Better document how the partial pipeline should be handeled

[PetrDlouhy]

I am trying to get social login working together with django-two-factor-auth (so that it requires additional authentication step for users with 2FA enabled). I am now stuck for several hours on this step from documentation: Partial Pipeline

There is written:

When it’s time to resume the process just redirect the user to /complete// or /disconnect// view. The pipeline will resume in the same function that cut the process.

I have already figured out, that it is not very precise description, because I have to pass the partial_token token to that URL. But I am still stuck on the fact, that the pipeline is returning to the same (two factor authentication) step again and again. To overcome this I am trying to store somewhere the information that the user has been authenticated by 2FA, but I don't know how to access the pipeline correctly or if I am not doing it completely wrong.

I would be glad if this is documented more deeply, possibly with some examples. I could also help to extend the documentation if I know how to implement this correctly.

[PetrDlouhy]

I have got this solved by storing the info about 2FA authentication in session. But I feel it is a bit hacky and unneedingly complicated.

The pipeline:

from django.shortcuts import redirect
from django.urls import reverse
from social_core.pipeline.partial import partial
from two_factor.utils import default_device

@partial
def two_factor_auth(strategy, details, *args, user=None, **kwargs):
    current_partial = kwargs.get("current_partial")
    request = kwargs["request"]
    if request.session.get("tfa_completed", False):
        return
    if default_device(user):
        return redirect(
            reverse("two_factor_authentication") + f"?partial_token={current_partial.token}"
        )
    return

The view:

from django.urls import reverse
from django.views.generic import FormView
from social_django.utils import load_strategy
from two_factor.forms import AuthenticationTokenForm
from two_factor.utils import default_device

class AuthenticationView(FormView):
    template_name = "two_factor/core/login.html"
    form_class = AuthenticationTokenForm

    def get_success_url(self):
        partial = self.get_partial()
        self.request.session["tfa_completed"] = True
        return (
            reverse("social:complete", kwargs={"backend": partial.backend})
            + f"?partial_token={partial.token}"
        )

    def get_partial(self):
        strategy = load_strategy()
        partial_token = self.request.GET.get("partial_token")
        partial = strategy.partial_load(partial_token)
        return partial

    def get_form_kwargs(self, *args, **kwargs):
        kwargs = super().get_form_kwargs(*args, **kwargs)
        user = self.get_partial().kwargs["user"]
        kwargs["user"] = user
        kwargs["initial_device"] = default_device(user)
        return kwargs

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context["step"] = "auth"
        return context