From 981615c6b55bdd2860c6281d4521627de90274dd Mon Sep 17 00:00:00 2001
From: Matthias Kestenholz <mk@feinheit.ch>
Date: Wed, 23 Feb 2022 11:51:52 +0100
Subject: [PATCH] Refs #33328 -- Added some advice regarding handling
 formset:added/removed in 3rd party libraries

---
 docs/ref/contrib/admin/javascript.txt | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/docs/ref/contrib/admin/javascript.txt b/docs/ref/contrib/admin/javascript.txt
index ce94176691..ae1e546461 100644
--- a/docs/ref/contrib/admin/javascript.txt
+++ b/docs/ref/contrib/admin/javascript.txt
@@ -50,3 +50,29 @@ Two points to keep in mind:
 * ``{{ block.super }}`` is added because Django's
   ``admin_change_form_document_ready`` block contains JavaScript code to handle
   various operations in the change form and we need that to be rendered too.
+
+Supporting versions of Django older than 4.1
+--------------------------------------------
+
+If your event listener still has to support older versions of Django you have
+to use jQuery to register your event listener. jQuery handles JavaScript events
+but the reverse isn't true.
+
+You could check for the presence of ``event.detail.formsetName`` and fall back
+to the old listener signature as follows:
+
+.. code-block:: javascript
+
+    function handleFormsetAdded(row, formsetName) {
+        // Do something
+    }
+
+    $(document).on('formset:added', (event, $row, formsetName) => {
+        if (event.detail.formsetName) {
+            // Django >= 4.1
+            handleFormsetAdded(event.target, event.detail.formsetName)
+        } else {
+            // Django < 4.1, use $row and formsetName
+            handleFormsetAdded($row.get(0), formsetName)
+        }
+    })