DupalCon Barcelona 2015 - The journey from the request to the response

The journey from the request to the Response Sarah Khalil
- @saro0h

WHO AM I? • Head of • Trainer & Developer
• Enjoying sharer • Contributor to

http://bit.do/sfcon2015

WHAT’S THE PLAN? • The philosophy of Symfony • Heart
of Drupal : Dependency Injection Component • And Templating?

PHILOSOPHY

request GET /users HTTP/1.1 Host: 127.0.0.1:8000 User-Agent: curl/7.37.1

request GET /users HTTP/1.1 Host: 127.0.0.1:8000 User-Agent: curl/7.37.1 response HTTP/1.1
200 OK Host: 127.0.0.1:8000 Content-Type: text/html; <html>Some content</html>

request GET /users HTTP/1.1 Host: 127.0.0.1:8000 User-Agent: curl/7.37.1 response HTTP/1.1
200 OK Host: 127.0.0.1:8000 Content-Type: text/html; <html>Some content</html> Symfony is an HTTP framework.

HTTP request View Model Controller Routing component HTTP response front
controller HttpKernel event listener HttpFoundation request HttpFoundation response

HTTP request

HTTP request front controller

HTTP request front controller HttpFoundation request

HTTP request front controller HttpKernel HttpFoundation request

• HttpFoundation • Abstraction of the Request & the Response
• HttpKernel • Turns the Request in a response COMPONENTS INVOLVED

IN DRUPAL?

$request = Request::createFromGlobals(); $response = $kernel-‐>handle($request); $response-‐>send();
$kernel-‐>terminate($request, $response); front controller

HTTP request front controller HttpKernel HttpFoundation request

HTTP request front controller HttpKernel Routing component HttpFoundation request

• Maps a URL to a set of parameters ROUTING
COMPONENT homepage: path: / defaults: { _controller: Todo\Controller\TodoController::indexAction }

IN DRUPAL?

HTTP request front controller HttpKernel Routing component HttpFoundation request

HTTP request front controller HttpKernel Routing component Controller HttpFoundation request

HTTP request front controller HttpKernel Routing component Controller HttpFoundation request
View Model

• A callable responsible of communication with the Model and
the View layers. • It must return an HttpFoundation response. CONTROLLER

CONTROLLER namespace Todo\Controller; use Symfony\Component\HttpFoundation\Request; use Symfony\Component\HttpFoundation\Response; class
TodoController { public function hello(Request $request) { return new Response('Some content'); } }

HTTP request View Model Controller Routing component front controller HttpKernel
HttpFoundation request

HttpFoundation request HttpFoundation response

controller HttpKernel HttpFoundation request HttpFoundation response

controller HttpKernel HttpFoundation request HttpFoundation response event system

EVENT DISPATCHER COMPONENT Allows to easily decouple code and plugin
new features to an object without using inheritance.

TWO MAIN CONCEPTS • Dispatch an Event • Listen /
Subscribe to an event

1. EVENT The dispatched event is an object which carries
all the needed data to retrieve into each listener.

2. LISTENER The listener can be any valid PHP «
callable » like a function name, an instance method, a static method or a closure.

EVENT LISTENER ≠ EVENT SUBSCRIBER

EVENT SUBSCRIBER 1/2 namespace SensioLabs\Article\Listener; use Symfony\Component\EventDispatcher\EventSubscriberInterface; class
ArticleListener implements EventSubscriberInterface { // ... public static function getSubscribedEvents() { return [ 'article.save' => [ [ 'onInsertArticle', 10 ], [ 'onUpdateArticle', 5 ], ], 'article.delete' => [ 'onDeleteArticle', 0 ], ]; } }

use Symfony\Component\EventDispatcher\Event; use Symfony\Component\EventDispatcher\EventDispatcher; $dispatcher = new EventDispatcher();
$dispatcher-‐>addSubscriber(new ArticleListener()); EVENT SUBSCRIBER 2/2

EVENT LISTENER 1/2 namespace SensioLabs\Article\EventListener; use Symfony\Component\HttpFoundation\Response; use
Symfony\Component\HttpKernel\Event\GetResponseEvent; class MyListener { public function onKernelRequest(GetResponseEvent $event) { if (!$event-‐>isMasterRequest()) { return; } $request = $event-‐>getRequest(); if ($file = $request-‐>attributes-‐>get('_file')) { $event-‐>setResponse(new Response('Some content')); } } }

EVENT LISTENER 2/2 use Symfony\Component\EventDispatcher\Event; use Symfony\Component\EventDispatcher\EventDispatcher; $dispatcher
= new EventDispatcher(); $dispatcher-‐>addListener( KernelEvents::REQUEST, [ new MyListener(), 'onKernelRequest' ] );

