Django REST Framework update foreign key field on PUT - django

Question

I'm using Django 2.x and Django REST Framework
My models.py file contents
class ModeOfPayment(models.Model):
id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
title = models.CharField()
class AmountGiven(models.Model):
id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
contact = models.ForeignKey(Contact, on_delete=models.PROTECT)
amount = models.FloatField()
mode_of_payment = models.ForeignKey(
ModeOfPayment,
on_delete=models.PROTECT,
blank=True,
default=None,
null=True
)
and serializers.py
class ModeOfPaymentSerializer(serializers.ModelSerializer):
class Meta:
model = ModeOfPayment
fields = ('id', 'title')
class AmountGivenSerializer(serializers.ModelSerializer):
mode_of_payment = ModeOfPaymentSerializer()
class Meta:
model = AmountGiven
depth = 1
fields = (
'id', 'contact', 'amount', 'mode_of_payment',
)
def update(self, instance, validated_data):
mode_of_payment = validated_data.pop('mode_of_payment')
instance.mode_of_payment_id = mode_of_payment.id
return instance
and views.py
class AmountGivenViewSet(viewsets.ModelViewSet):
serializer_class = AmountGivenSerializer
permission_classes = (IsAuthenticated, AdminAuthenticationPermission,)
filter_fields = ('contact__id',)
def get_queryset(self):
queryset = AmountGiven.objects.filter(
contact__user=self.request.user
)
return queryset
But when I post data using postman with PUT method to update the existing record
It still says
{
"mode_of_payment": [
"This field is required."
]
}
Edit 2: Response after Daniel answer
{
"id": "326218dc-66ab-4c01-95dc-ce85f226012d",
"contact": {
"id": "b1b87766-86c5-4029-aa7f-887f436d6a6e",
"first_name": "Prince",
"last_name": "Raj",
"user": 3
},
"amount": 3000,
"mode_of_payment": "0cd51796-a423-4b75-a0b5-80c03f7b1e65",
}

Answer 1

You've told AmountSerializer to accept a nested dict representing a ModeOfPayment instance, by setting the mode_of_payment field to ModeOfPaymentSerializer. But that's not what you're sending; you're sending the ID of the ModeOfPayment.
You should remove that line in AmountGivenSerializer.
Edit
I was wrong, you need to declare the field explicitly as a PrimaryKeyRelatedField:
class AmountGivenSerializer(serializers.ModelSerializer):
mode_of_payment = serializers.PrimaryKeyRelatedField(queryset=ModeOfPayment.objects.all())
class Meta:
...
Now it will accept a UUID in the data.