This document discusses various ways to customize Symfony2 applications, including: 1. Customizing the dependency injection container by modifying services, parameters, and adding compiler passes. 2. Leveraging events by creating custom event classes, dispatching events, and adding event listeners. 3. Extending and overriding bundles by creating child bundles, overriding controllers, routing, and templates. 4. Using external tools like Composer, React, PHP Process Manager, and Varnish to enhance applications.

1. Symfony2 your way
by Rafał Wrzeszcz, 2014
rafal.wrzeszcz@wrzasq.pl
http://wrzasq.pl/
http://chilldev.pl/
https://github.com/rafalwrzeszcz
https://linkedin.com/in/rafalwrzeszcz

2. Symfony2 – ways to customize
● Dependency Injection Container
● Code
● Bundles
● External tools

3. Dependency Injection
(yet without “Container”)
class DataSource {
protected $adapter;
protected $prefix;
public function __construct(
DataAdapter $adapter,
$prefix
) {
$this->adapter = $adapter;
$this->prefix = $prefix;
}
}
class DataAdapter {
protected $sources;
public function __construct(
array $sources
) {
$this->sources = $sources;
}
}
$conn = new DataAdapter(
['srv1', 'srv2']
);$db = new DataSource(
$conn,
'prod.'
);

4. Putting dependencies into Container
class MyExtension extends Extension
{
public function load(
array $configs,
ContainerBuilder $container
) {
$loader = new XmlFileLoader(
$container,
new FileLocator(__DIR__ .
'/../Resources/config')
);
$loader->load('services.xml');
}
}
<parameter key="my.prefix">prod.</parameter>
<parameter key="my.sources" type="collection">
<parameter>srv1</parameter>
<parameter>srv2</parameter>
</parameter>
<service id="my.dataadapter" class="DataAdapter">
<argument>%my.sources%</argument>
</service>
<service id="my.datasource" class="DataSource">
<argument type="service"
id="my.dataadapter"/>
<argument>%my.prefix%</argument>
</service>
$db = $di->get(
'my.datasource'
);

5. Semantic configuration
my:
prefix: "prod."
sources:
- "srv1"
- "srv2"
class Configuration
implements ConfigurationInterface
{
public function getConfigTreeBuilder() {
$treeBuilder = new TreeBuilder();
$treeBuilder->root('my')
->children()
->scalarNode('prefix')->end()
->arrayNode('sources')
->prototype('scalar')->end()
->end()
->end();
return $treeBuilder;
}
}
//MyExtension::load()
$config = $this->processConfiguration(
new Configuration(),
$configs);
$container->setParameter(
'my.prefix', $config['prefix']);
$container->setParameter(
'my.sources', $config['sources']);

6. Alles zusammen
my:
prefix: "prod."
sources:
- "srv1"
- "srv2"
$db = $di->get(
'my.datasource'
);
Services
definitions
Configuration
schema
DI
extension

7. Overriding services and parameters
services:
form.resolved_type_factory:
class: "MyBundleApplicationBundleFormProfiledTypeFactory"
arguments:
- "@profiler"
parameters:
web_profiler.debug_toolbar.position: "top"

8. Less invasive way - %*.class%
parameters:
form.resolved_type_factory.class: "MyBundleApplicationBundleFormProfiledTypeFactory"

9. Adding .class parameter
<service id="my.dataadapter" class="DataAdapter">
<argument>%my.sources%</argument>
</service>
<service id="my.datasource" class="DataSource">
<argument type="service"
id="my.dataadapter"/>
<argument>%my.prefix%</argument>
</service>
<parameter key="my.dataadapter.class">DataAdapter</parameter>
<parameter key="my.datasource.class">DataSource</parameter>
<service id="my.dataadapter" class="%my.dataadapter.class%">
<argument>%my.sources%</argument>
</service>
<service id="my.datasource" class="%my.datasource.class%">
<argument type="service" id="my.dataadapter"/>
<argument>%my.prefix%</argument>
</service>

