Parameter filtering (#4823)

* adds new field 'parameter type' to PartParameterTemplate model

* Move part parameter settings onto their own page

* Add "choices" and "regex" template types

* Adds validation for PartParameter based on template type

* javascript cleanup

* Fix for serializers.py

* Add unit testing for parameter validation

* Add filters

* Rename "type" field to "param_type"

- Should have seen that one coming

* Coerce 'boolean' value to True/False

* table update

* js linting

* Add requirement for "pint" package

* Add validator for physical unit types

- Revert a previous migration which adds "parameter type" and "validator" fields
- These will get implemented later, too much scope creep for this PR
- Add unit test for validation of "units" field

* Update PartParameter model

- Add data_numeric field (will be used later)
- Add MinLengthValidator to data field

* Run validation for part parameter data

- Ensure it can be converted to internal units

* Update admin interface to display partparameter values inline for a part

* Adds validation of part parameter data value

- Also converts to base units, and stores as "numeric" value
- Display "numeric" value in tables
- Create new file conversion.py for data conversion

* Update unit tests and fix some bugs

* Update docstring

* Add units to parameter columns in parameteric part table

* Allow part list to be ordered by a particular parameter value

- Annotate queryset with new "order_by_parameter" method
- Skeleton method for future work

* Bump API version

* Adds unit testing for sorting parts by parameter value

* Update historical data migrations

- Turns out RunPython.noop is a thing?

* Cache the unit registry

- Creating the unit registry takes a significant amount of time
- Construct when first called, and then cache for subsequent hits
- Massive improvement in performance

* Throw error on empty values when converting between units

* Data migration for converting existing part parameter values

* Handle more error cases

* Show parameteric table on top-level part page too

* Unit test for data migration

* Update credits in docs

* Improved error checking

* WIP docs updates

* Fix parameteric table filtering

* remove zoom property

* Fix for import path

* Update parameter docs

* Run background task to rebuild parameters when template changes

* Make "data_numeric" field nullable

- Defaulting to zero is not appropriate, as the actual value may be zero
- Sorting still seems to work just fine

* Fixes for unit test

* More unit test fixes

* Further fixes for unit tests

---------

Co-authored-by: Matthias Mair <code@mjmair.com>

InvenTree/InvenTree/api_version.py

@@ -2,11 +2,14 @@
 
 
 # InvenTree API version
-INVENTREE_API_VERSION = 115
+INVENTREE_API_VERSION = 116
 
 """
 Increment this API version number whenever there is a significant change to the API that any clients need to know about
 
+v116 -> 2023-05-18 : https://github.com/inventree/InvenTree/pull/4823
+    - Updates to part parameter implementation, to use physical units
+
 v115 - > 2023-05-18 : https://github.com/inventree/InvenTree/pull/4846
     - Adds ability to partially scrap a build output
 

InvenTree/InvenTree/conversion.py

@@ -0,0 +1,81 @@
+"""Helper functions for converting between units."""
+
+from django.core.exceptions import ValidationError
+from django.utils.translation import gettext_lazy as _
+
+import pint
+
+_unit_registry = None
+
+
+def get_unit_registry():
+    """Return a custom instance of the Pint UnitRegistry."""
+
+    global _unit_registry
+
+    # Cache the unit registry for speedier access
+    if _unit_registry is None:
+        _unit_registry = pint.UnitRegistry()
+
+    # TODO: Allow for custom units to be defined in the database
+
+    return _unit_registry
+
+
+def convert_physical_value(value: str, unit: str = None):
+    """Validate that the provided value is a valid physical quantity.
+
+    Arguments:
+        value: Value to validate (str)
+        unit: Optional unit to convert to, and validate against
+
+    Raises:
+        ValidationError: If the value is invalid
+
+    Returns:
+        The converted quantity, in the specified units
+    """
+
+    # Ensure that the value is a string
+    value = str(value).strip()
+
+    # Error on blank values
+    if not value:
+        raise ValidationError(_('No value provided'))
+
+    ureg = get_unit_registry()
+    error = ''
+
+    try:
+        # Convert to a quantity
+        val = ureg.Quantity(value)
+
+        if unit:
+
+            if val.units == ureg.dimensionless:
+                # If the provided value is dimensionless, assume that the unit is correct
+                val = ureg.Quantity(value, unit)
+            else:
+                # Convert to the provided unit (may raise an exception)
+                val = val.to(unit)
+
+        # At this point we *should* have a valid pint value
+        # To double check, look at the maginitude
+        float(val.magnitude)
+    except ValueError:
+        error = _('Provided value is not a valid number')
+    except pint.errors.UndefinedUnitError:
+        error = _('Provided value has an invalid unit')
+    except pint.errors.DefinitionSyntaxError:
+        error = _('Provided value has an invalid unit')
+    except pint.errors.DimensionalityError:
+        error = _('Provided value could not be converted to the specified unit')
+
+    if error:
+        if unit:
+            error += f' ({unit})'
+
+        raise ValidationError(error)
+
+    # Return the converted value
+    return val

InvenTree/InvenTree/static/css/inventree.css

@@ -319,7 +319,6 @@ main {
 .filter-input {
     display: inline-block;
     *display: inline;
-    zoom: 1;
 }
 
 .filter-tag:hover {

InvenTree/InvenTree/tasks.py

@@ -167,6 +167,7 @@ def offload_task(taskname, *args, force_async=False, force_sync=False, **kwargs)
     If workers are not running or force_sync flag
     is set then the task is ran synchronously.
     """
+
     try:
         import importlib
 

InvenTree/InvenTree/validators.py

@@ -8,9 +8,31 @@ from django.core import validators
 from django.core.exceptions import FieldDoesNotExist, ValidationError
 from django.utils.translation import gettext_lazy as _
 
+import pint
 from jinja2 import Template
 from moneyed import CURRENCIES
 
+import InvenTree.conversion
+
+
+def validate_physical_units(unit):
+    """Ensure that a given unit is a valid physical unit."""
+
+    unit = unit.strip()
+
+    # Ignore blank units
+    if not unit:
+        return
+
+    ureg = InvenTree.conversion.get_unit_registry()
+
+    try:
+        ureg(unit)
+    except AttributeError:
+        raise ValidationError(_('Invalid physical unit'))
+    except pint.errors.UndefinedUnitError:
+        raise ValidationError(_('Invalid physical unit'))
+
 
 def validate_currency_code(code):
     """Check that a given code is a valid currency code."""

InvenTree/build/migrations/0013_auto_20200425_0507.py

@@ -11,10 +11,6 @@ def update_tree(apps, schema_editor):
     Build.objects.rebuild()
 
 
-def nupdate_tree(apps, schema_editor):  # pragma: no cover
-    pass
-
-
 class Migration(migrations.Migration):
 
     atomic = False
@@ -53,5 +49,5 @@ class Migration(migrations.Migration):
             field=models.PositiveIntegerField(db_index=True, default=0, editable=False),
             preserve_default=False,
         ),
-        migrations.RunPython(update_tree, reverse_code=nupdate_tree),
+        migrations.RunPython(update_tree, reverse_code=migrations.RunPython.noop),
     ]

InvenTree/build/migrations/0018_build_reference.py

@@ -23,13 +23,6 @@ def add_default_reference(apps, schema_editor):
         print(f"\nUpdated build reference for {count} existing BuildOrder objects")
 
 
-def reverse_default_reference(apps, schema_editor):  # pragma: no cover
-    """
-    Do nothing! But we need to have a function here so the whole process is reversible.
-    """
-    pass
-
-
 class Migration(migrations.Migration):
 
     atomic = False
@@ -49,7 +42,7 @@ class Migration(migrations.Migration):
         # Auto-populate the new reference field for any existing build order objects
         migrations.RunPython(
             add_default_reference,
-            reverse_code=reverse_default_reference
+            reverse_code=migrations.RunPython.noop
         ),
 
         # Now that each build has a non-empty, unique reference, update the field requirements!

InvenTree/build/migrations/0029_auto_20210601_1525.py

@@ -51,14 +51,6 @@ def assign_bom_items(apps, schema_editor):
         logger.info(f"Assigned BomItem for {count_valid}/{count_total} entries")
 
 
-def unassign_bom_items(apps, schema_editor):  # pragma: no cover
-    """
-    Reverse migration does not do anything.
-    Function here to preserve ability to reverse migration
-    """
-    pass
-
-
 class Migration(migrations.Migration):
 
     dependencies = [
@@ -66,5 +58,5 @@ class Migration(migrations.Migration):
     ]
 
     operations = [
-        migrations.RunPython(assign_bom_items, reverse_code=unassign_bom_items),
+        migrations.RunPython(assign_bom_items, reverse_code=migrations.RunPython.noop),
     ]

InvenTree/build/migrations/0032_auto_20211014_0632.py

@@ -31,12 +31,6 @@ def build_refs(apps, schema_editor):
         build.reference_int = ref
         build.save()
 
