Slides from the 'Symfony internals' talk at DeSymfony

3. Who am I?
Raúl Fraile
@raulfraile
PHP/Symfony2 freelance developer

4. What do I do?

5. SensioLabsConnect

6. Why?

8. app[_dev].php
Front controller

9. app[_dev].php
// web/app[_env].php
1. require_once __DIR__.'/../app/bootstrap.php.cache';
2. require_once __DIR__.'/../app/AppKernel.php';
3. use SymfonyComponentHttpFoundationRequest;
4. $kernel = new AppKernel('dev', true);
5. $kernel->loadClassCache();
6. $kernel->handle(Request::createFromGlobals())->send();

10. bootstrap.php.cache
Several classes/interfaces
in the same file

11. bootstrap.php.cache
// app/bootstrap.php.cache
namespace { require_once __DIR__.'/autoload.php'; }
namespace SymfonyComponentDependencyInjection
{
interface ContainerAwareInterface
{
function setContainer(ContainerInterface $container = null);
}
...
}

12. bootstrap.php.cache
Reduces I/O operations

13. bootstrap.php.cache
Loads autoload.php

14. autoload.php
// app/autoload.php
use SymfonyComponentClassLoaderUniversalClassLoader;
$loader = new UniversalClassLoader();
$loader->registerNamespaces(array(
'Symfony' => array(
__DIR__.'/../vendor/symfony/src',
__DIR__.'/../vendor/bundles'),
'Assetic' => __DIR__.'/../vendor/assetic/src',
));
$loader->registerPrefixes(array(
'Twig_' => __DIR__.'/../vendor/twig/lib',
));

15. ClassLoader
Autoloading of
classes/interfaces in
Symfony2

16. ClassLoader

17. ClassLoader
Implements PSR-0

18. PSR-0
Approved by the “Framework Interop
Group”
github.com/php-fig/fig-standards/blob/master/accepted/PSR-0.md

19. PSR-0
Fully Qualified Name
SymfonyCoreRequest
ZendMailMessage
[vendor_path]/Symfony/Core/Request.php
[vendor_path]/Zend/Mail/Message.php
Filesystem

20. ClassLoader
// namespaced class name
$namespace = substr($class, 0, $pos);
foreach ($this->namespaces as $ns => $dirs) {
if (0 !== strpos($namespace, $ns)) {
continue;
}
foreach ($dirs as $dir) {
$className = substr($class, $pos + 1);
$file = $dir . DIR_SEPARATOR .
str_replace('',DIR_SEPARATOR, $namespace) .
DIR_SEPARATOR .
str_replace('_', DIR_SEPARATOR, $className) . '.php';
if (file_exists($file)) {
return $file;
}
}
}

21. ClassLoader
$loader->findFile(
'SymfonyComponentHttpFoundationRequest'
);
/Sites/desymfony/app/../vendor/symfony/src/
Symfony/Component/HttpFoundation/Request.php

22. app[_dev].php
// web/app[_env].php
1. require_once __DIR__.'/../app/bootstrap.php.cache';
2. require_once __DIR__.'/../app/AppKernel.php';
3. use SymfonyComponentHttpFoundationRequest;
4. $kernel = new AppKernel('dev', true);
5. $kernel->loadClassCache();
6. $kernel->handle(Request::createFromGlobals())->send();

23. AppKernel.php
// src/AppKernel.php
use SymfonyComponentHttpKernelKernel;
use SymfonyComponentConfigLoaderLoaderInterface;
class AppKernel extends Kernel
{
public function registerBundles()
{
$bundles = array(
new SymfonyBundleTwigBundleTwigBundle(),
...
);
return $bundles;
}
public function registerContainerConfiguration(LoaderInterface $loader)
{
$loader->load(__DIR__.'/config/config_'.$this->getEnvironment().'.yml');
}
}

