Download as PDF, PPTX
![Services
new
Tv('Samsung
40”’)
!
services:
tv:
class:
Tv
arguments:
[“Samsung
40"”]](https://image.slidesharecdn.com/2013-10-25-20-20phpcon-20pl-20-20dependency-20injection-20w-20php-131027041754-phpapp02/75/Dependency-Injection-in-PHP-42-2048.jpg)
![Parameters & Services
new
Tv('Samsung
40”’)
!
parameters:
tv_name:
Samsung
40"
!
services:
tv:
class:
Tv
arguments:
[“%tv_name%”]
!
$container-‐>get('tv');](https://image.slidesharecdn.com/2013-10-25-20-20phpcon-20pl-20-20dependency-20injection-20w-20php-131027041754-phpapp02/75/Dependency-Injection-in-PHP-44-2048.jpg)
![Compiled Container
!
!
!
!
protected
function
getTvService()
{
return
$this-‐>services['tv']
=
new
Tv('Samsung');
}](https://image.slidesharecdn.com/2013-10-25-20-20phpcon-20pl-20-20dependency-20injection-20w-20php-131027041754-phpapp02/75/Dependency-Injection-in-PHP-45-2048.jpg)
![Optional Dependencies
class
DvdPlayer
{
function
__construct(HdmiDevice
$device
=
null){}
}
!
services:
tv:
class:
Tv
arguments:
[%tv_name%]
dvd_player:
class:
DvdPlayer
arguments
["@?tv"]](https://image.slidesharecdn.com/2013-10-25-20-20phpcon-20pl-20-20dependency-20injection-20w-20php-131027041754-phpapp02/75/Dependency-Injection-in-PHP-48-2048.jpg)
![Lazy-loaded Services
services:
tv:
class:
Tv
arguments:
[“%tv_name%”]
lazy:
true](https://image.slidesharecdn.com/2013-10-25-20-20phpcon-20pl-20-20dependency-20injection-20w-20php-131027041754-phpapp02/75/Dependency-Injection-in-PHP-49-2048.jpg)
![Private Services
services:
drm_decryptor:
class:
DrmDecryptor
public:
false
dvd_player:
class:
DvdPlayer
arguments
[“@drm_decryptor”]](https://image.slidesharecdn.com/2013-10-25-20-20phpcon-20pl-20-20dependency-20injection-20w-20php-131027041754-phpapp02/75/Dependency-Injection-in-PHP-50-2048.jpg)
![Scopes
services:
tv:
class:
Tv
arguments:
[“%tv_name%”]
scope:
prototype](https://image.slidesharecdn.com/2013-10-25-20-20phpcon-20pl-20-20dependency-20injection-20w-20php-131027041754-phpapp02/75/Dependency-Injection-in-PHP-51-2048.jpg)
Uploaded byKacper Gunia
Dependency Injection in PHP
The document discusses dependency injection in PHP, emphasizing its role in decoupling components and promoting clean code practices. Various types of injection such as constructor, setter, and property injection are detailed, along with their advantages and disadvantages. Additionally, it introduces the concept of a dependency injection container for managing object instantiation in PHP applications.
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Dependency Injection in PHP
- 1. Dependency Injection in PHP PHPConPoland Szczyrk 25/10/13 ! by @cakper flickr.com/limowreck666/223731385/
- 2. Kacper Gunia //@cakper Software Engineer @SensioLabsUK Symfony Certified Developer #Symfony-PL // SymfonyLab.pl Silesian PHP User Group // SPUG.pl
- 3. Inversion of Control DependencyInjection Events Aspect Oriented Programming flickr.com/goetter/4559773791/
- 4.
- 5. Dependency Injection ! ! class DvdPlayer { public function playDisc(Disc $disc) { echo 'Now playing: '.$disc-‐>getMovieTitle(); ! $tv = new Tv('Samsung 40"'); $tv-‐>sendToOutput($disc-‐>getResource()); } }
- 6. Dependency Injection class DvdPlayer { private $tv; ! public function __construct() { $this-‐>tv = new Tv('Samsung 40"');; } ! public function playDisc(Disc $disc) { echo 'Now playing: ' . $disc-‐>getMovieTitle(); $this-‐>tv-‐>sendToOutput($disc-‐>getResource()); } }
- 7. Dependency Injection class DvdPlayer { private $tv; ! public function __construct(Tv $tv) { $this-‐>tv = $tv; } // (...) } ! $tv = new Tv('Samsung 40"'); $dvdPlayer = new DvdPlayer($tv);
- 8. Dependency Injection class DvdPlayer { private $device; ! public function __construct(HdmiDevice $device) { $this-‐>device = $device; } // (...) } ! $projector = new Projector('Epson EB'); $dvdPlayer = new DvdPlayer($tv);
- 9.
- 10. “Dependency Injection iswhere components are given their dependencies through their constructors, methods, or directly into fields.” ! “(...) it is a 25-dollar term for a 5-cent concept” source: picocontainer.codehaus.org jamesshore.com
- 11.
