EventSubscriber.php

<?php

namespace Drupal\config_collection_install_test;

use Drupal\Core\Config\ConfigCollectionEvents;
use Drupal\Core\Config\ConfigCollectionInfo;
use Drupal\Core\State\StateInterface;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
class EventSubscriber implements EventSubscriberInterface {
    
    /**
     * The state key value store.
     *
     * @var \Drupal\Core\State\StateInterface
     */
    protected $state;
    
    /**
     * Constructs the Event Subscriber object.
     *
     * @param \Drupal\Core\State\StateInterface $state
     *   The state key value store.
     */
    public function __construct(StateInterface $state) {
        $this->state = $state;
    }
    
    /**
     * Reacts to the ConfigCollectionEvents::COLLECTION_INFO event.
     *
     * @param \Drupal\Core\Config\ConfigCollectionInfo $collection_info
     *   The configuration collection info event.
     */
    public function addCollections(ConfigCollectionInfo $collection_info) {
        $collections = $this->state
            ->get('config_collection_install_test.collection_names', []);
        foreach ($collections as $collection) {
            $collection_info->addCollection($collection);
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public static function getSubscribedEvents() : array {
        $events[ConfigCollectionEvents::COLLECTION_INFO][] = [
            'addCollections',
        ];
        return $events;
    }

}