[#5621] Enhancing example of using bundle config

Author: weaverryan

bundles/configuration.rst

@@ -218,23 +218,64 @@ This class can now be used in your ``load()`` method to merge configurations and
 force validation (e.g. if an additional option was passed, an exception will be
 thrown)::
 
+    // src/Acme/SocialBundle/DependencyInjection/AcmeSocialExtension.php
+
     public function load(array $configs, ContainerBuilder $container)
     {
         $configuration = new Configuration();
 
         $config = $this->processConfiguration($configuration, $configs);
         
-        // Example configuration parameter usage: Set configuration variables as 
-        // parameters in the container.
-        $container->setParameter('twitter.client_id', $config['twitter']['client_id']);
-        $container->setParameter('twitter.client_secret', $config['twitter']['client_secret']);
-
+        // you now have these 2 config keys
+        // $config['twitter']['client_id'] and $config['twitter']['client_secret']
     }
 
 The ``processConfiguration()`` method uses the configuration tree you've defined
 in the ``Configuration`` class to validate, normalize and merge all the
 configuration arrays together.
 
+Now, you can use the ``$config`` variable to modify a service provided by your bundle.
+For example, imagine your bundle has the following example config:
+
+.. code-block:: xml
+
+    <!-- src/Acme/SocialBundle/Resources/config/services.xml -->
+    <?xml version="1.0" encoding="UTF-8" ?>
+    <container xmlns="http://symfony.com/schema/dic/services"
+        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+        xsi:schemaLocation="http://symfony.com/schema/dic/services
+            http://symfony.com/schema/dic/services/services-1.0.xsd">
+
+        <services>
+            <service id="acme.social.twitter_client" class="Acme\SocialBundle\TwitterClient">
+                <argument></argument> <!-- will be filled in with client_id dynamically -->
+                <argument></argument> <!-- will be filled in with client_secret dynamically -->
+            </service>
+        </services>
+    </container>
+
+In your extension, you can load this and dynamically set its arguments::
+
+    // src/Acme/SocialBundle/DependencyInjection/AcmeSocialExtension.php
+    // ...
+
+    use Symfony\Component\DependencyInjection\Loader\XmlFileLoader;
+    use Symfony\Component\Config\FileLocator;
+
+    public function load(array $configs, ContainerBuilder $container)
+    {
+        $loader = new XmlFileLoader($container, new FileLocator(dirname(__DIR__).'/Resources/config'));
+        $loader->load('services.xml');
+
+        $configuration = new Configuration();
+        $config = $this->processConfiguration($configuration, $configs);
+
+        $def = $container->getDefinition('acme.social.twitter_client');
+        $def->replaceArgument(0, $config['twitter']['client_id']);
+        $def->replaceArgument(1, $config['twitter']['client_secret']);
+    }
+
+
 .. tip::
 
     Instead of calling ``processConfiguration()`` in your extension each time you
@@ -258,9 +299,7 @@ configuration arrays together.
         }
 
     This class uses the ``getConfiguration()`` method to get the Configuration
-    instance. You should override it if your Configuration class is not called
-    ``Configuration`` or if it is not placed in the same namespace as the
-    extension.
+    instance.
 
 .. sidebar:: Processing the Configuration yourself