Fixes #19986: Fix plugin list view button URLs (#20019)

* Fixes #19986: Fix plugin list view button URLs

Plugin list view action buttons (Add, Import, Export) were generating 404
errors because ObjectAction.get_url() was manually constructing viewnames
without the required "plugins:" namespace prefix for plugin models.

Replace manual viewname construction with NetBox's get_viewname() utility
function, which properly handles plugin detection and namespace prefixing
for both core and plugin models.

* Ensure expected URL patterns are registered, ensures tests pass

netbox/netbox/object_actions.py

@@ -6,6 +6,7 @@ from django.utils.translation import gettext as _
 from core.models import ObjectType
 from extras.models import ExportTemplate
 from utilities.querydict import prepare_cloned_fields
+from utilities.views import get_viewname
 
 __all__ = (
     'AddObject',
@@ -42,7 +43,7 @@ class ObjectAction:
 
     @classmethod
     def get_url(cls, obj):
-        viewname = f'{obj._meta.app_label}:{obj._meta.model_name}_{cls.name}'
+        viewname = get_viewname(obj, action=cls.name)
         kwargs = {
             kwarg: getattr(obj, kwarg) for kwarg in cls.url_kwargs
         }

netbox/netbox/tests/dummy_plugin/urls.py

@@ -7,5 +7,8 @@ urlpatterns = (
     path('models/', views.DummyModelsView.as_view(), name='dummy_model_list'),
     path('models/add/', views.DummyModelAddView.as_view(), name='dummy_model_add'),
 
+    path('netboxmodel/', views.DummyNetBoxModelView.as_view(), name='dummynetboxmodel_list'),
+    path('netboxmodel/add/', views.DummyNetBoxModelView.as_view(), name='dummynetboxmodel_add'),
+    path('netboxmodel/import/', views.DummyNetBoxModelView.as_view(), name='dummynetboxmodel_bulk_import'),
     path('netboxmodel/<int:pk>/', views.DummyNetBoxModelView.as_view(), name='dummynetboxmodel'),
 )

netbox/netbox/tests/test_object_actions.py

@@ -0,0 +1,32 @@
+from unittest import skipIf
+
+from django.conf import settings
+from django.test import TestCase
+
+from dcim.models import Device
+from netbox.object_actions import AddObject, BulkImport
+from netbox.tests.dummy_plugin.models import DummyNetBoxModel
+
+
+class ObjectActionTest(TestCase):
+
+    def test_get_url_core_model(self):
+        """Test URL generation for core NetBox models"""
+        obj = Device()
+
+        url = AddObject.get_url(obj)
+        self.assertEqual(url, '/dcim/devices/add/')
+
+        url = BulkImport.get_url(obj)
+        self.assertEqual(url, '/dcim/devices/import/')
+
+    @skipIf('netbox.tests.dummy_plugin' not in settings.PLUGINS, "dummy_plugin not in settings.PLUGINS")
+    def test_get_url_plugin_model(self):
+        """Test URL generation for plugin models includes plugins: namespace"""
+        obj = DummyNetBoxModel()
+
+        url = AddObject.get_url(obj)
+        self.assertEqual(url, '/plugins/dummy-plugin/netboxmodel/add/')
+
+        url = BulkImport.get_url(obj)
+        self.assertEqual(url, '/plugins/dummy-plugin/netboxmodel/import/')