Python | Extending and customizing django-allauth

24 Aug, 2021
Prerequisite: Django-allauth setup and Configuration
Let’s deal with customizing django-allauth signup forms, intervening in registration flow to add custom processes and validations. 
Extending Signup Form or adding custom fields in django-allauth: 
One of the most common queries about allauth is about adding additional fields or custom fields to the signup form. You can extend the SignupForm class from allauth.account.forms. All you need to do is create a custom class pass the SignupForm to the custom class and define the custom fields and save it. It’s vital to return the user object as it will be passed to other modules for validation. You also need to include a variable in settings.py. 
Let’s see this using an example forms.py . 
Python3
from allauth.account.forms import SignupFormfrom django import forms  class CustomSignupForm(SignupForm):    first_name = forms.CharField(max_length=30, label='First Name')    last_name = forms.CharField(max_length=30, label='Last Name')     def save(self, request):         user = super(CustomSignupForm, self).save(request)        user.first_name = self.cleaned_data['first_name']        user.last_name = self.cleaned_data['last_name']        user.save()        return user
In the above snippet, CustomSignupForm is extended the class which inherits all the features of SignupForm class and adds the necessary features. Here custom fields by the name first_nameand last_name are created and saved using the signup module in the same class. 
The ACCOUNT_FORMS in settings.py for the above code is 
Python3
ACCOUNT_FORMS = {'signup': 'YourProject.forms.CustomSignupForm',}
Any other custom forms created can be extended in ACCOUNT_FORMS. The list is illustrated in the documentation.Similarly, LoginForm UserForm AddEmailForm and others can be extended. However, remember that when you extend these forms and link them in settings.py. Don’t forget to pass the original form (For example SignupForm) as a parameter to your class and sometimes you might have to handle custom validations and return users or some other value. Please refer to the source code to follow the correct flow.   User Intervention and Custom validations: 
Let’s discuss adding custom validations and intervening in the user registration flow. DefaultAccountAdapter is very useful and indeed can be used to solve most of the customization problems that a user might encounter while using django–allauth. 
Example #1: Restricted List of email’s 
After figuring out a way to store and fetch the restricted list, you can use the adapters and raise validation errors in the registration form when a restricted email tries to register. Extend a DefaultAccountAdapter and override the clean_email method. Create an adapter.py in your project directory and extend the default adapter class.
Python3
from allauth.account.adapter import DefaultAccountAdapterfrom django.forms import ValidationError class RestrictEmailAdapter(DefaultAccountAdapter):    def clean_email(self, email):        RestrictedList = ['Your restricted list goes here.']        if email in RestrictedList            raise ValidationError('You are restricted from registering.\                                                  Please contact admin.')        return email
Finally, point the account adapter in settings.py to your extended class. 
ACCOUNT_ADAPTER='YourProject.adapter.RestrictEmailAdapter'
Example #2: Add a Maximum length to a username 
As ACCOUNT_USERNAME_MAX_LENGTH doesn’t exist in the allauth library, DefaultAccountAdaptercan is used to achieve this feature without much pain. Extend the DefaultAccountAdapterclass and overriding the clean_username method. You need to also reference the clean_username once again after our custom validation to complete other inbuilt validations.
The last sentence in the above paragraph is the key to work with DefaultAccountAdapter. You should never forget to reference the original module name for the module to complete other validations. 
Python3
from allauth.account.adapter import DefaultAccountAdapterfrom django.forms import ValidationError class UsernameMaxAdapter(DefaultAccountAdapter):    def clean_username(self, username):        if len(username) > 'Your Max Size':            raise ValidationError('Please enter a username value\                                      less than the current one')                 # For other default validations.        return DefaultAccountAdapter.clean_username(self, username)
Finally, point to the subclass in your settings.py 
ACCOUNT_ADAPTER = 'YourProject.adapter.UsernameMaxAdapter'
You can refer to the adapters.py file in the source code and extend other modules and add a process or change their flow. The modules such as populate_username, clean_password (which can be customized to restrict commonly used passwords) can have the custom process and flow without rewriting them.DefaultAccountAdapter can be a potent tool if used in the right circumstances to intervene in allauth’s default process. allauth comes with a vast variety of inbuilt settings, and they are here. 
You can also download the entire source code from the link in the references below.References: django-allauth documentation stack overflow thread on Example 1 
Akanksha_Rai
kamrulhasan59246
sandeepagrawal8875
Python Django
Technical Scripter 2018
Python
Technical Scripter
Writing code in comment?
Please use ide.geeksforgeeks.org,
generate link and share the link here.
Python Dictionary
Different ways to create Pandas Dataframe
Enumerate() in Python
Python String | replace()
How to Install PIP on Windows ?
*args and **kwargs in Python
Python Classes and Objects
Convert integer to string in Python
Python OOPs Concepts
Python | os.path.join() method