Revert best_practices/templates.rst

Author: GuilhemN

best_practices/templates.rst

@@ -60,8 +60,8 @@ Twig Extensions
 
 .. best-practice::
 
-    Define your Twig extensions in the ``AppBundle/Twig/`` directory. Your
-    application will automatically detect them and configure them.
+    Define your Twig extensions in the ``AppBundle/Twig/`` directory and
+    configure them using the ``app/config/services.yml`` file.
 
 Our application needs a custom ``md2html`` Twig filter so that we can transform
 the Markdown contents of each post into HTML.
@@ -73,11 +73,21 @@ a new dependency of the project:
 
     $ composer require erusev/parsedown
 
-Then, create a new ``Markdown`` class that will be used later by the Twig
-extension. It just needs to define one single method to transform
+Then, create a new ``Markdown`` service that will be used later by the Twig
+extension. The service definition only requires the path to the class:
+
+.. code-block:: yaml
+
+    # app/config/services.yml
+    services:
+        # ...
+        app.markdown:
+            class: AppBundle\Utils\Markdown
+
+And the ``Markdown`` class just needs to define one single method to transform
 Markdown content into HTML::
 
-    namespace AppBundle\Service;
+    namespace AppBundle\Utils;
 
     class Markdown
     {
@@ -97,14 +107,14 @@ Markdown content into HTML::
     }
 
 Next, create a new Twig extension and define a new filter called ``md2html``
-using the ``Twig_SimpleFilter`` class. Inject the newly defined ``Markdown``
-class in the constructor of the Twig extension:
+using the ``Twig_SimpleFilter`` class. Inject the newly defined ``markdown``
+service in the constructor of the Twig extension:
 
 .. code-block:: php
 
     namespace AppBundle\Twig;
 
-    use AppBundle\Service\Markdown;
+    use AppBundle\Utils\Markdown;
 
     class AppExtension extends \Twig_Extension
     {
@@ -137,11 +147,18 @@ class in the constructor of the Twig extension:
         }
     }
 
-And that's it!
+Lastly define a new service to enable this Twig extension in the app (the service
+name is irrelevant because you never use it in your own code):
+
+.. code-block:: yaml
 
-Your application will :ref:`autoconfigure <services-autoconfigure>` your twig
-extension and inject a ``Markdown`` instance in it thanks to
-:doc:`autowiring </service_container/autowiring>`.
+    # app/config/services.yml
+    services:
+        app.twig.app_extension:
+            class:     AppBundle\Twig\AppExtension
+            arguments: ['@app.markdown']
+            public:    false
+            tags: [twig.extension]
 
 .. _`Twig`: http://twig.sensiolabs.org/
 .. _`Parsedown`: http://parsedown.org/