*/ interface ServiceSubscriberInterface { /** * Returns an array of service types required by such instances, optionally keyed by the service names used internally. * * For mandatory dependencies: * * * ['logger' => 'Psr\Log\LoggerInterface'] means the objects use the "logger" name * internally to fetch a service which must implement Psr\Log\LoggerInterface. * * ['loggers' => 'Psr\Log\LoggerInterface[]'] means the objects use the "loggers" name * internally to fetch an iterable of Psr\Log\LoggerInterface instances. * * ['Psr\Log\LoggerInterface'] is a shortcut for * * ['Psr\Log\LoggerInterface' => 'Psr\Log\LoggerInterface'] * * otherwise: * * * ['logger' => '?Psr\Log\LoggerInterface'] denotes an optional dependency * * ['loggers' => '?Psr\Log\LoggerInterface[]'] denotes an optional iterable dependency * * ['?Psr\Log\LoggerInterface'] is a shortcut for * * ['Psr\Log\LoggerInterface' => '?Psr\Log\LoggerInterface'] * * @return array The required service types, optionally keyed by service names */ public static function getSubscribedServices(); }