drf-url-filters
===============
**drf-url-filters** is a simple django app to apply filters on drf
modelviewset's queryset in a clean, simple and configurable way. It also
supports validations on incoming query params and their values. A
beautiful python package
`voluptouos <https://github.com/alecthomas/voluptuous>`__ is being used
for validations on the incoming query parameters. The best part about
voluptouos is you can define your own validations as per your query
params requirements.
# Quick start
-------------
**Installation**
1. Download ``drf-url-filters`` app package from this git repo or can be
installed using python-pip like ``pip install drf-url-filters``.
2. Add ``filters`` in INSTALLED\_APPS of settings.py file of django
project.
**How it works**
1. Your View or ModelViewSet should inherit ``FiltersMixin`` from
``filters.mixins.FiltersMixin``.
2. To apply filters using ``drf-url-filters`` we need to configure our
view to have a dict mapping ``filter_mappings`` which converts
incoming query parameters to query you want to make on the column
name on the queryset.
3. Optionally, to perform any preprocessing on the incoming values for
query params, add another dict ``filter_value_transformations`` which
maps incoming query parameters to functions that should be applied to
the values corresponding to them. The resultant value is used in the
final filtering.
validations.py
==============
.. code:: python
import six
from filters.schema import base_query_params_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": six.text_type, # Depends on python version
"team_id": CSVofIntegers(), # /?team_id=1,2,3
"install_ts": DatetimeWithTZ(),
"update_ts": DatetimeWithTZ(),
"taller_than": IntegerLike(),
}
)
views.py
========
.. code:: python
from rest_framework import (
viewsets,
filters,
)
from .models import Player, Team
from .pagination import ResultSetPagination
from .serializers import PlayerSerializer, TeamSerializer
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.
"""
queryset = Player.objects.prefetch_related(
'teams' # use prefetch_related to minimize db hits.
).all()
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',
'install_ts': 'install_ts',
'update_ts': 'update_ts',
'update_ts__gte': 'update_ts__gte',
'update_ts__lte': 'update_ts__lte',
'taller_than': 'height__gte',
}
field_value_transformations = {
'taller_than': lambda val: val / 30.48 # cm to ft
}
# add validation on filters
filter_validation_schema = players_query_schema
With the use of ``drf-url-filters`` adding a new filter on a new column
is as simple as adding a new key in the dict. Prohibitting a filter on
particular column is same as removing a key value mapping from the
``filter_mappings`` dict.
LICENSE
=======
`MIT License <LICENSE.MD>`__ Copyright (c) 2016 Manjit Kumar.
Credits
=======
Special thanks to authors of
`voluptouos <https://github.com/alecthomas/voluptuous>`__ and friends
`cdax <https://github.com/cdax>`__ and
`saurabhjha <https://github.com/SaurabhJha>`__ who encourage people to
contribute into open source community.
Support
=======
Please [open an issue]
(https://github.com/manjitkumar/drf-url-filters/issues/new) for support.