Improvements to PrintingOptionsSerializer (#12434)

* Fixed issue with default `driver_options on `InvenTreeLabelPlugin`

* Provide current `machine` to `LabelPrinterBaseDriver.get_printing_options_serializer`

src/backend/InvenTree/machine/machine_types/label_printer.py

@@ -207,6 +207,10 @@ class LabelPrinterBaseDriver(BaseDriver):
             ```
         """
 
+        def __init__(self, machine=None, *args, **kwargs):
+            """Initialize the printing options serializer."""
+            super().__init__(*args, **kwargs)
+
         copies = serializers.IntegerField(
             default=1,
             label=_('Copies'),

src/backend/InvenTree/machine/tests.py

@@ -62,7 +62,7 @@ class TestDriverMachineInterface(TestMachineRegistryMixin, TestCase):
 
         # Check state now
         self.assertEqual(len(registry.get_machine_types()), 1)
-        self.assertEqual(len(registry.get_driver_types()), 3)
+        self.assertEqual(len(registry.get_driver_types()), 4)
         self.assertEqual(len(registry.get_machines()), 0)
 
         # Check for expected machine registry errors
@@ -79,6 +79,7 @@ class TestDriverMachineInterface(TestMachineRegistryMixin, TestCase):
         for slug in [
             'sample-printer-driver',
             'test-label-printer-api',
+            'test-label-printer-options',
             'test-label-printer-error',
         ]:
             instance = registry.get_driver_instance(slug)
@@ -187,23 +188,22 @@ class TestLabelPrinterMachineType(InvenTreeAPITestCase):
             else:
                 self.assertIsNone(machine)
 
-    def create_machine(self):
+    def create_machine(self, driver_key):
         """Create a new label printing machine."""
         registry.initialize(main=True)
 
         PLG_KEY = 'label-printer-test-plugin'
-        DRIVER_KEY = 'test-label-printer-api'
 
         # Ensure that the driver is initialized
         plg_registry.set_plugin_state(PLG_KEY, True)
 
-        driver = registry.get_driver_instance(DRIVER_KEY)
+        driver = registry.get_driver_instance(driver_key)
         self.assertIsNotNone(driver)
 
         machine_config = MachineConfig.objects.create(
             name='Test Label Printer',
             machine_type='label-printer',
-            driver=DRIVER_KEY,
+            driver=driver_key,
             active=True,
         )
 
@@ -218,7 +218,7 @@ class TestLabelPrinterMachineType(InvenTreeAPITestCase):
         """Test arbitrary function calls against a machine."""
         from machine.registry import call_machine_function
 
-        machine = self.create_machine()
+        machine = self.create_machine('test-label-printer-api')
 
         with self.assertRaises(AttributeError):
             call_machine_function(machine.pk, 'fake_function', custom_arg=123)
@@ -231,7 +231,7 @@ class TestLabelPrinterMachineType(InvenTreeAPITestCase):
         """Test the print label method."""
         plugin_ref = 'inventreelabelmachine'
 
-        machine = self.create_machine()
+        machine = self.create_machine('test-label-printer-api')
 
         # setup the label app
         apps.get_app_config('report').create_default_labels()
@@ -297,9 +297,95 @@ class TestLabelPrinterMachineType(InvenTreeAPITestCase):
 
         self.assertIn('is not a valid choice', str(response.data['machine']))
 
+    def test_printing_options_serializer(self):
+        """Test the printing options serializer."""
+        plugin_ref = 'inventreelabelmachine'
+
+        machine = self.create_machine('test-label-printer-options')
+        machine.set_setting('LABEL', 'D', '18')
+
+        # setup the label app
+        apps.get_app_config('report').create_default_labels()
+        plg_registry.reload_plugins()
+
+        config = cast(PluginConfig, plg_registry.get_plugin(plugin_ref).plugin_config())
+        config.active = True
+        config.save()
+
+        parts = Part.objects.all()[:2]
+        template = LabelTemplate.objects.filter(enabled=True, model_type='part').first()
+        assert template
+
+        url = reverse('api-label-print')
+
+        # Test print using machine defaults (LABEL: 18)
+        with self.assertLogs('inventree', level='WARNING') as cm:
+            self.post(
+                url,
+                {
+                    'plugin': config.key,
+                    'items': [a.pk for a in parts],
+                    'template': template.pk,
+                    'machine': str(machine.pk),
+                },
+                expected_code=201,
+            )
+
+        # Check for expected messages
+        messages = [
+            'Printing Label: TestingLabelPrinterDriverOptions',
+            f'machine: {machine.pk}',
+            f'label: {template.pk}',
+            f'item: {parts[0].pk}',
+            f'item: {parts[1].pk}',
+            'options: label: 18',
+        ]
+
+        for message in messages:
+            result = False
+            for item in cm.records:
+                if message in str(item):
+                    result = True
+                    break
+
+            self.assertTrue(result, f'Message not found: {message}')
+
+        # Test print using print options (label: 24)
+        with self.assertLogs('inventree', level='WARNING') as cm:
+            self.post(
+                url,
+                {
+                    'plugin': config.key,
+                    'items': [a.pk for a in parts],
+                    'template': template.pk,
+                    'machine': str(machine.pk),
+                    'driver_options': {'label': '24'},
+                },
+                expected_code=201,
+            )
+
+        # Check for expected messages
+        messages = [
+            'Printing Label: TestingLabelPrinterDriverOptions',
+            f'machine: {machine.pk}',
+            f'label: {template.pk}',
+            f'item: {parts[0].pk}',
+            f'item: {parts[1].pk}',
+            'options: label: 24',
+        ]
+
+        for message in messages:
+            result = False
+            for item in cm.records:
+                if message in str(item):
+                    result = True
+                    break
+
+            self.assertTrue(result, f'Message not found: {message}')
+
     def test_location_invalid_pk(self):
         """Test that location property returns None for an invalid PK without raising."""
-        machine = self.create_machine()
+        machine = self.create_machine('test-label-printer-api')
 
