List Serializer multiple object creation - django

Question

My models are:
class User(models.Model):
id = models.AutoField(primary_key=True)
email = models.EmailField()
class Lawyer(models.Model):
user = models.OnetoOneField(User)
class Session(models.Model):
name = models.CharField()
lawyer = models.ForeignKey(Lawyer)
I am trying to create multiple objects with a list serializer for Session.
From the app side they don't have the id of lawyer, but have the email of each lawyer. How can I write a list serializer where I can take the following json input and use email to fetch lawyer to store multiple session objects?
The json input sent will be like:
[
{
"name": "sess1",
"email": "lawyer1#gmail.com",
},
{
"name": "sess1",
"email": "lawyer1#gmail.com",
}
]

Answer 1

You can do it in this way but I think email should be unique=True.
Then use a serializer like this:
from django.utils.translation import ugettext_lazy as _
class SessionCreateManySerializer(serializers.ModelSerializer):
email = serializers.SlugRelatedField(
source='lawyer',
slug_field='user__email',
queryset=Lawyer.objects.all(),
write_only=True,
error_messages={"does_not_exist": _('lawyer with email={value} does not exist.')}
)
class Meta:
model = Session
fields = ('name', 'email')
and a generic create view (just override get_serializer and place many=True in kwargs ):
from rest_framework.response import Response
from rest_framework import generics
class SessionCreateManyView(generics.CreateAPIView):
serializer_class = SessionCreateManySerializer
def get_serializer(self, *args, **kwargs):
kwargs['many'] = True
return super(SessionCreateManyView, self).get_serializer(*args, **kwargs)

Answer 2

You can use bulk creation as well:
# serializers.py
from myapp.models import Session
from rest_framework import serializers
class SessionSerializer(serializers.Serializer):
email = serializers.EmailField(required=True)
name = serializers.CharField(required=True)
def validate_email(self, email):
lawyer = Lawyer.objects.filter(user__email=email).first()
if not lawyer:
raise ValidationError(detail="user dose not exist.")
return lawyer
def create(self, validated_data):
return Session.objects.create(name=validated_data.get('name'), lawyer=validated_data.get('email'))
and in your api.py file allow bulk creation:
# api.py
from rest_framework import generics
class SessionCreateAPIView(generics.CreateAPIView):
"""Allows bulk creation of a resource."""
def get_serializer(self, *args, **kwargs):
if isinstance(kwargs.get('data', {}), list):
kwargs['many'] = True
return super().get_serializer(*args, **kwargs)