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mirror of https://gitlab.crans.org/bde/nk20 synced 2024-11-27 02:43:01 +00:00
nk20/apps/api/filters.py
2024-07-18 14:16:07 +02:00

43 lines
1.5 KiB
Python

import re
from functools import lru_cache
from rest_framework.filters import SearchFilter
class RegexSafeSearchFilter(SearchFilter):
@lru_cache
def validate_regex(self, search_term) -> bool:
try:
re.compile(search_term)
return True
except re.error:
return False
def get_search_fields(self, view, request):
"""
Ensure that given regex are valid.
If not, we consider that the user is trying to search by substring.
"""
search_fields = super().get_search_fields(view, request)
search_terms = self.get_search_terms(request)
for search_term in search_terms:
if not self.validate_regex(search_term):
# Invalid regex. We assume we don't query by regex but by substring.
search_fields = [f.replace('$', '') for f in search_fields]
break
return search_fields
def get_search_terms(self, request):
"""
Ensure that search field is a valid regex query. If not, we remove extra characters.
"""
terms = super().get_search_terms(request)
if not all(self.validate_regex(term) for term in terms):
# Invalid regex. If a ^ is prefixed to the search term, we remove it.
terms = [term[1:] if term[0] == '^' else term for term in terms]
# Same for dollars.
terms = [term[:-1] if term[-1] == '$' else term for term in terms]
return terms