Gift card API: Allow to inspect transactions (#1868)

src/pretix/api/serializers/organizer.py

@@ -9,8 +9,8 @@ from pretix.api.serializers.i18n import I18nAwareModelSerializer
 from pretix.api.serializers.order import CompatibleJSONField
 from pretix.base.auth import get_auth_backends
 from pretix.base.models import (
-    Device, GiftCard, Organizer, SeatingPlan, Team, TeamAPIToken, TeamInvite,
-    User,
+    Device, GiftCard, GiftCardTransaction, Organizer, SeatingPlan, Team,
+    TeamAPIToken, TeamInvite, User,
 )
 from pretix.base.models.seating import SeatingPlanLayoutValidator
 from pretix.base.services.mail import SendMailException, mail
@@ -59,6 +59,21 @@ class GiftCardSerializer(I18nAwareModelSerializer):
         fields = ('id', 'secret', 'issuance', 'value', 'currency', 'testmode', 'expires', 'conditions')
 
 
+class OrderEventSlugField(serializers.RelatedField):
+
+    def to_representation(self, obj):
+        return obj.event.slug
+
+
+class GiftCardTransactionSerializer(I18nAwareModelSerializer):
+    order = serializers.SlugRelatedField(slug_field='code', read_only=True)
+    event = OrderEventSlugField(source='order', read_only=True)
+
+    class Meta:
+        model = GiftCardTransaction
+        fields = ('id', 'datetime', 'value', 'event', 'order', 'text')
+
+
 class EventSlugField(serializers.SlugRelatedField):
     def get_queryset(self):
         return self.context['organizer'].events.all()