Update parentadmin.py

- fix parent admin form not behaving like an admin form (eg log out button context missing)
- add test for model type add form correctly embedding in the rest of the admin
- separate playwright admin form tests
- update changelog

Co-authored-by: TarunvirBains <61893384+TarunvirBains@users.noreply.github.com>
Co-authored-by: Brian Kohan <bkohan@example.com>

docs/changelog.rst

@@ -4,6 +4,7 @@ Changelog
 v4.2.0 (2025-12-01)
 -------------------
 
+* Fixed `Show full admin context (breadcrumb and logout nav) in model type selection admin form <https://github.com/jazzband/django-polymorphic/pull/580>`_
 * Fixed `Issue with Autocomplete Fields in StackedPolymorphicInline.Child Inline <https://github.com/jazzband/django-polymorphic/issues/546>`_
 * Support Python 3.14 and Django 6.0, drop support for EOL python 3.9, Django 3.2, 4.0, 4.1 and 5.0.
 * `Modernized package management with new build, test, docs tooling and improved CI 

src/polymorphic/admin/parentadmin.py

@@ -345,6 +345,7 @@ class PolymorphicParentModelAdmin(admin.ModelAdmin):
                 "opts": opts,
                 "add": True,
                 "save_on_top": self.save_on_top,
+                **self.admin_site.each_context(request),
             }
         )
 
@@ -356,7 +357,7 @@ class PolymorphicParentModelAdmin(admin.ModelAdmin):
         ]
 
         request.current_app = self.admin_site.name
-        return TemplateResponse(request, templates, context)
+        return self.admin_site.admin_view(TemplateResponse)(request, templates, context)
 
     @property
     def change_list_template(self):

src/polymorphic/tests/admin.py

@@ -1,6 +1,33 @@
-from django.contrib.admin import register, ModelAdmin
-from polymorphic.admin import StackedPolymorphicInline, PolymorphicInlineSupportMixin
-from polymorphic.tests.models import PlainA, InlineModelA, InlineModelB, InlineParent
+from django.contrib.admin import register, ModelAdmin, site as admin_site
+from polymorphic.admin import (
+    StackedPolymorphicInline,
+    PolymorphicInlineSupportMixin,
+    PolymorphicChildModelAdmin,
+    PolymorphicChildModelFilter,
+    PolymorphicParentModelAdmin,
+)
+
+from polymorphic.tests.models import (
+    PlainA,
+    Model2A,
+    Model2B,
+    Model2C,
+    Model2D,
+    InlineModelA,
+    InlineModelB,
+    InlineParent,
+)
+
+
+@register(Model2A)
+class Model2Admin(PolymorphicParentModelAdmin):
+    list_filter = (PolymorphicChildModelFilter,)
+    child_models = (Model2B, Model2C, Model2D)
+
+
+admin_site.register(Model2B, PolymorphicChildModelAdmin)
+admin_site.register(Model2C, PolymorphicChildModelAdmin)
+admin_site.register(Model2D, PolymorphicChildModelAdmin)
 
 
 @register(PlainA)

src/polymorphic/tests/test_admin.py

@@ -278,3 +278,88 @@ class StackedInlineTests(_GenericAdminFormTest):
 
         suggestions = self.page.locator("ul.select2-results__options > li").all_inner_texts()
         assert suggestions == ["Brian"]
+
+
+class PolymorphicFormTests(_GenericAdminFormTest):
+    def setUp(self):
+        Model2A.objects.all().delete()
+        super().setUp()
+
+    def tearDown(self):
+        Model2A.objects.all().delete()
+        super().tearDown()
+
+    def test_admin_polymorphic_add(self):
+        model2b_ct = ContentType.objects.get_for_model(Model2B)
+        model2c_ct = ContentType.objects.get_for_model(Model2C)
+        model2d_ct = ContentType.objects.get_for_model(Model2D)
+
+        for model_type, fields in [
+            (
+                model2b_ct,
+                {
+                    "field1": "2B1",
+                    "field2": "2B2",
+                },
+            ),
+            (
+                model2c_ct,
+                {
+                    "field1": "2C1",
+                    "field2": "2C2",
+                    "field3": "2C3",
+                },
+            ),
+            (
+                model2d_ct,
+                {
+                    "field1": "2D1",
+                    "field2": "2D2",
+                    "field3": "2D3",
+                    "field4": "2D4",
+                },
+            ),
+        ]:
+            self.page.goto(self.add_url(Model2A))
+
+            # https://github.com/jazzband/django-polymorphic/pull/580
+            expect(self.page.locator("div.breadcrumbs")).to_have_count(1)
+            expect(self.page.locator("form#logout-form")).to_have_count(1)
+
+            self.page.locator(f"input[type=radio][value='{model_type.pk}']").check()
+            with self.page.expect_navigation(timeout=10000) as nav_info:
+                self.page.click("input[name='_save']")
+
+            response = nav_info.value
+            assert response.status < 400
+
+            for field, value in fields.items():
+                self.page.fill(f"input[name='{field}']", value)
+
+            with self.page.expect_navigation(timeout=10000) as nav_info:
+                self.page.click("input[name='_save']")
+
+            response = nav_info.value
+            assert response.status < 400
+
+        assert Model2A.objects.count() == 3
+
+        object_ids = [int(oid) for oid in self.get_object_ids(Model2A)]
+
+        assert len(object_ids) == 3
+
+        assert Model2B.objects.first().pk in object_ids
+        assert Model2C.objects.first().pk in object_ids
+        assert Model2D.objects.first().pk in object_ids
+
+        assert Model2B.objects.first().field1 == "2B1"
+        assert Model2B.objects.first().field2 == "2B2"
+
+        assert Model2C.objects.first().field1 == "2C1"
+        assert Model2C.objects.first().field2 == "2C2"
+        assert Model2C.objects.first().field3 == "2C3"
+
+        assert Model2D.objects.first().field1 == "2D1"
+        assert Model2D.objects.first().field2 == "2D2"
+        assert Model2D.objects.first().field3 == "2D3"
+        assert Model2D.objects.first().field4 == "2D4"