Fix #180 -- Hide add to cart button if no products active or no quantity left (#200)

* Hide add to cart button if no products active or no quantity left(#180)

* Fix PEP errors and improve logic

* Fix tests for add to cart change

* Fix the logic for toggling the visibility of Add to Cart button

src/pretix/presale/templates/pretixpresale/event/index.html

@@ -202,7 +202,7 @@
                     {% endfor %}
                 </section>
             {% endfor %}
-            {% if event.presale_is_running %}
+            {% if event.presale_is_running and display_add_to_cart %}
                 <div class="row-fluid checkout-button-row">
                     <div class="col-md-4 col-md-offset-8 col-xs-12">
                         <button class="btn btn-block btn-primary btn-lg" type="submit">

src/pretix/presale/views/event.py

@@ -39,7 +39,7 @@ class EventIndex(EventViewMixin, CartMixin, TemplateView):
         ).annotate(quotac=Count('quotas')).filter(
             quotac__gt=0
         ).order_by('category__position', 'category_id', 'position', 'name')
-
+        display_add_to_cart = False
         for item in items:
             item.available_variations = list(item.variations.filter(active=True, quotas__isnull=False).distinct())
             item.has_variations = item.variations.exists()
@@ -49,12 +49,14 @@ class EventIndex(EventViewMixin, CartMixin, TemplateView):
                                      if item.cached_availability[1] is not None else sys.maxsize,
                                      int(self.request.event.settings.max_items_per_order))
                 item.price = item.default_price
+                display_add_to_cart = display_add_to_cart or item.order_max > 0
             else:
                 for var in item.available_variations:
                     var.cached_availability = list(var.check_quotas())
                     var.order_max = min(var.cached_availability[1]
                                         if var.cached_availability[1] is not None else sys.maxsize,
                                         int(self.request.event.settings.max_items_per_order))
+                    display_add_to_cart = display_add_to_cart or var.order_max > 0
                     var.price = var.default_price if var.default_price is not None else item.default_price
                 if len(item.available_variations) > 0:
                     item.min_price = min([v.price for v in item.available_variations])
@@ -64,6 +66,7 @@ class EventIndex(EventViewMixin, CartMixin, TemplateView):
 
         # Regroup those by category
         context['items_by_category'] = item_group_by_category(items)
+        context['display_add_to_cart'] = display_add_to_cart
 
         vouchers_exist = self.request.event.get_cache().get('vouchers_exist')
         if vouchers_exist is None:

src/tests/presale/test_event.py

@@ -55,6 +55,7 @@ class ItemDisplayTest(EventTestMixin, SoupTest):
         q.items.add(item)
         html = self.client.get('/%s/%s/' % (self.orga.slug, self.event.slug))
         self.assertNotIn("Early-bird", html)
+        self.assertNotIn('checkout-button-row', html)
 
     def test_without_category(self):
         q = Quota.objects.create(event=self.event, name='Quota', size=2)
@@ -62,6 +63,7 @@ class ItemDisplayTest(EventTestMixin, SoupTest):
         q.items.add(item)
         doc = self.get_doc('/%s/%s/' % (self.orga.slug, self.event.slug))
         self.assertIn("Early-bird", doc.select("section .product-row")[0].text)
+        self.assertIn("Add to cart", doc.select("div button")[0].text)
 
     def test_timely_available(self):
         q = Quota.objects.create(event=self.event, name='Quota', size=2)
@@ -217,7 +219,7 @@ class DeadlineTest(EventTestMixin, TestCase):
         )
         self.assertEqual(response.status_code, 200)
         self.assertNotIn('alert-info', response.rendered_content)
-        self.assertIn('checkout-button-row', response.rendered_content)
+        self.assertNotIn('checkout-button-row', response.rendered_content)
         response = self.client.post(
             '/%s/%s/cart/add' % (self.orga.slug, self.event.slug),
             {
@@ -235,7 +237,7 @@ class DeadlineTest(EventTestMixin, TestCase):
         )
         self.assertEqual(response.status_code, 200)
         self.assertNotIn('alert-info', response.rendered_content)
-        self.assertIn('checkout-button-row', response.rendered_content)
+        self.assertNotIn('checkout-button-row', response.rendered_content)
         response = self.client.post(
             '/%s/%s/cart/add' % (self.orga.slug, self.event.slug),
             {