Feature: #98912 - Installation-wide services configuration

See forge#98912

Description

It is possible to set up a global services configuration for a project that can be used in multiple project-specific extensions. This way you can, for example, alias an interface with a concrete implementation to be used in several extensions. It is also possible to register project-specific CLI commands without having the need for a project-specific extension.

However, this only works - due to security restrictions - if TYPO3 is configured in a way that the project root is outside the document root, which usually happens in Composer-based installations.

Impact

The global services configuration files services.yaml and services.php are now read within the config/system/ path of a TYPO3 project in Composer-based installations.

Example

You want to use the interface of the PHP package stella-maris/clock as type hint for DI in the service classes of your project's various extensions. Then the concrete implementation may change without touching your code. In this example we use lcobucci/clock for the concrete implementation.

config/system/services.php 
use Lcobucci\Clock\SystemClock;
use StellaMaris\Clock\ClockInterface;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Loader\Configurator\ContainerConfigurator;

return static function (ContainerConfigurator $containerConfigurator, ContainerBuilder $containerBuilder): void {
    $services = $containerConfigurator->services();
    $services->set(ClockInterface::class)
        ->factory([SystemClock::class, 'fromUTC']);
};
Copied!