1. The state of DI in PHP

2. The state of DI in PHP
About me
 Stephan Hochdörfer, bitExpert AG
 Department Manager Research Labs
 enjoying PHP since 1999
 7 years of DI experience (in PHP)
 S.Hochdoerfer@bitExpert.de
 @shochdoerfer

3. The state of DI in PHP
What`s this talk about?

4. The state of DI in PHP
What`s this talk about?
No framework bashing! Hopefully :)

5. The state of DI in PHP
What`s this talk about?
It`s all about how
DI is implemented.

6. The state of DI in PHP
What`s DI about?

7. The state of DI in PHP
Inversion of control

8. The state of DI in PHP
„Hollywood principle“

9. The state of DI in PHP
What`s DI about?
new TalkService(new TalkRepository());

10. The state of DI in PHP
What`s DI about?
Consumer

11. The state of DI in PHP
What`s DI about?
Consumer Dependencies

12. The state of DI in PHP
What`s DI about?
Consumer Dependencies Container

13. The state of DI in PHP
What`s DI about?
Consumer Dependencies Container

14. The state of DI in PHP
A little bit of history...

15. The state of DI in PHP
1988
„Designing Reusable Classes“
Ralph E. Johnson & Brian Foote

16. The state of DI in PHP
1996
„The Dependency Inversion Principle“
Robert C. Martin

17. The state of DI in PHP
2002

18. The state of DI in PHP
2003
Spring Framework 0.9 released

19. The state of DI in PHP
2004
„Inversion of Control Containers and
the Dependency Injection pattern“
Martin Fowler

20. The state of DI in PHP
2004
Spring Framework 1.0 released

21. The state of DI in PHP
2004
PHP 5.0 released

22. The state of DI in PHP
2005 / 2006
Garden, a lightweight
DI container for PHP.

23. The state of DI in PHP
2006
First PHP5 framework
with DI support

24. The state of DI in PHP
2007
International PHP Conference 2007
features 2 talks about DI.

25. The state of DI in PHP
2009
PHP 5.3.0 released

26. The state of DI in PHP
2010
Fabien Potencier talks about
„Dependency Injection in
PHP 5.2 and 5.3“

27. The state of DI in PHP
2011
Symfony2, Flow3,
Zend Framework 2 (beta)

28. The state of DI in PHP
2012
And now?

29. The state of DI in PHP
DI has finally arrived in the PHP world!

30. The state of DI in PHP
Let`s have a look at the
different implementations!

31. The state of DI in PHP

32. The state of DI in PHP
ZendDi – First steps
<?php
namespace Acme;
class TalkService {
public function __construct() {
}
public function getTalks() {
}
}

33. The state of DI in PHP
ZendDi – First steps
<?php
$di = new ZendDiDi();
$service = $di->get('AcmeTalkService');
$service->getTalks();

34. The state of DI in PHP
ZendDi – Constructor Injection
<?php
namespace Acme;
interface GenericRepository {
public function readTalks();
}
class TalkRepository implements GenericRepository {
public function readTalks() {
}
}
class TalkService {
public function __construct(TalkRepository $repo) {
}
public function getTalks() {
}
}

35. The state of DI in PHP
ZendDi – Constructor Injection
<?php
$di = new ZendDiDi();
$service = $di->get('AcmeTalkService');
$service->getTalks();

36. The state of DI in PHP
ZendDi – Setter Injection
<?php
namespace Acme;
class Logger {
public function doLog($logMsg) {
}
}
class TalkService {
public function __construct(TalkRepository $repo) {
}
public function setLogger(Logger $logger) {
}
public function getTalks() {
}
}

37. The state of DI in PHP
ZendDi – Setter Injection
<?php
$di = new ZendDiDi();
$di->configure(
new ZendDiConfiguration(
array(
'definition' => array(
'class' => array(
'AcmeTalkService' => array(
'setLogger' => array('required' => true)
)
)
)
)
)
);
$service = $di->get('AcmeTalkService');
var_dump($service);

38. The state of DI in PHP
ZendDi – Interface Injection
<?php
namespace Acme;
class Logger {
public function doLog($logMsg) {
}
}
interface LoggerAware {
public function setLogger(Logger $logger);
}
class TalkService implements LoggerAware {
public function __construct(TalkRepository $repo) {
}
public function setLogger(Logger $logger) {
}
public function getTalks() {
}
}

39. The state of DI in PHP
ZendDi – Interface Injection
<?php
$di = new ZendDiDi();
$service = $di->get('AcmeTalkService');
$service->getTalks();

40. The state of DI in PHP
ZendDi – General usage
<?php
$di = new ZendDiDi();
$service = $di->get('AcmeTalkService');
var_dump($service);
$service2 = $di->get('AcmeTalkService');
var_dump($service2); // same instance as $service
$service3 = $di->get(
'AcmeTalkService',
array(
'repo' => new phpbnl12TalkRepository()
)
);
var_dump($service3); // new instance