-def unbuild_refs(apps, schema_editor):  # pragma: no cover
-    """
-    Provided only for reverse migration compatibility
-    """
-    pass
-
 
 class Migration(migrations.Migration):
 
@@ -49,6 +43,6 @@ class Migration(migrations.Migration):
     operations = [
         migrations.RunPython(
             build_refs,
-            reverse_code=unbuild_refs
+            reverse_code=migrations.RunPython.noop
         )
     ]

InvenTree/build/migrations/0036_auto_20220707_1101.py

@@ -50,11 +50,6 @@ def update_build_reference(apps, schema_editor):
         print(f"Updated reference field for {n} BuildOrder objects")
 
 
-def nupdate_build_reference(apps, schema_editor):
-    """Reverse migration code. Does nothing."""
-    pass
-
-
 class Migration(migrations.Migration):
 
     dependencies = [
@@ -64,6 +59,6 @@ class Migration(migrations.Migration):
     operations = [
         migrations.RunPython(
             update_build_reference,
-            reverse_code=nupdate_build_reference,
+            reverse_code=migrations.RunPython.noop,
         )
     ]

InvenTree/order/migrations/0052_auto_20211014_0631.py

@@ -52,13 +52,6 @@ def build_refs(apps, schema_editor):
         order.save()
 
 
-def unbuild_refs(apps, schema_editor):  # pragma: no cover
-    """
-    Provided only for reverse migration compatibility
-    """
-    pass
-
-
 class Migration(migrations.Migration):
 
     dependencies = [
@@ -67,8 +60,5 @@ class Migration(migrations.Migration):
 
 
     operations = [
-        migrations.RunPython(
+        migrations.RunPython(build_refs, reverse_code=migrations.RunPython.noop)
-            build_refs,
-            reverse_code=unbuild_refs
-        )
     ]

InvenTree/order/migrations/0058_auto_20211126_1210.py

@@ -40,14 +40,6 @@ def calculate_shipped_quantity(apps, schema_editor):
         item.save()
 
 
-def reverse_calculate_shipped_quantity(apps, schema_editor):  # pragma: no cover
-    """
-    Provided only for reverse migration compatibility.
-    This function does nothing.
-    """
-    pass
-
-
 class Migration(migrations.Migration):
 
     dependencies = [
@@ -57,6 +49,6 @@ class Migration(migrations.Migration):
     operations = [
         migrations.RunPython(
             calculate_shipped_quantity,
-            reverse_code=reverse_calculate_shipped_quantity
+            reverse_code=migrations.RunPython.noop
         )
     ]

InvenTree/order/migrations/0074_auto_20220709_0108.py

@@ -84,11 +84,6 @@ def update_purchaseorder_reference(apps, schema_editor):
         print(f"Updated reference field for {n} PurchaseOrder objects")
 
 
-def nop(apps, schema_editor):
-    """Empty function for reverse migration"""
-    pass
-
-
 class Migration(migrations.Migration):
 
     dependencies = [
@@ -98,10 +93,10 @@ class Migration(migrations.Migration):
     operations = [
         migrations.RunPython(
             update_salesorder_reference,
-            reverse_code=nop,
+            reverse_code=migrations.RunPython.noop,
         ),
         migrations.RunPython(
             update_purchaseorder_reference,
-            reverse_code=nop,
+            reverse_code=migrations.RunPython.noop,
         )
     ]

InvenTree/order/migrations/0079_auto_20230304_0904.py

@@ -108,11 +108,6 @@ def update_sales_order_price(apps, schema_editor):
         logger.info(f"'total_price' field could not be updated for {invalid_count} SalesOrder instances")
 
 
-def reverse(apps, schema_editor):
-    """Reverse migration (does nothing)"""
-    pass
-
-
 class Migration(migrations.Migration):
 
     dependencies = [
@@ -122,10 +117,10 @@ class Migration(migrations.Migration):
     operations = [
         migrations.RunPython(
             update_purchase_order_price,
-            reverse_code=reverse
+            reverse_code=migrations.RunPython.noop
         ),
         migrations.RunPython(
             update_sales_order_price,
-            reverse_code=reverse,
+            reverse_code=migrations.RunPython.noop,
         )
     ]

InvenTree/part/admin.py

@@ -122,9 +122,9 @@ class PartImportResource(InvenTreeResource):
         ]
 
 
-class StocktakeInline(admin.TabularInline):
+class PartParameterInline(admin.TabularInline):
-    """Inline for part stocktake data"""
+    """Inline for part parameter data"""
-    model = models.PartStocktake
+    model = models.PartParameter
 
 
 class PartAdmin(ImportExportModelAdmin):
@@ -146,7 +146,7 @@ class PartAdmin(ImportExportModelAdmin):
     ]
 
     inlines = [
-        StocktakeInline,
+        PartParameterInline,
     ]
 
 

InvenTree/part/api.py

@@ -1,6 +1,7 @@
 """Provides a JSON API for the Part app."""
 
 import functools
+import re
 
 from django.db.models import Count, F, Q
 from django.http import JsonResponse
@@ -14,6 +15,7 @@ from rest_framework.exceptions import ValidationError
 from rest_framework.response import Response
 
 import order.models
+import part.filters
 from build.models import Build, BuildItem
 from InvenTree.api import (APIDownloadMixin, AttachmentMixin,
                            ListCreateDestroyAPIView, MetadataView)
@@ -1102,7 +1104,6 @@ class PartList(PartMixin, APIDownloadMixin, ListCreateAPI):
         # TODO: Querying bom_valid status may be quite expensive
         # TODO: (It needs to be profiled!)
         # TODO: It might be worth caching the bom_valid status to a database column
-
         if bom_valid is not None:
 
             bom_valid = str2bool(bom_valid)
@@ -1112,9 +1113,9 @@ class PartList(PartMixin, APIDownloadMixin, ListCreateAPI):
 
             pks = []
 
-            for part in queryset:
+            for prt in queryset:
-                if part.is_bom_valid() == bom_valid:
+                if prt.is_bom_valid() == bom_valid:
-                    pks.append(part.pk)
+                    pks.append(prt.pk)
 
             queryset = queryset.filter(pk__in=pks)
 
@@ -1217,6 +1218,34 @@ class PartList(PartMixin, APIDownloadMixin, ListCreateAPI):
 
             queryset = queryset.filter(pk__in=parts_needed_to_complete_builds)
 
+        queryset = self.filter_parameteric_data(queryset)
+
+        return queryset
+
+    def filter_parameteric_data(self, queryset):
+        """Filter queryset against part parameters.
+
+        Here we can perfom a number of different functions:
+
+        Ordering Based on Parameter Value:
+        - Used if the 'ordering' query param points to a parameter
+        - e.g. '&ordering=param_<id>' where <id> specifies the PartParameterTemplate
+        - Only parts which have a matching parameter are returned
+        - Queryset is ordered based on parameter value
+        """
+
+        # Extract "ordering" parameter from query args
+        ordering = self.request.query_params.get('ordering', None)
+
+        if ordering:
+            # Ordering value must match required regex pattern
+            result = re.match(r'^\-?parameter_(\d+)$', ordering)
+
+            if result:
+                template_id = result.group(1)
+                ascending = not ordering.startswith('-')
+                queryset = part.filters.order_by_parameter(queryset, template_id, ascending)
+
         return queryset
 
     filter_backends = SEARCH_ORDER_FILTER_ALIAS
@@ -1320,6 +1349,20 @@ class PartRelatedDetail(RetrieveUpdateDestroyAPI):
     serializer_class = part_serializers.PartRelationSerializer
 
 
+class PartParameterTemplateFilter(rest_filters.FilterSet):
+    """FilterSet for PartParameterTemplate objects."""
+
+    class Meta:
+        """Metaclass options"""
+
+        model = PartParameterTemplate
+
+        # Simple filter fields
+        fields = [
+            'units',
+        ]
+
+
 class PartParameterTemplateList(ListCreateAPI):
     """API endpoint for accessing a list of PartParameterTemplate objects.
 
