object_lookup_mixin.py 文件源码

def get_object(self):
        """
        Incase the lookup is on an object that has been hyperlinked
        then update the queryset filter appropriately
        """
        if self.kwargs.get(self.lookup_field, None) is None:
            raise ParseError(
                'Expected URL keyword argument `%s`.' % self.lookup_field
            )
        queryset = self.filter_queryset(self.get_queryset())

        filter_kwargs = {}
        serializer = self.get_serializer()
        lookup_field = self.lookup_field

        if self.lookup_field in serializer.get_fields():
            k = serializer.get_fields()[self.lookup_field]
            if isinstance(k, serializers.HyperlinkedRelatedField):
                lookup_field = '%s__%s' % (self.lookup_field, k.lookup_field)

        filter_kwargs[lookup_field] = self.kwargs[self.lookup_field]

        obj = get_object_or_404(queryset, **filter_kwargs)

        # May raise a permission denied
        self.check_object_permissions(self.request, obj)

        return obj