41. The state of DI in PHP
ZendDi – Builder Definition
<?php
// describe dependency
$dep = new ZendDiDefinitionBuilderPhpClass();
$dep->setName('AcmeTalkRepository');
// describe class
$class = new ZendDiDefinitionBuilderPhpClass();
$class->setName('AcmeTalkService');
// add injection method
$im = new ZendDiDefinitionBuilderInjectionMethod();
$im->setName('__construct');
$im->addParameter('repo', 'AcmeTalkRepository');
$class->addInjectionMethod($im);
// configure builder
$builder = new ZendDiDefinitionBuilderDefinition();
$builder->addClass($dep);
$builder->addClass($class);

42. The state of DI in PHP
ZendDi – Builder Definition
<?php
// add to Di
$defList = new ZendDiDefinitionList($builder);
$di = new ZendDiDi($defList);
$service = $di->get('AcmeTalkService');
var_dump($service);

43. The state of DI in PHP

44. The state of DI in PHP
Symfony2
<?php
namespace AcmeTalkBundleController;
use SymfonyBundleFrameworkBundleControllerController;
use SensioBundleFrameworkExtraBundleConfigurationRoute;
use SensioBundleFrameworkExtraBundleConfigurationTemplate;
class TalkController extends Controller {
/**
* @Route("/", name="_talk")
* @Template()
*/
public function indexAction() {
$service = $this->get('acme.talk.service');
return array();
}
}

45. The state of DI in PHP
Symfony2 – Configuration file
File services.xml in src/Acme/DemoBundle/Resources/config
<?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">
</container>

46. The state of DI in PHP
Symfony2 – Constructor Injection
<?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="acme.talk.repo"
class="AcmeTalkBundleServiceTalkRepository" />
<service id="acme.talk.service"
class="AcmeTalkBundleServiceTalkService">
<argument type="service" id="acme.talk.repo" />
</service>
</services>
</container>

47. The state of DI in PHP
Symfony2 – Setter Injection
<?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="acme.talk.logger"
class="AcmeTalkBundleServiceLogger" />
<service id="acme.talk.repo"
class="AcmeTalkBundleServiceTalkRepository" />
<service id="acme.talk.service"
class="AcmeTalkBundleServiceTalkService">
<argument type="service" id="acme.talk.repo" />
<call method="setLogger">
<argument type="service" id="acme.talk.logger" />
</call>
</service>
</services>
</container>

48. The state of DI in PHP
Symfony2 – Setter Injection (optional)
<?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="acme.talk.logger"
class="AcmeTalkBundleServiceLogger" />
<service id="acme.talk.repo"
class="AcmeTalkBundleServiceTalkRepository" />
<service id="acme.talk.service"
class="AcmeTalkBundleServiceTalkService">
<argument type="service" id="acme.talk.repo" />
<call method="setLogger">
<argument type="service" id="acme.talk.logger"
on-invalid="ignore" />
</call>
</service>
</services>
</container>

49. The state of DI in PHP
Symfony2 – Property Injection
<?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="acme.talk.repo"
class="AcmeTalkBundleServiceTalkRepository" />
<service id="acme.talk.service"
class="AcmeTalkBundleServiceTalkService">
<property name="talkRepository" type="service"
id="acme.talk.repo" />
</service>
</services>
</container>

50. The state of DI in PHP
Symfony2 – private/public Services
<?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="acme.talk.logger"
class="AcmeTalkBundleServiceLogger" public="false" />
<service id="acme.talk.repo"
class="AcmeTalkBundleServiceTalkRepository" />
<service id="acme.talk.service"
class="AcmeTalkBundleServiceTalkService">
<argument type="service" id="acme.talk.repo" />
<call method="setLogger">
<argument type="service" id="acme.talk.logger" />
</call>
</service>
</services>
</container>

51. The state of DI in PHP
Symfony2 – Service inheritance
<?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="acme.talk.serviceparent"
class="AcmeTalkBundleServiceTalkService" abstract="true">
<property name="talkRepository" type="service"
id="acme.talk.repo" />
</service>
<service id="acme.talk.service" parent="acme.talk.serviceparent" />
<service id="acme.talk.service2" parent="acme.talk.serviceparent" />
</services>
</container>

52. The state of DI in PHP
Symfony2 – Service scoping
<?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="acme.talk.repo"
class="AcmeTalkBundleServiceTalkRepository" />
<service id="acme.talk.service"
class="AcmeTalkBundleServiceTalkService" scope="prototype">
<property name="talkRepository" type="service"
id="acme.talk.repo" />
</service>
</services>
</container>

