Класс LoginRequiredMixin (Django 3.2)

def dispatch(self, request, *args, **kwargs):
    if not request.user.is_authenticated:
        return self.handle_no_permission()
    return super().dispatch(request, *args, **kwargs)

def get_login_url(self):
    """
    Override this method to override the login_url attribute.
    """
    login_url = self.login_url or settings.LOGIN_URL
    if not login_url:
        raise ImproperlyConfigured(
            '{0} is missing the login_url attribute. Define {0}.login_url, settings.LOGIN_URL, or override '
            '{0}.get_login_url().'.format(self.__class__.__name__)
        )
    return str(login_url)

def get_permission_denied_message(self):
    """
    Override this method to override the permission_denied_message attribute.
    """
    return self.permission_denied_message

def get_redirect_field_name(self):
    """
    Override this method to override the redirect_field_name attribute.
    """
    return self.redirect_field_name

def handle_no_permission(self):
    if self.raise_exception or self.request.user.is_authenticated:
        raise PermissionDenied(self.get_permission_denied_message())
    path = self.request.build_absolute_uri()
    resolved_login_url = resolve_url(self.get_login_url())
    # If the login url is the same scheme and net location then use the
    # path as the "next" url.
    login_scheme, login_netloc = urlparse(resolved_login_url)[:2]
    current_scheme, current_netloc = urlparse(path)[:2]
    if (
        (not login_scheme or login_scheme == current_scheme) and
        (not login_netloc or login_netloc == current_netloc)
    ):
        path = self.request.get_full_path()
    return redirect_to_login(
        path,
        resolved_login_url,
        self.get_redirect_field_name(),
    )