Enhancement: only include correspondent 'last_correspondence' if requested (#6792)

src/documents/serialisers.py

@@ -291,7 +291,7 @@ class OwnedObjectSerializer(
 
 
 class CorrespondentSerializer(MatchingModelSerializer, OwnedObjectSerializer):
-    last_correspondence = serializers.DateTimeField(read_only=True)
+    last_correspondence = serializers.DateTimeField(read_only=True, required=False)
 
     class Meta:
         model = Correspondent

src/documents/tests/test_api_objects.py

@@ -1,8 +1,10 @@
+import datetime
 import json
 from unittest import mock
 
 from django.contrib.auth.models import Permission
 from django.contrib.auth.models import User
+from django.utils import timezone
 from rest_framework import status
 from rest_framework.test import APITestCase
 
@@ -89,6 +91,57 @@ class TestApiObjects(DirectoriesMixin, APITestCase):
         results = response.data["results"]
         self.assertEqual(len(results), 2)
 
+    def test_correspondent_last_correspondence(self):
+        """
+        GIVEN:
+            - Correspondent with documents
+        WHEN:
+            - API is called
+        THEN:
+            - Last correspondence date is returned only if requested for list, and for detail
+        """
+
+        Document.objects.create(
+            mime_type="application/pdf",
+            correspondent=self.c1,
+            created=timezone.make_aware(datetime.datetime(2022, 1, 1)),
+            checksum="123",
+        )
+        Document.objects.create(
+            mime_type="application/pdf",
+            correspondent=self.c1,
+            created=timezone.make_aware(datetime.datetime(2022, 1, 2)),
+            checksum="456",
+        )
+
+        # Only if requested for list
+        response = self.client.get(
+            "/api/correspondents/",
+        )
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        results = response.data["results"]
+        self.assertNotIn("last_correspondence", results[0])
+
+        response = self.client.get(
+            "/api/correspondents/?last_correspondence=true",
+        )
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        results = response.data["results"]
+        self.assertIn(
+            "2022-01-02",
+            results[0]["last_correspondence"],
+        )
+
+        # Included in detail by default
+        response = self.client.get(
+            f"/api/correspondents/{self.c1.id}/",
+        )
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        self.assertIn(
+            "2022-01-02",
+            response.data["last_correspondence"],
+        )
+
 
 class TestApiStoragePaths(DirectoriesMixin, APITestCase):
     ENDPOINT = "/api/storage_paths/"

src/documents/views.py

@@ -253,14 +253,7 @@ class PermissionsAwareDocumentCountMixin(PassUserMixin):
 class CorrespondentViewSet(ModelViewSet, PermissionsAwareDocumentCountMixin):
     model = Correspondent
 
-    queryset = (
-        Correspondent.objects.prefetch_related("documents")
-        .annotate(
-            last_correspondence=Max("documents__created"),
-        )
-        .select_related("owner")
-        .order_by(Lower("name"))
-    )
+    queryset = Correspondent.objects.select_related("owner").order_by(Lower("name"))
 
     serializer_class = CorrespondentSerializer
     pagination_class = StandardPagination
@@ -279,6 +272,19 @@ class CorrespondentViewSet(ModelViewSet, PermissionsAwareDocumentCountMixin):
         "last_correspondence",
     )
 
+    def list(self, request, *args, **kwargs):
+        if request.query_params.get("last_correspondence", None):
+            self.queryset = self.queryset.annotate(
+                last_correspondence=Max("documents__created"),
+            )
+        return super().list(request, *args, **kwargs)
+
+    def retrieve(self, request, *args, **kwargs):
+        self.queryset = self.queryset.annotate(
+            last_correspondence=Max("documents__created"),
+        )
+        return super().retrieve(request, *args, **kwargs)
+
 
 class TagViewSet(ModelViewSet, PermissionsAwareDocumentCountMixin):
     model = Tag