53. The state of DI in PHP

54. The state of DI in PHP
Flow3 – Constructor Injection
<?php
namespace AcmeDemoController;
use TYPO3FLOW3Annotations as FLOW3;
/**
* @FLOW3Scope("session")
*/
class StandardController extends TYPO3FLOW3MVCControllerActionController {
/**
* @var AcmeDemoServiceTalkServiceInterface
*/
protected $talkService;
public function __construct(
AcmeDemoServiceTalkService $talkService) {
$this->talkService = $talkService;
}
public function indexAction() {
}
}

55. The state of DI in PHP
Flow3 – Constructor Injection (manually)
<?php
namespace AcmeDemoController;
use TYPO3FLOW3Annotations as FLOW3;
/**
* @FLOW3Scope("session")
*/
class StandardController extends TYPO3FLOW3MVCControllerActionController {
/**
* @var AcmeDemoServiceTalkServiceInterface
*/
protected $talkService;
public function __construct(
AcmeDemoServiceTalkService $talkService) {
$this->talkService = $talkService;
}
public function indexAction() {
}
}

56. The state of DI in PHP
Flow3 – Setter Injection (manually)
<?php
namespace AcmeDemoController;
use TYPO3FLOW3Annotations as FLOW3;
/**
* @FLOW3Scope("session")
*/
class StandardController extends TYPO3FLOW3MVCControllerActionController {
/**
* @var AcmeDemoServiceTalkServiceInterface
*/
protected $talkService;
public function setTalkService(
AcmeDemoServiceTalkService $talkService) {
$this->talkService = $talkService;
}
public function indexAction() {
}
}

57. The state of DI in PHP
Flow3 – Setter Injection (manually)
File Objects.yaml in Packages/Application/Acme.Demo/Configuration
# @package Acme
AcmeDemoControllerStandardController:
properties:
talkService:
object: AcmeDemoServiceTalkService

58. The state of DI in PHP
Flow3 – Setter Injection (Automagic)
<?php
namespace AcmeDemoController;
use TYPO3FLOW3Annotations as FLOW3;
/**
* @FLOW3Scope("session")
*/
class StandardController extends TYPO3FLOW3MVCControllerActionController {
/**
* @var AcmeDemoServiceTalkServiceInterface
*/
protected $talkService;
public function injectTalkService(
AcmeDemoServiceTalkService $talkService) {
$this->talkService = $talkService;
}
public function indexAction() {
}
}

59. The state of DI in PHP
Flow3 – Setter Injection (Automagic)
<?php
namespace AcmeDemoController;
use TYPO3FLOW3Annotations as FLOW3;
/**
* @FLOW3Scope("session")
*/
class StandardController extends TYPO3FLOW3MVCControllerActionController {
/**
* @var AcmeDemoServiceTalkServiceInterface
*/
protected $talkService;
public function injectSomethingElse(
AcmeDemoServiceTalkService $talkService) {
$this->talkService = $talkService;
}
public function indexAction() {
}
}

60. The state of DI in PHP
Flow3 – Property Injection
<?php
namespace AcmeDemoController;
use TYPO3FLOW3Annotations as FLOW3;
/**
* @FLOW3Scope("session")
*/
class StandardController extends TYPO3FLOW3MVCControllerActionController {
/**
* @var AcmeDemoServiceTalkService
* @FLOW3Inject
*/
protected $talkService;
public function indexAction() {
}
}

61. The state of DI in PHP
Flow3 – Property Injection (with Interface)
<?php
namespace AcmeDemoController;
use TYPO3FLOW3Annotations as FLOW3;
/**
* @FLOW3Scope("session")
*/
class StandardController extends TYPO3FLOW3MVCControllerActionController {
/**
* @var AcmeDemoServiceTalkServiceInterface
* @FLOW3Inject
*/
protected $talkService;
public function indexAction() {
}
}

62. The state of DI in PHP
Flow3 – Property Injection (with Interface)
File Objects.yaml in Packages/Application/Acme.Demo/Configuration
# @package Acme
AcmeDemoServiceTalkServiceInterface:
className: 'AcmeDemoServiceTalkService'

63. The state of DI in PHP
Flow3 – Scoping
<?php
namespace AcmeDemoController;
use TYPO3FLOW3Annotations as FLOW3;
/**
* @FLOW3Scope("session")
*/
class StandardController extends TYPO3FLOW3MVCControllerActionController {
/**
* @var AcmeDemoServiceTalkServiceInterface
* @FLOW3Inject
*/
protected $talkService;
public function indexAction() {
}
}

64. The state of DI in PHP
The future?

65. The state of DI in PHP
The future (or what`s missing)?

66. The state of DI in PHP
PSR for DI container missing!

67. The state of DI in PHP
IDE support is missing...

68. Thank you!

69. http://joind.in/4768