[Messenger] Document the validation middleware

94noni · 94noni · commit dd3f8035edc4 · 2021-12-28T14:13:49.000+01:00
diff --git a/messenger.rst b/messenger.rst
@@ -2256,6 +2256,7 @@ when building absolute URLs.
                     command_bus:
                         middleware:
                             - router_context
+                            - validation
 
     .. code-block:: xml
 
@@ -2273,6 +2274,7 @@ when building absolute URLs.
                 <framework:messenger>
                     <framework:bus name="command_bus">
                         <framework:middleware id="router_context"/>
+                        <framework:middleware id="validation"/>
                     </framework:bus>
                 </framework:messenger>
             </framework:config>
@@ -2288,9 +2290,15 @@ when building absolute URLs.
 
             $bus = $messenger->bus('command_bus');
             $bus->middleware()->id('router_context');
+            $bus->middleware()->id('validation');
         };
 
 
+Add the ``validation`` middleware if you need to validate the message object before handling it.
+Internally it uses the Symfony's validator. If validation fails, a ``ValidationFailedException``
+will be thrown that you can catch and read errors from.
+
+
 Messenger Events
 ~~~~~~~~~~~~~~~~
 
