How to update Foreign key field using nested serializer in django - django

Question

I am facing one issue for updating models using django serializer.
Here is my models:
class User(models.Model):
email = models.EmailField(unique=True)
first_name = models.CharField(max_length=30)
last_name = models.CharField(max_length=30)
class UserProfile(models.Model):
user = models.ForeignKey(User, on_delete=models.CASCADE)
designation = models.CharField(max_length=200, blank=True)
contact_number = models.CharField(max_length=20, blank=True)
team = models.CharField(max_length=200, blank=True)
manager = models.CharField(max_length=200, blank=True)
joining_date = models.DateField(default=datetime.now)
I need to create a serializer for editing profile details of the current user. In this User details like designation, contact_number , team , manager, joining_date are in UserProfile model and te first_name and last_name are in User model .... At one edit both the models needs to get update
This is my serializer.
class UserSerializer(ModelSerializer):
class Meta:
model = User
fields = ('id', 'first_name','last_name')
class UserProfileSerializer(ModelSerializer):
user = UserSerializer()
class Meta:
model = UserProfile
fields = ('id', 'designation', 'contact_number', 'team', 'manager',
'joining_date','user')
def update(self, instance, validated_data):
user = validated_data.get('user')
instance.user.first_name = user.get('first_name')
instance.user.save()
return instance
I am getting an error {
"user": [
"This field is required."
]
}

Answer 1

Change user field to DictField. In this way, it will not be treated as foreignkey.
In to_representation, serialize user object and you will get data in format in which you want to get.
class UserSerializer(ModelSerializer):
class Meta:
model = User
fields = ('id', 'first_name','last_name')
class UserProfileSerializer(ModelSerializer):
user = serializer.DictField(required=False, write_only=True, default={})
def to_representation(self, instance):
data = super().to_representation(instance)
data.update({'user': UserSerializer(instance.user).data})
return data
class Meta:
model = UserProfile
fields = ('id', 'designation', 'contact_number', 'team', 'manager',
'joining_date','user')
def update(self, instance, validated_data):
user = validated_data.get('user')
instance.user.first_name = user.get('first_name')
instance.user.save()
return instance