Closes: #16837 - Add EmptyStringFilter and type__empty filter on CableFilterSet

netbox/dcim/choices.py

@@ -1504,8 +1504,12 @@ class CableTypeChoices(ChoiceSet):
                 (TYPE_AOC, 'Active Optical Cabling (AOC)'),
             ),
         ),
-        (TYPE_USB, _('USB')),
-        (TYPE_POWER, _('Power')),
+        (
+            _('Other'), (
+                (TYPE_USB, _('USB')),
+                (TYPE_POWER, _('Power')),
+            )
+        )
     )
 
 

netbox/dcim/filtersets.py

@@ -18,7 +18,7 @@
 from users.models import User
 from utilities.filters import (
     ContentTypeFilter, MultiValueCharFilter, MultiValueMACAddressFilter, MultiValueNumberFilter, MultiValueWWNFilter,
-    NumericArrayFilter, TreeNodeMultipleChoiceFilter,
+    NumericArrayFilter, TreeNodeMultipleChoiceFilter, NullableMultipleChoiceFilter,
 )
 from virtualization.models import Cluster, ClusterGroup
 from vpn.models import L2VPN
@@ -1980,7 +1980,7 @@ class CableFilterSet(TenancyFilterSet, NetBoxModelFilterSet):
         method='_unterminated',
         label=_('Unterminated'),
     )
-    type = django_filters.MultipleChoiceFilter(
+    type = NullableMultipleChoiceFilter(
         choices=CableTypeChoices
     )
     status = django_filters.MultipleChoiceFilter(

netbox/dcim/forms/filtersets.py

@@ -10,7 +10,7 @@
 from netbox.forms import NetBoxModelFilterSetForm
 from tenancy.forms import ContactModelFilterForm, TenancyFilterForm
 from users.models import User
-from utilities.forms import BOOLEAN_WITH_BLANK_CHOICES, FilterForm, add_blank_choice
+from utilities.forms import BOOLEAN_WITH_BLANK_CHOICES, FilterForm, add_blank_choice, add_empty_filtering_choice
 from utilities.forms.fields import ColorField, DynamicModelMultipleChoiceField, TagFilterField
 from utilities.forms.rendering import FieldSet
 from utilities.forms.widgets import NumberWithOptions
@@ -1052,7 +1052,7 @@ class CableFilterForm(TenancyFilterForm, NetBoxModelFilterSetForm):
     )
     type = forms.MultipleChoiceField(
         label=_('Type'),
-        choices=add_blank_choice(CableTypeChoices),
+        choices=add_empty_filtering_choice(add_blank_choice(CableTypeChoices)),
         required=False
     )
     status = forms.MultipleChoiceField(

netbox/dcim/tests/test_filtersets.py

@@ -1,4 +1,5 @@
 from django.test import TestCase
+from django.conf import settings
 
 from circuits.models import Circuit, CircuitTermination, CircuitType, Provider
 from dcim.choices import *
@@ -5247,6 +5248,10 @@ def test_length_unit(self):
     def test_type(self):
         params = {'type': [CableTypeChoices.TYPE_CAT3, CableTypeChoices.TYPE_CAT5E]}
         self.assertEqual(self.filterset(params, self.queryset).qs.count(), 4)
+        params = {'type': [settings.FILTERS_NULL_CHOICE_VALUE]}
+        self.assertEqual(self.filterset(params, self.queryset).qs.count(), 8)
+        params = {'type': [settings.FILTERS_NULL_CHOICE_VALUE, CableTypeChoices.TYPE_CAT3]}
+        self.assertEqual(self.filterset(params, self.queryset).qs.count(), 10)
 
     def test_status(self):
         params = {'status': [LinkStatusChoices.STATUS_CONNECTED]}

netbox/netbox/filtersets.py

@@ -133,7 +133,7 @@ def _get_filter_lookup_dict(existing_filter):
             django_filters.ModelChoiceFilter,
             django_filters.ModelMultipleChoiceFilter,
             TagFilter
-        )) or existing_filter.extra.get('choices'):
+        )):
             # These filter types support only negation
             return FILTER_NEGATION_LOOKUP_MAP
 
@@ -172,21 +172,24 @@ def get_additional_lookups(cls, existing_filter_name, existing_filter):
         # Create new filters for each lookup expression in the map
         for lookup_name, lookup_expr in lookup_map.items():
             new_filter_name = f'{existing_filter_name}__{lookup_name}'
+            existing_filter_extra = deepcopy(existing_filter.extra)
 
             try:
                 if existing_filter_name in cls.declared_filters:
                     # The filter field has been explicitly defined on the filterset class so we must manually
                     # create the new filter with the same type because there is no guarantee the defined type
                     # is the same as the default type for the field
                     resolve_field(field, lookup_expr)  # Will raise FieldLookupError if the lookup is invalid
+                    for field_to_remove in ('choices', 'null_value'):
+                        existing_filter_extra.pop(field_to_remove, None)
                     filter_cls = django_filters.BooleanFilter if lookup_expr == 'empty' else type(existing_filter)
                     new_filter = filter_cls(
                         field_name=field_name,
                         lookup_expr=lookup_expr,
                         label=existing_filter.label,
                         exclude=existing_filter.exclude,
                         distinct=existing_filter.distinct,
-                        **existing_filter.extra
+                        **existing_filter_extra
                     )
                 elif hasattr(existing_filter, 'custom_field'):
                     # Filter is for a custom field

netbox/utilities/filters.py

@@ -18,6 +18,7 @@
     'MultiValueTimeFilter',
     'MultiValueWWNFilter',
     'NullableCharFieldFilter',
+    'NullableMultipleChoiceFilter',
     'NumericArrayFilter',
     'TreeNodeMultipleChoiceFilter',
 )
@@ -143,6 +144,16 @@ def filter(self, qs, value):
         return qs.distinct() if self.distinct else qs
 
 
+class NullableMultipleChoiceFilter(django_filters.MultipleChoiceFilter):
+    """
+    Similar to NullableCharFieldFilter, but allows multiple values including the special NULL string.
+    """
+    def filter(self, qs, value):
+        if settings.FILTERS_NULL_CHOICE_VALUE in value:
+            value.append('')
+        return super().filter(qs, value)
+
+
 class NumericArrayFilter(django_filters.NumberFilter):
     """
     Filter based on the presence of an integer within an ArrayField.

netbox/utilities/forms/utils.py

@@ -1,6 +1,7 @@
 import re
 
 from django import forms
+from django.conf import settings
 from django.forms.models import fields_for_model
 from django.utils.translation import gettext as _
 
@@ -10,6 +11,7 @@
 
 __all__ = (
     'add_blank_choice',
+    'add_empty_filtering_choice',
     'expand_alphanumeric_pattern',
     'expand_ipaddress_pattern',
     'form_from_model',
@@ -189,6 +191,14 @@ def add_blank_choice(choices):
     return ((None, '---------'),) + tuple(choices)
 
 
+def add_empty_filtering_choice(choices):
+    """
+    Add an empty (null) choice to the end of a choices list, to be used in filtering classes
+    such as NullableMultipleChoiceFilter to match on an empty value.
+    """
+    return tuple(choices) + ((settings.FILTERS_NULL_CHOICE_VALUE, '(unset)'),)
+
+
 def form_from_model(model, fields):
     """
     Return a Form class with the specified fields derived from a model. This is useful when we need a form to be used