@@ -1329,6 +1372,7 @@ class PartParameterTemplateList(ListCreateAPI):
 
     queryset = PartParameterTemplate.objects.all()
     serializer_class = part_serializers.PartParameterTemplateSerializer
+    filterset_class = PartParameterTemplateFilter
 
     filter_backends = SEARCH_ORDER_FILTER
 
@@ -1338,6 +1382,12 @@ class PartParameterTemplateList(ListCreateAPI):
 
     search_fields = [
         'name',
+        'description',
+    ]
+
+    ordering_fields = [
+        'name',
+        'units',
     ]
 
     def filter_queryset(self, queryset):

InvenTree/part/filters.py

@@ -19,8 +19,9 @@ Relevant PRs:
 from decimal import Decimal
 
 from django.db import models
-from django.db.models import (DecimalField, ExpressionWrapper, F, FloatField,
+from django.db.models import (Case, DecimalField, Exists, ExpressionWrapper, F,
-                              Func, IntegerField, OuterRef, Q, Subquery)
+                              FloatField, Func, IntegerField, OuterRef, Q,
+                              Subquery, Value, When)
 from django.db.models.functions import Coalesce
 
 from sql_util.utils import SubquerySum
@@ -210,3 +211,75 @@ def annotate_category_parts():
         0,
         output_field=IntegerField()
     )
+
+
+def filter_by_parameter(queryset, template_id: int, value: str, func: str = ''):
+    """Filter the given queryset by a given template parameter
+
+    Parts which do not have a value for the given parameter are excluded.
+
+    Arguments:
+        queryset - A queryset of Part objects
+        template_id - The ID of the template parameter to filter by
+        value - The value of the parameter to filter by
+        func - The function to use for the filter (e.g. __gt, __lt, __contains)
+
+    Returns:
+        A queryset of Part objects filtered by the given parameter
+    """
+
+    # TODO
+
+    return queryset
+
+
+def order_by_parameter(queryset, template_id: int, ascending=True):
+    """Order the given queryset by a given template parameter
+
+    Parts which do not have a value for the given parameter are ordered last.
+
+    Arguments:
+        queryset - A queryset of Part objects
+        template_id - The ID of the template parameter to order by
+
+    Returns:
+        A queryset of Part objects ordered by the given parameter
+    """
+
+    template_filter = part.models.PartParameter.objects.filter(
+        template__id=template_id,
+        part_id=OuterRef('id'),
+    )
+
+    # Annotate the queryset with the parameter value, and whether it exists
+    queryset = queryset.annotate(
+        parameter_exists=Exists(template_filter)
+    )
+
+    # Annotate the text data value
+    queryset = queryset.annotate(
+        parameter_value=Case(
+            When(
+                parameter_exists=True,
+                then=Subquery(template_filter.values('data')[:1], output_field=models.CharField()),
+            ),
+            default=Value('', output_field=models.CharField()),
+        ),
+        parameter_value_numeric=Case(
+            When(
+                parameter_exists=True,
+                then=Subquery(template_filter.values('data_numeric')[:1], output_field=models.FloatField()),
+            ),
+            default=Value(0, output_field=models.FloatField()),
+        )
+    )
+
+    prefix = '' if ascending else '-'
+
+    # Return filtered queryset
+
+    return queryset.order_by(
+        '-parameter_exists',
+        f'{prefix}parameter_value_numeric',
+        f'{prefix}parameter_value',
+    )

InvenTree/part/migrations/0039_auto_20200515_1127.py

@@ -10,10 +10,6 @@ def update_tree(apps, schema_editor):
     Part.objects.rebuild()
 
 
-def nupdate_tree(apps, schema_editor):  # pragma: no cover
-    pass
-
-
 class Migration(migrations.Migration):
 
     atomic = False
@@ -48,5 +44,5 @@ class Migration(migrations.Migration):
             preserve_default=False,
         ),
 
-        migrations.RunPython(update_tree, reverse_code=nupdate_tree)
+        migrations.RunPython(update_tree, reverse_code=migrations.RunPython.noop)
     ]

InvenTree/part/migrations/0083_auto_20220731_2357.py

@@ -34,12 +34,6 @@ def update_pathstring(apps, schema_editor):
         print(f"\n--- Updated 'pathstring' for {n} PartCategory objects ---\n")
 
 
-def nupdate_pathstring(apps, schema_editor):
-    """Empty function for reverse migration compatibility"""
-
-    pass
-
-
 class Migration(migrations.Migration):
 
     dependencies = [
@@ -49,6 +43,6 @@ class Migration(migrations.Migration):
     operations = [
         migrations.RunPython(
             update_pathstring,
-            reverse_code=nupdate_pathstring
+            reverse_code=migrations.RunPython.noop
         )
     ]

InvenTree/part/migrations/0102_auto_20230314_0112.py

@@ -94,11 +94,6 @@ def update_bom_item(apps, schema_editor):
         logger.info(f"Updated 'validated' flag for {n} BomItem objects")
 
 
-def meti_mob_etadpu(apps, schema_editor):
-    """Provided for reverse compatibility"""
-    pass
-
-
 class Migration(migrations.Migration):
 
     dependencies = [
@@ -108,6 +103,6 @@ class Migration(migrations.Migration):
     operations = [
         migrations.RunPython(
             update_bom_item,
-            reverse_code=meti_mob_etadpu
+            reverse_code=migrations.RunPython.noop
         )
     ]

InvenTree/part/migrations/0108_auto_20230516_1334.py

@@ -0,0 +1,30 @@
+# Generated by Django 3.2.19 on 2023-05-16 13:34
+
+import InvenTree.validators
+import django.core.validators
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('part', '0107_alter_part_tags'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='partparameter',
+            name='data_numeric',
+            field=models.FloatField(default=None, null=True, blank=True),
+        ),
+        migrations.AlterField(
+            model_name='partparameter',
+            name='data',
+            field=models.CharField(help_text='Parameter Value', max_length=500, validators=[django.core.validators.MinLengthValidator(1)], verbose_name='Data'),
+        ),
+        migrations.AlterField(
+            model_name='partparametertemplate',
+            name='units',
+            field=models.CharField(blank=True, help_text='Physical units for this parameter', max_length=25, validators=[InvenTree.validators.validate_physical_units], verbose_name='Units'),
+        ),
+    ]

InvenTree/part/migrations/0109_auto_20230517_1048.py

@@ -0,0 +1,147 @@
+# Generated by Django 3.2.19 on 2023-05-17 10:48
+
+import pint
+
+from django.core.exceptions import ValidationError
+from django.db import migrations
+
+import InvenTree.conversion
+
+
+def update_template_units(apps, schema_editor):
+    """Update the units for each parameter template:
+
+    - Check if the units are valid
+    - Attempt to convert to valid units (if possible)
+    """
+
+    PartParameterTemplate = apps.get_model('part', 'PartParameterTemplate')
+
+    n_templates = PartParameterTemplate.objects.count()
+
+    ureg = InvenTree.conversion.get_unit_registry()
+
+    n_converted = 0
+    invalid_units = []
+
+    for template in PartParameterTemplate.objects.all():
+
+        # Skip empty units
+        if not template.units:
+            continue
+
+        # Override '%' units (which are invalid)
+        if template.units == '%':
+            template.units = 'percent'
+            template.save()
+            n_converted += 1
+            continue
+
+        # Test if unit is 'valid'
+        try:
+            ureg.Unit(template.units)
+            continue
+        except pint.errors.UndefinedUnitError:
+            pass
+
+        # Check a lower-case version
+        try:
+            ureg.Unit(template.units.lower())
+            print(f"Found unit match: {template.units} -> {template.units.lower()}")
+            template.units = template.units.lower()
+            template.save()
+            n_converted += 1
+            continue
+        except pint.errors.UndefinedUnitError:
+            pass
+
+        found = False
+
+        # Attempt to convert to a valid unit
+        # Look for capitalization issues (e.g. "Ohm" -> "ohm")
+        for unit in ureg:
+            if unit.lower() == template.units.lower():
+                print(f"Found unit match: {template.units} -> {unit}")
+                template.units = str(unit)
+                template.save()
+                n_converted += 1
+                found = True
+                break
+
+        if not found:
+            print(f"warningCould not find unit match for {template.units}")
+            invalid_units.append(template.units)
+
+    print(f"Updated units for {n_templates} parameter templates")
+
+    if n_converted > 0:
+        print(f" - Converted {n_converted} units")
+
+    if len(invalid_units) > 0:
+        print(f" - Found {len(invalid_units)} invalid units:")
+
+        for unit in invalid_units:
+            print(f"   - {unit}")
+
+
+
+def convert_to_numeric_value(value: str, units: str):
+    """Convert a value (with units) to a numeric value.
+
+    Defaults to zero if the value cannot be converted.
+    """
+
+    # Default value is null
+    result = None
+
+    if units:
+        try:
+            result = InvenTree.conversion.convert_physical_value(value, units)
+            result = float(result.magnitude)
+        except (ValidationError, ValueError):
+            pass
+    else:
+        try:
+            result = float(value)
+        except ValueError:
+            pass
+
+    return result
+
+
+def update_parameter_values(apps, schema_editor):
+    """Update the parameter values for all parts:
+
+    - Calculate the 'data_numeric' value for each parameter
+    - If the template has invalid units, we'll ignore
+    """
+
+    PartParameter = apps.get_model('part', 'PartParameter')
+
+    n_params = PartParameter.objects.count()
+
+    # Convert each parameter value to a the specified units
+    for parameter in PartParameter.objects.all():
+        parameter.data_numeric = convert_to_numeric_value(parameter.data, parameter.template.units)
+        parameter.save()
+
+    if n_params > 0:
+        print(f"Updated {n_params} parameter values")
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('part', '0108_auto_20230516_1334'),
+    ]
+
+    operations = [
+        migrations.RunPython(
+            update_template_units,
+            reverse_code=migrations.RunPython.noop
+        ),
+        migrations.RunPython(
+            update_parameter_values,
+            reverse_code=migrations.RunPython.noop
+        )
+    ]

