[HttpFoundation] document Request::getPayload()

Author: kbond

components/http_foundation.rst

@@ -216,6 +216,17 @@ If the request body is a JSON string, it can be accessed using
 
     $data = $request->toArray();
 
+If the request data could be $_POST data *or* a JSON string, you can use
+:method:`Symfony\\Component\\HttpFoundation\\Request::getPayload`
+which returns an instance of :class:`Symfony\\Component\\HttpFoundation\\InputBag`
+wrapping this data::
+
+    $data = $request->getPayload();
+
+.. versionadded:: 6.3
+
+    The ``Request::getPayload()`` method was introduced in Symfony 6.3.
+
 Identifying a Request
 ~~~~~~~~~~~~~~~~~~~~~