Fixed #10743 -- Allowed lookups for related fields in ModelAdmin.list_display.

Co-authored-by: Alex Garcia <me@alexoteiza.com>
Co-authored-by: Natalia <124304+nessita@users.noreply.github.com>
Co-authored-by: Nina Menezes <https://github.com/nmenezes0>

tests/admin_changelist/admin.py

@@ -53,6 +53,10 @@ class ChildAdmin(admin.ModelAdmin):
         return super().get_queryset(request).select_related("parent")
 
 
+class GrandChildAdmin(admin.ModelAdmin):
+    list_display = ["name", "parent__name", "parent__parent__name"]
+
+
 class CustomPaginationAdmin(ChildAdmin):
     paginator = CustomPaginator
 

tests/admin_changelist/models.py

@@ -19,6 +19,11 @@ class Child(models.Model):
     age = models.IntegerField(null=True, blank=True)
 
 
+class GrandChild(models.Model):
+    parent = models.ForeignKey(Child, models.SET_NULL, editable=False, null=True)
+    name = models.CharField(max_length=30, blank=True)
+
+
 class Genre(models.Model):
     name = models.CharField(max_length=20)
 

tests/admin_changelist/tests.py

@@ -42,6 +42,7 @@ from .admin import (
     EmptyValueChildAdmin,
     EventAdmin,
     FilteredChildAdmin,
+    GrandChildAdmin,
     GroupAdmin,
     InvitationAdmin,
     NoListDisplayLinksParentAdmin,
@@ -61,6 +62,7 @@ from .models import (
     CustomIdUser,
     Event,
     Genre,
+    GrandChild,
     Group,
     Invitation,
     Membership,
@@ -1634,6 +1636,62 @@ class ChangeListTests(TestCase):
                     response, f'0 results (<a href="{href}">1 total</a>)'
                 )
 
+    def test_list_display_related_field(self):
+        parent = Parent.objects.create(name="I am your father")
+        child = Child.objects.create(name="I am your child", parent=parent)
+        GrandChild.objects.create(name="I am your grandchild", parent=child)
+        request = self._mocked_authenticated_request("/grandchild/", self.superuser)
+
+        m = GrandChildAdmin(GrandChild, custom_site)
+        response = m.changelist_view(request)
+        self.assertContains(response, parent.name)
+        self.assertContains(response, child.name)
+
+    def test_list_display_related_field_null(self):
+        GrandChild.objects.create(name="I am parentless", parent=None)
+        request = self._mocked_authenticated_request("/grandchild/", self.superuser)
+
+        m = GrandChildAdmin(GrandChild, custom_site)
+        response = m.changelist_view(request)
+        self.assertContains(response, '<td class="field-parent__name">-</td>')
+        self.assertContains(response, '<td class="field-parent__parent__name">-</td>')
+
+    def test_list_display_related_field_ordering(self):
+        parent_a = Parent.objects.create(name="Alice")
+        parent_z = Parent.objects.create(name="Zara")
+        Child.objects.create(name="Alice's child", parent=parent_a)
+        Child.objects.create(name="Zara's child", parent=parent_z)
+
+        class ChildAdmin(admin.ModelAdmin):
+            list_display = ["name", "parent__name"]
+            list_per_page = 1
+
+        m = ChildAdmin(Child, custom_site)
+
+        # Order ascending.
+        request = self._mocked_authenticated_request("/grandchild/?o=1", self.superuser)
+        response = m.changelist_view(request)
+        self.assertContains(response, parent_a.name)
+        self.assertNotContains(response, parent_z.name)
+
+        # Order descending.
+        request = self._mocked_authenticated_request(
+            "/grandchild/?o=-1", self.superuser
+        )
+        response = m.changelist_view(request)
+        self.assertNotContains(response, parent_a.name)
+        self.assertContains(response, parent_z.name)
+
+    def test_list_display_related_field_ordering_fields(self):
+        class ChildAdmin(admin.ModelAdmin):
+            list_display = ["name", "parent__name"]
+            ordering = ["parent__name"]
+
+        m = ChildAdmin(Child, custom_site)
+        request = self._mocked_authenticated_request("/", self.superuser)
+        cl = m.get_changelist_instance(request)
+        self.assertEqual(cl.get_ordering_field_columns(), {2: "asc"})
+
 
 class GetAdminLogTests(TestCase):
     def test_custom_user_pk_not_named_id(self):