ContentExportCommand.php

<?php

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

use Drupal\Core\Command\BootableCommandTrait;
use Drupal\Core\Entity\ContentEntityInterface;
use Drupal\Core\Entity\EntityTypeManagerInterface;
use Drupal\Core\Serialization\Yaml;
use Symfony\Component\Console\Command\Command;
use Symfony\Component\Console\Input\InputArgument;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Output\OutputInterface;
use Symfony\Component\Console\Style\SymfonyStyle;

/**
 * Exports a single content entity in YAML format.
 *
 * @internal
 *    This API is experimental.
 */
final class ContentExportCommand extends Command {
  use BootableCommandTrait;
  public function __construct(object $class_loader) {
    parent::__construct('content:export');
    $this->classLoader = $class_loader;
  }
  
  /**
   * {@inheritdoc}
   */
  protected function configure() : void {
    $this->setDescription('Exports a single content entity in YAML format.')
      ->addArgument('entity_type_id', InputArgument::REQUIRED, 'The type of entity to export (e.g., node, taxonomy_term).')
      ->addArgument('entity_id', InputArgument::REQUIRED, 'The ID of the entity to export. Will usually be a number.');
  }
  
  /**
   * {@inheritdoc}
   */
  protected function execute(InputInterface $input, OutputInterface $output) : int {
    $io = new SymfonyStyle($input, $output);
    $container = $this->boot()
      ->getContainer();
    $entity_type_id = $input->getArgument('entity_type_id');
    $entity_id = $input->getArgument('entity_id');
    $entity_type_manager = $container->get(EntityTypeManagerInterface::class);
    if (!$entity_type_manager->hasDefinition($entity_type_id)) {
      $io->error("The entity type \"{$entity_type_id}\" does not exist.");
      return 1;
    }
    if (!$entity_type_manager->getDefinition($entity_type_id)
      ->entityClassImplements(ContentEntityInterface::class)) {
      $io->error("{$entity_type_id} is not a content entity type.");
      return 1;
    }
    $entity = $entity_type_manager->getStorage($entity_type_id)
      ->load($entity_id);
    if (!$entity instanceof ContentEntityInterface) {
      $io->error("{$entity_type_id} {$entity_id} does not exist.");
      return 1;
    }
    $data = $container->get(Exporter::class)
      ->export($entity);
    $io->write(Yaml::encode($data));
    return 0;
  }

}