Symfony2 Architecture
Drupal Camp, Wrocław, 18 October 2014
Michał Pipa
About me
- Michał Pipa (@michalpipa)
- Software developer and trainer at Iteo
- Zend Certified Engineer
- Free software enthusiast (Symfony)
- PHPers Silesia
- Polish Symfony Community (#symfony-pl)
What is Symfony?
Symfony2 is a reusable set of standalone, decoupled, and cohesive PHP components that solve common web development problems.
Symfony2 is also a full-stack web framework.
What about MVC?
Symfony2 is an HTTP framework; it is a Request/Response framework.
Bridge
Bundle
Component
Components
- Console
- CssSelector
- Expression Language
- Finder
- Process
- YAML
Bridge
3rd party libraries integration
- Monolog
- Doctrine
- Propel
- Twig
- Swiftmailer
Bundle
Plugin, just fancy name
Bundle
- Doctrine
- Propel
- Twig
- Swiftmailer
Dependency Injection Container
Dependency Injection
<?php
class Newsletter
{
private $mailer;
public function __construct()
{
$this->mailer = new MyMailer();
}
}
<?php
$newsletter = new Newsletter();
Dependency Injection
<?php
interface Mailer
{
public function send();
}
Dependency Injection
<?php
class Newsletter
{
private $mailer;
public function __construct(Mailer $mailer)
{
$this->mailer = $mailer;
}
}
<?php
$mailer = new MyMailer();
$newsletter = new Newsletter($mailer);
Dependency Injection
<?php
class Newsletter
{
private $mailer;
public function __construct(Mailer $mailer)
{
$this->mailer = $mailer;
}
}
<?php
$mailer = new FakeMailer();
$newsletter = new Newsletter($mailer);
Dependency Injection Container
# app/config/config.yml
services:
mailer:
class: MyMailer
newsletter:
class: Newsletter
arguments: ["%mailer%"]
Dependency Injection Container
<?php
use Symfony\Component\DependencyInjection\ContainerBuilder;
$container = new ContainerBuilder();
// ...
$newsletter = $container->get('newsletter');
Event Dispatcher
Provides tools that allow your application components to communicate with each other by dispatching events and listening to them.
Event Dispatcher
<?php
use Symfony\Component\EventDispatcher\EventDispatcher;
$dispatcher = new EventDispatcher();
Event Dispatcher
<?php
$event = new Event();
$dispatcher->dispatch('order.create', $event);
Event Dispatcher
<?php
class OrderListener
{
public function onCreate(Event $event)
{
// do something
}
}
Event Dispatcher
<?php
$listener = new OrderListener();
$dispatcher->addListener('order.create', array($listener, 'onCreate'));
Event Dispatcher
# app/config/config.yml
services:
kernel.listener.order_listener:
class: OrderListener
tags:
- { name: kernel.event_listener, event: order.create, method: onCreate }
HttpFoundation
The HttpFoundation component defines an object-oriented layer for the HTTP specification.
HttpFoundation
- Request
- Response
- Session
HttpKernel
The HttpKernel component provides a structured process for converting a Request into a Response by making use of the EventDispatcher.
HttpKernel
- Thin wrapper on top of the Request and Response classes to standardize the way requests are handled
- Provides extension points and tools for web frameworks
- HttpKernel class
- HttpKernelInterface
HttpKernelInterface
<?php
namespace Symfony\Component\HttpKernel;
use Symfony\Component\HttpFoundation\Request;
interface HttpKernelInterface
{
/**
* @return Response A Response instance
*/
public function handle(
Request $request,
$type = self::MASTER_REQUEST,
$catch = true
);
}
HttpKernel events
- kernel.request
- kernel.controller
- kernel.view
- kernel.response
- kernel.terminate
The kernel.request Event
Typical Purposes: To add more information to the Request, initialize parts of the system, or return a Response if possible (e.g. a security layer that denies access).
The kernel.request Event
The kernel.request Event
The kernel.request in the Symfony Framework
- RouterListener
Resolve the Controller
ControllerResolverInterface
<?php
namespace Symfony\Component\HttpKernel\Controller;
use Symfony\Component\HttpFoundation\Request;
interface ControllerResolverInterface
{
public function getController(Request $request);
public function getArguments(Request $request, $controller);
}
The kernel.controller Event
Typical Purposes: Initialize things or change the controller just before the controller is executed.
The kernel.controller Event
The kernel.controller in the Symfony Framework
- @ParamConverter
Getting the Controller Arguments
Calling the Controller
Calling the Controller
The kernel.view Event
Typical Purposes: Transform a non-Response return value from a controller into a Response
The kernel.view Event
The kernel.view in the Symfony Framework
- @Template
- FOSRestBundle
The kernel.response Event
Typical Purposes: Modify the Response object just before it is sent
The kernel.response in the Symfony Framework
- WebDebugToolbarListener
- ContextListener serializes the current user's information into the session so that it can be reloaded on the next request
The kernel.terminate Event
Typical Purposes: To perform some "heavy" action after the response has been streamed to the user
The kernel.terminate Event
<?php
// send the headers and echo the content
$response->send();
// triggers the kernel.terminate event
$kernel->terminate($request, $response);
kernel.terminate in the Symfony Framework
- EmailSenderListener
The kernel.exception Event
Typical Purposes: Handle some type of exception and create an appropriate Response to return for the exception
The kernel.exception Event
