Use external modeladmin package where available

Author: gasman

README.rst

@@ -11,7 +11,32 @@ This module supports the creation of A/B testing experiments within a Wagtail si
 Installation
 ------------
 
-wagtail-experiments is compatible with Wagtail 4.1 to 5.1, and Django 3.2 to 4.2. To install::
+wagtail-experiments is compatible with Wagtail 4.1 to 5.2, and Django 3.2 to 4.2. It depends on the Wagtail ModelAdmin module, which is available as an external package as of Wagtail 5.0; we recommend using this rather than the bundled `wagtail.contrib.modeladmin` module to avoid deprecation warnings. The external package will be required as of Wagtail 6.0.
+
+### On Wagtail 5.0 and above
+
+To install::
+
+    pip install wagtail-experiments wagtail-modeladmin
+
+and ensure that the apps ``wagtail_modeladmin`` and ``experiments`` are included in your project's ``INSTALLED_APPS``:
+
+.. code-block:: python
+
+    INSTALLED_APPS = [
+        # ...
+        'wagtail_modeladmin',
+        'experiments',
+        # ...
+    ]
+
+Then migrate::
+
+    ./manage.py migrate
+
+### On Wagtail 4.x
+
+To install::
 
     pip install wagtail-experiments
 

experiments/wagtail_hooks.py

@@ -4,11 +4,18 @@
 
 from django.utils.translation import gettext_lazy as _
 from experiments import admin_urls
-from wagtail.contrib.modeladmin.helpers import ButtonHelper
-from wagtail.contrib.modeladmin.options import ModelAdmin, modeladmin_register
-from wagtail.contrib.modeladmin.views import CreateView, EditView
 from wagtail import hooks
 
+try:
+    from wagtail_modeladmin.helpers import ButtonHelper
+    from wagtail_modeladmin.options import ModelAdmin, modeladmin_register
+    from wagtail_modeladmin.views import CreateView, EditView
+except ImportError:
+    from wagtail.contrib.modeladmin.helpers import ButtonHelper
+    from wagtail.contrib.modeladmin.options import ModelAdmin, modeladmin_register
+    from wagtail.contrib.modeladmin.views import CreateView, EditView
+
+
 from .models import Experiment
 from .utils import get_user_id, impersonate_other_page
 

tests/settings.py

@@ -3,6 +3,14 @@
 
 from wagtail import VERSION as WAGTAIL_VERSION
 
+try:
+    import wagtail_modeladmin
+except ImportError:
+    HAS_MODELADMIN_PACKAGE = False
+else:
+    HAS_MODELADMIN_PACKAGE = True
+
+
 DATABASES = {
     'default': {
         'ENGINE': os.environ.get('DATABASE_ENGINE', 'django.db.backends.sqlite3'),
@@ -64,7 +72,7 @@
     'experiments',
     'tests',
 
-    'wagtail.contrib.modeladmin',
+    'wagtail_modeladmin' if HAS_MODELADMIN_PACKAGE else 'wagtail.contrib.modeladmin',
     'wagtail.search',
     'wagtail.sites',
     'wagtail.users',