Accelerate Drupal with Service Autowiring!

Services? Yea, you've basically got those down: registering them in {modulename}.services.yml, adding arguments, using them. Great! While you've been crushing it, Symfony has been busy too - with new features to accelerate how you work!

In this talk, we'll get an overview of service autowiring, auto-registration and autoconfiguration: a set of features that will make you move faster and *love* the process! Just created a new service class and ready to use it? No need to touch *any* configuration files. Need to add another constructor argument? Type-hint it and keep coding: no YAML involved.

This talk assumes an understanding of services in Drupal. By the end, you'll be ready to try out these new features and work faster. Zoom!

Transcript

1. Accelerate with Service Autowiring!
   Bring Symfony’s new Innovation
   into your Drupal App
   with your friend @weaverryan
   

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2. > Lead of the Symfony documentation team

   > Writer for SymfonyCasts.com
   > Symfony evangelist… Fanboy
   > Husband of the much more
   talented @leannapelham
   symfonycasts.com
   twitter.com/weaverryan
   Yo! I’m Ryan!
   > Father to my much more
   charming son, Beckett
   

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3. (0)
   So, Service
   Configuration
   @weaverryan
   

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4. // modules/custom/coffee_shop/src/Service/Barista.php
   namespace Drupal\coffee_shop\Service;
   class Barista {
   public function prepareDrink($type) {
   // ...
   return 'I just made you a '.$type;
   }
   }
   Barista: prepares drinks for us
   

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5. // modules/custom/coffee_shop/src/Service/Barista.php
   namespace Drupal\coffee_shop\Service;
   use Drupal\Core\Config\ConfigFactoryInterface;
   class Barista {
   private $configFactory;
   public function __construct(ConfigFactoryInterface $configFactory) {
   $this->configFactory = $configFactory;
   }
   public function prepareDrink($type) {
   // ...
   return 'I just made you a '.$type;
   }
   }
   With a config factory dependency
   

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6. Registered as a service
   # modules/custom/coffee_shop/coffee_shop.services.yml
   services:
   coffee_shop.barista:
   class: Drupal\coffee_shop\Service\Barista
   arguments: ['@config.factory']
   

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7. And used in our controller…
   // modules/custom/coffee_shop/src/Controller/CoffeeController.php
   namespace Drupal\coffee_shop\Controller;
   class CoffeeController {
   public function brewCoffee($type) {
   $barista = \Drupal::getContainer()
   ->get('coffee_shop.barista');
   $text = $barista->prepareDrink($type);
   return [
   '#type' => 'markup',
   '#markup' => $text,
   ];
   }
   }
   

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8. Brilliant!
   @weaverryan
   

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9. Except…
   @weaverryan
   

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10. We did WAY too
    much work!
    @weaverryan
    

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11. (1)
    Goodbye machine
    service ids
    @weaverryan
    

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12. Service id === Class name
    # modules/custom/coffee_shop/coffee_shop.services.yml
    services:
    - coffee_shop.barista:
    + Drupal\coffee_shop\Service\Barista:
    class: Drupal\coffee_shop\Service\Barista
    arguments: ['@config.factory']
    

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13. And used in our controller…
    // modules/custom/coffee_shop/src/Controller/CoffeeController.php
    namespace Drupal\coffee_shop\Controller;
    class CoffeeController {
    public function brewCoffee($type) {
    $barista = \Drupal::getContainer()
    ->get('coffee_shop.barista');
    ->get('Drupal\coffee_shop\Service\Barista');
    // ...
    }
    }
    

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14. Use the simple ::class Syntax
    // modules/custom/coffee_shop/src/Controller/CoffeeController.php
    namespace Drupal\coffee_shop\Controller;
    use Drupal\coffee_shop\Service\Barista;
    class CoffeeController {
    public function brewCoffee($type) {
    $barista = \Drupal::getContainer()
    ->get(Barista::class);
    // ...
    }
    }
    

