Rosolve internal links - change MYMODULE and put in src/Plugin/jsonapi/FieldEnhancer

AliasedLinkEnhancer.php

<?php

namespace Drupal\MYMODULE\Plugin\jsonapi\FieldEnhancer;

use Drupal\Core\Entity\EntityTypeManagerInterface;
use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
use Drupal\jsonapi_extras\Plugin\ResourceFieldEnhancerBase;
use Shaper\Util\Context;
use Symfony\Component\DependencyInjection\ContainerInterface;
use Drupal\Core\Url;

/**
 * Resolve a aliased URI for internal link field value.
 *
 * @ResourceFieldEnhancer(
 *   id = "aliased_link",
 *   label = @Translation("Resolve an aliased URL for internal links."),
 *   description = @Translation("Use a aliased URL for internal links instead of links like entity:node/123")
 * )
 */
class AliasedLinkEnhancer extends ResourceFieldEnhancerBase implements ContainerFactoryPluginInterface {

  /**
   * The entity type manager.
   *
   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
   */
  protected $entityTypeManager;

  /**
   * {@inheritdoc}
   */
  public function __construct(array $configuration, $plugin_id, array $plugin_definition, EntityTypeManagerInterface $entity_type_manager) {
    parent::__construct($configuration, $plugin_id, $plugin_definition);
    $this->entityTypeManager = $entity_type_manager;
  }

  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
    return new static(
      $configuration,
      $plugin_id,
      $plugin_definition,
      $container->get('entity_type.manager')
    );
  }

  /**
   * {@inheritdoc}
   */
  protected function doUndoTransform($data, Context $context) {

    $output = $data;
    if (isset($output['uri'])) {
      // Check if it is a link to an entity.
      preg_match("/entity:(.*)\/(.*)/", $output['uri'], $parsed_uri);
      if (!empty($parsed_uri)) {
        $entity_type = $parsed_uri[1];
        $entity_id = $parsed_uri[2];
        $entity = $this->entityTypeManager->getStorage($entity_type)->load($entity_id);
        if (!is_null($entity)) {
          $output['url'] = Url::fromUri($output['uri'], $output['options'])->toString();
        }
        // Unable to load the entity, so remove the value.
        else {
          $output = [
            'uri' => '',
            'url' => '',
            'title' => '',
            'options' => [],
          ];
        }
      }
      else {
        // Assume it's an external link which can be used as-is.
        $output['url'] = $output['uri'];
      }
    }

    return $output;
  }

  /**
   * {@inheritdoc}
   */
  protected function doTransform($data, Context $context) {
    $input = $data;
    unset($input['url']);
    return $input;
  }

  /**
   * {@inheritdoc}
   */
  public function getOutputJsonSchema() {
    return [
      'type' => 'any',
    ];

  }

  /**
   * {@inheritdoc}
   */
  public function getJsonSchema() {
    return [
      'type' => 'array',
    ];
  }

}