This django app applies filters on the queryset of a view using the incoming query parameters in an clean and elegant way.
Which can be installed with pip as
pip install drf-url-filters
Usage Example
validations.py
from filters.schema import base_query_param_schema
from filters.validations import (
CSVofIntegers,
IntegerLike,
DatetimeWithTZ
)
# make a validation schema for players filter query params
players_query_schema = base_query_param_schema.extend(
{
"id": IntegerLike(),
"name": unicode,
"team_id": CSVofIntegers(), # /?team_id=1,2,3
"install_ts": DatetimeWithTZ(),
"update_ts": DatetimeWithTZ(),
}
)
views.py
from rest_framework import (
viewsets,
filters,
)
from .models import Player, Team
from .serializers import PlayerSerializer, TeamSerializer
from .pagination import ResultSetPagination
from .validations import teams_query_schema, players_query_schema
from filters.mixins import (
FiltersMixin,
)
class PlayersViewSet(FiltersMixin, viewsets.ModelViewSet):
"""
This viewset automatically provides `list`, `create`, `retrieve`,
`update` and `destroy` actions.
"""
serializer_class = PlayerSerializer
pagination_class = ResultSetPagination
filter_backends = (filters.OrderingFilter,)
ordering_fields = ('id', 'name', 'update_ts')
ordering = ('id',)
# add a mapping of query_params to db_columns(queries)
filter_mappings = {
'id': 'id',
'name': 'name__icontains',
'team_id': 'teams', # many-to-many relationship
'install_ts': 'install_ts',
'update_ts': 'update_ts',
'update_ts__gte': 'update_ts__gte',
'update_ts__lte': 'update_ts__lte',
}
# add validation on filters
filter_validation_schema = players_query_schema
def get_queryset(self):
"""
Optionally restricts the queryset by filtering against
query parameters in the URL.
"""
query_params = self.request.query_params
queryset = Player.objects.prefetch_related(
'teams' # use prefetch_related to minimize db hits.
).all()
# This dict will hold filter kwargs to pass in to Django ORM calls.
db_filters = {}
# update filters dict with incoming query params and then pass as
# **kwargs to queryset.filter()
db_filters.update(
self.get_queryset_filters(
query_params
)
)
return queryset.filter(**db_filters)