Using the polymorphic inlines for Django admin instead of the regular one

src/personalisation/admin.py

@@ -1,36 +1,40 @@
 from django.contrib import admin
 
 from personalisation import models
+from polymorphic.admin import PolymorphicInlineSupportMixin, StackedPolymorphicInline
+
+class RulesInline(StackedPolymorphicInline):
+
+    class TimeRuleAdminInline(StackedPolymorphicInline.Child):
+        """Inline the Time Rule into the administration interface for segments"""
+        model = models.TimeRule
+        extra = 0
 
 
-class TimeRuleAdminInline(admin.TabularInline):
+    class ReferralRuleAdminInline(StackedPolymorphicInline.Child):
-    """Inline the Time Rule into the administration interface for segments"""
+        """
-    model = models.TimeRule
+        Inline the Referral Rule into the administration interface for segments
-    extra = 0
+        """
+        model = models.ReferralRule
+        extra = 0
 
 
-class ReferralRuleAdminInline(admin.TabularInline):
+    class VisitCountRuleAdminInline(StackedPolymorphicInline.Child):
-    """
+        """
-    Inline the Referral Rule into the administration interface for segments
+        Inline the Visit Count Rule into the administration interface for segments
-    """
+        """
-    model = models.ReferralRule
+        model = models.VisitCountRule
-    extra = 0
+        extra = 0
 
 
-class VisitCountRuleAdminInline(admin.TabularInline):
+    model = models.AbstractBaseRule
-    """
+    child_inlines = (
-    Inline the Visit Count Rule into the administration interface for segments
+        TimeRuleAdminInline,
-    """
+        ReferralRuleAdminInline,
-    model = models.VisitCountRule
+        VisitCountRuleAdminInline,
-    extra = 0
-
-
-class SegmentAdmin(admin.ModelAdmin):
-    """Add the inlines to the Segment admin interface"""
-    inlines = (
-        TimeRuleAdminInline, ReferralRuleAdminInline,
-        VisitCountRuleAdminInline
     )
 
 
-admin.site.register(models.Segment, SegmentAdmin)
+@admin.register(models.Segment)
+class SegmentAdmin(PolymorphicInlineSupportMixin, admin.ModelAdmin):
+    inlines = (RulesInline,)

src/personalisation/models.py

@@ -14,10 +14,9 @@ from modelcluster.fields import ParentalKey
 from modelcluster.models import ClusterableModel
 from polymorphic.models import PolymorphicModel
 from wagtail.utils.decorators import cached_classmethod
-from wagtail.wagtailadmin.edit_handlers import (FieldPanel, FieldRowPanel,
+from wagtail.wagtailadmin.edit_handlers import (
-                                                InlinePanel, MultiFieldPanel,
+    FieldPanel, FieldRowPanel, InlinePanel, MultiFieldPanel, ObjectList,
-                                                ObjectList, PageChooserPanel,
+    PageChooserPanel, TabbedInterface)
-                                                TabbedInterface)
 from wagtail.wagtailadmin.forms import WagtailAdminPageForm
 from wagtail.wagtailcore.models import Page
 
@@ -26,7 +25,7 @@ from wagtail.wagtailcore.models import Page
 class AbstractBaseRule(PolymorphicModel):
     """Base for creating rules to segment users with"""
     segment = ParentalKey(
-        'Segment',
+        'personalisation.Segment',
         # TODO: Make the related names accesible to wagtail admin
         # for inlining them.
         related_name="%(app_label)s_%(class)s_related",