10. DIC compiler
Loading all extensions
Merging them
DIC compiler
Dumping compiled DIC
into cache

11. Creating own compiler phase
class MyPass implements CompilerPassInterface
{
public function process(ContainerBuilder $container)
{
if ($container->hasDefinition('form.resolved_type_factory')) {
$definition = $container->getDefinition('form.resolved_type_factory');
$definition->setClass('MyBundleApplicationBundleFormProfiledTypeFactory');
$definition->addMethodCall(
'setProfiler',
[new Reference('profiler')]
);
}
}
}

12. Registering compiler pass
class MyBundle extends Bundle
{
public function build(ContainerBuilder $container)
{
parent::build($container);
$container->addCompilerPass(
new MyCompilerPass(),
PassConfig::TYPE_OPTIMIZE
);
}
}

13. Adding tags to services
<parameter key="my.dataadapter.class">DataAdapter</parameter>
<parameter key="my.datasource.class">DataSource</parameter>
<service id="my.dataadapter" class="%my.dataadapter.class%">
<argument>%my.sources%</argument>
<tag name="my.datasource" alias="data" prefix="%my.prefix_data%"/>
<tag name="my.datasource" alias="meta" prefix="%my.prefix_meta%"/>
</service>

14. Own tags handler
class MyPass implements CompilerPassInterface
{
public function process(ContainerBuilder $container)
{
$class = $container->getParameter('my.datasource.class');
foreach ($container->findTaggedServiceIds('my.datasource') as $id => $tags) {
foreach ($tags as $tag) {
$definition = $container->register($tag['alias'], $class);
$definition->setArguments([
new Reference($id),
$tag['prefix']
]);
}
}
}
}

15. Most important pre-defined tags
● twig.extension/templating.helper – registering templating helpers,
● security.voter – custom security access logic,
● monolog.logger – marking specific channels for the logger,
● kernel.event_listener/kernel.event_subscriber – subscribing to
events,
● data_collector – web profiler data collector.
More on http://symfony.com/doc/current/reference/dic_tags.html.

16. Symfony2 – ways to customize
● Dependency Injection Container
● Code
● Bundles
● External tools

17. Events
● move your non-core features to event handlers,
● keep core logic thin and simple,
● provide before and after events.

18. Custom event object
class MyLibFormEvent extends Event
{
const FORM_SUBMITTED = 'my_lib.form.event.submitted';
const FORM_HANDLED = 'my_lib.form.event.handled';
// properties
public function __construct(/* custom event params */)
{
// assign properties
}
// getters and setters
}

19. Dispatching the event
$eventDispatcher = $di->get('event_dispatcher');
$eventDispatcher->dispatch(
MyLibFormEvent::FORM_SUBMITTED,
new MyLibFormEvent(/* custom data */)
);
// process form
$eventDispatcher->dispatch(
MyLibFormEvent::FORM_HANDLED,
new MyLibFormEvent(/* custom data */)
);

20. Subscribing to events
$di->get('event_dispatcher')->addListener(
MyLibFormEvent::FORM_SUBMITTED,
function (MyLibFormEvent $event)
{
// handle the event
}
);

21. Symfony kernel events
● kernel.requestnew request is being dispatched,
● kernel.responseresponse is generated by request handler (like controller),
● kernel.finish_requestfired after request is handled – regardless of operation
status,
● kernel.terminateresponse is already sent – we can perform some heavy tasks that
won’t afect page load,
● kernel.exceptionunhandled exception occured during request handling.

22. DI tag event_listener
<service id="my.lib.response_listener" class="%my.lib.response_listener.class%">
<tag name="kernel.event_listener" event="kernel.response" method="onKernelResponse"/>
</service>

23. JMSAopBundle
"jms/aop-bundle": "1.0.1"

24. Writing own aspects
<service id="my.lib.security.pointcut" class="%my.lib.security.pointcut.class%">
<tag name="jms_aop.pointcut" interceptor="my.lib.security.interceptor"/>
</service>
<service id="my.lib.security.interceptor" class="%my.lib.security.interceptor.class%"/>

25. Pointcut
class MySecurityPointcut implements PointcutInterface
{
public function matchesClass(ReflectionClass $class)
{
return $class->implementsInterface('MyDataAdapterInterface');
}
public function matchesMethod(ReflectionMethod $method)
{
return $method->getName() == 'read';
}
}

