django-rest-framework-bulk/rest_framework_bulk/drf3/mixins.py

from __future__ import print_function, unicode_literals
import traceback
from rest_framework import status
from rest_framework.mixins import CreateModelMixin
from rest_framework.response import Response


__all__ = [
    'BulkCreateModelMixin',
    'BulkDestroyModelMixin',
    'BulkUpdateModelMixin',
]


class BulkCreateModelMixin(CreateModelMixin):
    """
    Either create a single or many model instances in bulk by using the
    Serializer's ``many=True`` ability from Django REST >= 2.2.5.

    .. note::
        This mixin uses the same method to create model instances
        as ``CreateModelMixin`` because both non-bulk and bulk
        requests will use ``POST`` request method.
    """

    def create(self, request, *args, **kwargs):
        bulk = isinstance(request.data, list)

        if not bulk:
            return super(BulkCreateModelMixin, self).create(request, *args, **kwargs)

        else:
            serializer = self.get_serializer(data=request.data, many=True)
            serializer.is_valid(raise_exception=True)
            self.perform_create(serializer)
            return Response(serializer.data, status=status.HTTP_201_CREATED)


class BulkUpdateModelMixin(object):
    """
    Update model instances in bulk by using the Serializer's
    ``many=True`` ability from Django REST >= 2.2.5.
    """

    def get_object(self):
        try:
            super(BulkUpdateModelMixin, self).get_object()
        except AssertionError:
            # probably happened when called get_object() within options()
            # via self.metadata_class which is not allowed on list viewset
            # however since we are enabling PUT here, we should handle the
            # exception if called within options()
            # We can simply swallow the exception since that method
            # does not actually do anythingwith the returned object
            for file, line, function, code in traceback.extract_stack():
                if all((file.endswith('rest_framework/views.py'),
                        function == 'options')):
                    return

            # not called inside metadata() so probably something went
            # wrong and so we should reraise exception
            raise

    def bulk_update(self, request, *args, **kwargs):
        partial = kwargs.pop('partial', False)

        # restrict the update to the filtered queryset
        serializer = self.get_serializer(
            self.filter_queryset(self.get_queryset()),
            data=request.data,
            many=True,
            partial=partial,
        )
        serializer.is_valid(raise_exception=True)
        self.perform_update(serializer)
        return Response(serializer.data, status=status.HTTP_200_OK)

    def perform_update(self, serializer):
        serializer.save()

    def partial_bulk_update(self, request, *args, **kwargs):
        kwargs['partial'] = True
        return self.bulk_update(request, *args, **kwargs)


class BulkDestroyModelMixin(object):
    """
    Destroy model instances.
    """

    def allow_bulk_destroy(self, qs, filtered):
        """
        Hook to ensure that the bulk destroy should be allowed.

        By default this checks that the destroy is only applied to
        filtered querysets.
        """
        return qs is not filtered

    def bulk_destroy(self, request, *args, **kwargs):
        qs = self.get_queryset()

        filtered = self.filter_queryset(qs)
        if not self.allow_bulk_destroy(qs, filtered):
            return Response(status=status.HTTP_400_BAD_REQUEST)

        for obj in filtered:
            self.perform_destroy(obj)

        return Response(status=status.HTTP_204_NO_CONTENT)

    def perform_destroy(self, instance):
        instance.delete()