24. app[_dev].php
// web/app[_env].php
1. require_once __DIR__.'/../app/bootstrap.php.cache';
2. require_once __DIR__.'/../app/AppKernel.php';
3. use SymfonyComponentHttpFoundationRequest;
4. $kernel = new AppKernel('dev', true);
5. $kernel->loadClassCache();
6. $kernel->handle(Request::createFromGlobals())->send();
Debug
Environment

25. AppKernel.php
If (true === $debug) {
Saves initial time (microtime)
display_errors = 1
error_reporting = -1
DebugUniversalClassLoader
} else {
display_errors = 0
}

26. app[_dev].php
// web/app[_env].php
1. require_once __DIR__.'/../app/bootstrap.php.cache';
2. require_once __DIR__.'/../app/AppKernel.php';
3. use SymfonyComponentHttpFoundationRequest;
4. $kernel = new AppKernel('dev', true);
5. $kernel->loadClassCache();
6. $kernel->handle(Request::createFromGlobals())->send();

27. LoadClassCache
Objective: map
FQN/filenames of
classes and interfaces

28. LoadClassCache
It is cached in
classes.map and
classes.php.meta

29. app[_dev].php
// web/app[_env].php
1. require_once __DIR__.'/../app/bootstrap.php.cache';
2. require_once __DIR__.'/../app/AppKernel.php';
3. use SymfonyComponentHttpFoundationRequest;
4. $kernel = new AppKernel('dev', true);
5. $kernel->loadClassCache();
6. $kernel->handle(Request::createFromGlobals())->send();

30. Request
HttpFoundation
Component

31. Request
OO abstraction of a
HTTP request

32. Request
Request
GET /index.php HTTP/1.1␍␊
Host: test.com␍␊ $_GET
query
Accept-Language:en;q=0.8␍␊
request
Accept-Encoding:gzip␍␊ $_POST
cookies
User-Agent: Mozilla/5.0␍␊
␍␊ files
$_COOKIE
server
headers
$_FILES
getHost
$_SERVER
getClientIp
...

33. app[_dev].php
// web/app[_env].php
1. require_once __DIR__.'/../app/bootstrap.php.cache';
2. require_once __DIR__.'/../app/AppKernel.php';
3. use SymfonyComponentHttpFoundationRequest;
4. $kernel = new AppKernel('dev', true);
5. $kernel->loadClassCache();
6. $kernel->handle(Request::createFromGlobals())->send();

34. HttpKernel
Wrapper on top of
Request/Response to
handle the dynamic
part of HTTP

35. HttpKernel
Handles an
environment consisting
of bundles, DIC...

36. $kernel->boot()
Initialize
bundles and DIC

37. $kernel->initializeBundles()
Loads bundles defined in
AppKernel::registerBundles()

38. $kernel->initializeContainer()
Generated using the
ContainerBuilder from
DependencyInjection

39. ContainerBuilder
// example.com/src/container.php
use SymfonyComponentDependencyInjection;
use SymfonyComponentDependencyInjectionReference;
$sc = new DependencyInjectionContainerBuilder();
$sc->register('context', 'SymfonyComponentRoutingRequestContext');
$sc->register('matcher', 'SymfonyComponentRoutingMatcherUrlMatcher')
->setArguments(array($routes, new Reference('context')));
$sc->register('framework', 'SimplexFramework')
->setArguments(array(new Reference('dispatcher'), new
Reference('resolver'))) ;
http://fabien.potencier.org/article/62/create-your-own-framework-on-top-of-the-symfony2-components-part-12

40. $kernel->initializeContainer()
{rootDir}{Environment}
[Debug]ProjectContainer

41. $kernel->initializeContainer()
For each bundle,
Bundle::build() method is
executed and extensions
are loaded

42. $kernel->boot()
For each bundle, the
container is injected and
the boot() method is
executed