- 12. Constructor Injection class Tv implements HdmiDevice{} class DvdPlayer { private $device; ! public function __construct(HdmiDevice $device) { $this-‐>device = $device; } } ! $tv = new Tv('Samsung 40"'); $dvdPlayer = new DvdPlayer($tv);
- 13. Setter Injection class BlurayDisc implements Disc{} class DvdPlayer { private $disc; ! public function setDisc(Disc $disc) { $this-‐>disc = $disc; } } ! $disc = new BlurayDisc('Pulp Fiction'); $dvdPlayer = new DvdPlayer(); $dvdPlayer-‐>setDisc($disc);
- 14. Property Injection class DvdPlayer { public $remote; } ! $dvdPlayer = new DvdPlayer(); $dvdPlayer-‐>remote = new Remote();
- 15. Reflection Injection class DvdPlayer { private $powerSupply; } ! $dvdPlayer = new DvdPlayer(); $reflector = new ReflectionClass($dvdPlayer); $powerSupply = $reflector-‐>getProperty('powerSupply'); $powerSupply-‐>setAccessible(true); ! $powerSupply-‐>setValue($dvdPlayer, new PowerSupply());
- 16.
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- 20.
- 21.
- 22.
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- 26.
- 27. “Dependency Injection Container issimply a PHP object that manages the instantiation of other objects” ! We call them “Services” source: symfony.com
- 28. Our DvdPlayer ! ! $tv = new Tv('Samsung 40"'); $dvdPlayer = new DvdPlayer($tv); ! $disc = new Disc('Pulp Fiction'); $dvdPlayer-‐>playDisc($disc);
- 29. Simple Container class class Container { public function getTv() { return new Tv('Samsung 40"'); } ! public function getDvdPlayer() { return new DvdPlayer($this-‐>getTv()); } }
- 30. Container use ! ! $container = new Container(); ! $dvdPlayer = $container-‐>getDvdPlayer(); ! $disc = new Disc('Pulp Fiction'); $dvdPlayer-‐>playDisc($disc);
- 31.
- 32. DI & DICPatterns flickr.com/thelearningcurvedotca/8645721482/
- 33. Pattern #1 Expect Interfaces, notImplementations flickr.com/deapeajay/2969264395/
- 34. Pattern #2 Don’t checknull values flickr.com/g-ratphotos/3328593629/
- 35. class DvdPlayer { public $disc; ! public function play() { if (!is_null($this-‐>disc)) { $this-‐>sendToOutput($this-‐>disc-‐>getResource()); } } ! public function play() { if ($this-‐>disc instanceof Disc) { $this-‐>sendToOutput($this-‐>disc-‐>getResource()); } } }
- 36. Pattern #3 Avoid ‘ServiceLocator’ flickr.com/mateus27_24-25/2224073271/
- 37. class DvdPlayer { private $locator; ! public function __construct() { $this-‐>locator = ServiceLocator::getInstance(); } ! ! public function playDisc(Disc $disc) { $this-‐>locator -‐>getTv() -‐>sendToOutput($disc-‐>getResource()); } }
- 38. Pattern #4 Don’t injectwhole container flickr.com/ucumari/580865728/
- 39. Pattern #5 In DICstore Services and Properties, but not Entities flickr.com/madlyinlovewithlife/8674850717/
- 40. Pattern #6 Don’t beafraid to create plenty of small Classes flickr.com/geoki/2691420977/
- 41.
- 42. Services new Tv('Samsung 40”’) ! services: tv: class: Tv arguments: [“Samsung 40"”]
- 43. Parameters new Tv('Samsung 40”’) ! parameters: tv_name: Samsung 40"
- 44. Parameters & Services new Tv('Samsung 40”’) ! parameters: tv_name: Samsung 40" ! services: tv: class: Tv arguments: [“%tv_name%”] ! $container-‐>get('tv');
- 45. Compiled Container ! ! ! ! protected function getTvService() { return $this-‐>services['tv'] = new Tv('Samsung'); }
- 46. Static Factory services: tv class: Tv factory_class: TvFactory factory_method: get
- 47. Factory services: tv_factory: class: TvFactory tv class: Tv factory_service: tv_factory factory_method: get
- 48. Optional Dependencies class DvdPlayer { function __construct(HdmiDevice $device = null){} } ! services: tv: class: Tv arguments: [%tv_name%] dvd_player: class: DvdPlayer arguments ["@?tv"]
- 49. Lazy-loaded Services services: tv: class: Tv arguments: [“%tv_name%”] lazy: true
- 50. Private Services services: drm_decryptor: class: DrmDecryptor public: false dvd_player: class: DvdPlayer arguments [“@drm_decryptor”]
- 51. Scopes services: tv: class: Tv arguments: [“%tv_name%”] scope: prototype
- 52.
- 53.