Closes #7619: Permit custom validation rules to be defined as plain data or dotted path to class

netbox/extras/signals.py

@@ -1,3 +1,4 @@
+import importlib
 import logging
 
 from django.conf import settings
@@ -6,6 +7,7 @@ from django.db.models.signals import m2m_changed, post_save, pre_delete
 from django.dispatch import receiver, Signal
 from django_prometheus.models import model_deletes, model_inserts, model_updates
 
+from extras.validators import CustomValidator
 from netbox.signals import post_clean
 from .choices import ObjectChangeActionChoices
 from .models import ConfigRevision, CustomField, ObjectChange
@@ -159,7 +161,18 @@ m2m_changed.connect(handle_cf_removed_obj_types, sender=CustomField.content_type
 def run_custom_validators(sender, instance, **kwargs):
     model_name = f'{sender._meta.app_label}.{sender._meta.model_name}'
     validators = settings.CUSTOM_VALIDATORS.get(model_name, [])
+
     for validator in validators:
+
+        # Loading a validator class by dotted path
+        if type(validator) is str:
+            module, cls = validator.rsplit('.', 1)
+            validator = getattr(importlib.import_module(module), cls)()
+
+        # Constructing a new instance on the fly from a ruleset
+        elif type(validator) is dict:
+            validator = CustomValidator(validator)
+
         validator(instance)
 
 

netbox/extras/tests/test_customvalidator.py

@@ -119,3 +119,38 @@ class CustomValidatorTest(TestCase):
     @override_settings(CUSTOM_VALIDATORS={'dcim.site': [custom_validator]})
     def test_custom_valid(self):
         Site(name='foo', slug='foo').clean()
+
+
+class CustomValidatorConfigTest(TestCase):
+
+    @override_settings(
+        CUSTOM_VALIDATORS={
+            'dcim.site': [
+                {'name': {'min_length': 5}}
+            ]
+        }
+    )
+    def test_plain_data(self):
+        """
+        Test custom validator configuration using plain data (as opposed to a CustomValidator
+        class)
+        """
+        with self.assertRaises(ValidationError):
+            Site(name='abcd', slug='abcd').clean()
+        Site(name='abcde', slug='abcde').clean()
+
+    @override_settings(
+        CUSTOM_VALIDATORS={
+            'dcim.site': (
+                'extras.tests.test_customvalidator.MyValidator',
+            )
+        }
+    )
+    def test_dotted_path(self):
+        """
+        Test custom validator configuration using a dotted path (string) reference to a
+        CustomValidator class.
+        """
+        Site(name='foo', slug='foo').clean()
+        with self.assertRaises(ValidationError):
+            Site(name='bar', slug='bar').clean()