43. $kernel->handle()
Goal: Return a Response
object

44. Event kernel.request
Dispatched as soon as
the request arrives

45. Event kernel.request
Any listener can return
a Response and 'end'
the execution

46. Event kernel.request
Used by
FrameworkBundle to set
the _controller value

47. RouterListener
Uses a RouterMatcher
(autogenerated by the
Routing component)

48. RouterListener
// app/cache/dev/appdevUrlMatcher.php
class appdevUrlMatcher extends RedirectableUrlMatcher
{
...
public function match($pathinfo)
{
...
// _demo_hello
if (0 === strpos($pathinfo, '/demo/hello') &&
preg_match('#^/demo/hello/(?P<name>[^/]+?)$#s', $pathinfo, $m)) {
return array_merge($this->mergeDefaults($m, array(
'_controller' => 'AcmeDemoBundleControllerDemoController::helloAction')
), array( '_route' => '_demo_hello'));
}
...
}

49. ControllerResolver
Must return the controller
+ arguments from
_controller

50. FrameworkBundle
Ties components and
libraries together to make
a MVC framework

51. FrameworkBundle
Moreover...

52. FrameworkBundle
php app/console

53. FrameworkBundle
// app/console
#!/usr/bin/env php
<?php
require_once __DIR__.'/bootstrap.php.cache';
require_once __DIR__.'/AppKernel.php';
use SymfonyBundleFrameworkBundleConsoleApplication;
use SymfonyComponentConsoleInputArgvInput;
$input = new ArgvInput();
$env = $input->getParameterOption(array('--env', '-e'), getenv('SYMFONY_ENV') ?: 'dev');
$debug = !$input->hasParameterOption(array('--no-debug', ''));
$kernel = new AppKernel($env, $debug);
$application = new Application($kernel);
$application->run();

54. FrameworkBundle
Commands
assets:install
cache:clear
cache:warmup
container:debug
router:dump-apache
router:debug

55. FrameworkBundle
Base Controller

56. FrameworkBundle
// src/Acme/DemoBundle/Controller/DemoController
namespace AcmeDemoBundleController;
use SymfonyBundleFrameworkBundleControllerController;
class DemoController extends Controller
{
public function helloAction($name)
{
...
}
}

57. FrameworkBundle
And much more: ESI,
WebTestCase,
DataCollectors...

58. Event kernel.controller
Once the controller has
been resolved, this
event is generated

59. Event kernel.controller
Any listener can
manipulate the
Controller callable

60. Event kernel.view
This event is called only
if the Controller does
not return a Response

61. Event kernel.view
Goal: build a Response
object from the return
value of the Controller

62. Event kernel.response
Allows to modify or
replace the Response
object after its creation

63. Event kernel.exception
Last change to convert a
Exception into a
Response object

64. Events
Extend from KernelEvent
getRequestType(): MASTER_REQUEST or SUB_REQUEST
getKernel();
getRequest();

65. Response
Response
HTTP/1.1 200 OK
Headers Content-type: text/html
Date:Thu, 31 May 2012 17:54:50 GMT
Version
Content <!DOCTYPE HTML>
<html lang="es">
<head>
Status code
<meta charset="utf-8">
...
Status text
Charset

66. app[_dev].php
// web/app[_env].php
1. require_once __DIR__.'/../app/bootstrap.php.cache';
2. require_once __DIR__.'/../app/AppKernel.php';
3. use SymfonyComponentHttpFoundationRequest;
4. $kernel = new AppKernel('dev', true);
5. $kernel->loadClassCache();
6. $kernel->handle(Request::createFromGlobals())->send();

67. Response::send()
Send headers and
content

68. Response::send()

69. Demo
https://github.com/raulfraile/
internals-desymfony2012

70. ¡Thank you!

71. Photos
http://www.flickr.com/photos/connectirmeli/7233514862
http://www.flickr.com/photos/barretthall/6070677596
http://www.flickr.com/photos/f-oxymoron/5005673112/

72. Questions?