Adds ContentTypeField

- Handles representation of content type
- Provides human-readable options

src/backend/InvenTree/InvenTree/serializers.py

@@ -7,6 +7,7 @@ from decimal import Decimal
 from typing import Any, Optional
 
 from django.conf import settings
+from django.contrib.contenttypes.models import ContentType
 from django.core.exceptions import ValidationError as DjangoValidationError
 from django.db import models
 from django.utils.translation import gettext_lazy as _
@@ -28,7 +29,7 @@ import InvenTree.ready
 from common.currency import currency_code_default, currency_code_mappings
 from InvenTree.fields import InvenTreeRestURLField, InvenTreeURLField
 from InvenTree.helpers import str2bool
-from InvenTree.helpers_model import getModelChoicesWithMixin
+from InvenTree.helpers_model import getModelsWithMixin
 
 from .setting.storages import StorageBackends
 
@@ -719,7 +720,7 @@ class RemoteImageMixin(metaclass=serializers.SerializerMetaclass):
         return url
 
 
-class ContentTypeField(serializers.Field):
+class ContentTypeField(serializers.ChoiceField):
     """Serializer field which represents a ContentType as 'app_label.model_name'.
 
     This field converts a ContentType instance to a string representation in the format 'app_label.model_name' during serialization, and vice versa during deserialization.
@@ -736,13 +737,26 @@ class ContentTypeField(serializers.Field):
             mixin_class: Optional mixin class to restrict valid content types.
         """
         self.mixin_class = mixin_class
-        super().__init__(*args, **kwargs)
 
         # Override the 'choices' field, to limit to the appropriate models
         if self.mixin_class is not None:
-            self.choices = getModelChoicesWithMixin(
+            models = getModelsWithMixin(self.mixin_class)
-                self.mixin_class, allow_null=kwargs.get('allow_null', False)
+
-            )
+            kwargs['choices'] = [
+                (
+                    f'{model._meta.app_label}.{model._meta.model_name}',
+                    model._meta.verbose_name,
+                )
+                for model in models
+            ]
+        else:
+            content_types = ContentType.objects.all()
+
+            kwargs['choices'] = [
+                (f'{ct.app_label}.{ct.model}', str(ct)) for ct in content_types
+            ]
+
+        super().__init__(*args, **kwargs)
 
     def to_representation(self, value):
         """Convert ContentType instance to string representation."""

src/backend/InvenTree/common/models.py

@@ -2386,11 +2386,6 @@ class ParameterTemplate(
         verbose_name = _('Parameter Template')
         verbose_name_plural = _('Parameter Templates')
 
-    class ModelChoices(RenderChoices):
-        """Model choices for parameter templates."""
-
-        choice_fnc = common.validators.parameter_template_model_options
-
     @staticmethod
     def get_api_url() -> str:
         """Return the API URL associated with the ParameterTemplate model."""

src/backend/InvenTree/common/serializers.py

@@ -21,7 +21,9 @@ from importer.registry import register_importer
 from InvenTree.helpers import get_objectreference
 from InvenTree.helpers_model import construct_absolute_url
 from InvenTree.mixins import DataImportExportSerializerMixin
+from InvenTree.models import InvenTreeParameterMixin
 from InvenTree.serializers import (
+    ContentTypeField,
     FilterableSerializerMixin,
     InvenTreeAttachmentSerializerField,
     InvenTreeImageSerializerField,
@@ -721,22 +723,12 @@ class ParameterTemplateSerializer(
             'enabled',
         ]
 
-    def __init__(self, *args, **kwargs):
-        """Override the model_type field to provide dynamic choices."""
-        super().__init__(*args, **kwargs)
-
-        if len(self.fields['model_type'].choices) == 0:
-            self.fields[
-                'model_type'
-            ].choices = common.validators.parameter_template_model_options()
-
     # Note: The choices are overridden at run-time on class initialization
-    model_type = serializers.ChoiceField(
+    model_type = ContentTypeField(
+        mixin_class=InvenTreeParameterMixin,
         label=_('Model Type'),
         default='',
-        choices=common.validators.parameter_template_model_options(),
         required=False,
-        allow_blank=True,
         allow_null=True,
     )
 
@@ -767,15 +759,6 @@ class ParameterSerializer(
 
         read_only_fields = ['updated', 'updated_by']
 
-    def __init__(self, *args, **kwargs):
-        """Override the model_type field to provide dynamic choices."""
-        super().__init__(*args, **kwargs)
-
-        if len(self.fields['model_type'].choices) == 0:
-            self.fields[
-                'model_type'
-            ].choices = common.validators.parameter_model_options()
-
     def save(self, **kwargs):
         """Save the Parameter instance."""
         from InvenTree.models import InvenTreeParameterMixin
@@ -813,13 +796,11 @@ class ParameterSerializer(
         return instance
 
     # Note: The choices are overridden at run-time on class initialization
-    model_type = serializers.ChoiceField(
+    model_type = ContentTypeField(
+        mixin_class=InvenTreeParameterMixin,
         label=_('Model Type'),
         default='',
-        choices=common.validators.parameter_model_options(),
         required=False,
-        allow_blank=True,
-        allow_null=True,
     )
 
     updated_by_detail = enable_filter(

src/backend/InvenTree/common/validators.py

@@ -9,67 +9,6 @@ import common.icons
 from common.settings import get_global_setting
 
 
-def parameter_model_types():
-    """Return a list of valid parameter model choices."""
-    import InvenTree.models
-
-    return list(
-        InvenTree.helpers_model.getModelsWithMixin(
-            InvenTree.models.InvenTreeParameterMixin
-        )
-    )
-
-
-def parameter_model_options():
-    """Return a list of options for models which support parameters."""
-    return [
-        (model.__name__.lower(), model._meta.verbose_name)
-        for model in parameter_model_types()
-    ]
-
-
-def parameter_template_model_options():
-    """Return a list of options for models which support parameter templates.
-
-    Note: This includes a blank option at the start, since ParameterTemplate.model_type may be blank.
-    """
-    return [('', _('Any model type')), *parameter_model_options()]
-
-
-def parameter_model_class_from_label(label: str):
-    """Return the model class for the given label."""
-    if not label:
-        raise ValidationError(_('No parameter model type provided'))
-
-    for model in parameter_model_types():
-        if model.__name__.lower() == label.lower():
-            return model
-
-    raise ValidationError(_('Invalid parameter model type') + f": '{label}'")
-
-
-def validate_parameter_model_type(value: str):
-    """Ensure that the provided parameter model is valid."""
-    model_names = [el[0] for el in parameter_model_options()]
-    if value not in model_names:
-        raise ValidationError('Model type does not support parameters')
-
-
-def validate_parameter_template_model_type(value: str):
-    """Ensure that the provided model type is valid.
-
-    Note: A ParameterTemplate may have a blank model type.
-    """
-    value = str(value).strip()
-
-    if not value:
-        # Empty values are allowed
-        return
-
-    # Pass any other value to the Parameter model type validator
-    validate_parameter_model_type(value)
-
-
 def attachment_model_types():
     """Return a list of valid attachment model choices."""
     import InvenTree.models