State Manager

The StateManagerInterface is the central, public service of this extension. It bootstraps an environment for a given context, applies it to the global TYPO3 state and is able to back up and restore that state.

Note

Currently only frontend environments are bootstrapped (the examples below use ApplicationType::FRONTEND). Backend environment handling is planned to be added later.

The state manager is registered as a public service and resolved to a TYPO3 core version compatible implementation. Inject it through dependency injection:

use FGTCLB\EnvironmentStateManager\StateManagerInterface;

final class MyService
{
    public function __construct(
        private readonly StateManagerInterface $stateManager,
    ) {}
}

Note

Always type-hint StateManagerInterface, never a concrete Core12StateManager or Core13StateManager. The dependency injection container resolves the implementation for the running TYPO3 core version. See Public API and stability for the full public API surface.

Execute code within an environment

The recommended way to run code inside a built environment is the execute() method. It backs up the current environment, bootstraps the environment described by the StateBuildContext, runs the given closure and restores the previous environment afterwards – even if the closure throws:

use FGTCLB\EnvironmentStateManager\StateBuildContext;
use TYPO3\CMS\Core\Http\ApplicationType;

$stateBuildContext = new StateBuildContext(
    applicationType: ApplicationType::FRONTEND,
    pageId: 42,
    languageId: 0,
);

$this->stateManager->execute($stateBuildContext, function () {
    // Code in here runs within the frontend environment built for page 42.
    // The previous environment is restored automatically afterwards.
});

Manual backup, bootstrap and restore

If you need finer control, the individual steps are available as well. Always make sure to restore a previously created backup, for example by using a try/finally block:

use FGTCLB\EnvironmentStateManager\StateBuildContext;
use TYPO3\CMS\Core\Http\ApplicationType;

$stateBuildContext = new StateBuildContext(
    applicationType: ApplicationType::FRONTEND,
    pageId: 42,
    languageId: 0,
);

$this->stateManager->backup();
try {
    $state = $this->stateManager->bootstrap($stateBuildContext);
    // work with the bootstrapped $state ...
} finally {
    $this->stateManager->restore();
}

Applying a pre-built state

A StateInterface instance – for example one created through the environment builder – can be applied to the global environment directly:

$this->stateManager->apply($state);

PSR-14 events

The state manager dispatches the following events that can be used to react on state changes:

Event	Dispatched
`FGTCLBEnvironmentStateManagerEventStateApplyEvent`	When a state is applied to the global environment.
`FGTCLBEnvironmentStateManagerEventStateBackupEvent`	When the current environment is backed up onto the snapshot stack.

Register an event listener as usual through the Services.yaml / Services.php or the #[AsEventListener] attribute:

use FGTCLB\EnvironmentStateManager\Event\StateApplyEvent;
use TYPO3\CMS\Core\Attribute\AsEventListener;

final class MyStateApplyListener
{
    #[AsEventListener]
    public function __invoke(StateApplyEvent $event): void
    {
        // react on the applied state
    }
}