SettingsValidator.php

<?php

declare (strict_types=1);
namespace Drupal\package_manager\Validator;

use Drupal\Core\Site\Settings;
use Drupal\Core\StringTranslation\StringTranslationTrait;
use Drupal\package_manager\Event\PreApplyEvent;
use Drupal\package_manager\Event\PreCreateEvent;
use Drupal\package_manager\Event\PreOperationStageEvent;
use Drupal\package_manager\Event\StatusCheckEvent;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;

/**
 * Checks that Drupal's settings are valid for Package Manager.
 *
 * @internal
 *   This is an internal part of Package Manager and may be changed or removed
 *   at any time without warning. External code should not interact with this
 *   class.
 */
final class SettingsValidator implements EventSubscriberInterface {
    use StringTranslationTrait;
    
    /**
     * Checks that Drupal's settings are valid for Package Manager.
     */
    public function validate(PreOperationStageEvent $event) : void {
        if (Settings::get('update_fetch_with_http_fallback')) {
            $event->addError([
                $this->t('The <code>update_fetch_with_http_fallback</code> setting must be disabled.'),
            ]);
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public static function getSubscribedEvents() : array {
        return [
            PreCreateEvent::class => 'validate',
            PreApplyEvent::class => 'validate',
            StatusCheckEvent::class => 'validate',
        ];
    }

}