InvenTree/part/models.py

@@ -12,7 +12,7 @@ from decimal import Decimal, InvalidOperation
 
 from django.contrib.auth.models import User
 from django.core.exceptions import ValidationError
-from django.core.validators import MinValueValidator
+from django.core.validators import MinLengthValidator, MinValueValidator
 from django.db import models, transaction
 from django.db.models import ExpressionWrapper, F, Q, Sum, UniqueConstraint
 from django.db.models.functions import Coalesce
@@ -35,6 +35,7 @@ from taggit.managers import TaggableManager
 
 import common.models
 import common.settings
+import InvenTree.conversion
 import InvenTree.fields
 import InvenTree.ready
 import InvenTree.tasks
@@ -982,7 +983,7 @@ class Part(InvenTreeBarcodeMixin, InvenTreeNotesMixin, MetadataMixin, MPTTModel)
         max_length=20, default="",
         blank=True, null=True,
         verbose_name=_('Units'),
-        help_text=_('Units of measure for this part')
+        help_text=_('Units of measure for this part'),
     )
 
     assembly = models.BooleanField(
@@ -3295,6 +3296,7 @@ class PartParameterTemplate(MetadataMixin, models.Model):
     Attributes:
         name: The name (key) of the Parameter [string]
         units: The units of the Parameter [string]
+        description: Description of the parameter [string]
     """
 
     @staticmethod
@@ -3332,7 +3334,14 @@ class PartParameterTemplate(MetadataMixin, models.Model):
         unique=True
     )
 
-    units = models.CharField(max_length=25, verbose_name=_('Units'), help_text=_('Parameter Units'), blank=True)
+    units = models.CharField(
+        max_length=25,
+        verbose_name=_('Units'), help_text=_('Physical units for this parameter'),
+        blank=True,
+        validators=[
+            validators.validate_physical_units,
+        ]
+    )
 
     description = models.CharField(
         max_length=250,
@@ -3342,6 +3351,23 @@ class PartParameterTemplate(MetadataMixin, models.Model):
     )
 
 
+@receiver(post_save, sender=PartParameterTemplate, dispatch_uid='post_save_part_parameter_template')
+def post_save_part_parameter_template(sender, instance, created, **kwargs):
+    """Callback function when a PartParameterTemplate is created or saved"""
+
+    import part.tasks as part_tasks
+
+    if InvenTree.ready.canAppAccessDatabase() and not InvenTree.ready.isImportingData():
+
+        # Schedule a background task to rebuild the parameters against this template
+        if not created:
+            InvenTree.tasks.offload_task(
+                part_tasks.rebuild_parameters,
+                instance.pk,
+                force_async=True
+            )
+
+
 class PartParameter(models.Model):
     """A PartParameter is a specific instance of a PartParameterTemplate. It assigns a particular parameter <key:value> pair to a part.
 
@@ -3363,18 +3389,79 @@ class PartParameter(models.Model):
 
     def __str__(self):
         """String representation of a PartParameter (used in the admin interface)"""
-        return "{part} : {param} = {data}{units}".format(
+        return "{part} : {param} = {data} ({units})".format(
             part=str(self.part.full_name),
             param=str(self.template.name),
             data=str(self.data),
             units=str(self.template.units)
         )
 
-    part = models.ForeignKey(Part, on_delete=models.CASCADE, related_name='parameters', verbose_name=_('Part'), help_text=_('Parent Part'))
+    def save(self, *args, **kwargs):
+        """Custom save method for the PartParameter model."""
 
-    template = models.ForeignKey(PartParameterTemplate, on_delete=models.CASCADE, related_name='instances', verbose_name=_('Template'), help_text=_('Parameter Template'))
+        # Validate the PartParameter before saving
+        self.calculate_numeric_value()
 
-    data = models.CharField(max_length=500, verbose_name=_('Data'), help_text=_('Parameter Value'))
+        super().save(*args, **kwargs)
+
+    def clean(self):
+        """Validate the PartParameter before saving to the database."""
+
+        super().clean()
+
+        # Validate the parameter data against the template units
+        if self.template.units:
+            try:
+                InvenTree.conversion.convert_physical_value(self.data, self.template.units)
+            except ValidationError as e:
+                raise ValidationError({
+                    'data': e.message
+                })
+
+    def calculate_numeric_value(self):
+        """Calculate a numeric value for the parameter data.
+
+        - If a 'units' field is provided, then the data will be converted to the base SI unit.
+        - Otherwise, we'll try to do a simple float cast
+        """
+
+        if self.template.units:
+            try:
+                converted = InvenTree.conversion.convert_physical_value(self.data, self.template.units)
+                self.data_numeric = float(converted.magnitude)
+            except (ValidationError, ValueError):
+                self.data_numeric = None
+
+        # No units provided, so try to cast to a float
+        else:
+            try:
+                self.data_numeric = float(self.data)
+            except ValueError:
+                self.data_numeric = None
+
+    part = models.ForeignKey(
+        Part, on_delete=models.CASCADE, related_name='parameters',
+        verbose_name=_('Part'), help_text=_('Parent Part')
+    )
+
+    template = models.ForeignKey(
+        PartParameterTemplate, on_delete=models.CASCADE, related_name='instances',
+        verbose_name=_('Template'), help_text=_('Parameter Template')
+    )
+
+    data = models.CharField(
+        max_length=500,
+        verbose_name=_('Data'), help_text=_('Parameter Value'),
+        validators=[
+            MinLengthValidator(1),
+        ]
+    )
+
+    data_numeric = models.FloatField(
+        default=None,
+        null=True,
+        blank=True,
+    )
 
     @classmethod
     def create(cls, part, template, data, save=False):

InvenTree/part/serializers.py

@@ -240,7 +240,8 @@ class PartParameterSerializer(InvenTreeModelSerializer):
             'part',
             'template',
             'template_detail',
-            'data'
+            'data',
+            'data_numeric',
         ]
 
     def __init__(self, *args, **kwargs):

InvenTree/part/tasks.py

@@ -428,3 +428,31 @@ def scheduled_stocktake_reports():
 
     # Record the date of this report
     common.models.InvenTreeSetting.set_setting('STOCKTAKE_RECENT_REPORT', datetime.now().isoformat(), None)
+
+
+def rebuild_parameters(template_id):
+    """Rebuild all parameters for a given template.
+
+    This method is called when a base template is changed,
+    which may cause the base unit to be adjusted.
+    """
+
+    try:
+        template = part.models.PartParameterTemplate.objects.get(pk=template_id)
+    except part.models.PartParameterTemplate.DoesNotExist:
+        return
+
+    parameters = part.models.PartParameter.objects.filter(template=template)
+
+    n = 0
+
+    for parameter in parameters:
+        # Update the parameter if the numeric value has changed
+        value_old = parameter.data_numeric
+        parameter.calculate_numeric_value()
+
+        if value_old != parameter.data_numeric:
+            parameter.save()
+            n += 1
+
+    logger.info(f"Rebuilt {n} parameters for template '{template.name}'")

InvenTree/part/templates/part/category.html

@@ -284,15 +284,6 @@
         );
     });
 
-    onPanelLoad('parameters', function() {
-        loadParametricPartTable(
-            "#parametric-part-table",
-            {
-                category: {{ category.pk }},
-            }
-        );
-    });
-
     $("#toggle-starred").click(function() {
         toggleStar({
             url: '{% url "api-part-category-detail" category.pk %}',
@@ -302,6 +293,17 @@
 
     {% endif %}
 
+    onPanelLoad('parameters', function() {
+        loadParametricPartTable(
+            "#parametric-part-table",
+            {
+                {% if category %}
+                category: {{ category.pk }},
+                {% endif %}
+            }
+        );
+    });
+
     // Enable breadcrumb tree view
     enableBreadcrumbTree({
         label: 'category',

InvenTree/part/templates/part/category_sidebar.html

@@ -16,6 +16,6 @@
 {% if category %}
 {% trans "Stock Items" as text %}
 {% include "sidebar_item.html" with label='stock' text=text icon='fa-boxes' %}
+{% endif %}
 {% trans "Parameters" as text %}
 {% include "sidebar_item.html" with label="parameters" text=text icon="fa-tasks" %}
-{% endif %}

InvenTree/part/test_api.py

@@ -2699,91 +2699,6 @@ class BomItemTest(InvenTreeAPITestCase):
         self.assertEqual(response.data['available_variant_stock'], 1000)
 
