Activate Django user after successful PayPal payment

Question

I am attempting to implement a PayPal gateway after user sign-up for a webapp. Once the user registration form is submitted, a signal sets the user to inactive (on purpose). I want to set the user to active after a successful PayPal payment; however, Im having trouble identifying how to get the user id to the receiver to activate the user account since the PayPal button has a separate landing page (and the user isn't authenticated at this point).

Is it possible to pass the newly created user instance from the registration page as context to the payment-process page? Any help would be greatly appreciated.

Code below: VIEWS

def register(request):
    if request.method == "POST":
        form = RegisterForm(request.POST)
        if form.is_valid():
            form.save()
            return redirect("process-payment")
    else:
        # create empty form for user to fill in
        form = RegisterForm()
    return render(request, "register/register.html", {"form": form})


def payment_done(request):
    return redirect('login')


def process_payment(request):
    host = request.get_host()
    paypal_dict = {
        "cmd": "_xclick-subscriptions",
        'business': settings.PAYPAL_RECEIVER_EMAIL,
        "a3": "1.75",  # monthly price
        "p3": "1",  # duration of each unit (depends on unit)
        "t3": "M",  # duration unit ("M for Month")
        "src": "1",  # make payments recur
        "sra": "1",  # reattempt payment on payment error
        "no_note": "1",  # remove extra notes (optional)
        'item_name': 'subscription',
        'custom': f"{}",  # User ID passed here
        'currency_code': 'USD',
        'notify_url': f'http://{host}{reverse("paypal-ipn")}',
        'return_url': f'http://{host}{reverse("payment-done")}',
        'cancel_return': f'http://{host}{reverse("payment-cancelled")}',
    }

    form = PayPalPaymentsForm(initial=paypal_dict, button_type="subscribe")
    return render(request, 'main/process-payment.html', {"form":form})

SIGNALS

@receiver(post_save, sender=User)
def set_user_inactive(sender, instance, created, update_fields, **kwargs):
    if created:
        instance.is_active = False
        instance.save()


@receiver(valid_ipn_received)
def ipn_receiver(sender, **kwargs):
    ipn_obj = sender

    # check for subscription signup IPN
    if ipn_obj.txn_type == "subscr_signup":

        # get user id and activate the account
        id = ipn_obj.custom
        user = User.objects.get(id=id)
        user.is_active = True
        user.save()

        subject = 'Registration Complete'

        message = 'Thanks for signing up with our appl!'

        email = EmailMessage(subject,
                             message,
                             '[email protected]',
                             [user.email])

        email.send()

    # check for subscription payment IPN
    elif ipn_obj.txn_type == "subscr_payment":

        # get user id and extend the subscription
        id = ipn_obj.custom
        user = User.objects.get(id=id)
        user.extend()  # extend the subscription

        subject = 'Your Invoice for {} is available'.format(
            datetime.strftime(datetime.now(), "%b %Y"))

        message = 'Thanks for using our app. This is a reoccurring payment notification for your subscription ' \
                  'to our app. $1.75 charged to your account.'

        email = EmailMessage(subject,
                             message,
                             '[email protected]',
                             [user.email])

        email.send()

    # check for failed subscription payment IPN
    elif ipn_obj.txn_type == "subscr_failed":
        pass

    # check for subscription cancellation IPN
    elif ipn_obj.txn_type == "subscr_cancel":
        pass

Answer 1

        "cmd": "_xclick-subscriptions",
        'business': settings.PAYPAL_RECEIVER_EMAIL,

That is a very old, deprecated legacy integration method. Do not use it for new integrations.

See the current PayPal Subscription documentation. You can create plans via its API calls (authenticate with a clientid and secret to obtain an access token) or in the account's web interface:

• Sandbox https://www.sandbox.paypal.com/billing/plans
• Live https://www.paypal.com/billing/plans

Answer 2

I was able to figure out the how to pass user information between view methods without* them being authenticated/active (by storing the info in session) in case anyone else runs into a similar issue:

def registration(request):
    username = request.POST['username']
    user = User.objects.get(username=username)
    request.session['username'] = user.username
    return redirect('next_view')

def next_view(request):
    username = request.session.get('username')
    user = User.objects.get(username=username)

Now the user object can be passed around for background operations if the user isn't authenticated.