![What Magic do we have in *.services.yml ?
services:
# Defines a simple service of which requires no parameter for its constructor.
example.simple:
class: DrupalExampleSimple
# Defines a service which requires the module_handler for its constructor.
example.with_module_handler
class: DrupalExampleWithModuleHandler
arguments: ['@module_handler']](https://image.slidesharecdn.com/noladipresentation-160507075155/85/Dependency-injection-in-Drupal-8-DrupalCon-NOLA-33-320.jpg)
Dependency injection in Drupal 8 : DrupalCon NOLA
- 2. Dependency injection in Drupal 8 Ashwini Kumar
- 3. Who am I? Ashwini Kumar Tech Architect @ashclimb
- 4. Agenda ✤ Mystery about DI ✤ Why to give my 2 cents to learn DI? ✤ DI in Symfony ✤ DI in Drupal 8
- 5. What is Dependency Injection? Well, the literal meaning is injecting the dependency into your Class.
- 10. Types of Dependency Injection ✤ Constructor Injection ✤ Setter Injection ✤ Property Injection
- 11. Constructor Injection class NewsletterManager { protected $mailer; public function __construct(Mailer $mailer) { $this->mailer = $mailer; } // ... }
- 12. Setter Injection class NewsletterManager { protected $mailer; public function setMailer(Mailer $mailer) { $this->mailer = $mailer; } // ... }
- 13. Property Injection class NewsletterManager { public $mailer; // ... }
- 18. Without dependency injection class GoogleMaps { public function getCoordinatesFromAddress($address) { // calls Google Maps webservice } } class OpenStreetMap { public function getCoordinatesFromAddress($address) { // calls OpenStreetMap webservice } }
- 19. class StoreService { public function getStoreCoordinates($store) { $geolocationService = new GoogleMaps(); // or $geolocationService = GoogleMaps::getInstance() if you use singletons return $geolocationService->getCoordinatesFromAddress($store->getAddress()); } } Without dependency injection
- 20. With dependency injectionclass StoreService { private $geolocationService; public function __construct(GeolocationService $geolocationService) { $this->geolocationService = $geolocationService; } public function getStoreCoordinates($store) { return $this->geolocationService->getCoordinatesFromAddress($store- >getAddress()); } }
- 21. With dependency injection interface GeolocationService { public function getCoordinatesFromAddress($address); } class GoogleMaps implements GeolocationService { ... class OpenStreetMap implements GeolocationService { ...
- 22. What we also get from this… ✤ Cleaner and Modular ✤ Reusable and Flexible ✤ Abstraction ✤ Testable
- 23. DI in a Framework Dependency Injector == Dependency Injection Container(DIC) == IoC Container == Service Container er
- 24. What is Service Container? It basically deals with creating a map of your dependencies which your class needs and check do we have it loaded?
- 26. Symfony’s DI Component ✤ Services Keys are strings, e.g. ‘some_service’ ✤ Service definitions in addition to specifying which class to instantiate and what constructor arguments to pass in, allow you to specify additional methods to call on the object after instantiation.
- 27. Symfony’s DI Component ✤ Default scope: Container ✤ Can be configured in PHP, XML or YAML ✤ Can be “compiled” down to plain PHP
- 28. Dependency Injection in Drupal 8
- 29. D8 Services mostly we will be using ✤ The default DB connection (‘database’) ✤ The module handler (‘module handler’) ✤ The HTTP request object (‘request’)
- 30. 2 ways you can use core’s services 1. Service location : From procedural code, using a helper: Drupal::service(‘some_service’) 2. DI way : Write OO code and get wired into the container
- 31. How and Where does it all happen? ✤ The Drupal Kernel: code/lib/Drupal/Core/DrupalKernel.php ✤ Services are defined in : core/core.services.yml ✤ Compiler passes get added in: core/lib/Drupal/Core/CoreBundle.php ✤ Compiler pass classes live here: core/lib/Drupal/Core/DependenciesInjection/compiler/…
- 32. How does it happen for my Module? ✤ Services are defined in : mymodule/mymodule.services.yml ✤ Compiler passes get added in: my module/lib/Drupal/mymodule/MymoduleBundle.php ✤ All classes, including compiler pass classes must live in : my module/lib/Drupal/mymodule/
- 33. What Magic do we have in *.services.yml ? services: # Defines a simple service of which requires no parameter for its constructor. example.simple: class: DrupalExampleSimple # Defines a service which requires the module_handler for its constructor. example.with_module_handler class: DrupalExampleWithModuleHandler arguments: ['@module_handler']
- 34. Implement:Dependency Injection for a Form
- 36. “Start Small, then work your way up!” ~ The person who is quoted
- 37. Questions?
- 38. So How Was It? - Tell Us What You Think Evaluate this session - thisistheurltotheschedule Thanks!