EVENT DISPATCHER COMPONENT use Symfony\Component\EventDispatcher\Event; use Symfony\Component\EventDispatcher\EventDispatcher; $dp
= new EventDispatcher(); // Add event listeners and/or event subscribers $dp-‐>dispatch('event.name', new Event());

IN DRUPAL? services: weather.job_listener:
class: Drupal\weather\Listener\AddJobHeaderListener arguments: ['[email protected]'] tags: -‐ { name: event_subscriber } services: weather.job_listener: class: Drupal\weather\Listener\AddJobHeaderListener arguments: ['[email protected]'] tags: -‐ { name: kernel.event_listener, event: kernel.request, method: onKernelRequest }

1.kernel.request 2.kernel.controller 3.kernel.view EVENTS TRIGGERED BY THE HTTPKERNEL COMPONENT 4.kernel.response
5.kernel.terminate 6.kernel.ﬁnish_request

ALL TOGETHER NOW !

HTTP request

HTTP request front controller

HTTP request front controller HttpKernel

HTTP request Routing component front controller HttpKernel

HTTP request Controller Routing component front controller HttpKernel

HttpFoundation request

HttpFoundation request HttpFoundation response

controller HttpKernel HttpFoundation request HttpFoundation response

controller HttpKernel event listener HttpFoundation request HttpFoundation response

DRUPAL 8 AND SYMFONY

COMPONENTS USED symfony/class-loader symfony/css-selector symfony/dependency-injection symfony/event-dispatcher symfony/http-foundation symfony/http-kernel symfony/routing symfony/serializer
symfony/validator symfony/yaml

DEPENDENCY INJECTION The DI component allows you to standardize and
centralize the way objects are constructed in your application.

3 KEY CONCEPTS 1. Service container 2. Services 3. Parameters

1. SERVICE CONTAINER Manages the instantiation of your service. Makes
sure that there is only one instance of a service. Stores the parameters.

2. SERVICES PHP object. Perform global task. Does not have
any state.

3. PARAMETERS Global conﬁguration.

IN DRUPAL?

parameters: weather_endpoint: 'http://api.openweathermap.org' admin_email: '[email protected]'
services: weather.forecasts: class: Drupal\weather\Services\ForecastService arguments: ['@http_client', '%weather_endpoint%'] weather.job_listener: class: Drupal\weather\Listener\AddJobHeaderListener arguments: ['%admin_email%'] tags: -‐ { name: event_subscriber }

TEMPLATING

# views/layout.twig <!DOCTYPE html> <html>
<head> <meta http-‐equiv="Content-‐Type" content="text/html; charset=UTF-‐8"> <title>{% block title 'Todo Application' %}</title> <link rel="stylesheet" media="screen" type="text/css" href="/ style.css"/> {% block stylesheets '' %} </head> <body> <div id="container"> <h1> <a href="index.php">My Todos List</a> </h1> <div id="content"> {% block content %}{% endblock %} </div> <div id="footer"> (c) copyright -‐ not sensio </div> </div> {% block javascripts '' %} </body> </html>

block title block stylesheets block content <html> </html> <head> </head>
<body> </body>  block javascripts

# views/home.twig {% extends 'layout.twig' %} {% block
title 'Tasks Management' %} {% block content %} <form action="/index.php/todo/new" method="post"> <div> <label for="title">Title:</label> <input type="text" id="title" name="title" size="45"/> <input type="hidden" name="action" value="create"/> <button type="submit">send</button> </div> </form> <p> There are <strong>{{ count }}</strong> tasks. </p> {% endblock %}

IN DRUPAL? 1/3

IN DRUPAL? 2/3 // weather.module /** * Implements
hook_theme(). */ function weather_theme() { $theme['forecasts'] = [ 'variables' => ['country' => NULL, 'city' => NULL, 'forecast' => NULL], 'template' => 'forecasts', ]; return $theme; }

IN DRUPAL?3/3 // In the Controller public function forecasts($country,
$city) { $forecast = $this-‐>forecastService-‐>getForecasts($country, $city); return [ '#theme' => 'forecasts', '#country' => $country, '#city' => $city, '#forecast' => $forecast, ]; }

http://twig.sensiolabs.org

Need training? Come see us at the SensioLabs booth!

Come see us at the SensioLabs booth! Wanna know more
about

Come see us at the SensioLabs booth! Wanna make jokes
or know more about Lannister? @catlannister

Thank you! @saro0h speakerdeck.com/saro0h/ saro0h This is a zero guys!

DupalCon Barcelona 2015 - The journey from the request to the response

DupalCon Barcelona 2015 - The journey from the request to the response

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