         machine.set_setting('LOCATION', 'M', 999999)
 

src/backend/InvenTree/plugin/builtin/labels/inventree_machine.py

@@ -181,16 +181,17 @@ class InvenTreeLabelPlugin(LabelPrintingMixin, InvenTreePlugin):
             label=_('Options'),
             depends_on=['machine'],
             field_serializer='get_driver_options',
+            default={},
             required=False,
         )
 
         def get_driver_options(self, fields):
             """Returns the selected machines serializer."""
-            _, driver = get_machine_and_driver(fields['machine'])
+            machine, driver = get_machine_and_driver(fields['machine'])
 
             if driver is None:
                 return None
 
             return driver.get_printing_options_serializer(
-                self.context['request'], context=self.context
+                self.context['request'], context=self.context, machine=machine
             )

src/backend/InvenTree/plugin/testing/label_machines.py

@@ -1,6 +1,7 @@
 """Plugins for testing label machines."""
 
 import structlog
+from rest_framework import serializers
 
 from machine.machine_type import BaseDriver
 from plugin import InvenTreePlugin
@@ -46,6 +47,52 @@ class TestingLabelPrinterDriver(LabelPrinterBaseDriver):
         return x * y
 
 
+class TestingLabelPrinterDriverOptions(LabelPrinterBaseDriver):
+    """Test driver for label printing."""
+
+    SLUG = 'test-label-printer-options'
+    NAME = 'Test label printer options'
+    DESCRIPTION = 'This is a test label printer driver for testing.'
+
+    MACHINE_SETTINGS = {
+        'LABEL': {
+            'name': 'Label Media',
+            'description': 'Select label media type',
+            'choices': [('12', '12mm'), ('18', '18mm'), ('24', '24mm')],
+            'default': '12',
+            'required': True,
+        }
+    }
+
+    def print_label(self, machine, label, item, **kwargs) -> None:
+        """Override print_label."""
+        # Simply output some warning messages,
+        # which we can check for in the unit test
+        logger.warn('Printing Label: TestingLabelPrinterDriverOptions')
+        logger.warn(f'machine: {machine.pk}')
+        logger.warn(f'label: {label.pk}')
+        logger.warn(f'item: {item.pk}')
+
+        for k, v in kwargs['printing_options'].items():
+            logger.warn(f'options: {k}: {v}')
+
+    class PrintingOptionsSerializer(LabelPrinterBaseDriver.PrintingOptionsSerializer):
+        """Printing options serializer for print driver testing."""
+
+        def __init__(self, machine=None, *args, **kwargs):
+            """Initialize the printing options serializer."""
+            super().__init__(*args, **kwargs)
+
+            self.fields['label'].default = machine.get_setting('LABEL', 'D')
+
+        label = serializers.ChoiceField(
+            label='Label Media',
+            help_text='Select label media type',
+            choices=[('12', '12mm'), ('18', '18mm'), ('24', '24mm')],
+            default='12',
+        )
+
+
 class TestingLabelPrinterDriverError1(LabelPrinterBaseDriver):
     """Test driver for label printing."""
 
@@ -93,6 +140,7 @@ class LabelPrinterMachineTest(MachineDriverMixin, SettingsMixin, InvenTreePlugin
         """Return a list of drivers registered by this plugin."""
         return [
             TestingLabelPrinterDriver,
+            TestingLabelPrinterDriverOptions,
             TestingLabelPrinterDriverError1,
             TestingLabelPrinterDriverError2,
             TestingLabelPrinterDriverNotImplemented,