Add a new kernel subscriber to wrap old-style controllers in a closure to...

Add a new kernel subscriber to wrap old-style controllers in a closure to avoid dynamic argument issues.  This is a BC shim only.

core/lib/Drupal/Core/DrupalKernel.php

@@ -7,8 +7,8 @@
 use Symfony\Component\Routing\RequestContext;
 use Symfony\Component\HttpKernel\HttpKernelInterface;
 use Symfony\Component\HttpKernel\HttpKernel;
-use Symfony\Component\HttpKernel\Controller\ControllerResolver;
 use Symfony\Component\HttpKernel\KernelEvents;
+use Symfony\Component\HttpKernel\Controller\ControllerResolver;
 use Symfony\Component\EventDispatcher\EventDispatcher;
 use Symfony\Component\EventDispatcher\Event;
 use Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent;
@@ -17,6 +17,7 @@
 use Drupal\Core\EventSubscriber\HtmlSubscriber;
 use Drupal\Core\EventSubscriber\AccessSubscriber;
 use Drupal\Core\EventSubscriber\PathSubscriber;
+use Drupal\Core\EventSubscriber\LegacyControllerSubscriber;
 
 use Exception;
 
@@ -47,6 +48,7 @@ function handle(Request $request, $type = self::MASTER_REQUEST, $catch = true) {
       $dispatcher->addSubscriber(new RouterListener($matcher));
       $dispatcher->addSubscriber(new AccessSubscriber());
       $dispatcher->addSubscriber(new PathSubscriber());
+      $dispatcher->addSubscriber(new LegacyControllerSubscriber());
 
       $resolver = new ControllerResolver();
 

core/lib/Drupal/Core/EventSubscriber/LegacyControllerSubscriber.php

+<?php
+
+namespace Drupal\Core\EventSubscriber;
+
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpKernel\KernelEvents;
+use Symfony\Component\HttpKernel\Event\FilterControllerEvent;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+
+/**
+ * @file
+ *
+ * Definition of Drupal\Core\EventSubscriber\LegacyControllerSubscriber
+ */
+
+/**
+ * Access subscriber for controller requests.
+ */
+class LegacyControllerSubscriber implements EventSubscriberInterface {
+
+  /**
+   * Wraps legacy controllers in a closure to handle old-style arguments.
+   *
+   * This is a backward compatibility layer only.  This is a rather ugly way
+   * to piggyback Drupal's existing menu router items onto the Symfony model,
+   * but it works for now.  If we did not do this, any menu router item with
+   * a variable number of arguments would fail to work.  This bypasses Symfony's
+   * controller argument handling entirely and lets the old-style approach work.
+   *
+   * @todo Convert Drupal to use the IETF-draft-RFC style {placeholders}. That
+   * will allow us to use the native Symfony conversion, including out-of-order
+   * argument mapping, name-based mapping, and with another listener
+   * auto-conversion of parameters to full objects.  That may necessitate not
+   * using func_get_args()-based controllers.  That is likely for the best,
+   * as those are quite hard to document anyway.
+   *
+   * @param GetResponseEvent $event
+   *   The Event to process.
+   */
+  public function onKernelControllerLegacy(FilterControllerEvent $event) {
+    $router_item = $event->getRequest()->attributes->get('drupal_menu_item');
+    $controller = $event->getController();
+
+    // This BC logic applies only to functions.  Otherwise, skip it.
+    if (function_exists($controller)) {
+      $new_controller = function() use ($router_item) {
+        return call_user_func_array($router_item['page_callback'], $router_item['page_arguments']);
+      };
+      $event->setController($new_controller);
+    }
+  }
+
+  /**
+   * Registers the methods in this class that should be listeners.
+   *
+   * @return array
+   *   An array of event listener definitions.
+   */
+  static function getSubscribedEvents() {
+    $events[KernelEvents::CONTROLLER][] = array('onKernelControllerLegacy', 30);
+
+    return $events;
+  }
+}