Check-in API: Fall back from attendee_name

doc/api/resources/checkinlists.rst

@@ -351,6 +351,9 @@ Order position endpoints
    * An additional boolean property ``require_attention`` will inform you whether either the order or the item
      have the ``checkin_attention`` flag set.
 
+   * If ``attendee_name`` is empty, it will automatically fall back to values from a parent product or from invoice
+     addresses.
+
    **Example request**:
 
    .. sourcecode:: http
@@ -453,8 +456,15 @@ Order position endpoints
 .. http:get:: /api/v1/organizers/(organizer)/events/(event)/checkinlists/(list)/positions/(id)/
 
    Returns information on one order position, identified by its internal ID.
-   The result format is the same as the :ref:`order-position-resource`, with one important difference: the
-   ``checkins`` value will only include check-ins for the selected list.
+   The result is the same as the :ref:`order-position-resource`, with the following differences:
+
+   * The ``checkins`` value will only include check-ins for the selected list.
+
+   * An additional boolean property ``require_attention`` will inform you whether either the order or the item
+     have the ``checkin_attention`` flag set.
+
+   * If ``attendee_name`` is empty, it will automatically fall back to values from a parent product or from invoice
+     addresses.
 
    **Instead of an ID, you can also use the ``secret`` field as the lookup parameter.**
 

src/pretix/api/serializers/order.py

@@ -184,8 +184,40 @@ class RequireAttentionField(serializers.Field):
         return instance.order.checkin_attention or instance.item.checkin_attention
 
 
+class AttendeeNameField(serializers.Field):
+    def to_representation(self, instance: OrderPosition):
+        an = instance.attendee_name
+        if not an:
+            if instance.addon_to_id:
+                an = instance.addon_to.attendee_name
+        if not an:
+            try:
+                an = instance.order.invoice_address.name
+            except InvoiceAddress.DoesNotExist:
+                pass
+        return an
+
+
+class AttendeeNamePartsField(serializers.Field):
+    def to_representation(self, instance: OrderPosition):
+        an = instance.attendee_name
+        p = instance.attendee_name_parts
+        if not an:
+            if instance.addon_to_id:
+                an = instance.addon_to.attendee_name
+                p = instance.addon_to.attendee_name_parts
+        if not an:
+            try:
+                p = instance.order.invoice_address.name_parts
+            except InvoiceAddress.DoesNotExist:
+                pass
+        return p
+
+
 class CheckinListOrderPositionSerializer(OrderPositionSerializer):
     require_attention = RequireAttentionField(source='*')
+    attendee_name = AttendeeNameField(source='*')
+    attendee_name_parts = AttendeeNamePartsField(source='*')
     order__status = serializers.SlugRelatedField(read_only=True, slug_field='status', source='order')
 
     class Meta:

src/pretix/api/views/checkin.py

@@ -229,7 +229,7 @@ class CheckinListPositionViewSet(viewsets.ReadOnlyModelViewSet):
                     )
                 ))
             ).select_related(
-                'item', 'variation', 'item__category', 'addon_to', 'order'
+                'item', 'variation', 'item__category', 'addon_to', 'order', 'order__invoice_address'
             )
         else:
             qs = qs.prefetch_related(

src/tests/api/test_checkin.py

@@ -474,6 +474,23 @@ def test_custom_datetime(token_client, organizer, clist, event, order):
     assert Checkin.objects.last().datetime == dt
 
 
+@pytest.mark.django_db
+def test_name_fallback(token_client, organizer, clist, event, order):
+    order.invoice_address.name_parts = {'_legacy': 'Paul'}
+    order.invoice_address.save()
+    op = order.positions.first()
+    op.attendee_name_cached = None
+    op.attendee_name_parts = {}
+    op.save()
+    resp = token_client.post('/api/v1/organizers/{}/events/{}/checkinlists/{}/positions/{}/redeem/'.format(
+        organizer.slug, event.slug, clist.pk, op.pk
+    ), {}, format='json')
+    assert resp.status_code == 201
+    assert resp.data['status'] == 'ok'
+    assert resp.data['position']['attendee_name'] == 'Paul'
+    assert resp.data['position']['attendee_name_parts'] == {'_legacy': 'Paul'}
+
+
 @pytest.mark.django_db
 def test_by_secret(token_client, organizer, clist, event, order):
     resp = token_client.post('/api/v1/organizers/{}/events/{}/checkinlists/{}/positions/{}/redeem/'.format(