Fix: cleanup saved view references on custom field deletion, auto-refresh views, show error on saved view save (#9225)

src/documents/serialisers.py

@@ -1136,8 +1136,9 @@ class SavedViewSerializer(OwnedObjectSerializer):
                 ):  # i.e. check for 'custom_field_' prefix
                     field_id = int(re.search(r"\d+", field)[0])
                     if not CustomField.objects.filter(id=field_id).exists():
-                        # In case the field was deleted, just remove from the list
-                        attrs["display_fields"].remove(field)
+                        raise serializers.ValidationError(
+                            f"Invalid field: {field}",
+                        )
                 elif field not in SavedView.DisplayFields.values:
                     raise serializers.ValidationError(
                         f"Invalid field: {field}",

src/documents/signals/handlers.py

@@ -36,6 +36,7 @@ from documents.models import Document
 from documents.models import DocumentType
 from documents.models import MatchingModel
 from documents.models import PaperlessTask
+from documents.models import SavedView
 from documents.models import Tag
 from documents.models import Workflow
 from documents.models import WorkflowAction
@@ -549,6 +550,33 @@ def check_paths_and_prune_custom_fields(sender, instance: CustomField, **kwargs)
             update_filename_and_move_files(sender, cf_instance)
 
 
+@receiver(models.signals.post_delete, sender=CustomField)
+def cleanup_custom_field_deletion(sender, instance: CustomField, **kwargs):
+    """
+    When a custom field is deleted, ensure no saved views reference it.
+    """
+    field_identifier = SavedView.DisplayFields.CUSTOM_FIELD % instance.pk
+    # remove field from display_fields of all saved views
+    for view in SavedView.objects.filter(display_fields__isnull=False).distinct():
+        if field_identifier in view.display_fields:
+            logger.debug(
+                f"Removing custom field {instance} from view {view}",
+            )
+            view.display_fields.remove(field_identifier)
+            view.save()
+
+    # remove from sort_field of all saved views
+    views_with_sort_updated = SavedView.objects.filter(
+        sort_field=field_identifier,
+    ).update(
+        sort_field=SavedView.DisplayFields.CREATED,
+    )
+    if views_with_sort_updated > 0:
+        logger.debug(
+            f"Removing custom field {instance} from sort field of {views_with_sort_updated} views",
+        )
+
+
 def add_to_index(sender, document, **kwargs):
     from documents import index
 

src/documents/tests/test_api_documents.py

@@ -1911,7 +1911,7 @@ class TestDocumentApi(DirectoriesMixin, DocumentConsumeDelayMixin, APITestCase):
             ],
         )
 
-        # Custom field not found, removed from list
+        # Custom field not found
         response = self.client.patch(
             f"/api/saved_views/{v1.id}/",
             {
@@ -1923,9 +1923,43 @@ class TestDocumentApi(DirectoriesMixin, DocumentConsumeDelayMixin, APITestCase):
             },
             format="json",
         )
-        self.assertEqual(response.status_code, status.HTTP_200_OK)
-        v1.refresh_from_db()
-        self.assertNotIn(SavedView.DisplayFields.CUSTOM_FIELD % 99, v1.display_fields)
+        self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
+
+    def test_saved_view_cleanup_after_custom_field_deletion(self):
+        """
+        GIVEN:
+            - Saved view with custom field in display fields and as sort field
+        WHEN:
+            - Custom field is deleted
+        THEN:
+            - Custom field is removed from display fields and sort field
+        """
+        custom_field = CustomField.objects.create(
+            name="stringfield",
+            data_type=CustomField.FieldDataType.STRING,
+        )
+
+        view = SavedView.objects.create(
+            owner=self.user,
+            name="test",
+            sort_field=SavedView.DisplayFields.CUSTOM_FIELD % custom_field.id,
+            show_on_dashboard=True,
+            show_in_sidebar=True,
+            display_fields=[
+                SavedView.DisplayFields.TITLE,
+                SavedView.DisplayFields.CREATED,
+                SavedView.DisplayFields.CUSTOM_FIELD % custom_field.id,
+            ],
+        )
+
+        custom_field.delete()
+
+        view.refresh_from_db()
+        self.assertEqual(view.sort_field, SavedView.DisplayFields.CREATED)
+        self.assertEqual(
+            view.display_fields,
+            [str(SavedView.DisplayFields.TITLE), str(SavedView.DisplayFields.CREATED)],
+        )
 
     def test_get_logs(self):
         log_data = "test\ntest2\n"