Django REST Framework, save to extra field on custom user model

Question

Using Django REST Framework (DRF) I added a custom user model with one extra field. I have posted my code at the bottom.

Now, when registering a new user ('/rest-auth/registration/') using DRF's graphical interface, I do get an extra input for the new model field. When I enter a value into this form input and hit POST, a new user is indeed created, but the extra field stays empty.

I have been looking into how to get this to work, and found another SO question with a good example and answers, but the problem with this SO post is that the poster uses AbstractBaseUser as the class that his custom user models inherits from, and I want to use AbstractUser instead. (Why? Since I read that this is recommended, unless you truly understand what you are doing.)

Because the poster in the other SO answer uses AbstractBaseUser, his solution seems to involve much more code and compliation than I need.

So, can anyone tell advice me on how I can have the extra field also be filled during registration, when POSTing the correct data?

users.models.py:

from django.contrib.auth.models import AbstractUser
from django.db import models


class CustomUser(AbstractUser):
    preferred_locale = models.CharField(max_length=2,
                                        blank=True,
                                        null=True)

user.serializers.py:

from rest_framework import serializers

from allauth.account.adapter import get_adapter
from allauth.account.utils import setup_user_email

from rest_auth.registration.serializers import RegisterSerializer


class CustomRegisterSerializer(RegisterSerializer):
    preferred_locale = serializers.CharField(
        required=False,
        max_length=2,
    )

    def get_cleaned_data(self):
        return {
            'preferred_locale': self.validated_data.get('preferred_locale', 'en'),
            'username': self.validated_data.get('username', ''),
            'password1': self.validated_data.get('password1', ''),
            'email': self.validated_data.get('email', '')
        }

    def save(self, request):
        adapter = get_adapter()
        user = adapter.new_user(request)
        self.cleaned_data = self.get_cleaned_data()
        adapter.save_user(request, user, self)
        user.preferred_locale = self.cleaned_data.get('preferred_locale')
        self.custom_signup(request, user)
        setup_user_email(request, user, [])
        return user

settings.py:

import os

# Build paths inside the project like this: os.path.join(BASE_DIR, ...)
BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))


# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/2.1/howto/deployment/checklist/

# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = '5qb_(&@h!8pf@lh^)$i)1mq-35lh*k5g5t#^tl1z(delxs68)5'

# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = True

ALLOWED_HOSTS = []

SITE_ID = 1


# Application definition

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',

    'rest_framework',
    'rest_auth',
    'django.contrib.sites',
    'allauth',
    'allauth.account',
    'rest_auth.registration',
    'rest_framework.authtoken',
    'allauth.socialaccount',

    'users.apps.UsersConfig',
]

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

ROOT_URLCONF = 'my_project.urls'

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

WSGI_APPLICATION = 'my_project.wsgi.application'


# Database
# https://docs.djangoproject.com/en/2.1/ref/settings/#databases

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
    }
}


# Password validation
# https://docs.djangoproject.com/en/2.1/ref/settings/#auth-password-validators

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]

AUTH_USER_MODEL = 'users.CustomUser'


# Internationalization
# https://docs.djangoproject.com/en/2.1/topics/i18n/

LANGUAGE_CODE = 'en-us'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_L10N = True

USE_TZ = True


# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/2.1/howto/static-files/

STATIC_URL = '/static/'

#This is required otherwise it asks for email server
EMAIL_BACKEND = 'django.core.mail.backends.console.EmailBackend'
# ACCOUNT_EMAIL_REQUIRED = True
# AUTHENTICATION_METHOD = 'EMAIL'
# ACCOUNT_EMAIL_VERIFICATION = 'optional'

ACCOUNT_AUTHENTICATION_METHOD = 'email'
ACCOUNT_EMAIL_REQUIRED = True
ACCOUNT_USERNAME_REQUIRED = False

#Following is added to enable registration with email instead of username
AUTHENTICATION_BACKENDS = (
 # Needed to login by username in Django admin, regardless of `allauth`
 "django.contrib.auth.backends.ModelBackend",

 # `allauth` specific authentication methods, such as login by e-mail
 "allauth.account.auth_backends.AuthenticationBackend",
)

REST_AUTH_REGISTER_SERIALIZERS = {
    'REGISTER_SERIALIZER': 'users.serializers.CustomRegisterSerializer',
}

Answer 1

When you call adapter.save_user() , only a predefined set of fields are saved (source code here ). And after saving the user, he isn't saved again, as far as I know. Therefore, this should work:

def save(self, request):
    adapter = get_adapter()
    user = adapter.new_user(request)
    user = adapter.save_user(request, user, self, commit=False)
    user.preferred_locale = self.validated_data.get('preferred_locale', 'en')
    user.save()
    self.custom_signup(request, user)
    setup_user_email(request, user, [])
    return user