 
-class PartParameterTest(InvenTreeAPITestCase):
-    """Tests for the ParParameter API."""
-    superuser = True
-
-    fixtures = [
-        'category',
-        'part',
-        'location',
-        'params',
-    ]
-
-    def test_list_params(self):
-        """Test for listing part parameters."""
-        url = reverse('api-part-parameter-list')
-
-        response = self.get(url)
-
-        self.assertEqual(len(response.data), 7)
-
-        # Filter by part
-        response = self.get(
-            url,
-            {
-                'part': 3,
-            }
-        )
-
-        self.assertEqual(len(response.data), 3)
-
-        # Filter by template
-        response = self.get(
-            url,
-            {
-                'template': 1,
-            }
-        )
-
-        self.assertEqual(len(response.data), 4)
-
-    def test_create_param(self):
-        """Test that we can create a param via the API."""
-        url = reverse('api-part-parameter-list')
-
-        response = self.post(
-            url,
-            {
-                'part': '2',
-                'template': '3',
-                'data': 70
-            }
-        )
-
-        self.assertEqual(response.status_code, 201)
-
-        response = self.get(url)
-
-        self.assertEqual(len(response.data), 8)
-
-    def test_param_detail(self):
-        """Tests for the PartParameter detail endpoint."""
-        url = reverse('api-part-parameter-detail', kwargs={'pk': 5})
-
-        response = self.get(url)
-
-        self.assertEqual(response.status_code, 200)
-
-        data = response.data
-
-        self.assertEqual(data['pk'], 5)
-        self.assertEqual(data['part'], 3)
-        self.assertEqual(data['data'], '12')
-
-        # PATCH data back in
-        response = self.patch(url, {'data': '15'})
-
-        self.assertEqual(response.status_code, 200)
-
-        # Check that the data changed!
-        response = self.get(url)
-
-        data = response.data
-
-        self.assertEqual(data['data'], '15')
-
-
 class PartAttachmentTest(InvenTreeAPITestCase):
     """Unit tests for the PartAttachment API endpoint"""
 

InvenTree/part/test_migrations.py

@@ -82,3 +82,75 @@ class TestBomItemMigrations(MigratorTestCase):
 
         for bom_item in BomItem.objects.all():
             self.assertFalse(bom_item.validated)
+
+
+class TestParameterMigrations(MigratorTestCase):
+    """Unit test for part parameter migrations"""
+
+    migrate_from = ('part', '0106_part_tags')
+    migrate_to = ('part', '0109_auto_20230517_1048')
+
+    def prepare(self):
+        """Create some parts, and templates with parameters"""
+
+        Part = self.old_state.apps.get_model('part', 'part')
+        PartParameter = self.old_state.apps.get_model('part', 'partparameter')
+        PartParameterTemlate = self.old_state.apps.get_model('part', 'partparametertemplate')
+
+        # Create some parts
+        a = Part.objects.create(
+            name='Part A', description='My part A',
+            level=0, lft=0, rght=0, tree_id=0,
+        )
+
+        b = Part.objects.create(
+            name='Part B', description='My part B',
+            level=0, lft=0, rght=0, tree_id=0,
+        )
+
+        # Create some templates
+        t1 = PartParameterTemlate.objects.create(name='Template 1', units='mm')
+        t2 = PartParameterTemlate.objects.create(name='Template 2', units='AMPERE')
+
+        # Create some parameter values
+        PartParameter.objects.create(part=a, template=t1, data='1.0')
+        PartParameter.objects.create(part=a, template=t2, data='-2mA',)
+
+        PartParameter.objects.create(part=b, template=t1, data='1/10 inch')
+        PartParameter.objects.create(part=b, template=t2, data='abc')
+
+    def test_data_migration(self):
+        """Test that the template units and values have been updated correctly"""
+
+        Part = self.new_state.apps.get_model('part', 'part')
+        PartParameter = self.new_state.apps.get_model('part', 'partparameter')
+        PartParameterTemlate = self.new_state.apps.get_model('part', 'partparametertemplate')
+
+        # Extract the parts
+        a = Part.objects.get(name='Part A')
+        b = Part.objects.get(name='Part B')
+
+        # Check that the templates have been updated correctly
+        t1 = PartParameterTemlate.objects.get(name='Template 1')
+        self.assertEqual(t1.units, 'mm')
+
+        t2 = PartParameterTemlate.objects.get(name='Template 2')
+        self.assertEqual(t2.units, 'ampere')
+
+        # Check that the parameter values have been updated correctly
+        p1 = PartParameter.objects.get(part=a, template=t1)
+        self.assertEqual(p1.data, '1.0')
+        self.assertEqual(p1.data_numeric, 1.0)
+
+        p2 = PartParameter.objects.get(part=a, template=t2)
+        self.assertEqual(p2.data, '-2mA')
+        self.assertEqual(p2.data_numeric, -0.002)
+
+        p3 = PartParameter.objects.get(part=b, template=t1)
+        self.assertEqual(p3.data, '1/10 inch')
+        self.assertEqual(p3.data_numeric, 2.54)
+
+        # This one has not converted correctly
+        p4 = PartParameter.objects.get(part=b, template=t2)
+        self.assertEqual(p4.data, 'abc')
+        self.assertEqual(p4.data_numeric, None)

InvenTree/part/test_param.py

@@ -2,8 +2,11 @@
 
 import django.core.exceptions as django_exceptions
 from django.test import TestCase, TransactionTestCase
+from django.urls import reverse
 
-from .models import (PartCategory, PartCategoryParameterTemplate,
+from InvenTree.unit_test import InvenTreeAPITestCase
+
+from .models import (Part, PartCategory, PartCategoryParameterTemplate,
                      PartParameter, PartParameterTemplate)
 
 
@@ -23,7 +26,7 @@ class TestParams(TestCase):
         self.assertEqual(str(t1), 'Length (mm)')
 
         p1 = PartParameter.objects.get(pk=1)
-        self.assertEqual(str(p1), 'M2x4 LPHS : Length = 4mm')
+        self.assertEqual(str(p1), 'M2x4 LPHS : Length = 4 (mm)')
 
         c1 = PartCategoryParameterTemplate.objects.get(pk=1)
         self.assertEqual(str(c1), 'Mechanical | Length | 2.8')
@@ -87,3 +90,252 @@ class TestCategoryTemplates(TransactionTestCase):
 
