Update PartParameterTemplate API (#6538)

* Update PartParameterTemplate API

- Expose number of "parts" using a particular template
- Improve filtering visibility
- Update PUI table

* Update API version

InvenTree/InvenTree/api_version.py

@@ -1,11 +1,14 @@
 """InvenTree API version information."""
 
 # InvenTree API version
-INVENTREE_API_VERSION = 174
+INVENTREE_API_VERSION = 175
 """Increment this API version number whenever there is a significant change to the API that any clients need to know about."""
 
 INVENTREE_API_TEXT = """
 
+v175 - 2024-02-21 : https://github.com/inventree/InvenTree/pull/6538
+    - Adds "parts" count to PartParameterTemplate serializer
+
 v174 - 2024-02-21 : https://github.com/inventree/InvenTree/pull/6536
     - Expose PartCategory filters to the API documentation
     - Expose StockLocation filters to the API documentation

InvenTree/part/api.py

@@ -1494,7 +1494,7 @@ class PartParameterTemplateFilter(rest_filters.FilterSet):
         model = PartParameterTemplate
 
         # Simple filter fields
-        fields = ['units', 'checkbox']
+        fields = ['name', 'units', 'checkbox']
 
     has_choices = rest_filters.BooleanFilter(
         method='filter_has_choices', label='Has Choice'
@@ -1516,65 +1516,68 @@ class PartParameterTemplateFilter(rest_filters.FilterSet):
 
         return queryset.filter(Q(units=None) | Q(units='')).distinct()
 
+    part = rest_filters.ModelChoiceFilter(
+        queryset=Part.objects.all(), method='filter_part', label=_('Part')
+    )
 
-class PartParameterTemplateList(ListCreateAPI):
+    def filter_part(self, queryset, name, part):
+        """Filter queryset to include only PartParameterTemplates which are referenced by a part."""
+        parameters = PartParameter.objects.filter(part=part)
+        template_ids = parameters.values_list('template').distinct()
+        return queryset.filter(pk__in=[el[0] for el in template_ids])
+
+    # Filter against a "PartCategory" - return only parameter templates which are referenced by parts in this category
+    category = rest_filters.ModelChoiceFilter(
+        queryset=PartCategory.objects.all(),
+        method='filter_category',
+        label=_('Category'),
+    )
+
+    def filter_category(self, queryset, name, category):
+        """Filter queryset to include only PartParameterTemplates which are referenced by parts in this category."""
+        cats = category.get_descendants(include_self=True)
+        parameters = PartParameter.objects.filter(part__category__in=cats)
+        template_ids = parameters.values_list('template').distinct()
+        return queryset.filter(pk__in=[el[0] for el in template_ids])
+
+
+class PartParameterTemplateMixin:
+    """Mixin class for PartParameterTemplate API endpoints."""
+
+    queryset = PartParameterTemplate.objects.all()
+    serializer_class = part_serializers.PartParameterTemplateSerializer
+
+    def get_queryset(self, *args, **kwargs):
+        """Return an annotated queryset for the PartParameterTemplateDetail endpoint."""
+        queryset = super().get_queryset(*args, **kwargs)
+
+        queryset = part_serializers.PartParameterTemplateSerializer.annotate_queryset(
+            queryset
+        )
+
+        return queryset
+
+
+class PartParameterTemplateList(PartParameterTemplateMixin, ListCreateAPI):
     """API endpoint for accessing a list of PartParameterTemplate objects.
 
     - GET: Return list of PartParameterTemplate objects
     - POST: Create a new PartParameterTemplate object
     """
 
-    queryset = PartParameterTemplate.objects.all()
-    serializer_class = part_serializers.PartParameterTemplateSerializer
     filterset_class = PartParameterTemplateFilter
 
     filter_backends = SEARCH_ORDER_FILTER
 
-    filterset_fields = ['name']
-
     search_fields = ['name', 'description']
 
-    ordering_fields = ['name', 'units', 'checkbox']
-
-    def filter_queryset(self, queryset):
-        """Custom filtering for the PartParameterTemplate API."""
-        queryset = super().filter_queryset(queryset)
-
-        params = self.request.query_params
-
-        # Filtering against a "Part" - return only parameter templates which are referenced by a part
-        part = params.get('part', None)
-
-        if part is not None:
-            try:
-                part = Part.objects.get(pk=part)
-                parameters = PartParameter.objects.filter(part=part)
-                template_ids = parameters.values_list('template').distinct()
-                queryset = queryset.filter(pk__in=[el[0] for el in template_ids])
-            except (ValueError, Part.DoesNotExist):
-                pass
-
-        # Filtering against a "PartCategory" - return only parameter templates which are referenced by parts in this category
-        category = params.get('category', None)
-
-        if category is not None:
-            try:
-                category = PartCategory.objects.get(pk=category)
-                cats = category.get_descendants(include_self=True)
-                parameters = PartParameter.objects.filter(part__category__in=cats)
-                template_ids = parameters.values_list('template').distinct()
-                queryset = queryset.filter(pk__in=[el[0] for el in template_ids])
-            except (ValueError, PartCategory.DoesNotExist):
-                pass
-
-        return queryset
+    ordering_fields = ['name', 'units', 'checkbox', 'parts']
 
 
-class PartParameterTemplateDetail(RetrieveUpdateDestroyAPI):
+class PartParameterTemplateDetail(PartParameterTemplateMixin, RetrieveUpdateDestroyAPI):
     """API endpoint for accessing the detail view for a PartParameterTemplate object."""
 
-    queryset = PartParameterTemplate.objects.all()
-    serializer_class = part_serializers.PartParameterTemplateSerializer
+    pass
 
 
 class PartParameterAPIMixin:

InvenTree/part/serializers.py

@@ -245,7 +245,18 @@ class PartParameterTemplateSerializer(InvenTree.serializers.InvenTreeModelSerial
         """Metaclass defining serializer fields."""
 
         model = PartParameterTemplate
-        fields = ['pk', 'name', 'units', 'description', 'checkbox', 'choices']
+        fields = ['pk', 'name', 'units', 'description', 'parts', 'checkbox', 'choices']
+
+    parts = serializers.IntegerField(
+        read_only=True,
+        label=_('Parts'),
+        help_text=_('Number of parts using this template'),
+    )
+
+    @staticmethod
+    def annotate_queryset(queryset):
+        """Annotate the queryset with the number of parts which use each parameter template."""
+        return queryset.annotate(parts=SubqueryCount('instances'))
 
 
 class PartBriefSerializer(InvenTree.serializers.InvenTreeModelSerializer):

src/frontend/src/tables/part/PartParameterTemplateTable.tsx

@@ -51,6 +51,11 @@ export default function PartParameterTemplateTable() {
         sortable: true,
         switchable: false
       },
+      {
+        accessor: 'parts',
+        sortable: true,
+        switchable: true
+      },
       {
         accessor: 'units',
         sortable: true