✨ [#667] Add nested ordering filter backend

backend/src/openarchiefbeheer/destruction/api/backends.py

@@ -1,5 +1,6 @@
 from django_filters.rest_framework import DjangoFilterBackend
 from django_filters.utils import translate_validation
+from rest_framework.filters import OrderingFilter
 
 
 class NestedFilterBackend(DjangoFilterBackend):
@@ -35,3 +36,77 @@ def get_nested_filterset(self, request, view):
             "request": request,
         }
         return nested_filterset_class(**kwargs)
+
+
+class NestedOrderingFilterBackend(OrderingFilter):
+    def get_valid_fields(self, queryset, view, context={}) -> list[tuple[str, str]]:
+        valid_fields = getattr(
+            view, context.get("ordering_fields_view_attr", "ordering_fields"), []
+        )
+
+        if valid_fields is None:
+            # Default to allowing filtering on serializer fields
+            return self.get_default_valid_fields(queryset, view, {})
+
+        elif valid_fields == "__all__":
+            # View explicitly allows filtering on any model field
+            valid_fields = [
+                (field.name, field.verbose_name)
+                for field in queryset.model._meta.fields
+            ]
+            valid_fields += [
+                (key, key.title().split("__")) for key in queryset.query.annotations
+            ]
+        else:
+            valid_fields = [
+                (item, item) if isinstance(item, str) else item for item in valid_fields
+            ]
+        return valid_fields
+
+    def get_valid_fields_keys(self, valid_fields) -> list[str]:
+        return [item[0] for item in valid_fields]
+
+    def is_term_valid(self, term, valid_fields) -> bool:
+        if term.startswith("-"):
+            term = term[1:]
+        return term in valid_fields
+
+    def get_ordering(self, request, queryset, view) -> list[str]:
+        base_ordering_param = (
+            f"{view.nested_ordering_prefix}-{self.ordering_param}"
+            if view.nested_ordering_prefix
+            else self.ordering_param
+        )
+        base_params = request.query_params.get(base_ordering_param)
+        formatted_fields = []
+        if base_params:
+            fields = [param.strip() for param in base_params.split(",")]
+            valid_fields = self.get_valid_fields_keys(
+                self.get_valid_fields(queryset, view)
+            )
+            formatted_fields = [
+                term for term in fields if self.is_term_valid(term, valid_fields)
+            ]
+
+        nested_params = request.query_params.get(self.ordering_param)
+        if nested_params:
+            fields = [param.strip() for param in nested_params.split(",")]
+            nested_queryset = view.nested_ordering_model.objects.all()
+            valid_fields = self.get_valid_fields_keys(
+                self.get_valid_fields(
+                    nested_queryset,
+                    view,
+                    context={"ordering_fields_view_attr": "nested_ordering_fields"},
+                )
+            )
+
+            for term in fields:
+                if not self.is_term_valid(term, valid_fields):
+                    continue
+
+                if is_reverse := term.startswith("-"):
+                    term = term[1:]
+                formatted_fields.append(
+                    f"{"-" if is_reverse else ""}{view.nested_ordering_relation_field}__{term}"
+                )
+        return formatted_fields

backend/src/openarchiefbeheer/destruction/api/viewsets.py

@@ -22,6 +22,7 @@
 from openarchiefbeheer.logging import logevent
 from openarchiefbeheer.utils.paginators import PageNumberPagination
 from openarchiefbeheer.zaken.api.filtersets import ZaakFilterSet
+from openarchiefbeheer.zaken.models import Zaak
 
 from ..constants import DestructionListItemAction, InternalStatus, ListRole, ListStatus
 from ..models import (
@@ -36,7 +37,7 @@
 )
 from ..tasks import delete_destruction_list
 from ..utils import process_new_reviewer
-from .backends import NestedFilterBackend
+from .backends import NestedFilterBackend, NestedOrderingFilterBackend
 from .filtersets import (
     DestructionListCoReviewFilterset,
     DestructionListFilterset,
@@ -465,12 +466,17 @@ class DestructionListItemsViewSet(
     viewsets.GenericViewSet,
 ):
     serializer_class = DestructionListItemReadSerializer
-    filter_backends = (NestedFilterBackend,)
+    filter_backends = (NestedFilterBackend, NestedOrderingFilterBackend)
     filterset_class = DestructionListItemFilterset
     filterset_kwargs = {"prefix": "item"}
     nested_filterset_class = ZaakFilterSet
     nested_filterset_relation_field = "zaak"
     pagination_class = PageNumberPagination
+    ordering_fields = "__all__"
+    nested_ordering_fields = "__all__"
+    nested_ordering_model = Zaak
+    nested_ordering_relation_field = "zaak"
+    nested_ordering_prefix = "item"
 
     def get_queryset(self):
         review_response_items = ReviewItemResponse.objects.filter(
@@ -593,10 +599,15 @@ class DestructionListItemReviewViewSet(mixins.ListModelMixin, viewsets.GenericVi
         "destruction_list_item__zaak"
     )
     filterset_class = DestructionListReviewItemFilterset
-    filter_backends = (NestedFilterBackend,)
+    filter_backends = (NestedFilterBackend, NestedOrderingFilterBackend)
     filterset_kwargs = {"prefix": "item-review"}
     nested_filterset_class = ZaakFilterSet
     nested_filterset_relation_field = "destruction_list_item__zaak"
+    ordering_fields = "__all__"
+    nested_ordering_fields = "__all__"
+    nested_ordering_model = Zaak
+    nested_ordering_relation_field = "destruction_list_item__zaak"
+    nested_ordering_prefix = "item-review"
 
 
 @extend_schema_view(