         n = PartCategoryParameterTemplate.objects.all().count()
         self.assertEqual(n, 3)
+
+
+class ParameterTests(TestCase):
+    """Unit tests for parameter validation"""
+
+    fixtures = [
+        'location',
+        'category',
+        'part',
+        'params'
+    ]
+
+    def test_unit_validation(self):
+        """Test validation of 'units' field for PartParameterTemplate"""
+
+        # Test that valid units pass
+        for unit in [None, '', 'mm', 'A', 'm^2', 'Pa', 'V', 'C', 'F', 'uF', 'mF', 'millifarad']:
+            tmp = PartParameterTemplate(name='test', units=unit)
+            tmp.full_clean()
+
+        # Test that invalid units fail
+        for unit in ['mmmmm', '-', 'x', int]:
+            tmp = PartParameterTemplate(name='test', units=unit)
+            with self.assertRaises(django_exceptions.ValidationError):
+                tmp.full_clean()
+
+    def test_param_validation(self):
+        """Test that parameters are correctly validated against template units"""
+
+        template = PartParameterTemplate.objects.create(
+            name='My Template',
+            units='m',
+        )
+
+        prt = Part.objects.get(pk=1)
+
+        # Test that valid parameters pass
+        for value in ['1', '1m', 'm', '-4m', -2, '2.032mm', '99km', '-12 mile', 'foot', '3 yards']:
+            param = PartParameter(part=prt, template=template, data=value)
+            param.full_clean()
+
+        # Test that invalid parameters fail
+        for value in ['3 Amps', '-3 zogs', '3.14F']:
+            param = PartParameter(part=prt, template=template, data=value)
+            with self.assertRaises(django_exceptions.ValidationError):
+                param.full_clean()
+
+    def test_param_conversion(self):
+        """Test that parameters are correctly converted to template units"""
+
+        template = PartParameterTemplate.objects.create(
+            name='My Template',
+            units='m',
+        )
+
+        tests = {
+            '1': 1.0,
+            '-1': -1.0,
+            '23m': 23.0,
+            '-89mm': -0.089,
+            '100 foot': 30.48,
+            '-17 yards': -15.54,
+        }
+
+        prt = Part.objects.get(pk=1)
+        param = PartParameter(part=prt, template=template, data='1')
+
+        for value, expected in tests.items():
+            param.data = value
+            param.calculate_numeric_value()
+            self.assertAlmostEqual(param.data_numeric, expected, places=2)
+
+
+class PartParameterTest(InvenTreeAPITestCase):
+    """Tests for the ParParameter API."""
+    superuser = True
+
+    fixtures = [
+        'category',
+        'part',
+        'location',
+        'params',
+    ]
+
+    def test_list_params(self):
+        """Test for listing part parameters."""
+        url = reverse('api-part-parameter-list')
+
+        response = self.get(url)
+
+        self.assertEqual(len(response.data), 7)
+
+        # Filter by part
+        response = self.get(
+            url,
+            {
+                'part': 3,
+            }
+        )
+
+        self.assertEqual(len(response.data), 3)
+
+        # Filter by template
+        response = self.get(
+            url,
+            {
+                'template': 1,
+            }
+        )
+
+        self.assertEqual(len(response.data), 4)
+
+    def test_create_param(self):
+        """Test that we can create a param via the API."""
+        url = reverse('api-part-parameter-list')
+
+        response = self.post(
+            url,
+            {
+                'part': '2',
+                'template': '3',
+                'data': 70
+            }
+        )
+
+        self.assertEqual(response.status_code, 201)
+
+        response = self.get(url)
+
+        self.assertEqual(len(response.data), 8)
+
+    def test_param_detail(self):
+        """Tests for the PartParameter detail endpoint."""
+        url = reverse('api-part-parameter-detail', kwargs={'pk': 5})
+
+        response = self.get(url)
+
+        self.assertEqual(response.status_code, 200)
+
+        data = response.data
+
+        self.assertEqual(data['pk'], 5)
+        self.assertEqual(data['part'], 3)
+        self.assertEqual(data['data'], '12')
+
+        # PATCH data back in
+        response = self.patch(url, {'data': '15'})
+
+        self.assertEqual(response.status_code, 200)
+
+        # Check that the data changed!
+        response = self.get(url)
+
+        data = response.data
+
+        self.assertEqual(data['data'], '15')
+
+    def test_order_parts_by_param(self):
+        """Test that we can order parts by a specified parameter."""
+
+        def get_param_value(response, template, index):
+            """Helper function to extract a parameter value from a response"""
+            params = response.data[index]['parameters']
+
+            for param in params:
+                if param['template'] == template:
+                    return param['data']
+
+            # No match
+            return None
+
+        # Create a new parameter template
+        template = PartParameterTemplate.objects.create(
+            name='Test Template',
+            description='My test template',
+            units='m'
+        )
+
+        # Create parameters for each existing part
+        params = []
+
+        parts = Part.objects.all().order_by('pk')
+
+        for idx, part in enumerate(parts):
+
+            # Skip parts every now and then
+            if idx % 10 == 7:
+                continue
+
+            suffix = 'mm' if idx % 3 == 0 else 'm'
+
+            params.append(
+                PartParameter.objects.create(
+                    part=part,
+                    template=template,
+                    data=f'{idx}{suffix}'
+                )
+            )
+
+        # Now, request parts, ordered by this parameter
+        url = reverse('api-part-list')
+
+        response = self.get(
+            url,
+            {
+                'ordering': 'parameter_{pk}'.format(pk=template.pk),
+                'parameters': 'true',
+            },
+            expected_code=200
+        )
+
+        # All parts should be returned
+        self.assertEqual(len(response.data), len(parts))
+
+        # Check that the parts are ordered correctly (in increasing order)
+        expectation = {
+            0: '0mm',
+            1: '3mm',
+            7: '4m',
+            9: '8m',
+            -2: '13m',
+            -1: None,
+        }
+
+        for idx, expected in expectation.items():
+            actual = get_param_value(response, template.pk, idx)
+            self.assertEqual(actual, expected)
+
+        # Next, check reverse ordering
+        response = self.get(
+            url,
+            {
+                'ordering': '-parameter_{pk}'.format(pk=template.pk),
+                'parameters': 'true',
+            },
+            expected_code=200
+        )
+
+        expectation = {
+            0: '13m',
+            1: '11m',
+            -3: '3mm',
+            -2: '0mm',
+            -1: None,
+        }
+
+        for idx, expected in expectation.items():
+            actual = get_param_value(response, template.pk, idx)
+            self.assertEqual(actual, expected)

InvenTree/plugin/registry.py

@@ -314,7 +314,7 @@ class PluginsRegistry:
                         handle_error(error, do_raise=False, log_name='discovery')
 
         # Log collected plugins
-        logger.info(f'Collected {len(collected_plugins)} plugins!')
+        logger.info(f'Collected {len(collected_plugins)} plugins')
         logger.debug(", ".join([a.__module__ for a in collected_plugins]))
 
         return collected_plugins

InvenTree/stock/migrations/0061_auto_20210511_0911.py

@@ -203,12 +203,6 @@ def update_history(apps, schema_editor):
         print(f"\n==========================\nUpdated {update_count} StockItemHistory entries")  # pragma: no cover
 
 
-def reverse_update(apps, schema_editor):
-    """
-    """
-    pass  # pragma: no cover
-
-
 class Migration(migrations.Migration):
 
     dependencies = [
@@ -216,5 +210,5 @@ class Migration(migrations.Migration):
     ]
 
     operations = [
-        migrations.RunPython(update_history, reverse_code=reverse_update)
+        migrations.RunPython(update_history, reverse_code=migrations.RunPython.noop)
     ]

InvenTree/stock/migrations/0064_auto_20210621_1724.py

@@ -60,12 +60,6 @@ def extract_purchase_price(apps, schema_editor):
     if update_count > 0:  # pragma: no cover
         print(f"Updated pricing for {update_count} stock items")
 
-def reverse_operation(apps, schema_editor):  # pragma: no cover
-    """
-    DO NOTHING!
-    """
-    pass
-
 
 class Migration(migrations.Migration):
 
@@ -74,5 +68,5 @@ class Migration(migrations.Migration):
     ]
 
     operations = [
-        migrations.RunPython(extract_purchase_price, reverse_code=reverse_operation)
+        migrations.RunPython(extract_purchase_price, reverse_code=migrations.RunPython.noop)
     ]

InvenTree/stock/migrations/0069_auto_20211109_2347.py

@@ -36,13 +36,6 @@ def update_serials(apps, schema_editor):
         item.save()
 
 
-def nupdate_serials(apps, schema_editor):  # pragma: no cover
-    """
-    Provided only for reverse migration compatibility
-    """
-    pass
-
-
 class Migration(migrations.Migration):
 
     dependencies = [
@@ -52,6 +45,6 @@ class Migration(migrations.Migration):
     operations = [
         migrations.RunPython(
             update_serials,
-            reverse_code=nupdate_serials,
+            reverse_code=migrations.RunPython.noop,
         )
     ]

InvenTree/stock/migrations/0071_auto_20211205_1733.py

@@ -35,10 +35,6 @@ def delete_scheduled(apps, schema_editor):
     Task.objects.filter(func='stock.tasks.delete_old_stock_items').delete()
 
 
-def reverse(apps, schema_editor):  # pragma: no cover
-    pass
-
-
 class Migration(migrations.Migration):
 
     dependencies = [
@@ -48,6 +44,6 @@ class Migration(migrations.Migration):
     operations = [
         migrations.RunPython(
             delete_scheduled,
-            reverse_code=reverse,
+            reverse_code=migrations.RunPython.noop,
         )
     ]

InvenTree/stock/migrations/0081_auto_20220801_0044.py

@@ -34,13 +34,6 @@ def update_pathstring(apps, schema_editor):
         print(f"\n--- Updated 'pathstring' for {n} StockLocation objects ---\n")
 
 
-def nupdate_pathstring(apps, schema_editor):
-    """Empty function for reverse migration compatibility"""
-
-    pass
-
-
-
 class Migration(migrations.Migration):
 
     dependencies = [
@@ -50,6 +43,6 @@ class Migration(migrations.Migration):
     operations = [
         migrations.RunPython(
             update_pathstring,
-            reverse_code=nupdate_pathstring
+            reverse_code=migrations.RunPython.noop
         )
     ]

InvenTree/stock/migrations/0094_auto_20230220_0025.py

@@ -62,9 +62,6 @@ def fix_purchase_price(apps, schema_editor):
         logger.info(f"Corrected purchase_price field for {n_updated} stock items.")
 
 
-def reverse(apps, schema_editor):  # pragmae: no cover
-    pass
-
 class Migration(migrations.Migration):
 
     dependencies = [
@@ -74,6 +71,6 @@ class Migration(migrations.Migration):
     operations = [
         migrations.RunPython(
             fix_purchase_price,
-            reverse_code=reverse,
+            reverse_code=migrations.RunPython.noop,
         )
     ]

InvenTree/stock/migrations/0096_auto_20230330_1121.py

@@ -52,11 +52,6 @@ def update_stock_history(apps, schema_editor):
         print(f"Updated {n} StockItemTracking entries with SalesOrder data")
 
 
-def nope(apps, schema_editor):
-    """Provided for reverse migration compatibility"""
-    pass
-
-
 class Migration(migrations.Migration):
 
     dependencies = [
@@ -65,6 +60,6 @@ class Migration(migrations.Migration):
 
     operations = [
         migrations.RunPython(
-            update_stock_history, reverse_code=nope,
+            update_stock_history, reverse_code=migrations.RunPython.noop,
         )
     ]

InvenTree/templates/InvenTree/settings/part.html

@@ -55,19 +55,4 @@
     </tbody>
 </table>
 
-<div class='panel-heading'>
-    <span class='d-flex flex-span'>
-        <h4>{% trans "Part Parameter Templates" %}</h4>
-        {% include "spacer.html" %}
-        <div class='btn-group' role='group'>
-            <button class='btn btn-success' id='new-param'>
-                <span class='fas fa-plus-circle'></span> {% trans "New Parameter" %}
-            </button>
-        </div>
-    </span>
-</div>
-
-<table class='table table-striped table-condensed' id='param-table' data-toolbar='#param-buttons'>
-</table>
-
 {% endblock content %}

