How can i use nested serializer inside the same serializer? - django

Question

class UserViewSerializer(DynamicFieldsMixin,serializers.ModelSerializer):
followers_set = UserViewSerializer(required=False,many=True)
class Meta:
model = User
fields = ('id','email','username','password','followers_set')
depth = 2
is there anyway i can use this function without getting this error?
followers_set = UserViewSerializer(source='follows',required=False,many=True)
NameError: name 'UserViewSerializer' is not defined
i tried SerializerMethodField but then i can't use depth option there
following_set = serializers.SerializerMethodField()
def get_following_set(self, user):
return UserViewSerializer(User.objects.filter(follows__author=user), many=True).data
using SerializerMethodField gives me error of:
RecursionError at /api/users/
maximum recursion depth exceeded
Can somebody help me please?

Answer 1

The simplest way to handle this is to make three serializers: one without a followers_set, one with a followers_set that uses the previous one, and one that users the second model, so:
# no followers_set
class UserViewSerializer0(DynamicFieldsMixin,serializers.ModelSerializer):
class Meta:
model = User
fields = ('id','email','username')
# followers_set, but only depth 1
class UserViewSerializer1(DynamicFieldsMixin,serializers.ModelSerializer):
followers_set = UserViewSerializer0(source='follows',required=False,many=True)
class Meta:
model = User
fields = ('id','email','username')
# followers_set, with depth 2
class UserViewSerializer(DynamicFieldsMixin,serializers.ModelSerializer):
followers_set = UserViewSerializer1(source='follows',required=False,many=True)
class Meta:
model = User
fields = ('id','email','username')
This is more safe as well, since you can not define recursive loops, unless you indeed work with SerializerMethodField, which is not a good idea if you add extra serializers.
It might however be better no to go to depth two, but stick to depth one. It will generate large responses already, make creating objects more cumbersome, and it will result in a lot of extra queries.