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15. Because… if a class will only be
    registered once as a service…
    …why add the extra layer of
    abstraction?
    @weaverryan
    

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16. The "class" key is optional
    # modules/custom/coffee_shop/coffee_shop.services.yml
    services:
    Drupal\coffee_shop\Service\Barista:
    arguments: ['@config.factory']
    

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17. Let's add a second
    service
    @weaverryan
    

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18. New CoffeeMachine Service
    // modules/custom/coffee_shop/src/Service/CoffeeMachine.php
    namespace Drupal\coffee_shop\Service;
    class CoffeeMachine {
    public function brew()
    {
    return 'coffee brewed!';
    }
    }
    

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19. Use it in Barista
    // modules/custom/coffee_shop/src/Service/Barista.php
    class Barista {
    private $configFactory;
    private $coffeeMachine;
    public function __construct($configFactory, CoffeeMachine $coffeeMachine) {
    $this->configFactory = $configFactory;
    $this->coffeeMachine = $coffeeMachine;
    }
    // ...
    }
    

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20. Add service & update arguments
    # modules/custom/coffee_shop/coffee_shop.services.yml
    services:
    Drupal\coffee_shop\Service\Barista:
    arguments:
    - '@config.factory',
    + - '@Drupal\coffee_shop\Service\CoffeeMachine'
    + Drupal\coffee_shop\Service\CoffeeMachine:
    + arguments: []
    

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21. (2)
    Autowiring
    @weaverryan
    

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22. Autowire: automatically add my arguments
    # modules/custom/coffee_shop/coffee_shop.services.yml
    services:
    Drupal\coffee_shop\Service\Barista:
    + autowire: true
    arguments:
    - - '@config.factory',
    - - '@Drupal\coffee_shop\Service\CoffeeMachine'
    Drupal\coffee_shop\Service\CoffeeMachine:
    arguments: []
    

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23. It works by reading the type-hint
    // modules/custom/coffee_shop/src/Service/Barista.php
    class Barista {
    private $configFactory;
    private $coffeeMachine;
    public function __construct(
    ConfigFactoryInterface $configFactory,
    CoffeeMachine $coffeeMachine) {
    $this->configFactory = $configFactory;
    $this->coffeeMachine = $coffeeMachine;
    }
    // ...
    }
    

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24. Autowire: automatically add my arguments
    # modules/custom/coffee_shop/coffee_shop.services.yml
    services:
    Drupal\coffee_shop\Service\Barista:
    autowire: true
    arguments: []
    Drupal\coffee_shop\Service\CoffeeMachine:
    arguments: []
    

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25. (3)
    Default Service Config
    @weaverryan
    

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26. Default options for all services?
    # modules/custom/coffee_shop/coffee_shop.services.yml
    services:
    + # defaults for services in this file
    + _defaults:
    + autowire: true
    Drupal\coffee_shop\Service\Barista:
    arguments: []
    Drupal\coffee_shop\Service\CoffeeMachine:
    arguments: []
    

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27. (4)
    Service Auto-Registration
    @weaverryan
    

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28. Auto-register your services
    # modules/custom/coffee_shop/coffee_shop.services.yml
    services:
    _defaults:
    autowire: true
    # auto-registers all services in this directory
    # using the class name as the service id
    Drupal\coffee_shop\Service\:
    resource: '../src/Service'
    

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29. Amazing!
    @weaverryan
    

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30. 1) Create & use services and
    touch zero config
    2) Add new constructor args to a
    service and touch zero config
    @weaverryan
    

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31. It doesn't work :(
    @weaverryan
    

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32. _defaults & service auto-
    registration are not (yet)
    supported by Drupal :(
    @weaverryan
    

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33. (5) & (6)
    Let's build it ourselves!
    @weaverryan
    

