Documented the new kernel.controller_arguments event

components/http_kernel/introduction.rst

@@ -306,6 +306,8 @@ on the event object that's passed to listeners on this event.
     those to objects, which are then stored in the ``attributes`` property of
     the ``Request`` object. Read the next section to see why this is important.
 
+.. _component-http-kernel-kernel-controller-arguments:
+
 4) Getting the Controller Arguments
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -341,6 +343,13 @@ of arguments that should be passed when executing that callable.
        :class:`Symfony\\Component\\HttpFoundation\\Request` object, then the
        ``Request`` is passed in as the value.
 
+.. versionadded:: 3.1
+     The ``kernel.controller_arguments`` event was introduced in Symfony 3.1.
+
+Once controller arguments have been resolved by Symfony, the ``kernel.controller_arguments``
+event is triggered. This allows to modify or replace the arguments to fit your
+application needs.
+
 .. _component-http-kernel-calling-controller:
 
 5) Calling the Controller

reference/events.rst

@@ -80,6 +80,33 @@ Listener Class Name
 :class:`Symfony\\Bundle\\FrameworkBundle\\DataCollector\\RequestDataCollector`  0
 ==============================================================================  ========
 
+``kernel.controller_arguments``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. versionadded:: 3.1
+     The ``kernel.controller_arguments`` event was introduced in Symfony 3.1.
+
+**Event Class**: :class:`Symfony\\Component\\HttpKernel\\Event\\FilterControllerArgumentsEvent`
+
+This event can be an entry point used to modify the arguments of the controller
+once they have been resolved by Symfony::
+
+    use Symfony\Component\HttpKernel\Event\FilterControllerArgumentsEvent;
+
+    public function onKernelControllerArguments(FilterControllerArgumentsEvent $event)
+    {
+        $controller = $event->getController();
+        $arguments = $event->getArguments();
+        // ...
+
+        // the arguments can be changed as needed
+        $event->setArguments(array('foo', 'bar'));
+    }
+
+.. seealso::
+
+    Read more on the :ref:`kernel.controller_arguments event <component-http-kernel-kernel-controller-arguments>`.
+
 ``kernel.view``
 ~~~~~~~~~~~~~~~