Symfony Internals

PHPBenelux 2018

Transcript

1. Symfony Internals
   

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2. Symfony Internals
   Andreas Hucks
   CTO @ SensioLabs Germany
   

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4. Conference Hotel
   

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5. Auditorium
   

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6. Lunch
   

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7. Socials
   

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8. VIP Lounge
   

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9. Wellness
   

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10. Survey
    

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11. Motivation
    

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12. What to expect
    

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13. The Request
    $kernel = new Kernel($env, $debug);
    $request = Request::createFromGlobals();
    $response = $kernel->handle($request);
    $response->send();
    

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14. HttpKernel
    $kernel->handle($request);
    

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15. Request-Response Flow
    Request Response
    Front

    Controller
    Kernel
    

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16. Symfony is not an

    MVC framework
    

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18. Symfony is a

    Request-Response Framework
    

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19. Request-Response Flow
    Request Response
    Front

    Controller
    Kernel
    

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20. Request-Response Flow
    Kernel
    

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21. Request-Response Flow
    Kernel
    kernel.request
    kernel.controller
    kernel.response
    kernel.exception kernel.view
    kernel.terminate
    

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22. EventDispatcher
    $dispatcher = new EventDispatcher();
    $dispatcher->addListener('kernel.request', $callable);
    

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23. EventDispatcher
    $dispatcher->dispatch(
    'kernel.request',
    $responseEvent
    );
    

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24. EventDispatcher
    $dispatcher->dispatch(
    'kernel.request',
    $responseEvent
    );
    payload
    What happened.
    

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25. Request-Response Flow
    Kernel
    kernel.request
    kernel.controller
    kernel.response
    kernel.exception kernel.view
    kernel.terminate
    

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26. GetResponseEvent
    class GetResponseEvent extends KernelEvent
    {
    public function getResponse()
    {
    return $this->response;
    }
    public function setResponse(Response $response)
    {
    $this->response = $response;
    $this->stopPropagation();
    }
    kernel.request
    

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27. RouterListener
    /**
    * @Route(path="/books/{id}", name="book_show")
    */
    $params = [
    '_controller' => ‘App\Controller\BookController::showAction’,
    '_route' => 'book_show',
    '_route_params' => [
    'id' => '37'
    ],
    'id' => ’37'
    ];
    kernel.request
    

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28. RouterListener
    $parameters = $this
    ->matcher->match($request->getPathInfo());
    $request->attributes->add($parameters);
    unset(
    $parameters[‘_route'],
    $parameters[‘_controller']
    );
    $request->attributes->set(
    '_route_params',
    $parameters
    );
    kernel.request
    

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29. LocaleListener
    $request = $event->getRequest();
    $request->setDefaultLocale($this->defaultLocale);
    if ($locale = $request->attributes->get('_locale')) {
    $request->setLocale($locale);
    }
    kernel.request
    

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30. Customize!
    • Content Negotiation - Parse headers and add attribute
    • Verify signed Cookies
    • Redirects based on arbitrary criteria
    • Custom Locale stuff
    • … ?
    

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31. Request-Response Flow
    Kernel
    kernel.request
    kernel.controller
    kernel.response
    kernel.exception kernel.view
    kernel.terminate
    

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32. FilterControllerEvent
    class FilterControllerEvent extends KernelEvent
    {
    public function getController()
    {
    return $this->controller;
    }
    public function setController(callable $controller)
    {
    $this->controller = $controller;
    }
    kernel.controller
    

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33. ControllerListener
    class ControllerListener implements EventSubscriberInterface
    {
    public function __construct(Reader $reader)
    {
    $this->reader = $reader;
    }
    public function onKernelController(FilterControllerEvent $event)
    {
    $controller = $event->getController();
    // read annotations for class and method
    $request = $event->getRequest();
    foreach ($configurations as $key => $attributes) {
    $request->attributes->set($key, $attributes);
    }
    kernel.controller
    

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34. ParamConverterListener
    class ParamConverterListener implements EventSubscriberInterface
    {
    /**
    * @var ParamConverterManager
    */
    private $manager;
    kernel.controller
    

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35. Request-Response Flow
    Kernel
    kernel.request
    kernel.controller
    kernel.response
    kernel.exception kernel.view
    kernel.terminate
    

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36. Wait… Controllers?
    

