Updates for metadata information (#7343)

* Updates for metadata information

- Override 'label' values with 'verbose_name' values
- Only if 'label' is *not* translated, but 'verbose_name' is
- Allows the translated model fields name to be pushed through to the metadata framework

* Remove unused import

* Add unit testing for metadata lookup

* Update serializer: allow 'category' to be blank

* Bump API version

* Fix for unit test

src/backend/InvenTree/InvenTree/api_version.py

@@ -1,12 +1,15 @@
 """InvenTree API version information."""
 
 # InvenTree API version
-INVENTREE_API_VERSION = 201
+INVENTREE_API_VERSION = 202
 
 """Increment this API version number whenever there is a significant change to the API that any clients need to know about."""
 
 INVENTREE_API_TEXT = """
 
+v202 - 2024-05-27 : https://github.com/inventree/InvenTree/pull/7343
+    - Adjust "required" attribute of Part.category field to be optional
+
 v201 - 2024-05-21 : https://github.com/inventree/InvenTree/pull/7074
     - Major refactor of the report template / report printing interface
     - This is a *breaking change* to the report template API

src/backend/InvenTree/InvenTree/metadata.py

@@ -115,6 +115,31 @@ class InvenTreeMetadata(SimpleMetadata):
 
         return metadata
 
+    def override_value(self, field_name, field_value, model_value):
+        """Override a value on the serializer with a matching value for the model.
+
+        This is used to override the serializer values with model values,
+        if (and *only* if) the model value should take precedence.
+
+        The values are overridden under the following conditions:
+        - field_value is None
+        - model_value is callable, and field_value is not (this indicates that the model value is translated)
+        - model_value is not a string, and field_value is a string (this indicates that the model value is translated)
+        """
+        if model_value and not field_value:
+            return model_value
+
+        if field_value and not model_value:
+            return field_value
+
+        if callable(model_value) and not callable(field_value):
+            return model_value
+
+        if type(model_value) is not str and type(field_value) is str:
+            return model_value
+
+        return field_value
+
     def get_serializer_info(self, serializer):
         """Override get_serializer_info so that we can add 'default' values to any fields whose Meta.model specifies a default value."""
         self.serializer = serializer
@@ -134,7 +159,12 @@ class InvenTreeMetadata(SimpleMetadata):
         model_class = None
 
         # Attributes to copy extra attributes from the model to the field (if they don't exist)
-        extra_attributes = ['help_text', 'max_length']
+        # Note that the attributes may be named differently on the underlying model!
+        extra_attributes = {
+            'help_text': 'help_text',
+            'max_length': 'max_length',
+            'label': 'verbose_name',
+        }
 
         try:
             model_class = serializer.Meta.model
@@ -165,10 +195,12 @@ class InvenTreeMetadata(SimpleMetadata):
                     elif name in model_default_values:
                         serializer_info[name]['default'] = model_default_values[name]
 
-                    for attr in extra_attributes:
-                        if attr not in serializer_info[name]:
-                            if hasattr(field, attr):
-                                serializer_info[name][attr] = getattr(field, attr)
+                    for field_key, model_key in extra_attributes.items():
+                        field_value = serializer_info[name].get(field_key, None)
+                        model_value = getattr(field, model_key, None)
+
+                        if value := self.override_value(name, field_value, model_value):
+                            serializer_info[name][field_key] = value
 
             # Iterate through relations
             for name, relation in model_fields.relations.items():
@@ -186,13 +218,12 @@ class InvenTreeMetadata(SimpleMetadata):
                     relation.model_field.get_limit_choices_to()
                 )
 
-                for attr in extra_attributes:
-                    if attr not in serializer_info[name] and hasattr(
-                        relation.model_field, attr
-                    ):
-                        serializer_info[name][attr] = getattr(
-                            relation.model_field, attr
-                        )
+                for field_key, model_key in extra_attributes.items():
+                    field_value = serializer_info[name].get(field_key, None)
+                    model_value = getattr(relation.model_field, model_key, None)
+
+                    if value := self.override_value(name, field_value, model_value):
+                        serializer_info[name][field_key] = value
 
                 if name in model_default_values:
                     serializer_info[name]['default'] = model_default_values[name]

src/backend/InvenTree/part/serializers.py

@@ -851,7 +851,9 @@ class PartSerializer(
     starred = serializers.SerializerMethodField()
 
     # PrimaryKeyRelated fields (Note: enforcing field type here results in much faster queries, somehow...)
-    category = serializers.PrimaryKeyRelatedField(queryset=PartCategory.objects.all())
+    category = serializers.PrimaryKeyRelatedField(
+        queryset=PartCategory.objects.all(), required=False, allow_null=True
+    )
 
     # Pricing fields
     pricing_min = InvenTree.serializers.InvenTreeMoneySerializer(

src/backend/InvenTree/part/test_api.py

@@ -541,13 +541,58 @@ class PartOptionsAPITest(InvenTreeAPITestCase):
         category = actions['category']
 
         self.assertEqual(category['type'], 'related field')
-        self.assertTrue(category['required'])
+        self.assertFalse(category['required'])
         self.assertFalse(category['read_only'])
         self.assertEqual(category['label'], 'Category')
         self.assertEqual(category['model'], 'partcategory')
         self.assertEqual(category['api_url'], reverse('api-part-category-list'))
         self.assertEqual(category['help_text'], 'Part category')
 
+    def test_part_label_translation(self):
+        """Test that 'label' values are correctly translated."""
+        response = self.options(reverse('api-part-list'))
+
+        labels = {
+            'IPN': 'IPN',
+            'category': 'Category',
+            'assembly': 'Assembly',
+            'ordering': 'On Order',
+            'stock_item_count': 'Stock Items',
+        }
+
+        help_text = {
+            'IPN': 'Internal Part Number',
+            'active': 'Is this part active?',
+            'barcode_hash': 'Unique hash of barcode data',
+            'category': 'Part category',
+        }
+
+        # Check basic return values
+        for field, value in labels.items():
+            self.assertEqual(response.data['actions']['POST'][field]['label'], value)
+
+        for field, value in help_text.items():
+            self.assertEqual(
+                response.data['actions']['POST'][field]['help_text'], value
+            )
+
+        # Check again, with a different locale
+        response = self.options(
+            reverse('api-part-list'), headers={'Accept-Language': 'de'}
+        )
+
+        translated = {
+            'IPN': 'IPN (Interne Produktnummer)',
+            'category': 'Kategorie',
+            'assembly': 'Baugruppe',
+            'ordering': 'Bestellt',
+            'stock_item_count': 'Lagerartikel',
+        }
+
+        for field, value in translated.items():
+            label = response.data['actions']['POST'][field]['label']
+            self.assertEqual(label, value)
+
     def test_category(self):
         """Test the PartCategory API OPTIONS endpoint."""
         actions = self.getActions(reverse('api-part-category-list'))