Add unlimited_items_per_order-flag to Sales Channels (#1508)

* Add unlimited_items_per_order-flag to Sales Channels

* Test for unlimited_items_per_order Sales Channels-flag

* Fix test

src/pretix/base/channels.py

@@ -53,6 +53,14 @@ class SalesChannel:
         """
         return True
 
+    @property
+    def unlimited_items_per_order(self) -> bool:
+        """
+        If this property is ``True``, purchases made using this sales channel are not limited to the maximum amount of
+        items defined in the event settings.
+        """
+        return False
+
 
 def get_all_sales_channels():
     global _ALL_CHANNELS

src/pretix/base/services/cart.py

@@ -12,6 +12,7 @@ from django.utils.timezone import make_aware, now
 from django.utils.translation import pgettext_lazy, ugettext as _
 from django_scopes import scopes_disabled
 
+from pretix.base.channels import get_all_sales_channels
 from pretix.base.i18n import language
 from pretix.base.models import (
     CartPosition, Event, InvoiceAddress, Item, ItemBundle, ItemVariation, Seat,
@@ -218,13 +219,14 @@ class CartManager:
         })
 
     def _check_max_cart_size(self):
-        cartsize = self.positions.filter(addon_to__isnull=True).count()
-        cartsize += sum([op.count for op in self._operations if isinstance(op, self.AddOperation) and not op.addon_to])
-        cartsize -= len([1 for op in self._operations if isinstance(op, self.RemoveOperation) if
-                         not op.position.addon_to_id])
-        if cartsize > int(self.event.settings.max_items_per_order):
-            # TODO: i18n plurals
-            raise CartError(_(error_messages['max_items']) % (self.event.settings.max_items_per_order,))
+        if not get_all_sales_channels()[self._sales_channel].unlimited_items_per_order:
+            cartsize = self.positions.filter(addon_to__isnull=True).count()
+            cartsize += sum([op.count for op in self._operations if isinstance(op, self.AddOperation) and not op.addon_to])
+            cartsize -= len([1 for op in self._operations if isinstance(op, self.RemoveOperation) if
+                             not op.position.addon_to_id])
+            if cartsize > int(self.event.settings.max_items_per_order):
+                # TODO: i18n plurals
+                raise CartError(_(error_messages['max_items']) % (self.event.settings.max_items_per_order,))
 
     def _check_item_constraints(self, op):
         if isinstance(op, self.AddOperation) or isinstance(op, self.ExtendOperation):

src/pretix/presale/views/event.py

@@ -17,6 +17,7 @@ from django.views import View
 from django.views.decorators.csrf import csrf_exempt
 from django.views.generic import TemplateView
 
+from pretix.base.channels import get_all_sales_channels
 from pretix.base.models import ItemVariation, Quota, SeatCategoryMapping
 from pretix.base.models.event import SubEvent
 from pretix.base.models.items import ItemBundle
@@ -119,7 +120,10 @@ def get_grouped_items(event, subevent=None, voucher=None, channel='web', require
             item.available_variations = [v for v in item.available_variations
                                          if v.pk == voucher.variation_id]
 
-        max_per_order = item.max_per_order or int(event.settings.max_items_per_order)
+        if get_all_sales_channels()[channel].unlimited_items_per_order:
+            max_per_order = sys.maxsize
+        else:
+            max_per_order = item.max_per_order or int(event.settings.max_items_per_order)
 
         if item.hidden_if_available:
             q = item.hidden_if_available.availability(_cache=quota_cache)

src/tests/presale/test_cart.py

@@ -4,6 +4,7 @@ from datetime import timedelta
 from decimal import Decimal
 
 from bs4 import BeautifulSoup
+from django.dispatch import receiver
 from django.test import TestCase
 from django.utils.timezone import now
 from django_countries.fields import Country
@@ -21,6 +22,7 @@ from pretix.base.models.items import (
 from pretix.base.services.cart import (
     CartError, CartManager, error_messages, update_tax_rates,
 )
+from pretix.base.signals import register_sales_channels
 from pretix.testutils.scope import classscope
 from pretix.testutils.sessions import get_cart_session_key
 
@@ -29,7 +31,15 @@ class FoobarSalesChannel(SalesChannel):
     identifier = "bar"
     verbose_name = "Foobar"
     icon = "home"
-    testmode_supported = True
+    testmode_supported = False
+    unlimited_items_per_order = True
+
+
+@receiver(register_sales_channels, dispatch_uid="test_cart_register_sales_channels")
+def base_sales_channels(sender, **kwargs):
+    return (
+        FoobarSalesChannel(),
+    )
 
 
 class CartTestMixin:
@@ -816,6 +826,23 @@ class CartTest(CartTestMixin, TestCase):
         with scopes_disabled():
             self.assertEqual(CartPosition.objects.filter(cart_id=self.session_key, event=self.event).count(), 1)
 
+    def test_max_items_unlimited_sales_channel(self):
+        with scopes_disabled():
+            CartPosition.objects.create(
+                event=self.event, cart_id=self.session_key, item=self.ticket,
+                price=23, expires=now() + timedelta(minutes=10)
+            )
+        self.event.settings.max_items_per_order = 5
+        response = self.client.post('/%s/%s/cart/add' % (self.orga.slug, self.event.slug), {
+            'item_%d' % self.ticket.id: '5',
+        }, follow=True, PRETIX_SALES_CHANNEL=FoobarSalesChannel)
+        self.assertRedirects(response, '/%s/%s/?require_cookie=true' % (self.orga.slug, self.event.slug),
+                             target_status_code=200)
+        doc = BeautifulSoup(response.rendered_content, "lxml")
+        self.assertNotIn('more than', doc.select('.alert-danger')[0].text)
+        with scopes_disabled():
+            self.assertEqual(CartPosition.objects.filter(cart_id=self.session_key, event=self.event).count(), 1)
+
     def test_max_per_item_failed(self):
         self.ticket.max_per_order = 2
         self.ticket.save()