Question

I’ve had a read of this

http://docs.b-list.org/django-registration/0.8/backend-api.html

and i’ve had a shot at making my own backend. I am doing this because I want to create a backend that disallows having the same email used for registration, and I wanted to change the email-error message. I also wanted to add in my own field!

Here is what I came up with:

from django import forms
from registration.forms import RegistrationForm
from django.utils.translation import ugettext_lazy as _
from django.contrib.auth.models import User
from registration.forms import attrs_dict

class customRegistrationForm(RegistrationForm):
    email2 = forms.EmailField(widget=forms.TextInput(attrs=dict(attrs_dict,
        maxlength=75)),
        label=_("Confirm email"))

    def clean_email(self):
        """
        Validate that the email is alphanumeric and is not already
        in use.
        """
        try:
            email = User.objects.get(email__iexact=self.cleaned_data['email'])
        except User.DoesNotExist:
            return self.cleaned_data['email']
        raise forms.ValidationError(_("That email already exists - if you have forgotten your password, go to the login screen and then select \"forgot password\""))

    def clean(self):
        """
        Verifiy that the values entered into the two email fields
        match. Note that an error here will end up in
        ``non_field_errors()`` because it doesn't apply to a single
        field.

        """
        if 'email' in self.cleaned_data and 'email2' in self.cleaned_data:
            if self.cleaned_data['email'] != self.cleaned_data['email2']:
                raise forms.ValidationError(_("The two email fields didn't match."))
        return super(RegistrationForm,clean)

The above goes in my init.py file (whetever that is)

Then, I have in my urls.py code:

url(r'^accounts/register/$',
    register,
        { 'backend': 'myapp.forms.customRegistrationForm' },
    name='registration_register'),
... #other urls here!

Now, when i go to the /accounts/register page, I get the following error:

AttributeError at /accounts/register/

‘customRegistrationForm’ object has no attribute ‘registration_allowed’

Which is weird. It seems to be telling me I need a "registration_allowed" method added to my subclass. BUT, the subclass is a subclass of the RegistrationForm, which works fine and doesn’t have that stuff defined… I know I can add these members in, but it seems to beat the purpose of extension, right?

UPDATE

Here is the code now that it works!

I broke up the varying classes into varying init.py files in different folders – one called "forms" and one called "backends", both of which sit in a folder "djangoRegistration" under my main project.

/forms/init.py

from django import forms
from registration.forms import RegistrationForm
from django.utils.translation import ugettext_lazy as _
from django.contrib.auth.models import User
from registration.forms import attrs_dict

class customRegistrationForm(RegistrationForm):
    def __init__(self, *args, **kw):
        super(RegistrationForm, self).__init__(*args, **kw)
        self.fields.keyOrder = [
            'username',
            'email',
            'email2',
            'password1',
            'password2'
        ]

    email2 = forms.EmailField(widget=forms.TextInput(attrs=dict(attrs_dict,
        maxlength=75)),
        label=_("Confirm email"))

    def clean_email(self):
        """
        Validate that the email is alphanumeric and is not already
        in use.
        """
        try:
            email = User.objects.get(email__iexact=self.cleaned_data['email'])
        except User.DoesNotExist:
            return self.cleaned_data['email']
        raise forms.ValidationError(_("That email already exists - if you have forgotten your password, go to the login screen and then select \"forgot password\""))

    def clean(self):
        """
        Verifiy that the values entered into the two email fields
        match. Note that an error here will end up in
        ``non_field_errors()`` because it doesn't apply to a single
        field.

        """
        if 'email' in self.cleaned_data and 'email2' in self.cleaned_data:
            if self.cleaned_data['email'] != self.cleaned_data['email2']:
                raise forms.ValidationError(_("The two email fields didn't match."))
        return super(RegistrationForm,clean)

/backends/init.py

from registration.backends.default import DefaultBackend
from dumpstownapp.djangoRegistration.forms import customRegistrationForm

class customDefaultBackend(DefaultBackend):
    def get_form_class(self, request):
        """
        Return the default form class used for user registration.

        """
        return customRegistrationForm

and finally, my urls.py just references the new backend:

url(r'^accounts/register/$',
    register,
        { 'backend': 'myapp.djangoRegistration.backends.customDefaultBackend' },
    name='registration_register'),
#more urls here! yay!

As a final note, I had to add some code to "order" the way the fields were presented, which is what the init method in the customRegistrationForm is doing

thanks!

Answer 1

You’re trying to use a form as a backend, but that’s not what a backend is at all. As the document you link to explains, a backend is a class that implements certain methods, including registration_allowed. The form doesn’t implement any of those, which is not surprising, because it’s meant for user input and validation, not the backend actions.

However, that page does give a hint as to the correct way to implement this. One of the methods that the backend can define is get_form_class(), which returns the form class to use. So, it seems that what you need is a custom backend that inherits from registration.backends.default.DefaultBackend and overrides just the get_form_class method, which simply returns customRegistrationForm.