Viktor Danilov Viktor Danilov - 4 months ago 47
JSON Question

REST Framework: how to serialize objects?

I want to create a ListView with a array of nested objects. Here what I've tried so far:

rest.py

class GroupDetailSerializer(serializers.ModelSerializer):
class Meta:
model = Group
fields = (
'id',
'num',
'students',
)

@permission_classes((permissions.IsAdminUser,))
class GroupDetailView(mixins.ListModelMixin, viewsets.GenericViewSet):
serializer_class = GroupDetailSerializer

def get_queryset(self):
return Group.objects.all()


models.py

class Group(models.Model):
office = models.ForeignKey(Offices)
num = models.IntegerField()

@property
def students(self):
from pupils.models import Pupils
return Pupils.objects.filter(group=self)


But it returns a type error:


<Pupils: John Doe> is not JSON serializable



I guess I need to use another serializer on my
students
field, but how?

Answer

Error is because your model is not json serializable.

you can see @yuwang comment to follow nested serializer http://www.django-rest-framework.org/api-guide/serializers/#dealing-with-nested-objects

or for now, particular for this case you can change your code to:

@property
def students(self):
    from pupils.models import Pupils
    return list(Pupils.objects.filter(group=self).values())