New implementation of sales channels (#4111)

Co-authored-by: Martin Gross <gross@rami.io>

src/pretix/api/serializers/checkin.py

@@ -25,14 +25,20 @@ from rest_framework.exceptions import ValidationError
 
 from pretix.api.serializers.event import SubEventSerializer
 from pretix.api.serializers.i18n import I18nAwareModelSerializer
-from pretix.base.channels import get_all_sales_channels
 from pretix.base.media import MEDIA_TYPES
-from pretix.base.models import Checkin, CheckinList
+from pretix.base.models import Checkin, CheckinList, SalesChannel
 
 
 class CheckinListSerializer(I18nAwareModelSerializer):
     checkin_count = serializers.IntegerField(read_only=True)
     position_count = serializers.IntegerField(read_only=True)
+    auto_checkin_sales_channels = serializers.SlugRelatedField(
+        slug_field="identifier",
+        queryset=SalesChannel.objects.none(),
+        required=False,
+        allow_empty=True,
+        many=True,
+    )
 
     class Meta:
         model = CheckinList
@@ -43,6 +49,8 @@ class CheckinListSerializer(I18nAwareModelSerializer):
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
 
+        self.fields['auto_checkin_sales_channels'].child_relation.queryset = self.context['event'].organizer.sales_channels.all()
+
         if 'subevent' in self.context['request'].query_params.getlist('expand'):
             self.fields['subevent'] = SubEventSerializer(read_only=True)
 
@@ -72,10 +80,6 @@ class CheckinListSerializer(I18nAwareModelSerializer):
             if full_data.get('subevent'):
                 raise ValidationError(_('The subevent does not belong to this event.'))
 
-        for channel in full_data.get('auto_checkin_sales_channels') or []:
-            if channel not in get_all_sales_channels():
-                raise ValidationError(_('Unknown sales channel.'))
-
         CheckinList.validate_rules(data.get('rules'))
 
         return data