"""
Ordering filter.
"""
from rest_framework.filters import OrderingFilter as DjangoOrderingFilter
__title__ = 'rest_framework_tricks.filters.ordering'
__author__ = 'Artur Barseghyan <artur.barseghyan@gmail.com>'
__copyright__ = '2017-2019 Artur Barseghyan'
__license__ = 'GPL 2.0/LGPL 2.1'
__all__ = ('OrderingFilter',)
[docs]class OrderingFilter(DjangoOrderingFilter):
"""Ordering filter improved.
Example:
>>> from rest_framework_tricks.filters import OrderingFilter
>>>
>>> class BooksViewSet(mixins.RetrieveModelMixin,
>>> mixins.ListModelMixin,
>>> viewsets.GenericViewSet):
>>>
>>> serializer_class = BookSerializer
>>> filter_backends = (
>>> OrderingFilter,
>>> )
>>> ordering_fields = {
>>> 'email': 'user__email',
>>> 'full_name': 'user__first_name',
>>> 'last_login': 'user__last_login',
>>> 'is_active': 'user__is_active',
>>> }
Then it can be used in a view set as follows:
GET /books/api/proxy-books/?ordering=email
"""
[docs] def get_valid_fields(self, queryset, view, context={}):
"""Done.
:param queryset:
:param view:
:param context:
:return:
"""
valid_fields = getattr(view, 'ordering_fields', self.ordering_fields)
if isinstance(valid_fields, dict):
return valid_fields.items()
else:
return super(OrderingFilter, self).get_valid_fields(
queryset,
view,
context
)
[docs] def get_ordering(self, request, queryset, view):
"""Get ordering.
Important: list returned in this method is used directly
in the filter_queryset method like:
>>> queryset.order_by(*ordering)
Ordering is set by a comma delimited ?ordering=... query parameter.
The `ordering` query parameter can be overridden by setting
the `ordering_param` value on the OrderingFilter or by
specifying an `ORDERING_PARAM` value in the API settings.
"""
valid_fields = getattr(view, 'ordering_fields', self.ordering_fields)
# If valid_fields is a dictionary, treat it differently
if isinstance(valid_fields, dict):
params = request.query_params.get(self.ordering_param)
if params:
fields = [param.strip() for param in params.split(',')]
_ordering = self.remove_invalid_fields(
queryset,
fields,
view,
request
)
ordering = []
for item in _ordering:
if '-' in item:
value = valid_fields.get(item[1:])
if isinstance(value, (tuple, list)):
value = ['-{}'.format(__v) for __v in value]
ordering += value
else:
ordering.append(
'-{}'.format(value)
)
else:
value = valid_fields.get(item)
if isinstance(value, (tuple, list)):
ordering += value
else:
ordering.append(value)
if ordering:
return ordering
# No ordering was included, or all the ordering fields were invalid
return self.get_default_ordering(view)
# In all other cases, use default behaviour
else:
return super(OrderingFilter, self).get_ordering(
request,
queryset,
view
)