[app] make the app/config/services.yml file use the new Symfony autoregistration and autowiring features.

Author: Hugo Hamon

app/AppKernel.php

@@ -32,6 +32,7 @@ public function registerBundles()
         if (in_array($this->getEnvironment(), ['dev', 'test'])) {
             $bundles[] = new Symfony\Bundle\DebugBundle\DebugBundle();
             $bundles[] = new Symfony\Bundle\WebProfilerBundle\WebProfilerBundle();
+            $bundles[] = new Symfony\Bundle\WebServerBundle\WebServerBundle();
             $bundles[] = new Sensio\Bundle\DistributionBundle\SensioDistributionBundle();
             $bundles[] = new Sensio\Bundle\GeneratorBundle\SensioGeneratorBundle();
 

app/config/services.yml

@@ -1,83 +1,123 @@
 services:
-    # First we define some basic services to make these utilities available in
-    # the entire application
-    slugger:
-        class: AppBundle\Utils\Slugger
 
-    markdown:
-        class: AppBundle\Utils\Markdown
+    # The special "_defaults" section configure the default behaviors for registering
+    # new services into the Symfony service container. This section has a local scope
+    # only, which means it only affects the service definitions being registered by
+    # this file.
+    #
+    # The "autowire" section tells Symfony to make its best to autowire new services
+    # by introspecting their constructor.
+    #
+    # The "public" section with the FALSE boolean value forces all new autowired classes
+    # to be declared as private services. Marking services private limits their scope to
+    # the Symfony service container itself only. They're not accessible from the outside
+    # world and thus let the service container optimizes itself when it's being compiled
+    # and dumped to raw PHP code.
+    _defaults:
+        autowire: true
+        public: false
 
-    # These are the Twig extensions that create new filters and functions for
-    # using them in the templates
-    app.twig.app_extension:
-        public:    false
-        class:     AppBundle\Twig\AppExtension
-        arguments: ['@markdown', '%app_locales%']
-        tags:
-            - { name: twig.extension }
+    # The special "_instanceof" section appends additional wiring configuration 
+    # to any service definitions that match the listed types.
+    #
+    # For instance, the first rule adds a special "kernel.event_subscriber" tag
+    # to any definitions declared in this file whose class is an instance of the
+    # "Symfony\Component\EventDispatcher\EventSubscriberInterface" class or interface.
+    _instanceof:
+        Symfony\Component\EventDispatcher\EventSubscriberInterface:
+            tags: ['kernel.event_subscriber']
+
+        Symfony\Component\Form\FormTypeInterface:
+            tags: ['form.type']
+
+        Symfony\Component\Security\Core\Authorization\VoterInterface:
+            tags: ['security.voter']
+
+        Twig_ExtensionInterface:
+            tags: ['twig.extension']
+
+        # The following settings will be appended to any local service definitions
+        # whose class matches this type. In this example, it will only apply to
+        # the "AppBundle\Controller\Admin\BlogController" service discovered by
+        # the "AppBundle\Controller\" rule below.
+        AppBundle\Controller\Admin\BlogController:
+            getters:
+                getSlugger: '@AppBundle\Utils\Slugger'
 
+    # This section enables to automatically register all classes found in the matching
+    # file paths and directories as services in the container. File and directory
+    # matching uses any valid glob pattern to create a white list of paths.
+    #
+    # In this example, the classes found in the following directories will be
+    # automatically registered as services:
+    #
+    # * src/AppBundle/Form/Type/
+    # * src/AppBundle/Security/
+    # * src/AppBundle/Twig/
+    # * src/AppBundle/Utils/
+    #
+    # Thus, only the classes whose corresponding filename ends with the "Subscriber.php"
+    # suffix in the src/AppBundle/EventListener/ directory will be registered as
+    # services in the service container. Other classes of this directory will be simply
+    # ignored.
+    AppBundle\:
+        # Register all classes in the src/AppBundle directory as services
+        resource: '../../src/AppBundle/{EventListener/*Subscriber.php,Form/Type,Security,Twig,Utils}'
+
+    # The other section defines a rule to automatically register and autowire the
+    # controller classes found in the src/AppBundle/Controller/ directory.
+    #
+    # By default all services are made private according to the global "_defaults"
+    # section at the top of this file.
+    #
+    # However, in Symfony, controllers must always be declared public in order to
+    # be lazy instanciated when they're really needed. This is why the inherited
+    # default "public" attribute is overriden to force the registered controller
+    # services to be marked public.
+    AppBundle\Controller\:
+        resource: '../../src/AppBundle/Controller'
+        public: true
+
+    # This third party Twig extension must be manually registered as a service
+    # because its class doesn't live in any of the previous defined directories.
+    #
+    # Thus, its class is not namespaced and cannot be defined in a global rule.
+    # Indeed, registering new classes whose filename matches a glob pattern as
+    # services like in the two previous sections only works for namespaced classes.
     app.twig.intl_extension:
-        public: false
         class:  Twig_Extensions_Extension_Intl
-        tags:
-            - { name: twig.extension }
 
