Add waiting list

src/pretix/presale/views/waiting.py

@@ -0,0 +1,76 @@
+from django.contrib import messages
+from django.shortcuts import redirect
+from django.utils import translation
+from django.utils.functional import cached_property
+from django.utils.translation import ugettext_lazy as _
+from django.views.generic import FormView
+
+from ...base.models import Item, ItemVariation, WaitingListEntry
+from ...multidomain.urlreverse import eventreverse
+from ..forms.waitinglist import WaitingListForm
+
+
+class WaitingView(FormView):
+    template_name = 'pretixpresale/event/waitinglist.html'
+    form_class = WaitingListForm
+
+    def get_form_kwargs(self):
+        kwargs = super().get_form_kwargs()
+        kwargs['event'] = self.request.event
+        kwargs['instance'] = WaitingListEntry(
+            item=self.item_and_variation[0], variation=self.item_and_variation[1],
+            event=self.request.event, locale=translation.get_language()
+        )
+        return kwargs
+
+    def get_context_data(self, **kwargs):
+        ctx = super().get_context_data()
+        ctx['event'] = self.request.event
+        ctx['item'], ctx['variation'] = self.item_and_variation
+        return ctx
+
+    @cached_property
+    def item_and_variation(self):
+        try:
+            item = self.request.event.items.get(pk=self.request.GET.get('item'))
+            if 'var' in self.request.GET:
+                var = item.variations.get(pk=self.request.GET['var'])
+            elif item.has_variations:
+                return None
+            else:
+                var = None
+            return item, var
+        except (Item.DoesNotExist, ItemVariation.DoesNotExist):
+            return None
+
+    def dispatch(self, request, *args, **kwargs):
+        self.request = request
+
+        if not self.request.event.settings.waiting_list_enabled:
+            messages.error(request, _("Waiting lists are disabled for this event."))
+            return redirect(eventreverse(self.request.event, 'presale:event.index'))
+
+        if not self.item_and_variation:
+            messages.error(request, _("We could not identify the product you selected."))
+            return redirect(eventreverse(self.request.event, 'presale:event.index'))
+
+        return super().dispatch(request, *args, **kwargs)
+
+    def form_valid(self, form):
+        availability = (
+            self.item_and_variation[1].check_quotas(count_waitinglist=False)
+            if self.item_and_variation[1]
+            else self.item_and_variation[0].check_quotas(count_waitinglist=False)
+        )
+        if availability[0] == 100:
+            messages.error(self.request, _("You cannot add yourself to the waiting list as this product ist currently "
+                                           "available."))
+            return redirect(eventreverse(self.request.event, 'presale:event.index'))
+
+        form.save()
+        messages.success(self.request, _("We've added you to the waiting list. You will receive "
+                                         "an email as soon as tickets get available again."))
+        return super().form_valid(form)
+
+    def get_success_url(self):
+        return eventreverse(self.request.event, 'presale:event.index')