Right way to implement email whitelist solution for Django-registration-redux?

Question

I have working solution however I affraid my solution isn't much pythonic. So I hope somebody will suggest a better way.

With Django ver 1.8.2 I am using django-registration-redux ver 1.2. I have my own form therefore I have setting REGISTRATION_FORM = 'login_app.forms.MyRegForm'.

Additionally I need a feature so that only whitelisted emails are allowed to register. According to registration/backends/default/urls.py register view is handled by class RegistrationView in registration/backends/default/views.py:

...
from registration.backends.default.views import RegistrationView
...
url(r'^register/$',
    RegistrationView.as_view(),
        name='registration_register'),
...

RegistrationView class can be viewed on Github. Because this class with it's functions provides required functionality I have subclassed it and copied all it's content only adding few lines of my code. In my login_app.views.py:

from registration.backends.default.views import RegistrationView
# and many other imports to satisfy actions inside MyRegView

class MyRegView(RegistrationView):
    # some copied code
    def register(self, request, form):
        # some copied code
        WHITELISTED_EMAILS = getattr(settings, 'WHITELISTED_EMAILS')
        email_to_check = form.cleaned_data['email']
        if email_to_check in WHITELISTED_EMAILS:
            # registration performed
            # by using copied code
        else:
            raise PermissionDenied

    def registration_allowed(self, request):
        # remaining copied code

Finally I have overwritten url so that the right view is used:

...
from login_app.views import MyRegView

urlpatterns = [
     ...
     url(r'^accounts/register/', MyRegView.as_view(), name='registration_register'),
     ... 
    ]

This solution works fine, but I am copying too much code. What is more elegant solution for whitelist implementation?

There is normally no need to copy entire methods unchanged from superclass to subclass. Why are you doing that? — Kevin, Oct 19 '15 at 13:47
Most likely because of lacking OOP concepts. I was trying to avoid. — baltasvejas, Oct 19 '15 at 13:50

Alasdair · Accepted Answer · 2015-10-19T13:56:02.880

2

I think the easiest solution is to add a clean_email method to your registration form, and do the whitelisting there.

class MyRegForm(ParentForm):
    def clean_email(self):
        email = self.cleaned_data['email']
        # If the parent class already cleans the email, you might want to do
        # email = super(MyRegForm, self).clean_email()
        # Then check email here, and raise forms.ValidationError() 
        # if the email is not in the whitelist
        return email

edited Oct 19 '15 at 13:56

answered Oct 19 '15 at 13:49

Alasdair

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I will check it out and will come back most likely tomorrow. – baltasvejas Oct 19 '15 at 13:53
Although I don't get why I might use option `email = super(MyRegForm, self).clean_email()`, the suggested solution works fine and simple to implement. Thanks. – baltasvejas Oct 19 '15 at 15:51
If `ParentForm` already had a `clean_email` method, then your `clean_method` method would replace it. Calling `super()` would call the method of the parent class. This avoids having to copy paste code from the parent class to the child class. Overriding a method and calling `super()` is a pretty standard technique. On second thoughts, I think it's unlikely that your parent class has a `clean_email` method, but you didn't include it in your question, so I mentioned it for completeness. – Alasdair Oct 19 '15 at 15:54
As provided in [this SO answer](http://stackoverflow.com/a/31358213/2647009) I am subclassing `RegistrationForm` from [registration.forms](https://github.com/macropin/django-registration/blob/master/registration/forms.py). While looking into `RegistrationForm` class I don't find `clean_email` method. So that means code is ok. – baltasvejas Oct 19 '15 at 16:32
Yes, if `RegistrationForm` (or its parent classes) do not have a `clean_email` method, then you don't have to call `super()`. – Alasdair Oct 19 '15 at 16:38

Right way to implement email whitelist solution for Django-registration-redux?

1 Answers1