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?

Answer 1

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