Introduce KernelServiceProvider in order to "hacks"

This introduces a new KernelServiceProvider that is auto registered
by Silex\Application.

The main reason for including this is to remove the ugly
"dispatcher_class" hack we used to have. But since we introduced a
seperate interface for listeners to use for subscribing we can just have
a nice normal service.

src/Silex/Application.php

@@ -20,7 +20,6 @@ use Symfony\Component\HttpKernel\TerminableInterface;
 use Symfony\Component\HttpKernel\Event\FilterResponseEvent;
 use Symfony\Component\HttpKernel\Event\GetResponseEvent;
 use Symfony\Component\HttpKernel\Event\PostResponseEvent;
-use Symfony\Component\HttpKernel\EventListener\ResponseListener;
 use Symfony\Component\HttpKernel\Exception\HttpException;
 use Symfony\Component\HttpKernel\KernelEvents;
 use Symfony\Component\HttpFoundation\Request;
@@ -33,10 +32,8 @@ use Symfony\Component\Routing\RouteCollection;
 use Silex\Api\BootableProviderInterface;
 use Silex\Api\EventListenerProviderInterface;
 use Silex\Api\ControllerProviderInterface;
-use Silex\EventListener\MiddlewareListener;
-use Silex\EventListener\ConverterListener;
-use Silex\EventListener\StringToResponseListener;
 use Silex\Provider\RoutingServiceProvider;
+use Silex\Provider\KernelServiceProvider;
 
 /**
  * The Silex framework class.
@@ -87,20 +84,6 @@ class Application extends Container implements HttpKernelInterface, TerminableIn
             return new ExceptionHandler($app['debug']);
         };
 
-        $this['dispatcher_class'] = 'Symfony\\Component\\EventDispatcher\\EventDispatcher';
-        $this['dispatcher'] = function () use ($app) {
-            $dispatcher = new $app['dispatcher_class']();
-
-            if (isset($app['exception_handler'])) {
-                $dispatcher->addSubscriber($app['exception_handler']);
-            }
-            $dispatcher->addSubscriber(new ResponseListener($app['charset']));
-            $dispatcher->addSubscriber(new MiddlewareListener($app));
-            $dispatcher->addSubscriber(new ConverterListener($app['routes'], $app['callback_resolver']));
-            $dispatcher->addSubscriber(new StringToResponseListener());
-
-            return $dispatcher;
-        };
 
         $this['callback_resolver'] = function () use ($app) {
             return new CallbackResolver($app);
@@ -124,6 +107,7 @@ class Application extends Container implements HttpKernelInterface, TerminableIn
         $this['charset'] = 'UTF-8';
         $this['logger'] = null;
 
+        $this->register(new KernelServiceProvider());
         $this->register(new RoutingServiceProvider());
 
         foreach ($values as $key => $value) {

src/Silex/Provider/KernelServiceProvider.php

+<?php
+
+namespace Silex\Provider;
+
+use Pimple\ServiceProviderInterface;
+use Pimple\Container;
+use Silex\Api\EventListenerProviderInterface;
+use Silex\EventListener\ConverterListener;
+use Silex\EventListener\MiddlewareListener;
+use Silex\EventListener\StringToResponseListener;
+use Symfony\Component\EventDispatcher\EventDispatcher;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
+use Symfony\Component\HttpKernel\EventListener\ResponseListener;
+
+class KernelServiceProvider implements ServiceProviderInterface, EventListenerProviderInterface
+{
+    /**
+     * {@inheritDoc}
+     */
+    public function register(Container $pimple)
+    {
+        $pimple['dispatcher'] = function () {
+            return new EventDispatcher();
+        };
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function subscribe(Container $app, EventDispatcherInterface $dispatcher)
+    {
+        if (isset($app['exception_handler'])) {
+            $dispatcher->addSubscriber($app['exception_handler']);
+        }
+
+        $dispatcher->addSubscriber(new ResponseListener($app['charset']));
+        $dispatcher->addSubscriber(new MiddlewareListener($app));
+        $dispatcher->addSubscriber(new ConverterListener($app['routes'], $app['callback_resolver']));
+        $dispatcher->addSubscriber(new StringToResponseListener());
+    }
+}