邀请未被接受的用户也已注册

我的应用程序中的功能是用户应首先请求邀请，如果管理员（来自管理员）接受了他的邀请，则应发送一条可以注册的消息 .

功能的流程

用户使用他/她的电子邮件地址提交表单，将发送邮件说谢谢 . 现在，如果管理员接受他/她的请求，即request_accepted现在将为True，并且将发送一封邮件，说现在您可以注册 . 最后，当用户进入注册页面并提交表单时，应检查他在注册期间填写和提交的电子邮件是否已被接受 . 如果已接受，则注册已成功完成，否则会显示错误，指出此电子邮件地址尚未被邀请 .

class Invitation(models.Model):
    email = models.EmailField(unique=True, verbose_name=_("e-mail Address"))
    request_approved = models.BooleanField(default=False, verbose_name=_('request accepted'))

@receiver(post_save, sender=Invitation)
def send_email_when_invite_is_accepted_by_admin(sender, instance, *args, **kwargs):
    request_approved = instance.request_approved
    if request_approved:
        subject = "Request Approved"
        message = "Hello {0}! Your request has been approved. You can now signup".format(instance.email)
        from_email = None
        to_email = [instance.email]
        send_mail(subject, message, from_email, to_email, fail_silently=True)

def requestInvitation(request):
    form = InviteForm(request.POST or None)
    if form.is_valid():
        join = form.save(commit=False)
        email = form.cleaned_data.get('email')
        already_join, created = Invitation.objects.get_or_create(email=email)
        if created:
            already_join.save()
            subject = "Thank you for your request to sign up our community"
            message = "Welcome! We will be in contact with you."
            from_email = None
            to_email = [email]
            send_mail(subject, message, from_email, to_email, fail_silently=True)
            messages.success(request, '{0} has been invited'.format(email))
        return HttpResponseRedirect("/")
    context = {"form": form}
    return render(request, 'home.html', context)


ACCOUNT_SIGNUP_FORM_CLASS = 'pages.custom_sign_up_form.CustomSignupForm'

custom_signup_form.py

from invitation.models import Invitation

class CustomSignupForm(forms.Form):
    def __init__(self, *args, **kwargs):
        super(CustomSignupForm, self).__init__(*args, **kwargs)

    def clean_email(self):
        value = self.cleaned_data.get('email')
        print ('value before adapter', value)
        value = get_adapter().clean_email(value)
        print ('value', value)
        if value and app_settings.UNIQUE_EMAIL:
            value = self.validate_unique_email(value)
        try:
            Invitation.objects.get(email=value, request_approved=True)
        except Invitation.DoesNotExist:
            raise forms.ValidationError(errors['Sorry! you are not yet invited'])
        return value

    def signup(self, request, user):
      user.save()

我正在做的方式也允许注册到不被接受的用户 .

UPDATE

如果我把clean_email逻辑放在注册中

def signup(self, request, user):
      print ('request', request, user)
      value = self.cleaned_data.get('email')
      print ('email is', value)
      try:
          Invitation.objects.get(email=value, request_approved=True)
      except:
          raise forms.ValidationError(errors['sorry! You are not yet invited'])
      user.save()

我得到'名称错误未定义'