[Messenger] Routing & Inheritance

Author: sylfabre

messenger.rst

@@ -431,6 +431,35 @@ transport and "sending" messages there to be handled immediately:
             ],
         ]);
 
+Message Inheritance & Routing Configuration
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+With the following code and configuration, messages will be dispatched like this:
+* `Notification` to `async_1`
+* `SmsNotification` to `async_1`
+* `SmsNotification` to `async_2`
+
+.. code-block::php
+
+    <?php
+    namespace App\Message;
+    class SmsNotification extends Notification {}
+
+.. code-block::yaml
+
+    # config/packages/messenger.yaml
+    framework:
+        messenger:
+            routing:
+                App\Message\Notification: async_1
+                App\Message\SmsNotification: async_2
+
+.. code-block::php
+
+    <?php
+    $messageBus->dispatch(new Notification());
+    $messageBus->dispatch(new SmsNotification());
+
 Creating your Own Transport
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~