Django Rest Framework - OneToOne reverse relation - django

Question

I have a custom User model and the User Profile model.
class User(AbstractUser):
"""Custom User authentication class to use email as username"""
username = None
email = models.EmailField(verbose_name='email', max_length=255, unique=True,
error_messages={
'unique': _(
"A user is already registered with this email address"),
}, )
USERNAME_FIELD = 'email'
REQUIRED_FIELDS = []
objects = UserManager()
def __str__(self):
return self.email
class UserProfile(models.Model):
user = models.OneToOneField(User, to_field='email', on_delete=models.CASCADE)
emp_id = models.CharField(max_length=20, blank=False, default='0', null=False)
department = models.CharField(max_length=50, blank=True, default='', null=True)
I am trying to write a serializer that combines both these models are produces a nested JSON.
for example:
{
"email":"user#gmail.com",
"is_active":true,
"profile":
{
"emp_id":2,
"department":2
}
}
This is what I tried to do
class UserProfileSerializer(serializers.ModelSerializer):
class Meta:
model = UserProfile
fields = ('id', 'user', 'emp_id', 'department')
class UserPairSerializer(serializers.ModelSerializer):
profile = UserProfileSerializer(read_only=True)
class Meta:
model = User
fields = ('id', 'email', 'is_active', 'profile')
But for some reason, there is neither the field profile in my response nor am I getting any errors.
I tried following this docs: https://www.django-rest-framework.org/api-guide/relations/
What is the issue and how do I solve this?

Answer 1

As per the documentation implicitly refering to this, 'reverse' queries are done using the name of the Model, lowercased (in this case user.userprofile).
So you have two options:
Either you specify a custom related_name on the user field on the UserProfile model.
class UserProfile(models.Model):
user = models.OneToOneField(User, to_field='email', on_delete=models.CASCADE, related_name='profile')
Or, you specify a source argument on your nested serializer (see documentation):
class UserProfileSerializer(serializers.ModelSerializer):
class Meta:
model = UserProfile
fields = ('id', 'user', 'emp_id', 'department')
class UserPairSerializer(serializers.ModelSerializer):
profile = UserProfileSerializer(read_only=True, source='userprofile')
class Meta:
model = User
fields = ('id', 'email', 'is_active', 'profile')