Bug fixes for Note model (#12835)

* Bug fixes for Note model

- Allow note to be created as "primary"
- Reset note creation fields in editor

* Tweak to ensure that the API spec does not change

src/backend/InvenTree/common/serializers.py

@@ -929,6 +929,10 @@ class NoteSerializer(FilterableSerializerMixin, InvenTreeModelSerializer):
 
         read_only_fields = ['updated', 'updated_by']
 
+    def get_unique_together_validators(self):
+        """Suppress the auto-generated validator for 'unique_primary_note_per_model'."""
+        return []
+
     def validate(self, data):
         """Validate note data — templates need no model_id; regular notes require both."""
         data = super().validate(data)

src/backend/InvenTree/common/test_api.py

@@ -1471,6 +1471,25 @@ class NoteAPITests(InvenTreeAPITestCase):
         primary_pks = [n['pk'] for n in list_response.data if n['primary']]
         self.assertEqual(primary_pks, [third.data['pk']])
 
+    def test_creating_primary_note_demotes_existing_primary(self):
+        """Explicitly creating a new note with primary=True demotes the existing primary note.
+
+        Regression test: DRF auto-generates a UniqueTogetherValidator from the
+        'unique_primary_note_per_model' partial unique constraint, which used to
+        reject this at the serializer-validation stage (before Note.save()'s
+        demote-then-save logic ever ran), raising a spurious 'unique set' error.
+        """
+        first = self._create_note('First Note')
+        self.assertTrue(first.data['primary'])
+
+        second = self._create_note('Second Note', primary=True)
+        self.assertTrue(second.data['primary'])
+
+        from common.models import Note
+
+        self.assertFalse(Note.objects.get(pk=first.data['pk']).primary)
+        self.assertTrue(Note.objects.get(pk=second.data['pk']).primary)
+
     def test_primary_flag_isolated_per_model_instance(self):
         """Primary flag changes on one model instance do not affect notes on another."""
         from part.models import Part

src/frontend/src/components/editors/NotesEditor.tsx

@@ -306,7 +306,7 @@ export default function NotesEditor({
     return notesQuery.data && notesQuery.data.length > 0;
   }, [notesQuery.data]);
 
-  const noteFields = useNoteFields({
+  const { fields: noteFields, resetFields: resetNoteFields } = useNoteFields({
     modelType: modelType!,
     modelId: modelId!
   });
@@ -711,7 +711,10 @@ export default function NotesEditor({
               <Button
                 color='green'
                 leftSection={<IconCirclePlus />}
-                onClick={createNote.open}
+                onClick={() => {
+                  resetNoteFields();
+                  createNote.open();
+                }}
                 disabled={isEditing}
               >
                 {t`Add Note`}

src/frontend/src/forms/CommonForms.tsx

@@ -330,13 +330,19 @@ export function useNoteFields({
 }: {
   modelType: ModelType;
   modelId: number;
-}): ApiFormFieldSet {
+}): { fields: ApiFormFieldSet; resetFields: () => void } {
   const api = useApi();
 
   const [title, setTitle] = useState<string>('');
   const [description, setDescription] = useState<string>('');
   const [content, setContent] = useState<string>('');
 
+  const resetFields = useCallback(() => {
+    setTitle('');
+    setDescription('');
+    setContent('');
+  }, []);
+
   const fetchTemplate = useCallback(
     (pk: number | null) => {
       if (!pk) return;
@@ -352,7 +358,7 @@ export function useNoteFields({
     [api]
   );
 
-  return useMemo(() => {
+  const fields = useMemo<ApiFormFieldSet>(() => {
     return {
       model_type: {
         hidden: true,
@@ -392,6 +398,8 @@ export function useNoteFields({
       }
     };
   }, [modelType, modelId, title, description, content, fetchTemplate]);
+
+  return { fields, resetFields };
 }
 
 export function selectionListFields(): ApiFormFieldSet {