Wojciech Sznapka - XSolve - Osiąganie mądrej architektury z Symfony2

1. Achieving wise architecture
with Symfony2
Wojciech Sznapka
ALEJE.IT

2. Cześć!

3. Wojciech Sznapka
Technical Manager @ XSolve
Zend Certified Engineer since 2010
Symfony Framework since 2008
PHP since 2004
Web development since 2001
Besides: ice hockey, windsurfing, skiing, crime stories

4. How can
architecture
be bad?

5. Classes with
hundreds
lines of code?

6. Model mixed with
View located in
Controler ?

7. Changes and
maintanance
costing fortune ?

8. Crashing due to
enormous load ?

9. Unable to migrate
to cloud ?

10. Yes, that's bad!

11. Make it
wisely
with Symfony2

12. Most popular
framework in
PHP ecosystem

13. 2078 Forks
6245 Favs
1910 Bundles

14. Built on top of
best patterns

15. So... is
Symfony2
a silver bullet?

16. Symfony2 is only
good tool ...

17. … but even good tools
can be used poorly

18. So let's keep in mind
three good rules...

19. Rule #1:
SOLID

20. S ingle responsibility principle
O pen/closed principle
L iskov substitution principle
I nterface segregation principle
D ependency inversion principle

21. Each service should have
exactly one
purpose

22. Other responsibilities
should be
aggregated in services
injected as dependencies

23. <?php
namespace WowoNewsletterBundleNewsletterModel;
class MailingManager implements MailingManagerInterface
{
protected $templateManager;
public function __construct(TemplateManagerInterface $templateManager)
{
$this->templateManager = $templateManager;
}
public function createMailing($data, Mailing $mailing)
{
$body = $this->templateManager->applyTemplate($mailing->getBody(), $mailing->getTitle());
$mailing->setBody($body);
$mailing->setSubject($data['subject']);
return $mailing;
}
}

24. Services should be
closed for modification
But opened for extension

25. Abstract classes
helps with
Open/Closed principle

26. <?php
abstract class Animal
{
public function makeHappySound()
{
return sprintf("Happilly %sn", $this->speak());
}
abstract public function speak();
}
class Dog extends Animal
{
function speak()
{
return "Woof, woof!";
}
}
class Cat extends Animal
{
function speak()
{
return "Meow...";
}
}
foreach (array(new Dog, new Cat) as $creature) {
printf($creature->makeHappySound());
}

27. It should be possible to
replace class with other
implementation

28. <?xml version="1.0" ?>
<container xmlns="http://symfony.com/schema/dic/services"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://symfony.com/schema/dic/services
http://symfony.com/schema/dic/services/services-1.0.xsd">
<parameters>
<parameter
key="mailing_manager.class">WowoNewsletterBundleNewsletterModelMailingManager</parameter>
</parameters>
<services>
<service id="wowo_newsletter.mailing_manager" class="%mailing_manager.class%">
<argument type="service" id="wowo_newsletter.entity_manager" />
<argument>%wowo_newsletter.model.contact.class%</argument>
<call method="setTemplateManager">
<argument type="service" id="wowo_newsletter.template_manager"/>
</call>
</service>
</services>
</container>
#config_dev.yml
parameters:
mailing_manager.class: WowoNewsletterBundleMocksMailingManagerFancyMock

29. Interfaces should be
fine grained

30. Many specific interfaces
Are better than one
general­purpose

31. <?php
interface PlaceholderProcessorInterface
{
public function process($object, $body);
}
interface TemplateManagerInterface
{
public function setAvailableTemplates(array $templates);
public function getAvailableTemplates();
public function applyTemplate($body, $title);
}
interface MediaManagerInterface
{
public function embed($body, Swift_Message $message);
public function getRegex($name);
}
interface BuilderInterface
{
public function buildMessage($mailingId, $contactId, $contactClass);
}
interface SenderInterface
{
public function send($mailingId, $contactId, $contactClass);
}

32. Application should be
decoupled into
dependant upon
abstractions modules

33. <?xml version="1.0" ?>
<container xmlns="http://symfony.com/schema/dic/services"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://symfony.com/schema/dic/services
http://symfony.com/schema/dic/services/services-1.0.xsd">
<services>
<service id="twig.extension.acme.demo"
class="AcmeDemoBundleTwigExtensionDemoExtension" public="false">
<tag name="twig.extension" />
<argument type="service" id="twig.loader" />
</service>
<service id="acme.demo.listener" class="AcmeDemoBundleEventListenerControllerListener">
<tag name="kernel.event_listener" event="kernel.controller"
method="onKernelController" />
<argument type="service" id="twig.extension.acme.demo" />
</service>
</services>
</container>

34. Rule #2:
Maintainability

35. Live application needs
to be tested

36. Behat and/or unit tests

37. Live application needs
logging

38. <?php
class MailingPersistService implements PersistService, LoggerAware
{
// [...]
protected $logger;
public function setLogger(Logger $logger)
{
$this->logger = $logger;
}
public function Mailing(EntityMailing $mailing)
{
$user = $this->security->getUser();
try {
$this->entityManager->persist($mailing);
$this->logger->info(sprintf('Mailing #%d %s has been saved by %s',
$mailing->getId(), $mailing, $user),
array('mailing' => $mailing, 'user' => $user));
} catch (Exception $e) {
$this->logger->err(sprintf('Problem while saving mailing by user %s: %s',
$user, $e->getMessage()),
array('exception' => $e, 'user' => $user));
}
}

39. Live application needs
monitoring

40. Nagios or New Relic

41. Rule #3:
Scalability

42. Forget about local disk!

43. Keep sessions in
global storage
like database or NoSQL

44. Store user files
global storage
like S3 or MongoFS

45. Write logs to
central logger
like syslogd or logstash

46. Scale your DB with
master/slave connections
using Doctrine

47. Wise
architecture
ingridients

48. Design based on
SOLID principles

49. Problems solved with
existing bundles
made by community

50. Code covered with
automatic tests

51. Logging and monitoring

52. Ready to
scale horizontally

53. Dziękuję!

55. Wojciech Sznapka
wojciech@sznapka.pl
blog.sznapka.pl
@sznapka
@wowo