[PUI] Add view of all defined units to Admin center (#8040)

* Add API endpoint for all defined units
Fixes #7858

* render all units in API

* bump API

* Add display for all units

* remove logging

* fix types

* ignore favicon errors

* fix for new pint version

* add tests

* prove against units that are not defined

* append trailing slash to url

* make pagination disableable again

src/backend/InvenTree/InvenTree/api_version.py

@@ -1,13 +1,16 @@
 """InvenTree API version information."""
 
 # InvenTree API version
-INVENTREE_API_VERSION = 251
+INVENTREE_API_VERSION = 252
 
 """Increment this API version number whenever there is a significant change to the API that any clients need to know about."""
 
 
 INVENTREE_API_TEXT = """
 
+v252 - 2024-09-30 : https://github.com/inventree/InvenTree/pull/8035
+    - Add endpoint for listing all known units
+
 v251 - 2024-09-06 : https://github.com/inventree/InvenTree/pull/8018
     - Adds "attach_to_model" field to the ReporTemplate model
 

src/backend/InvenTree/common/api.py

@@ -1,6 +1,7 @@
 """Provides a JSON API for common components."""
 
 import json
+from typing import Type
 
 from django.conf import settings
 from django.contrib.contenttypes.models import ContentType
@@ -19,6 +20,7 @@ from django_q.tasks import async_task
 from djmoney.contrib.exchange.models import ExchangeBackend, Rate
 from drf_spectacular.utils import OpenApiResponse, extend_schema
 from error_report.models import Error
+from pint._typing import UnitLike
 from rest_framework import permissions, serializers
 from rest_framework.exceptions import NotAcceptable, NotFound, PermissionDenied
 from rest_framework.permissions import IsAdminUser
@@ -27,6 +29,7 @@ from rest_framework.views import APIView
 
 import common.models
 import common.serializers
+import InvenTree.conversion
 from common.icons import get_icon_packs
 from common.settings import get_global_setting
 from generic.states.api import urlpattern as generic_states_api_urls
@@ -533,6 +536,36 @@ class CustomUnitDetail(RetrieveUpdateDestroyAPI):
     permission_classes = [permissions.IsAuthenticated, IsStaffOrReadOnly]
 
 
+class AllUnitList(ListAPI):
+    """List of all defined units."""
+
+    serializer_class = common.serializers.AllUnitListResponseSerializer
+    permission_classes = [permissions.IsAuthenticated, IsStaffOrReadOnly]
+
+    def get(self, request, *args, **kwargs):
+        """Return a list of all available units."""
+        reg = InvenTree.conversion.get_unit_registry()
+        all_units = {k: self.get_unit(reg, k) for k in reg}
+        data = {
+            'default_system': reg.default_system,
+            'available_systems': dir(reg.sys),
+            'available_units': {k: v for k, v in all_units.items() if v},
+        }
+        return Response(data)
+
+    def get_unit(self, reg, k):
+        """Parse a unit from the registry."""
+        if not hasattr(reg, k):
+            return None
+        unit: Type[UnitLike] = getattr(reg, k)
+        return {
+            'name': k,
+            'is_alias': reg.get_name(k) == k,
+            'compatible_units': [str(a) for a in unit.compatible_units()],
+            'isdimensionless': unit.dimensionless,
+        }
+
+
 class ErrorMessageList(BulkDeleteMixin, ListAPI):
     """List view for server error messages."""
 
@@ -900,6 +933,7 @@ common_api_urls = [
                     path('', CustomUnitDetail.as_view(), name='api-custom-unit-detail')
                 ]),
             ),
+            path('all/', AllUnitList.as_view(), name='api-all-unit-list'),
             path('', CustomUnitList.as_view(), name='api-custom-unit-list'),
         ]),
     ),

src/backend/InvenTree/common/serializers.py

@@ -382,6 +382,22 @@ class CustomUnitSerializer(DataImportExportSerializerMixin, InvenTreeModelSerial
         fields = ['pk', 'name', 'symbol', 'definition']
 
 
+class AllUnitListResponseSerializer(serializers.Serializer):
+    """Serializer for the AllUnitList."""
+
+    class Unit(serializers.Serializer):
+        """Serializer for the AllUnitListResponseSerializer."""
+
+        name = serializers.CharField()
+        is_alias = serializers.BooleanField()
+        compatible_units = serializers.ListField(child=serializers.CharField())
+        isdimensionless = serializers.BooleanField()
+
+    default_system = serializers.CharField()
+    available_systems = serializers.ListField(child=serializers.CharField())
+    available_units = Unit(many=True)
+
+
 class ErrorMessageSerializer(InvenTreeModelSerializer):
     """DRF serializer for server error messages."""
 

src/backend/InvenTree/common/tests.py

@@ -1495,6 +1495,14 @@ class CustomUnitAPITest(InvenTreeAPITestCase):
         for name in invalid_name_values:
             self.patch(url, {'name': name}, expected_code=400)
 
+    def test_api(self):
+        """Test the CustomUnit API."""
+        response = self.get(reverse('api-all-unit-list'))
+        self.assertIn('default_system', response.data)
+        self.assertIn('available_systems', response.data)
+        self.assertIn('available_units', response.data)
+        self.assertEqual(len(response.data['available_units']) > 100, True)
+
 
 class ContentTypeAPITest(InvenTreeAPITestCase):
     """Unit tests for the ContentType API."""