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37. HttpKernel
    $response = \call_user_func_array(
    $controller,
    $arguments
    );
    

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38. Request-Response Flow
    Kernel
    kernel.request
    kernel.controller
    kernel.response
    kernel.exception kernel.view
    kernel.terminate
    

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39. GetResponseForControllerResultEvent
    class GetResponseForControllerResultEvent extends GetResponseEvent
    {
    public function getControllerResult()
    {
    return $this->controllerResult;
    }
    public function setControllerResult($controllerResult)
    {
    $this->controllerResult = $controllerResult;
    }
    kernel.view
    

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40. TemplateListener
    public function onKernelView(
    GetResponseForControllerResultEvent $event
    ) {
    /* @var Template $template */
    $request = $event->getRequest();
    $template = $request->attributes->get(‘_template');
    // …
    $event->setResponse(
    new Response(
    $this->twig->render($template->getTemplate()),
    $parameters
    )
    );
    kernel.view
    

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41. Customize!
    • Auto serializing and encoding for web service responses
    • Together with kernel.controller: 

    Action Domain Responder, other patterns?
    

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42. Request-Response Flow
    Kernel
    kernel.request
    kernel.controller
    kernel.response
    kernel.exception kernel.view
    kernel.terminate
    

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43. GetResponseForExceptionEvent
    class GetResponseForExceptionEvent extends GetResponseEvent
    {
    public function getException()
    {
    return $this->exception;
    }
    kernel.exception
    

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44. ExceptionListener
    public function onKernelException(
    GetResponseForExceptionEvent $event
    ) {
    $exception = $event->getException();
    $request = $event->getRequest();
    $this->logException($exception
    kernel.exception
    

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45. Customize!
    • Customize for every exception type you like
    • Redirect for some errors
    • “were you looking for…” suggestions on 404 pages
    • Custom alerts
    • … ?
    

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46. Request-Response Flow
    Kernel
    kernel.request
    kernel.controller
    kernel.response
    kernel.exception kernel.view
    kernel.terminate
    

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47. FilterResponseEvent
    class FilterResponseEvent extends KernelEvent
    {
    public function getResponse()
    {
    return $this->response;
    }
    public function setResponse(Response $response)
    {
    $this->response = $response;
    }
    kernel.response
    

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48. WebDebugToolbarListener
    $response->headers->set(
    'X-Debug-Token-Link',
    $this->urlGenerator->generate(
    ‘_profiler',
    array(
    'token' => $response->headers->get(‘X-Debug-Token')
    ),
    UrlGeneratorInterface::ABSOLUTE_URL
    )
    );
    $this->injectToolbar($response, $request, $nonces);
    kernel.response
    

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49. SaveSessionListener
    $session = $event->getRequest()->getSession();
    if ($session && $session->isStarted()) {
    $session->save();
    $event->getResponse()
    ->setPrivate()
    ->setMaxAge(0)
    ->headers->addCacheControlDirective('must-revalidate');
    }
    kernel.response
    

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50. Customize!
    • Sign cookies
    • Add custom headers
    • … ?
    

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51. Request-Response Flow
    Kernel
    kernel.request
    kernel.controller
    kernel.response
    kernel.exception kernel.view
    kernel.terminate
    

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52. PostResponseEvent
    class PostResponseEvent extends KernelEvent
    {
    public function getResponse()
    {
    return $this->response;
    }
    kernel.terminate
    

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53. EmailSenderListener
    public function onTerminate()
    {
    // send spooled Emails
    kernel.terminate
    

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54. Other Listeners kernel.request
    • FirewallListener
    • Collector Listeners
    

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55. Recap
    Request Response
    Front

    Controller
    Kernel
    

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56. Container & Cache
    

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57. Container & Cache
    protected function getRouterService()
    {
    $this->services[‘router']
    = $instance
    = new \Symfony\Bundle\…\Router(
    $this, ‘/app/config/routing_dev.yml'
    )
    // [snip]
    return $instance;
    }
    

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58. Container & Cache
    Cache class for this
    request?
    Does it exists?
    require() it
    yes
    Build Container
    no
    

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59. Container & Cache
    Cache class for this
    request?
    Does it exists?
    require() it
    yes
    Build Container
    no
    

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60. Container Build
    Register Bundles
    Register Extensions &
    Compiler Passes
    Register Project Config
    Run Extensions
    Run compiler Passes Dump Container
    Run Cache Warmers
    (quite a few)
    

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61. Container Build
    Register Bundles
    Register Extensions &
    Compiler Passes
    Register Project Config
    Run Extensions
    Run compiler Passes Dump Container
    Run Cache Warmers
    

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62. Registering Bundles
    public function registerBundles()
    {
    $bundles = [
    new Symfony\Bundle\FrameworkBundle\FrameworkBundle(),
    new Symfony\Bundle\SecurityBundle\SecurityBundle(),
    new Symfony\Bundle\TwigBundle\TwigBundle(),
    // [snip]
    ];
    return $bundles;
    }
    