InvenTree/templates/InvenTree/settings/part_parameters.html

@@ -0,0 +1,25 @@
+{% extends "panel.html" %}
+{% load i18n %}
+
+{% block label %}part-parameters{% endblock label %}
+
+{% block heading %}
+{% trans "Part Parameter Templates" %}
+{% endblock heading %}
+
+{% block actions %}
+<button class='btn btn-success' id='new-param'>
+    <span class='fas fa-plus-circle'></span> {% trans "New Parameter" %}
+</button>
+{% endblock actions %}
+
+{% block content %}
+<div id='param-buttons'>
+    <div class='btn-group' role='group'>
+        {% include "filter_list.html" with id="parameter-templates" %}
+    </div>
+</div>
+<table class='table table-striped table-condensed' id='param-table' data-toolbar='#param-buttons'>
+</table>
+
+{% endblock content %}

InvenTree/templates/InvenTree/settings/settings.html

@@ -36,6 +36,7 @@
 {% include "InvenTree/settings/label.html" %}
 {% include "InvenTree/settings/report.html" %}
 {% include "InvenTree/settings/part.html" %}
+{% include "InvenTree/settings/part_parameters.html" %}
 {% include "InvenTree/settings/part_stocktake.html" %}
 {% include "InvenTree/settings/category.html" %}
 {% include "InvenTree/settings/pricing.html" %}

InvenTree/templates/InvenTree/settings/settings_staff_js.html

@@ -302,50 +302,10 @@ onPanelLoad('category', function() {
     });
 });
 
-// Javascript for the Part settings panel
+// Javascript for the Part parameters settings panel
-onPanelLoad('parts', function() {
+onPanelLoad('part-parameters', function() {
-    $("#param-table").inventreeTable({
-        url: "{% url 'api-part-parameter-template-list' %}",
-        queryParams: {
-            ordering: 'name',
-        },
-        formatNoMatches: function() { return '{% trans "No part parameter templates found" %}'; },
-        columns: [
-            {
-                field: 'pk',
-                title: '{% trans "ID" %}',
-                visible: false,
-                switchable: false,
-            },
-            {
-                field: 'name',
-                title: '{% trans "Name" %}',
-                sortable: true,
-            },
-            {
-                field: 'units',
-                title: '{% trans "Units" %}',
-                sortable: true,
-                switchable: true,
-            },
-            {
-                field: 'description',
-                title: '{% trans "Description" %}',
-                sortable: false,
-                switchable: true,
-            },
-            {
-                formatter: function(value, row, index, field) {
-                    var bEdit = "<button title='{% trans "Edit Template" %}' class='template-edit btn btn-outline-secondary' type='button' pk='" + row.pk + "'><span class='fas fa-edit icon-green'></span></button>";
-                    var bDel = "<button title='{% trans "Delete Template" %}' class='template-delete btn btn-outline-secondary' type='button' pk='" + row.pk + "'><span class='fas fa-trash-alt icon-red'></span></button>";
 
-                    var html = "<div class='btn-group float-right' role='group'>" + bEdit + bDel + "</div>";
+    loadPartParameterTemplateTable("#param-table", {});
-
-                    return html;
-                }
-            }
-        ]
-    });
 
     $("#new-param").click(function() {
         constructForm('{% url "api-part-parameter-template-list" %}', {
@@ -359,45 +319,10 @@ onPanelLoad('parts', function() {
             refreshTable: '#param-table',
         });
     });
-
-    $("#param-table").on('click', '.template-edit', function() {
-        var button = $(this);
-        var pk = button.attr('pk');
-
-        constructForm(
-            `/api/part/parameter/template/${pk}/`,
-            {
-                fields: {
-                    name: {},
-                    units: {},
-                    description: {},
-                },
-                title: '{% trans "Edit Part Parameter Template" %}',
-                refreshTable: '#param-table',
-            }
-        );
-    });
-
-    $("#param-table").on('click', '.template-delete', function() {
-        var button = $(this);
-        var pk = button.attr('pk');
-
-        var html = `
-        <div class='alert alert-block alert-danger'>
-            {% trans "Any parameters which reference this template will also be deleted" %}
-        </div>`;
-
-        constructForm(
-            `/api/part/parameter/template/${pk}/`,
-            {
-                method: 'DELETE',
-                preFormContent: html,
-                title: '{% trans "Delete Part Parameter Template" %}',
-                refreshTable: '#param-table',
-            }
-        );
 });
 
+// Javascript for the Part settings panel
+onPanelLoad('parts', function() {
     $("#import-part").click(function() {
         launchModalForm("{% url 'api-part-import' %}?reset", {});
     });

InvenTree/templates/InvenTree/settings/sidebar.html

@@ -44,6 +44,8 @@
 {% include "sidebar_item.html" with label='category' text=text icon="fa-sitemap" %}
 {% trans "Parts" as text %}
 {% include "sidebar_item.html" with label='parts' text=text icon="fa-shapes" %}
+{% trans "Part Parameters" as text %}
+{% include "sidebar_item.html" with label='part-parameters' text=text icon="fa-th-list" %}
 {% trans "Stock" as text %}
 {% include "sidebar_item.html" with label='stock' text=text icon="fa-boxes" %}
 {% trans "Stocktake" as text %}

InvenTree/templates/js/translated/part.js

@@ -31,6 +31,7 @@
     loadParametricPartTable,
     loadPartCategoryTable,
     loadPartParameterTable,
+    loadPartParameterTemplateTable,
     loadPartPurchaseOrderTable,
     loadPartTable,
     loadPartTestTemplateTable,
@@ -1286,11 +1287,27 @@ function loadPartParameterTable(table, options) {
                     return row.template_detail.name;
                 }
             },
+            {
+                field: 'description',
+                title: '{% trans "Description" %}',
+                switchable: true,
+                sortable: false,
+                formatter: function(value, row) {
+                    return row.template_detail.description;
+                }
+            },
             {
                 field: 'data',
                 title: '{% trans "Value" %}',
                 switchable: false,
                 sortable: true,
+                formatter: function(value, row) {
+                    if (row.data_numeric && row.template_detail.units) {
+                        return `<span title='${row.data_numeric} ${row.template_detail.units}'>${row.data}</span>`;
+                    } else {
+                        return row.data;
+                    }
+                }
             },
             {
                 field: 'units',
@@ -1345,6 +1362,107 @@ function loadPartParameterTable(table, options) {
 }
 
 
+/*
+ * Construct a table showing a list of part parameter templates
+ */
+function loadPartParameterTemplateTable(table, options={}) {
+
+    let params = options.params || {};
+
+    params.ordering = 'name';
+
+    let filters = loadTableFilters('part-parameter-templates', params);
+
+    let filterTarget = options.filterTarget || '#filter-list-parameter-templates';
+
+    setupFilterList('part-parameter-templates', $(table), filterTarget);
+
+    $(table).inventreeTable({
+        url: '{% url "api-part-parameter-template-list" %}',
+        original: params,
+        queryParams: filters,
+        name: 'part-parameter-templates',
+        formatNoMatches: function() {
+            return '{% trans "No part parameter templates found" %}';
+        },
+        columns: [
+            {
+                field: 'pk',
+                title: '{% trans "ID" %}',
+                visible: false,
+                switchable: false,
+            },
+            {
+                field: 'name',
+                title: '{% trans "Name" %}',
+                sortable: true,
+            },
+            {
+                field: 'units',
+                title: '{% trans "Units" %}',
+                sortable: true,
+                switchable: true,
+            },
+            {
+                field: 'description',
+                title: '{% trans "Description" %}',
+                sortable: false,
+                switchable: true,
+            },
+            {
+                formatter: function(value, row, index, field) {
+
+                    let buttons = '';
+
+                    buttons += makeEditButton('template-edit', row.pk, '{% trans "Edit Template" %}');
+                    buttons += makeDeleteButton('template-delete', row.pk, '{% trans "Delete Template" %}');
+
+                    return wrapButtons(buttons);
+                }
+            }
+        ]
+    });
+
+    $(table).on('click', '.template-edit', function() {
+        var button = $(this);
+        var pk = button.attr('pk');
+
+        constructForm(
+            `/api/part/parameter/template/${pk}/`,
+            {
+                fields: {
+                    name: {},
+                    units: {},
+                    description: {},
+                },
+                title: '{% trans "Edit Part Parameter Template" %}',
+                refreshTable: table,
+            }
+        );
+    });
+
+    $(table).on('click', '.template-delete', function() {
+        var button = $(this);
+        var pk = button.attr('pk');
+
+        var html = `
+        <div class='alert alert-block alert-danger'>
+            {% trans "Any parameters which reference this template will also be deleted" %}
+        </div>`;
+
+        constructForm(
+            `/api/part/parameter/template/${pk}/`,
+            {
+                method: 'DELETE',
+                preFormContent: html,
+                title: '{% trans "Delete Part Parameter Template" %}',
+                refreshTable: table,
+            }
+        );
+    });
+}
+
+
 /*
  * Construct a table showing a list of purchase orders for a given part.
  *
@@ -1663,6 +1781,12 @@ function loadRelatedPartsTable(table, part_id, options={}) {
  */
 function loadParametricPartTable(table, options={}) {
 
