Added voucher redemption

src/pretix/presale/views/__init__.py

@@ -48,8 +48,8 @@ class CartMixin:
         def keyfunc(pos):
             if answers and ((pos.item.admission and self.request.event.settings.attendee_names_asked)
                             or pos.item.questions.all()):
-                return pos.id, 0, 0, 0
-            return 0, pos.item_id, pos.variation_id, pos.price
+                return pos.id, 0, 0, 0, None
+            return 0, pos.item_id, pos.variation_id, pos.price, pos.voucher
 
         positions = []
         for k, g in groupby(sorted(list(cartpos), key=keyfunc), key=keyfunc):

src/pretix/presale/views/cart.py

@@ -26,7 +26,7 @@ class CartActionMixin:
     def get_error_url(self):
         return self.get_next_url()
 
-    def _items_from_post_data(self):
+    def _items_from_post_data(self, warn=True):
         """
         Parses the POST data and returns a list of tuples in the
         form (item id, variation id or None, number)
@@ -47,7 +47,7 @@ class CartActionMixin:
                 except ValueError:
                     messages.error(self.request, _('Please enter numbers only.'))
                     return []
-        if len(items) == 0:
+        if len(items) == 0 and warn:
             messages.warning(self.request, _('You did not select any products.'))
             return []
         return items
@@ -93,9 +93,11 @@ class CartAdd(EventViewMixin, CartActionMixin, AsyncAction, View):
         return super().get_error_message(exception)
 
     def post(self, request, *args, **kwargs):
-        items = self._items_from_post_data()
-        if items:
-            return self.do(self.request.event.id, items, self.request.session.session_key)
+        voucher = self.request.POST.get('voucher')
+        items = self._items_from_post_data(warn=not voucher)
+        if items or voucher:
+            return self.do(self.request.event.id, items, self.request.session.session_key,
+                           voucher)
         else:
             if 'ajax' in self.request.GET or 'ajax' in self.request.POST:
                 return JsonResponse({

src/pretix/presale/views/event.py

@@ -60,5 +60,11 @@ class EventIndex(EventViewMixin, CartMixin, TemplateView):
                 group[0] is not None and group[0].id is not None) else (0, 0)
         )
 
+        vouchers_exist = self.request.event.get_cache().get('vouchers_exist')
+        if vouchers_exist is None:
+            vouchers_exist = self.request.event.vouchers.exists()
+            self.request.event.get_cache().set('vouchers_exist', vouchers_exist)
+        context['vouchers_exist'] = vouchers_exist
+
         context['cart'] = self.get_cart()
         return context