Fixes #4613: Fix tag assignment on config contexts (regression from #4527)

netbox/extras/forms.py

@@ -2,7 +2,7 @@ from django import forms
 from django.contrib.auth.models import User
 from django.contrib.contenttypes.models import ContentType
 from mptt.forms import TreeNodeMultipleChoiceField
-from taggit.forms import TagField
+from taggit.forms import TagField as TagField_
 
 from dcim.models import DeviceRole, Platform, Region, Site
 from tenancy.models import Tenant, TenantGroup
@@ -142,6 +142,15 @@ class CustomFieldFilterForm(forms.Form):
 # Tags
 #
 
+class TagField(TagField_):
+
+    def widget_attrs(self, widget):
+        # Apply the "tagfield" CSS class to trigger the special API-based selection widget for tags
+        return {
+            'class': 'tagfield'
+        }
+
+
 class TagForm(BootstrapMixin, forms.ModelForm):
     slug = SlugField()