26. Interceptor
class MySecurityInterceptor implements MethodInterceptorInterface
{
public function intercept(MethodInvocation $invocation)
{
if (/* security checks */) {
// you can modify $invocation->arguments array
$result = $invocation->proceed();
// you can post-process results
return $result;
} else {
throw new SecurityException('Unauthorized access attempt.');
}
}
}

27. Symfony2 – ways to customize
● Dependency Injection Container
● Code
● Bundles
● External tools

28. Bundles inheritance
class MySecurityBundle extends Bundle
{
public function getParent()
{
return 'SonataUserBundle';
}
}

29. Overriding controllers
class AdminSecurityController
extends SonataUserBundleControllerAdminSecurityController
{
public function loginAction()
{
// own login handling logic
}
}

30. Overriding routing
_admin_security:
# cascade checks:
# MySecurityBundle/Resources/config/routing/admin_security.xml
# SonataUserBundle/Resources/config/routing/admin_security.xml
resource: "@SonataUserBundle/Resources/config/routing/admin_security.xml"
prefix: "/admin"

31. Overriding templates
public function loginAction()
{
// action logic
return $this->templating->renderResponse(
'SonataUserBundle:Admin:Security/login.html.php',
$params
);
}

32. Overriding versus extending
{# MySecurityBundle/Resources/views/Admin/Security/login.html.twig #}
{% extends '::layout.html.twig' %}
{% block sidebar %}
<h3>Table of Contents</h3>
{# ... #}
{{ parent() }}
{% endblock %}

33. Application templates
● app/Resources/MySecurityBundle/views/Admin/Security/login.html.php
application resource,
● src/MySecurityBundle/Resources/views/Admin/Security/login.html.php
inheriting bundle,
● src/SonataUserBundle/Resources/views/Admin/Security/login.html.php
source template.

34. Symfony2 – ways to customize
● Dependency Injection Container
● Code
● Bundles
● External tools

35. Composer
https://getcomposer.org/
wget -O - https://getcomposer.org/installer
| php -- --install-dir=/usr/local/bin

36. Scripts
incenteev/composer-parameter-handler:
ScriptHandler::buildParameters
sensio/distribution-bundle:
ScriptHandler::buildBootstrap
ScriptHandler::clearCache
ScriptHandler::installAssets
ScriptHandler::installRequirementsFile
ScriptHandler::removeSymfonyStandardFiles

37. Autoloading overriding
{
"autoload": {
"classmap": ["src/Symfony/"]
}
}

38. React
(react/http)
$app = function ($request, $response) {
$response->writeHead(200, ['Content-Type' => 'text/plain']);
$response->end("Hello Worldn");
};
$loop = ReactEventLoopFactory::create();
$socket = new ReactSocketServer($loop);
$http = new ReactHttpServer($socket, $loop);
$http->on('request', $app);
$socket->listen(1337);
$loop->run();

39. PHP ProcessManager
(marcj/php-pm)
http://marcjschmidt.de/blog/2014/02/08/php-high-performance.html
./bin/ppm start ~/my/path/to/symfony/ --bridge=httpkernel

40. Varnish
templating:
esi: true

41. ESI example
<body>
<?php echo $this['actions']->render(
$this['actions']->controller('MySecurityBundle:Panel:sidebar'),
['strategy' => 'esi']
); ?>
<h1>My blog</h1>
<?php /* page content */ ?>
</body>

42. QA tools – CLI
● php -l
● phpcs (squizlabs/php_codesniffer)
● phpcpd (sebastian/phpcpd)
● phpmd (phpmd/phpmd)
● phpunit (phpunit/phpunit)
● phpdoc (phpdocumentor/phpdocumentor)

43. QA tools – in the cloud
● CIfor open source – Travis (https://travis-ci.org/),
● Version Eyedependencies tracking
(https://www.versioneye.com/),
● Coverallscode coverage tracking (https://coveralls.io/).

44. Scrutinizer
https://scrutinizer-ci.com/

45. SensioLabs Insights
https://insight.sensiolabs.com/

46. Thank you!