+    options.params = options.params || {};
+
+    options.params['parameters'] = true;
+
+    let filters = loadTableFilters('parameters', options.params);
+
     setupFilterList('parameters', $(table), '#filter-list-parameters');
 
     var columns = [
@@ -1691,11 +1815,18 @@ function loadParametricPartTable(table, options={}) {
             async: false,
             success: function(response) {
                 for (var template of response) {
+
+                    let template_name = template.name;
+
+                    if (template.units) {
+                        template_name += ` [${template.units}]`;
+                    }
+
                     columns.push({
                         field: `parameter_${template.pk}`,
-                        title: template.name,
+                        title: template_name,
                         switchable: true,
-                        sortable: false,
+                        sortable: true,
                         filterControl: 'input',
                     });
                 }
@@ -1703,20 +1834,21 @@ function loadParametricPartTable(table, options={}) {
         }
     );
 
-    // TODO: Re-enable filter control for parameter values
 
     $(table).inventreeTable({
         url: '{% url "api-part-list" %}',
-        queryParams: {
+        queryParams: filters,
-            category: options.category,
+        original: options.params,
-            cascade: true,
-            parameters: true,
-        },
         groupBy: false,
         name: options.name || 'part-parameters',
         formatNoMatches: function() {
             return '{% trans "No parts found" %}';
         },
+        // TODO: Re-enable filter control for parameter values
+        // Ref: https://github.com/inventree/InvenTree/issues/4851
+        // filterControl: true,
+        // showFilterControlSwitch: true,
+        // sortSelectOptions: true,
         columns: columns,
         showColumns: true,
         sidePagination: 'server',
@@ -1751,8 +1883,8 @@ function loadParametricPartTable(table, options={}) {
 }
 
 
-function partGridTile(part) {
 // Generate a "grid tile" view for a particular part
+function partGridTile(part) {
 
     // Rows for table view
     var rows = '';
@@ -1822,6 +1954,8 @@ function partGridTile(part) {
  */
 function loadPartTable(table, url, options={}) {
 
+    options.params = options.params || {};
+
     // Ensure category detail is included
     options.params['category_detail'] = true;
 

InvenTree/templates/js/translated/status_codes.js

@@ -55,7 +55,6 @@ function renderStatusLabel(key, codes, options={}) {
     return `<span class='${classes}'>${text}</span>`;
 }
 
-
 {% include "status_codes.html" with label='stock' data=StockStatus.list %}
 {% include "status_codes.html" with label='stockHistory' data=StockHistoryCode.list %}
 {% include "status_codes.html" with label='build' data=BuildStatus.list %}

InvenTree/templates/js/translated/table_filters.js

@@ -700,6 +700,19 @@ function getCompanyFilters() {
 }
 
 
+// Return a dictionary of filters for the "part parameter template" table
+function getPartParameterTemplateFilters() {
+    return {};
+}
+
+
+// Return a dictionary of filters for the "parameteric part" table
+function getParametricPartTableFilters() {
+    let filters = getPartTableFilters();
+
+    return filters;
+}
+
 
 // Return a dictionary of filters for a given table, based on the name of the table
 function getAvailableTableFilters(tableKey) {
@@ -723,6 +736,10 @@ function getAvailableTableFilters(tableKey) {
         return getBuildItemTableFilters();
     case 'location':
         return getStockLocationFilters();
+    case 'parameters':
+        return getParametricPartTableFilters();
+    case 'part-parameter-templates':
+        return getPartParameterTemplateFilters();
     case 'parts':
         return getPartTableFilters();
     case 'parttests':

docs/docs/credits.md

@@ -44,6 +44,7 @@ InvenTree relies on the following Python libraries:
 | [coveralls](https://pypi.org/project/coveralls/) | MIT | coverage uploader |
 | [django-formtools](https://pypi.org/project/django-formtools/) | MIT | better forms / wizards |
 | [django-allauth](https://pypi.org/project/django-allauth/) | MIT | SSO for django |
+| [pint](https://pint.readthedocs.io/en/stable/) | [licence](https://github.com/hgrecco/pint/blob/master/LICENSE) | Physical unit conversion |
 
 ## Frontend libraries
 

docs/docs/part/parameter.md

@@ -4,26 +4,30 @@ title: Part Parameters
 
 ## Part Parameters
 
+A part *parameter* describes a particular "attribute" or "property" of a specific part.
+
 Part parameters are located in the "Parameters" tab, on each part detail page.
-There is no limit for the number of part parameters and they are fully customizable through the use of parameters templates.
+There is no limit for the number of part parameters and they are fully customizable through the use of [parameters templates](#parameter-templates).
 
 Here is an example of parameters for a capacitor:
 {% with id="part_parameters_example", url="part/part_parameters_example.png", description="Part Parameters Example List" %}
 {% include 'img.html' %}
 {% endwith %}
 
-### Create Template
+## Parameter Templates
 
-A *Parameter Template* is required for each part parameter.
+Parameter templates are used to define the different types of parameters which are available for use. These are edited via the [settings interface](../settings/global.md).
+
+### Create Template
 
 To create a template:
 
-- navigate to the "Settings" page
+- Navigate to the "Settings" page
-- click on the "Parts" tab
+- Click on the "Parts" tab
-- scroll down to the "Part Parameter Templates" section
+- Scroll down to the "Part Parameter Templates" section
-- click on the "New Parameter" button
+- Click on the "New Parameter" button
-- fill out the `Create Part Parameter Template` form: `Name` (required) and `Units` (optional) fields
+- Fill out the `Create Part Parameter Template` form: `Name` (required) and `Units` (optional) fields
-- finally click on the "Submit" button.
+- Click on the "Submit" button.
 
 ### Create Parameter
 
@@ -37,9 +41,9 @@ To add a parameter, navigate to a specific part detail page, click on the "Param
 
 Select the parameter `Template` you would like to use for this parameter, fill-out the `Data` field (value of this specific parameter) and click the "Submit" button.
 
-### Parametric Tables
+## Parametric Tables
 
-Parametric tables gather all parameters from all parts inside a category to be sorted and filtered.
+Parametric tables gather all parameters from all parts inside a particular [part category](./part.md#part-category) to be sorted and filtered.
 
 To access a category's parametric table, click on the "Parameters" tab within the category view:
 
@@ -52,3 +56,36 @@ Below is an example of capacitor parametric table filtered with `Package Type =
 {% with id="parametric_table_example", url="part/parametric_table_example.png", description="Parametric Table Example" %}
 {% include 'img.html' %}
 {% endwith %}
+
+### Sorting by Parameter Value
+
+The parametric parts table allows the returned parts to be sorted by particular parameter values. Click on the header of a particular parameter column to sort results by that parameter:
+
+{% with id="sort_by_param", url="part/part_sort_by_param.png", description="Sort by Parameter" %}
+{% include 'img.html' %}
+{% endwith %}
+
+## Parameter Units
+
+The *units* field (which is defined against a [parameter template](#parameter-templates)) defines the base unit of that template. Any parameters which are created against that unit *must* be specified in compatible units. Unit conversion is implemented using the [pint](https://pint.readthedocs.io/en/stable/) Python library. This conversion library is used to perform two main functions:
+
+- Enforce use of compatible units when creating part parameters
+- Perform conversion to the base template unit
+
+The in-built conversion functionality means that parameter values can be input in different dimensions - *as long as the dimension is compatible with the base template units*.
+
+### Incompatible Units
+
+If a part parameter is created with a value which is incompatible with the units specified for the template, it will be rejected:
+
+{% with id="invalid_units", url="part/part_invalid_units.png", description="Invalid Parameter Units" %}
+{% include 'img.html' %}
+{% endwith %}
+
+### Parameter Sorting
+
+Parameter sorting takes unit conversion into account, meaning that values provided in different (but compatible) units are sorted correctly:
+
+{% with id="sort_by_param_units", url="part/part_sorting_units.png", description="Sort by Parameter Units" %}
+{% include 'img.html' %}
+{% endwith %}

requirements.in

@@ -33,6 +33,7 @@ feedparser                              # RSS newsfeed parser
 gunicorn                                # Gunicorn web server
 pdf2image                               # PDF to image conversion
 pillow                                  # Image manipulation
+pint                                    # Unit conversion
 python-barcode[images]                  # Barcode generator
 qrcode[pil]                             # QR code generator
 rapidfuzz==0.7.6                        # Fuzzy string matching

requirements.txt

@@ -186,6 +186,8 @@ pillow==9.5.0
     #   python-barcode
     #   qrcode
     #   weasyprint
+pint==0.21
+    # via -r requirements.in
 py-moneyed==1.2
     # via
     #   -r requirements.in