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34. A Service Provider
    // modules/custom/coffee_shop/src/CoffeeShopServiceProvider.php
    namespace Drupal\coffee_shop;
    use Drupal\Core\DependencyInjection\ContainerBuilder;
    use Drupal\Core\DependencyInjection\ServiceProviderInterface;
    class CoffeeShopServiceProvider implements ServiceProviderInterface {
    public function register(ContainerBuilder $container) {
    // called when the services are being built
    }
    }
    

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35. Find all files in the Service directory
    // modules/custom/custom/coffee_shop/src/CoffeeShopServiceProvider.php
    public function register(ContainerBuilder $container)
    {
    $finder = new Finder();
    $finder->in(__DIR__.'/Service')
    ->files()
    ->name('*.php');
    foreach ($finder as $fileInfo) {
    $class = 'Drupal\coffee_shop\Service\\'
    .substr($fileInfo->getFilename(), 0, -4);
    // ...
    }
    }
    

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36. Register them as autowired services!
    // modules/custom/custom/coffee_shop/src/CoffeeShopServiceProvider.php
    public function register(ContainerBuilder $container) {
    // ...
    foreach ($finder as $fileInfo) {
    $class = 'Drupal\coffee_shop\Service\\'
    .substr($fileInfo->getFilename(), 0, -4);
    // don't override any existing service
    if ($container->hasDefinition($class)) {
    continue;
    }
    $definition = new Definition($class);
    $definition->setAutowired(true);
    $container->setDefinition($class, $definition);
    }
    }
    

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37. Smallest File in your App
    # modules/custom/coffee_shop/coffee_shop.services.yml
    # just crickets here!
    

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38. (7)
    Named Arguments
    @weaverryan
    

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39. Add a scalar argument
    // modules/custom/custom/coffee_shop/src/Service/CoffeeMachine.php
    namespace Drupal\coffee_shop\Service;
    class CoffeeMachine {
    private $numberOfScoops;
    public function __construct(int $numberOfScoops) {
    $this->numberOfScoops = $numberOfScoops;
    }
    public function brew()
    {
    return sprintf('using %d scoops!', $this->numberOfScoops);
    }
    }
    

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40. Autowiring Fails!!
    

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41. Smallest File in your App
    # modules/custom/custom/coffee_shop/coffee_shop.services.yml
    services:
    Drupal\coffee_shop\Service\CoffeeMachine:
    autowire: true
    arguments:
    $numberOfScoops: 3
    public function __construct(int $numberOfScoops) {
    $this->numberOfScoops = $numberOfScoops;
    }
    Arguments are
    bound by name!
    

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42. (8)
    Only use the
    "New" Autowiring
    @weaverryan
    

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43. Smallest File in your App
    # modules/custom/custom/coffee_shop/coffee_shop.services.yml
    parameters:
    container.autowiring.strict_mode: true
    services:
    # ...
    

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44. Autowiring Fails!!
    

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45. Create "aliases" for your type-hints
    # modules/custom/custom/coffee_shop/coffee_shop.services.yml
    services:
    # ...
    Drupal\Core\Config\ConfigFactoryInterface:
    alias: 'config.factory'
    

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46. Ideally, core would
    add these aliases
    and empower autowiring
    @weaverryan
    

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47. Wait, so, do what?
    @weaverryan
    

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48. (1)
    Use class names as your
    service ids and remove the
    class key.
    @weaverryan
    

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49. (2)
    Use autowire: true and
    omit arguments that Drupal
    can guess.
    @weaverryan
    

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50. (3) & (4)
    Leverage a service provider
    to auto-register services &
    default them to autowire.
    @weaverryan
    

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51. (5)
    Specify any non-
    autowireable arguments
    with $named arguments
    @weaverryan
    

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52. (6)
    Turn off "magic" autowiring and
    add service aliases for the type-
    hints you want to autowire
    @weaverryan
    

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53. Ryan Weaver
    @weaverryan
    THANK YOU!
    Free Symfony Tutorial
    https://symfonycasts.com/symfony
    http://bit.ly/drupal-autowiring-code
    

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