Symfony2 Architecture
PHPCon, Szczyrk, 28 September 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)
Paul Erdős
Paul Erdős (1913–1996) was an influential mathematician who spent a large portion of his later life writing papers with a large number of colleagues, working on solutions to outstanding mathematical problems. He published more papers during his lifetime (at least 1,525) than any other mathematician in history.
Erdős number
The Erdős number describes the "collaborative distance" between a person and mathematician Paul Erdős, as measured by authorship of mathematical papers.
Erdős number
To be assigned an Erdős number, someone must be a coauthor of a research paper with another person who has a finite Erdős number. Paul Erdős has an Erdős number of zero. Anybody else's Erdős number is k + 1 where k is the lowest Erdős number of any coauthor.
Mariusz Gil number
# of Mariusz Gil PHPCon talks - # of your PHPCon talks
My Mariusz Gil number
1
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
Dependency Injection Container
Dependency Injection
<?php
class Newsletter
{
private $mailer;
public function __construct()
{
$this->mailer = new Mailer();
}
}
<?php
$newsletter = new Newsletter();
Dependency Injection
<?php
class Newsletter
{
private $mailer;
public function __construct(Mailer $mailer)
{
$this->mailer = $mailer;
}
}
<?php
$mailer = new Mailer();
$newsletter = new Newsletter($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: Mailer
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
Bridge
3rd party libraries integration
- Monolog
- Doctrine
- Propel
- Twig
- Swiftmailer
Bundle
Plugin, just fancy name
Bundle
- Doctrine
- Propel
- Twig
- Swiftmailer