Django REST, Accessing methods of the selected object - django

Question

this part of my code fills the queryset with [category_object].subcats.all(). let subcats be a method of category object:
serializer:
class CatSrlz(serializers.ModelSerializer):
class Meta:
model = Category
fields = ('id', 'label', )
View:
class CatsViewSet(viewsets.ReadOnlyModelViewSet):
queryset = Category.objects.filter(parent=None)
serializer_class = CatSrlz
def retrieve(self, request, *args, **kwargs):
# return Response({'res': self.kwargs})
queryset = Category.objects.get(pk=str(self.kwargs['pk'])).subCats.all()
dt = CatSrlz(queryset, many=True)
return Response(dt.data)
and url:
router.register(r'cats', views.CatsViewSet)
it works but i'm pretty sure that there must be a more correct way of doing so
Is there one?
thanks

Answer 1

When retrieving a single object, you can use the get_object method in your view, which look like this in DRF without modifications :
def get_object(self):
"""
Returns the object the view is displaying.
You may want to override this if you need to provide non-standard
queryset lookups. Eg if objects are referenced using multiple
keyword arguments in the url conf.
"""
queryset = self.filter_queryset(self.get_queryset())
# Perform the lookup filtering.
lookup_url_kwarg = self.lookup_url_kwarg or self.lookup_field
assert lookup_url_kwarg in self.kwargs, (
'Expected view %s to be called with a URL keyword argument '
'named "%s". Fix your URL conf, or set the `.lookup_field` '
'attribute on the view correctly.' %
(self.__class__.__name__, lookup_url_kwarg)
)
filter_kwargs = {self.lookup_field: self.kwargs[lookup_url_kwarg]}
obj = get_object_or_404(queryset, **filter_kwargs)
# May raise a permission denied
self.check_object_permissions(self.request, obj)
return obj
So you could adapt the part where you get your object :
filter_kwargs = {self.lookup_field: self.kwargs[lookup_url_kwarg]}
obj = get_object_or_404(queryset, **filter_kwargs)
and add your subcat logic there.
By the way, I don't get why you are using
dt = CatSrlz(queryset, many=True)
Shouldn't "retrieve" return a single object?