Symfony2 Service Container: Inject me, my friend

Kirill chEbba [email protected]

Symfony Service Container.Inject me, my friend.

mailto:[email protected]

Theory

Service Container. Theory

Kirill chEbba Chebunin

•Inversion of Control•Dependency Injection•IoC(DI) Container

Don't call us, we'll call you



IoC Implementation



•Interfaces•Abstract Factory•Service Locator

Dependency Injection



•Constructor Injection•Setter Injection•Interface Injection

IoC Container



•Service Definitions•Factory•Service Locator

IoC Container



Symfony2 Service Container=

IoC Container

Service Container. Implementation


Service Definition



<service id="monolog.logger.event" class="%logger.class%"> <argument>event</argument> <call method="pushHandler"> <argument type="service" id="monolog.handler.main"/> </call> <call method="pushHandler"> <argument type="service" id="monolog.handler.firephp"/> </call> <call method="pushHandler"> <argument type="service" id="monolog.handler.debug"/> </call></service>

Constructor Injection



class IdentityTranslator implements TranslatorInterface{ public function __construct(MessageSelector $selector) {/**/}}

<service id="translator" class="Symfony\Component\Translation\IdentityTranslator"> <argument type="service" id="translator.selector"/></service>

Setter Injection



class Configuration{ public function setSQLLogger(SQLLogger $logger = null) {/**/}}

<service class="Doctrine\DBAL\Configuration"> <call method="setSQLLogger"> <argument type="service" id="doctrine.dbal.logger"/> </call></service>

Dynamic Service Locator



public function some(){ $this->container->get('logger');}

Additional capabilities



•Parameters•Imports•Private & Abstract Services•Aliases•Tags•…

Scopes



•Container•Prototype•Request•Custom

Custom scope



$this->container->enterScope('request'); $this->container->set('request', $request, 'request');

try { $response = parent::handle($request, $type, $catch); } catch (\Exception $e) { $this->container->leaveScope('request');

throw $e; }

$this->container->leaveScope('request');

Advanced Features

Service Container. Advanced


Extensions



Extensions



doctrine: dbal: driver: %database_driver% host: %database_host% port: %database_port% dbname: %database_name% user: %database_user% password: %database_password% charset: UTF8

Extensions



interface ExtensionInterface{ /* … */ function load(array $config, ContainerBuilder $container); /* … */}

Container Compiler



•Compiler•PassConfig•Freeze

Compiler Passes



Compiler Pass



interface CompilerPassInterface{ /** * You can modify the container here before * it is dumped to PHP code. * * @param ContainerBuilder $container */ function process(ContainerBuilder $container);}

Compiler Passes



•Merge•BeforeOptimization•Optimization•BeforeRemoving•Removing•AfterRemoving

Optimization Passes



•ResolveParameterPlaceHolders•ResolveReferencesToAliases•CheckCircularReferences•...

Removing Passes



•RemovePrivateAliases•RemoveAbstractDefinitions•ReplaceAliasByActualDefinition•...

Compiler Pass Hooks



•BeforeOptimization•BeforeRemoving•AfterRemoving

MergePassAdd

Extension Services



Frozen Container



Container Dumper



Container Dumper



•XmlDumper•YamlDumper•PhpDumper

appDevDebugProjectContainer



protected function getLoggerService(){ $this->services['logger'] = $instance = new \Symfony\Bridge\Monolog\Logger('app');

$instance->pushHandler($this->get('monolog.handler.main')); $instance->pushHandler($this->get('monolog.handler.firephp')); $instance->pushHandler($this->get('monolog.handler.debug'));

return $instance;}

Container & Bundles

Service Container. Bundles


Container & Bundles



•Extension•Compiler Passes•Bundle Boot

Bundle Extension



Bundle Extension



SecurityBundle/Resources/config/templating_php.xml

<services> <service id="templating.helper.security" class="%templating.helper.security.class%"> <tag name="templating.helper" alias="security" /> <argument type="service" id="security.context" on-invalid="ignore" /> </service></services>

Bundle Extension



// load services $loader = new XmlFileLoader( $container, new FileLocator(__DIR__.'/../Resources/config') ); $loader->load('security.xml'); $loader->load('security_listeners.xml'); $loader->load('security_rememberme.xml'); $loader->load('templating_php.xml'); $loader->load('templating_twig.xml'); $loader->load('collectors.xml');

Bundle Compiler Passes






TwigBundle

public function build(ContainerBuilder $container){ parent::build($container);

$container->addCompilerPass( new TwigEnvironmentPass()); $container->addCompilerPass( new ExceptionListenerPass());}




TwigEnvironmentPass

$definition = $container->getDefinition('twig');

foreach ($container->findTaggedServiceIds('twig.extension') as $id => $attributes) {

$definition->addMethodCall('addExtension', array(new Reference($id)));}

Bundle Boot



It is Your Choice

Service Container. Afterword


•Constructor VS Setter injection•DI VS Service Locator•Extension VS Compiler Pass

The End



Time for Questions



•[email protected]•http://github.com/chEbba•@iamchEbba

mailto:[email protected]

http://github.com/chEbba

http://twitter.com/#!/iamchEbba

Documents

Symfony2 Service Container: Inject me, my friend