Allow to hide payment methods behind a secret link

src/pretix/presale/urls.py

@@ -53,6 +53,8 @@ event_patterns = [
         csrf_exempt(pretix.presale.views.cart.CartAdd.as_view()),
         name='event.cart.add'),
 
+    url(r'unlock/(?P<hash>[a-z0-9]{64})/$', pretix.presale.views.user.UnlockHashView.as_view(),
+        name='event.payment.unlock'),
     url(r'resend/$', pretix.presale.views.user.ResendLinkView.as_view(), name='event.resend_link'),
 
     url(r'^order/(?P<order>[^/]+)/(?P<secret>[A-Za-z0-9]+)/open/(?P<hash>[a-z0-9]+)/$', pretix.presale.views.order.OrderOpen.as_view(),

src/pretix/presale/views/user.py

@@ -5,6 +5,7 @@ from django.contrib import messages
 from django.shortcuts import redirect
 from django.utils.functional import cached_property
 from django.utils.translation import ugettext_lazy as _
+from django.views import View
 from django.views.generic import TemplateView
 
 from pretix.base.email import get_email_context
@@ -60,3 +61,13 @@ class ResendLinkView(EventViewMixin, TemplateView):
         context = super().get_context_data(**kwargs)
         context['form'] = self.link_form
         return context
+
+
+class UnlockHashView(EventViewMixin, View):
+    # Allows to register an unlock hash in the user's session, e.g. to unlock a hidden payment provider
+
+    def get(self, request, *args, **kwargs):
+        hashes = request.session.get('pretix_unlock_hashes', [])
+        hashes.append(kwargs.get('hash'))
+        request.session['pretix_unlock_hashes'] = hashes
+        return redirect(eventreverse(self.request.event, 'presale:event.index'))