Add ModelViewSet.add_to_reference_index to allow opting out of the ReferenceIndex

docs/advanced_topics/reference_index.md

@@ -11,7 +11,8 @@ By default, the index will store references between objects managed within the W
 -   all Page types
 -   Images
 -   Documents
--   models registered as Snippets
+-   models registered as [Snippets](snippets)
+-   models registered with [`ModelViewSet`](../extending/generic_views)
 -   models registered with ModelAdmin
 
 The reference index does not require any further configuration. However there are circumstances where it may be necessary to add or remove models from the index.

docs/reference/viewsets.md

@@ -79,6 +79,7 @@ Viewsets are Wagtail's mechanism for defining a group of related admin views wit
       Defaults to the title-cased version of the model's
       :attr:`~django.db.models.Options.verbose_name_plural`.
 
+   .. autoattribute:: add_to_reference_index
    .. autoattribute:: index_view_class
    .. autoattribute:: add_view_class
    .. autoattribute:: edit_view_class

docs/releases/5.2.md

@@ -43,3 +43,7 @@ depth: 1
 ## Upgrade considerations - deprecation of old functionality
 
 ## Upgrade considerations - changes affecting Wagtail customisations
+
+### `ModelViewSet` automatically registers the model to the reference index
+
+Models that are registered with a `ModelViewSet` now have reference index tracking enabled by default. This means that you no longer need to call `ReferenceIndex.register_model()` in your app's `ready()` method for such models. If this is undesired, you can disable it by setting {attr}`~wagtail.admin.viewsets.model.ModelViewSet.add_to_reference_index` to `False` on the `ModelViewSet` subclass. For more details, see [](managing_the_reference_index).

wagtail/admin/viewsets/model.py

@@ -22,6 +22,10 @@ class ModelViewSet(ViewSet):
     are available.
     """
 
+    #: Register the model to the reference index to track its usage.
+    #: For more details, see :ref:`managing_the_reference_index`.
+    add_to_reference_index = True
+
     #: The view class to use for the index view; must be a subclass of ``wagtail.admin.views.generic.IndexView``.
     index_view_class = generic.IndexView
 
@@ -185,7 +189,8 @@ class ModelViewSet(ViewSet):
         register_admin_url_finder(self.model, self.url_finder_class)
 
     def register_reference_index(self):
-        ReferenceIndex.register_model(self.model)
+        if self.add_to_reference_index:
+            ReferenceIndex.register_model(self.model)
 
     def get_urlpatterns(self):
         return super().get_urlpatterns() + [