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63. Container Build
    Register Bundles
    Register Extensions &
    Compiler Passes
    Register Project Config
    Run Extensions
    Run compiler Passes Dump Container
    Run Cache Warmers
    

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64. Registering Extensions
    protected function prepareContainer(ContainerBuilder $container)
    {
    $extensions = array();
    foreach ($this->bundles as $bundle) {
    if ($extension = $bundle->getContainerExtension()) {
    $container->registerExtension($extension);
    $extensions[] = $extension->getAlias();
    }
    // [snip]
    }
    

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65. Container Build
    Register Bundles
    Register Extensions &
    Compiler Passes
    Register Project Config
    Run Extensions
    Run compiler Passes Dump Container
    Run Cache Warmers
    

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66. Register Project-Level
    Container Config
    public function registerContainerConfiguration(
    LoaderInterface $loader
    ) {
    $loader->load(
    $this->getRootDir().
    ’/config/config_’.$this->getEnvironment().'.yml'
    );
    }
    

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67. Container Build
    Register Bundles
    Register Extensions &
    Compiler Passes
    Register Project Config
    Run Extensions
    Run compiler Passes Dump Container
    Run Cache Warmers
    

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68. Extensions
    class TwigExtension extends Extension
    {
    public function load(array $configs, ContainerBuilder $container)
    {
    $loader = new XmlFileLoader(
    $container,
    new FileLocator(__DIR__.’/../Resources/config')
    );
    $loader->load('twig.xml');
    

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69. Customize!
    • Load config files
    • Do not load config files depending on parameter
    • Set Parameters, manipulate parameters
    • BETTER NOT manipulate services (they are not complete
    at this point, see next slides)
    

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70. Container Build
    Register Bundles
    Register Extensions &
    Compiler Passes
    Register Project Config
    Run Extensions
    Run compiler Passes Dump Container
    Run Cache Warmers
    

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71. Compiler Passes
    public function process(ContainerBuilder $container)
    {
    if (!$container->has('app.myservice')) {
    return;
    }
    $definition = $container->findDefinition(
    'app.myservice'
    );
    // find formatter service
    $definition->addMethodCall(
    'addFormatter',
    array(new Reference($formatterId))
    );
    }
    

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72. (A few) Compiler Passes
    • ServiceLocatorTagPass
    • DecoratorServicePass
    • ResolveParameterPlaceHoldersPass
    • ResolveFactoryClassPass
    • ResolveNamedArgumentsPass
    • AutowirePass
    • RemovePrivateAliasesPass
    • ReplaceAliasByActualDefinitionPass
    • RemoveAbstractDefinitionsPass
    • InlineServiceDefinitionsPass
    • RemoveUnusedDefinitionsPass
    

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73. (A few) Compiler Passes
    • ServiceLocatorTagPass
    • DecoratorServicePass
    • ResolveParameterPlaceHoldersPass
    • ResolveFactoryClassPass
    • ResolveNamedArgumentsPass
    • AutowirePass
    • RemovePrivateAliasesPass
    • ReplaceAliasByActualDefinitionPass
    • RemoveAbstractDefinitionsPass
    • InlineServiceDefinitionsPass
    • RemoveUnusedDefinitionsPass
    

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74. Customize!
    • Add method calls to services based on tags
    • Manipulate services that depend on the full service config
    

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75. Container Build
    Register Bundles
    Register Extensions &
    Compiler Passes
    Register Project Config
    Run Extensions
    Run compiler Passes Dump Container
    Run Cache Warmers
    

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76. Dump Container
    protected function dumpContainer(
    ConfigCache $cache,
    ContainerBuilder $container,
    $class,
    $baseClass
    ) {
    $dumper = new PhpDumper($container);
    $content = $dumper->dump(/*…*/);
    

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77. … and use it
    $this->container = require $cache->getPath();
    

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78. Container Build
    Register Bundles
    Register Extensions &
    Compiler Passes
    Register Project Config
    Run Extensions
    Run compiler Passes Dump Container
    Run Cache Warmers
    

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79. Cache Warmers
    public function warmUp($cacheDir)
    {
    $filesystem = new Filesystem();
    $templates = array();
    foreach ($this->finder->findAllTemplates() as $template) {
    // [snip]
    }
    // [snip]
    $this->writeCacheFile($cacheDir.’/templates.php', // [snip]
    }
    

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80. Customize!
    • You have full access to services, the container in ready
    • Create custom caches your application needs
    • Prefetch and cache data from external sources
    

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82. Thank you :)
    https://joind.in/talk/bd64e
    

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