Odtnhj

I've got this serializers:

class PublicProgramSerializer(serializers.ModelSerializer):
 class Meta:
 model = Program
 fields = (
 ...
 'questions'
 )

 questions = CustomQuestionSerializer(source="custom_questions", many=True)

And:

class CustomQuestionSerializer(serializers.ModelSerializer):

 class Meta:
 model = CustomQuestion
 fields = (
 'label',
 'type',
 'scope'
 )

Now the 'scope' is a choice field with 3 options: REGISTRATION, PARTICIPANT, EVENT and I want to serialize only custom questions where the scope is set to REGISTRATION. How can I achieve that?

Thanks for any answer!

Edit: The models:

Program.py

class Program(models.Model):
 created = models.DateTimeField(u'Created', auto_now_add=True)
 name = models.CharField(u'Program Name', max_length=100)
 description = models.TextField(u'Description', help_text=mark_safe(MARKDOWN_HELP_STRING), blank=True, null=True)

etc... Theres nothing really fancy about Program

CustomQuestion.py

class CustomQuestion(models.Model):
 class Meta:
 order_with_respect_to = 'program'

 SCOPE_REGISTRATION = "registration"
 SCOPE_PARTICIPANT = "participant"
 SCOPE_EVENT = "event"

 SCOPE_CHOICES = (
 (SCOPE_REGISTRATION, "Registration"),
 (SCOPE_PARTICIPANT, "Participant"),
 (SCOPE_EVENT, "Event"),
 )

 program = models.ForeignKey("Program", related_name="custom_questions")
 scope = models.CharField(
 verbose_name="Scope",
 choices=SCOPE_CHOICES,
 null=False,
 max_length=50
 )
 description = models.CharField(
 verbose_name=u"Description",
 null=True, blank=True,
 max_length=100
 )
 label = models.CharField(
 verbose_name="Label",
 null=False, blank=False,
 max_length=80
 )

And the Viewset for the Program:

class ProgramList(generics.ListAPIView):
 model = Program
 permission_classes = (AllowAny,)
 serializer_class = PublicProgramSerializer
 queryset = Program.objects.exclude(visibility='hidden').filter(is_archived=False)

 def get(self, request, *args, **kwargs):
 programs = self.get_queryset()
 data = self.serializer_class(programs, context='request': request, many=True).data
 response = Response(data)
 response['Cache-Control'] = 'no-cache'
 return response

 def get_queryset(self):
 scope = self.request.GET.get('scope')
 if scope and scope in CustomQuestion.SCOPE_CHOICES:
 return Program.objects.filter(participant_questions__scope=scope)
 else:
 return Program.objects.all()

Create a method called "get_queryset" in your viewset like this

class ProgramViewSet(viewsets.ViewSet):
 serializer_class = ProgramSerializer

 def get_queryset(self):
 scope = self.request.GET.get('scope')
 if scope and scope in CustomQuestion.SCOPE_CHOICE:
 return Program.objects.filter(questions__scope=scope)
 else
 return Program.objects.all()

 def list(self, request):
 paginator = LimitOffsetPagination()
 if request.GET.get('limit'):
 page = paginator.paginate_queryset(self.get_queryset(), request)
 serializer = self.serializer_class(page, many=True)
 if page is not None:
 return paginator.get_paginated_response(serializer.data)
 else:
 serializer = self.serializer_class(self.get_queryset(), many=True)
 return response.Response(serializer.data)

Well I have found a solution that works for me pretty well:

I didn't know that you can use a custom method as the source in the Serializer Method like:

questions = CustomQuestionSerializer(source="get_participant_questions", many=True)

So I just created the get_participant_questions method in my program.py, where I filtered for those exact questions:

def get_participant_questions(self):
 return self.custom_questions.filter(scope=CustomQuestion.SCOPE_PARTICIPANT)

and et voila my API showed me exactly what I wanted.

Thanks a lot @Bast, your answer helped me find this way :)