FormBase provides create() factory method with autowired parameters

Classes that implement \Drupal\Core\DependencyInjection\ContainerInjectionInterface must provide a create() factory method to instantiate the object.

Now that services can be autowired and plugins can be autowired, the FormBase class has also been extended with AutowireTrait, providing a generic version of the create() method suitable for most forms that need dependency injection.

Previously, a constructor and create() method would be something like this:

  public function __construct(EntityDisplayRepositoryInterface $entity_display_repository, ConfigFactoryInterface $config_factory) {
    $this->entityDisplayRepository = $entity_display_repository;
    $this->configFactory = $config_factory;
  }

  public static function create(ContainerInterface $container) {
    return new static(
      $container->get('entity_display.repository'),
      $container->get('config.factory')
    );
  }

Now it is possible to drop the create() method:

  public function __construct(EntityDisplayRepositoryInterface $entity_display_repository, ConfigFactoryInterface $config_factory) {
    $this->entityDisplayRepository = $entity_display_repository;
    $this->configFactory = $config_factory;
  }

In simple cases, the service can be inferred from the interface name alone. If a service cannot be determined from the interface directly, an exception will be raised, and you can add the #[Autowire] attribute to specify the service ID.