thead",
"tbody",
"th",
"tr",
"td", # tables
]
allowed_attributes = {
"*": ["class", "style"],
"img": ["alt", "src", "title"],
"a": ["href", "title"],
"th": ["scope"],
"ol": ["start"],
}
allowed_styles = [
"color",
"background-color",
"height",
"width",
"text-align",
"float",
"padding",
"text-decoration",
]
def validate_html(html: str) -> str:
"""
This method takes a string and escapes all non-whitelisted html entries.
Every field of a model that is loaded trusted in the DOM should be validated.
During copy and paste from Word maybe some tabs are spread over the html. Remove them.
"""
html = html.replace("\t", "")
return bleach.clean(
html, tags=allowed_tags, attributes=allowed_attributes, styles=allowed_styles
)
def validate_json(json: Any, max_depth: int) -> Any:
"""
Traverses through the JSON structure (dicts and lists) and runs
validate_html on every found string.
Give max-depth to protect against stack-overflows. This should be the
maximum nested depth of the object expected.
"""
if max_depth == 0:
raise ValidationError({"detail": "The JSON is too nested."})
if isinstance(json, dict):
return {key: validate_json(value, max_depth - 1) for key, value in json.items()}
if isinstance(json, list):
return [validate_json(item, max_depth - 1) for item in json]
if isinstance(json, str):
return validate_html(json)
return json