Adds support for multi select custom fields

docs/release-notes/version-2.10.md

@@ -62,6 +62,7 @@ All end-to-end cable paths are now cached using the new CablePath backend model.
 
 ### Enhancements
 
+* [#5451](https://github.com/netbox-community/netbox/issues/5451) - Add ability to create multi selection custom fields
 * [#609](https://github.com/netbox-community/netbox/issues/609) - Add min/max value and regex validation for custom fields
 * [#1503](https://github.com/netbox-community/netbox/issues/1503) - Allow assigment of secrets to virtual machines
 * [#1692](https://github.com/netbox-community/netbox/issues/1692) - Allow assigment of inventory items to parent items in web UI

netbox/extras/admin.py

@@ -114,7 +114,7 @@ class CustomFieldAdmin(admin.ModelAdmin):
         }),
         ('Choices', {
             'description': 'A selection field must have two or more choices assigned to it.',
-            'fields': ('choices',)
+            'fields': ('choices','multiple_selection')
         })
     )
 

netbox/extras/models/customfields.py

@@ -12,7 +12,7 @@ from django.utils.safestring import mark_safe
 
 from extras.choices import *
 from extras.utils import FeatureQuery
-from utilities.forms import CSVChoiceField, DatePicker, LaxURLField, StaticSelect2, add_blank_choice
+from utilities.forms import CSVChoiceField, DatePicker, LaxURLField, StaticSelect2Multiple, StaticSelect2, add_blank_choice
 from utilities.querysets import RestrictedQuerySet
 from utilities.validators import validate_regex
 
@@ -151,6 +151,10 @@ class CustomField(models.Model):
         null=True,
         help_text='Comma-separated list of available choices (for selection fields)'
     )
+    multiple_selection = models.BooleanField(
+        default=False,
+        help_text='Allow multiple choice selection'
+    )
 
     objects = CustomFieldManager()
 
@@ -203,6 +207,12 @@ class CustomField(models.Model):
                 'choices': "Choices may be set only for custom selection fields."
             })
 
+        # Multiple selection can only be set for selection fields
+        if self.multiple_selection and self.type != CustomFieldTypeChoices.TYPE_SELECT:
+            raise ValidationError({
+                'multiple_selection': "Multiple selection can only be set for selection fields."
+            })
+
         # A selection field must have at least two choices defined
         if self.type == CustomFieldTypeChoices.TYPE_SELECT and self.choices and len(self.choices) < 2:
             raise ValidationError({
@@ -262,9 +272,13 @@ class CustomField(models.Model):
             if set_initial and default_choice:
                 initial = default_choice
 
-            field_class = CSVChoiceField if for_csv_import else forms.ChoiceField
+            # Use multiple choice field if multi_selection is enabled
+            default_field_class = forms.MultipleChoiceField if self.multiple_selection else forms.ChoiceField
+            select_widget = StaticSelect2Multiple() if self.multiple_selection else StaticSelect2()
+
+            field_class = CSVChoiceField if for_csv_import else default_field_class
             field = field_class(
-                choices=choices, required=required, initial=initial, widget=StaticSelect2()
+                choices=choices, required=required, initial=initial, widget=select_widget
             )
 
         # URL
@@ -324,10 +338,14 @@ class CustomField(models.Model):
 
             # Validate selected choice
             if self.type == CustomFieldTypeChoices.TYPE_SELECT:
-                if value not in self.choices:
-                    raise ValidationError(
-                        f"Invalid choice ({value}). Available choices are: {', '.join(self.choices)}"
-                    )
+                if not isinstance(value, list):
+                    value = [value]
+
+                for val in value:
+                    if val not in self.choices:
+                        raise ValidationError(
+                            f"Invalid choice ({value}). Available choices are: {', '.join(self.choices)}"
+                        )
 
         elif self.required:
             raise ValidationError("Required field cannot be empty.")

netbox/extras/tests/test_customfields.py

@@ -90,6 +90,38 @@ class CustomFieldTest(TestCase):
         # Delete the custom field
         cf.delete()
 
+    def test_multiple_select_field(self):
+        obj_type = ContentType.objects.get_for_model(Site)
+
+        # Create a custom field
+        cf = CustomField(
+            type=CustomFieldTypeChoices.TYPE_SELECT,
+            name='my_field',
+            required=False,
+            choices=['Option A', 'Option B', 'Option C'],
+            multiple_selection=True
+        )
+        cf.save()
+        cf.content_types.set([obj_type])
+
+        # Assign a value to the first Site
+        site = Site.objects.first()
+        site.custom_field_data[cf.name] = ['Option A', 'Option B']
+        site.save()
+
+        # Retrieve the stored value
+        site.refresh_from_db()
+        self.assertEqual(site.custom_field_data[cf.name], ['Option A', 'Option B'])
+
+        # Delete the stored value
+        site.custom_field_data.pop(cf.name)
+        site.save()
+        site.refresh_from_db()
+        self.assertIsNone(site.custom_field_data.get(cf.name))
+
+        # Delete the custom field
+        cf.delete()
+
 
 class CustomFieldManagerTest(TestCase):
 

netbox/templates/inc/custom_fields_panel.html

@@ -15,6 +15,8 @@
                                 <i class="mdi mdi-close-thick text-danger" title="False"></i>
                             {% elif field.type == 'url' and value %}
                                 <a href="{{ value }}">{{ value|truncatechars:70 }}</a>
+                            {% elif field.type == 'select' and field.multiple_selection == True and value is not None %}
+                                {{ value|join:", " }}
                             {% elif value is not None %}
                                 {{ value }}
                             {% elif field.required %}