feat: New / Refactor "Nav Mixin" (#9283)

* [FR/P-UI] New / Refactor "Nav Mixin"
Fixes #5269

* remove logging

* fix sample item that causes issues

* Add test coverage

* Update src/frontend/src/components/plugins/PluginUIFeatureTypes.ts

Co-authored-by: Lukas <76838159+wolflu05@users.noreply.github.com>

* [FR/P-UI] New / Refactor "Nav Mixin"
Fixes #5269

* fix style

* remove requirement for source

* fix import

* bump api version

---------

Co-authored-by: Lukas <76838159+wolflu05@users.noreply.github.com>

src/backend/InvenTree/InvenTree/api_version.py

@@ -1,13 +1,16 @@
 """InvenTree API version information."""
 
 # InvenTree API version
-INVENTREE_API_VERSION = 338
+INVENTREE_API_VERSION = 339
 
 """Increment this API version number whenever there is a significant change to the API that any clients need to know about."""
 
 
 INVENTREE_API_TEXT = """
 
+v339 -> 2025-04-15 : https://github.com/inventree/InvenTree/pull/9283
+    - Remove need for source in /plugins/ui/features
+
 v338 -> 2025-04-15 : https://github.com/inventree/InvenTree/pull/9333
     - Adds oAuth2 support for the API
 

src/backend/InvenTree/plugin/base/ui/mixins.py

@@ -19,6 +19,7 @@ FeatureType = Literal[
     'panel',  # Custom panels
     'template_editor',  # Custom template editor
     'template_preview',  # Custom template preview
+    'navigation',  # Custom navigation items
 ]
 
 
@@ -102,6 +103,7 @@ class UserInterfaceMixin:
             'panel': self.get_ui_panels,
             'template_editor': self.get_ui_template_editors,
             'template_preview': self.get_ui_template_previews,
+            'navigation': self.get_ui_navigation_items,
         }
 
         if feature_type in feature_map:
@@ -169,3 +171,18 @@ class UserInterfaceMixin:
         """
         # Default implementation returns an empty list
         return []
+
+    def get_ui_navigation_items(
+        self, request: Request, context: dict, **kwargs
+    ) -> list[UIFeature]:
+        """Return a list of custom navigation items to be injected into the UI.
+
+        Args:
+            request: HTTPRequest object (including user information)
+            context: Additional context data provided by the UI (query parameters)
+
+        Returns:
+            list: A list of custom navigation items to be injected into the UI
+        """
+        # Default implementation returns an empty list
+        return []

src/backend/InvenTree/plugin/base/ui/serializers.py

@@ -61,5 +61,5 @@ class PluginUIFeatureSerializer(serializers.Serializer):
     context = serializers.DictField(label=_('Feature Context'), default=None)
 
     source = serializers.CharField(
-        label=_('Feature Source (javascript)'), required=True, allow_blank=False
+        label=_('Feature Source (javascript)'), required=False, allow_blank=True
     )

src/backend/InvenTree/plugin/base/ui/tests.py

@@ -223,3 +223,13 @@ class UserInterfaceMixinTests(InvenTreeAPITestCase):
 
         # Set the setting back to True for subsequent tests
         InvenTreeSetting.set_setting('ENABLE_PLUGINS_INTERFACE', True, change_user=None)
+
+    def test_ui_navigation_items(self):
+        """Test that the sample UI plugin provides custom navigation items."""
+        response = self.get(
+            reverse('api-plugin-ui-feature-list', kwargs={'feature': 'navigation'})
+        )
+        self.assertEqual(1, len(response.data))
+        self.assertEqual(response.data[0]['plugin_name'], 'sampleui')
+        self.assertEqual(response.data[0]['key'], 'sample-nav-item')
+        self.assertEqual(response.data[0]['title'], 'Sample Nav Item')

src/backend/InvenTree/plugin/samples/integration/user_interface_sample.py

@@ -197,6 +197,17 @@ class SampleUserInterfacePlugin(SettingsMixin, UserInterfaceMixin, InvenTreePlug
             }
         ]
 
+    def get_ui_navigation_items(self, request, context, **kwargs):
+        """Return a list of custom navigation items."""
+        return [
+            {
+                'key': 'sample-nav-item',
+                'title': 'Sample Nav Item',
+                'icon': 'ti:menu',
+                'options': {'url': '/sample/page/'},
+            }
+        ]
+
     def get_admin_context(self) -> dict:
         """Return custom context data which can be rendered in the admin panel."""
         return {'apple': 'banana', 'foo': 'bar', 'hello': 'world'}