views.py

class PayPalSuccessView(JSONResponseMixin, OwnerAccessMixin, DetailView):
    template_name = 'payment_success.html'
    context_object_name = 'order'
    pk_url_kwarg = 'order_id'
    model = Order

    def get_context_data(self, **kwargs):

        context = super(PayPalSuccessView, self).get_context_data(**kwargs)
        context.update({"paypal_data": self.get_object().paypalextrapayment_set.last()})
        return context

    def get(self, request, *args, **kwargs):
        return super(PayPalSuccessView, self).get(request, *args, **kwargs)

    def post(self, request, *args, **kwargs):
        order = self.get_object()
        paypal_extra_payment, err = process_express(request, order)
        if err:
            return self.render_json_response(err)

        is_paid = payment_action(
            order_id=paypal_extra_payment.invoice_number,
            amount=paypal_extra_payment.price_total,
            payment_method=PAYPAL,
            response=paypal_extra_payment,
            is_paid=(not err)
        )

        if is_paid:
            for package in order.package_set.all():
                UserActivity.objects.create(
                    package=package,
                    number=package.get_identifier(),
                    message_code=SAVE_LABEL,
                    user=request.user
                )
        data = {'url': reverse('paypal_payment_success', kwargs={'order_id': paypal_extra_payment.invoice_number})}

        return self.render_json_response(data)