PreImportEvent.php

<?php

declare (strict_types=1);
namespace Drupal\Core\DefaultContent;

use Symfony\Contracts\EventDispatcher\Event;

/**
 * Event dispatched before default content is imported.
 *
 * Subscribers to this event should avoid modifying content, because it is
 * probably about to change again. This event is best used for tasks like
 * notifications, logging, or updating a value in state. It can also be used
 * to skip importing certain entities, identified by their UUID.
 */
final class PreImportEvent extends Event {
    
    /**
     * Entity UUIDs that should not be imported.
     *
     * @var string[]
     */
    private array $skip = [];
    
    /**
     * Constructs a PreImportEvent object.
     *
     * @param \Drupal\Core\DefaultContent\Finder $finder
     *   The content finder, which has information on the entities to create
     *   in the necessary dependency order.
     * @param \Drupal\Core\DefaultContent\Existing $existing
     *   What the importer will do when importing an entity that already exists.
     */
    public function __construct(Finder $finder, Existing $existing) {
    }
    
    /**
     * Adds an entity UUID to the skip list.
     *
     * @param string $uuid
     *   The UUID of an entity that should not be imported.
     * @param string|\Stringable|null $reason
     *   (optional) A reason why the entity is being skipped. Defaults to NULL.
     *
     * @throws \InvalidArgumentException
     *   If the given UUID is not one of the ones being imported.
     */
    public function skip(string $uuid, string|\Stringable|null $reason = NULL) : void {
        if (array_key_exists($uuid, $this->finder->data)) {
            $this->skip[$uuid] = $reason;
        }
        else {
            throw new \InvalidArgumentException("Content entity '{$uuid}' cannot be skipped, because it is not one of the entities being imported.");
        }
    }
    
    /**
     * Returns the list of entity UUIDs that should not be imported.
     *
     * @return string|\Stringable|null[]
     *   An array whose keys are the UUIDs of the entities that should not be
     *   imported, and the values are either a short explanation of why that
     *   entity was skipped, or NULL if no explanation was given.
     */
    public function getSkipList() : array {
        return $this->skip;
    }

}