how to add data to child model along with parent mode? - django

Question

I am working with Django REST framework. I want to add data to child model along with the parent model. Basically creating two records at a time.
models.py
class Visit(models.Model):
name = models.CharField(max_length=200)
gender = models.CharField(choices=GENDER_CHOICE, max_length=1)
mobile = models.CharField(max_length=18,default="")
email = models.CharField(max_length=256, null=True, blank=True)
address = models.TextField(null=True, blank=True)
visit_type = models.IntegerField(choices=VISIT_TYPE)
visit_purpose = models.CharField(max_length=250)
visitor_photo = models.FileField(upload_to="visitor/",null=True, blank=True)
id_photo = models.FileField(upload_to="id_card/",null=True, blank=True)
date_created = models.DateTimeField(default=timezone.now, editable=False)
class Status(models.Model):
visit = models.ForeignKey(Visit,on_delete=models.CASCADE)
description = models.CharField(max_length=200)
from_time = models.DateField()
to_time = models.DateTimeField(null=True, blank=True)
aproved = models.BooleanField(default=False)
visit_complete = models.BooleanField(default=False)
exit_time = models.DateTimeField(null=True, blank=True)
date_created = models.DateTimeField(default=timezone.now, editable=False)
serializers.py
class StatusSerializers(serializers.ModelSerializer):
class Meta:
model = Status
fields = "__all__"
class VisitSerializers(serializers.ModelSerializer):
visit = StatusSerializers(many=True)
class Meta:
model = Visit
fields = "__all__"
def create(self, validated_data):
print(validated_data)
model_b = Visit.objects.create(**validated_data)
# print(self.context.request.data.get('description'))
child_model_data = {
'description': self.context.request.data.get('description'),
}
child_model_serializer = StatusSerializers(data=child_model_data)
child_model_serializer.is_valid(raise_exception=True)
child_model_serializer.save(status=model_b)
return model_b
views.py
#api_view(['GET', 'POST'])
def create_visitor(request):
if request.method == 'GET':
visitor = Visit.objects.all()
serializer = VisitSerializers(visitor,context={'request': request},many=True)
return Response(serializer.data)
elif request.method == 'POST':
serializer = VisitSerializers(data=request.data,context={'request': request})
if serializer.is_valid():
serializer.save()
return Response(serializer.data, status=status.HTTP_201_CREATED)
return Response(serializer.errors,
status=status.HTTP_400_BAD_REQUEST)
In the above code I am able to create child record i.e. Status model record but I don't know how to add other fields to it during its creation.

Answer 1

In your serializer child model data can be found in self.context.request.data and you can simply use child serializer to validate and save in db.
class VisitSerializers(serializers.ModelSerializer):
class Meta:
model = Visit
fields = "__all__"
def create(self, validated_data):
print(validated_data)
model_b = Visit.objects.create(**validated_data)
child_model_data = {
'field': self.context['request'].data.get('your_field');
.....
}
child_model_serializer = ChildSerializer(data=child_model_data)
child_model_serializer.is_valid(raise_exception=True)
child_model_serializer.save()
return model_b
Update you need to change in multiple places
First in your view, in post method serializer initialization you need to pass context object.
#api_view(['GET', 'POST'])
def create_visitor(request):
if request.method == 'GET':
visitor = Visit.objects.all()
serializer = VisitSerializers(visitor,context={'request': request},many=True)
return Response(serializer.data)
elif request.method == 'POST':
serializer = VisitSerializers(data=request.data, context={'request': request})
if serializer.is_valid():
serializer.save()
return Response(serializer.data, status=status.HTTP_201_CREATED)
return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
And then in your VisitSerializer
class VisitSerializers(serializers.ModelSerializer):
visit = StatusSerializers(many=True) # not sure why you did this, this should be removed i guess
class Meta:
model = Visit
fields = "__all__"
def create(self, validated_data):
print(validated_data)
model_b = Visit.objects.create(**validated_data)
# print(self.context.request.data.get('description'))
child_model_data = {
'description': self.context.request.data.get('description'),
'status': model_b
# and make sure all other necessary fields.
}
child_model_serializer = StatusSerializers(data=child_model_data)
child_model_serializer.is_valid(raise_exception=True)
child_model_serializer.save()
return model_b

Answer 2

You can have extra fields in your serializer along with default fields. For reverse relations, you can add a field like this
class VisitSerializers(serializers.ModelSerializer):
status = StatusSerializer(many=True)
class Meta:
model = Visit
You can pass data to VisitSerializer like this. {, status: [, ]}