-    # Defining a form type as a service is only required when the form type
-    # needs to use some other services, such as the entity manager.
-    # See http://symfony.com/doc/current/best_practices/forms.html
-    app.form.type.tagsinput:
-        class: AppBundle\Form\Type\TagsInputType
-        arguments: ['@doctrine.orm.entity_manager']
-        tags:
-            - { name: form.type }
+    # Some classes cannot be fully autowired because their methods accept either
+    # some scalar arguments that Symfony cannot guess or a typehinted dependency
+    # for which the container has at least two registered services matching the
+    # type.
+    #
+    # Both the "AppBundle\Twig\AppExtension" and "AppBundle\EventListener\RedirectToPreferredLocaleSubscriber"
+    # classes have a "__construct()" method that receives a "$locales" scalar argument
+    # that Symfony cannot guess. This is why we must manually and explicitly provide
+    # the wiring of this argument to complete their service definitions.
+    #
+    # To do so, the remaining unwired named arguments must be defined with their
+    # corresponding values. Here, the "$locales" named argument is configured to
+    # receive the value of the global "%app_locales%" parameter defined under the
+    # "parameters" section of the "app/config/config.yml" file.
+    #
+    # Note that the order in which the named arguments are defined below doesn't
+    # matter as they're referenced here by their real names in the PHP code.
+    # Symfony is then smart enough to make the corresponding matching when compiling,
+    # optimizing and dumping the container as a raw PHP class in the cache directory.
+    AppBundle\Twig\AppExtension:
+        $locales: '%app_locales%'
+
+    AppBundle\EventListener\RedirectToPreferredLocaleSubscriber:
+        $locales: '%app_locales%'
 
     # Event Listeners are classes that listen to one or more specific events.
     # Those events are defined in the tags added to the service definition.
     # See http://symfony.com/doc/current/event_dispatcher.html#creating-an-event-listener
-    app.redirect_to_preferred_locale_listener:
-        class: AppBundle\EventListener\RedirectToPreferredLocaleListener
-        arguments: ['@router', '%app_locales%', '%locale%']
-        tags:
-            - { name: kernel.event_listener, event: kernel.request, method: onKernelRequest }
-
-    app.comment_notification:
-        class: AppBundle\EventListener\CommentNotificationListener
+    AppBundle\EventListener\CommentNotificationListener:
         arguments: ['@mailer', '@router', '@translator', '%app.notifications.email_sender%']
         # The "method" attribute of this tag is optional and defaults to "on + camelCasedEventName"
         # If the event is "comment.created" the method executed by default is "onCommentCreated()".
         tags:
             - { name: kernel.event_listener, event: comment.created, method: onCommentCreated }
-
-    # Event subscribers are similar to event listeners but they don't need service tags.
-    # Instead, the PHP class of the event subscriber includes a method that returns
-    # the list of events listened by that class.
-    # See http://symfony.com/doc/current/event_dispatcher.html#creating-an-event-subscriber
-    app.requirements_subscriber:
-        class: AppBundle\EventListener\CheckRequirementsSubscriber
-        arguments: ['@doctrine.orm.entity_manager']
-        tags:
-            - { name: kernel.event_subscriber }
-
-    # To inject the voter into the security layer, you must declare it as a service and tag it with security.voter.
-    # See http://symfony.com/doc/current/security/voters.html#configuring-the-voter
-    app.post_voter:
-        class: AppBundle\Security\PostVoter
-        public: false
-        tags:
-            - { name: security.voter }
-
-    # Uncomment the following lines to define a service for the Post Doctrine repository.
-    # It's not mandatory to create these services, but if you use repositories a lot,
-    # these services simplify your code:
-    #
-    # app.post_repository:
-    #     class:     Doctrine\ORM\EntityRepository
-    #     factory:   ['@doctrine.orm.entity_manager', getRepository]
-    #     arguments: [AppBundle\Entity\Post]
-    #
-    # // traditional code inside a controller
-    # $entityManager = $this->getDoctrine()->getManager();
-    # $posts = $entityManager->getRepository('AppBundle:Post')->findAll();
-    #
-    # // same code using repository services
-    # $posts = $this->get('app.post_repository')->findAll();

composer.json

@@ -25,7 +25,7 @@
         "symfony/monolog-bundle"               : "^3.0",
         "symfony/polyfill-apcu"                : "^1.0",
         "symfony/swiftmailer-bundle"           : "^2.3",
-        "symfony/symfony"                      : "^3.2",
+        "symfony/symfony"                      : "^3.3@dev",
         "twig/extensions"                      : "^1.3",
         "twig/twig"                            : "^1.28 || ^2.0",
         "white-october/pagerfanta-bundle"      : "^1.0"