class EntitySearchPage

class EntitySearchPage extends EntityConfigBase {
    
    /**
     * The module handler.
     *
     * @var \Drupal\Core\Extension\ModuleHandlerInterface
     */
    protected $moduleHandler;
    
    /**
     * Constructs a new EntitySearchPage.
     *
     * @param array $configuration
     *   A configuration array containing information about the plugin instance.
     * @param string $plugin_id
     *   The plugin_id for the plugin instance.
     * @param mixed $plugin_definition
     *   The plugin implementation definition.
     * @param \Drupal\migrate\plugin\MigrationInterface $migration
     *   The migration.
     * @param \Drupal\Core\Entity\EntityStorageInterface $storage
     *   The storage for this entity type.
     * @param array $bundles
     *   The list of bundles this entity type has.
     * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
     *   The language manager.
     * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
     *   The configuration factory.
     * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
     *   The module handler.
     */
    public function __construct(array $configuration, $plugin_id, $plugin_definition, MigrationInterface $migration, EntityStorageInterface $storage, array $bundles, LanguageManagerInterface $language_manager, ConfigFactoryInterface $config_factory, ModuleHandlerInterface $module_handler) {
        parent::__construct($configuration, $plugin_id, $plugin_definition, $migration, $storage, $bundles, $language_manager, $config_factory);
        $this->moduleHandler = $module_handler;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition, MigrationInterface $migration = NULL) {
        $entity_type_id = static::getEntityTypeId($plugin_id);
        return new static($configuration, $plugin_id, $plugin_definition, $migration, $container->get('entity_type.manager')
            ->getStorage($entity_type_id), array_keys($container->get('entity_type.bundle.info')
            ->getBundleInfo($entity_type_id)), $container->get('language_manager'), $container->get('config.factory'), $container->get('module_handler'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function import(Row $row, array $old_destination_id_values = []) {
        // The search page settings may be for a module not enabled on the
        // destination so make sure it is enabled for updating search page settings.
        if ($this->moduleHandler
            ->moduleExists($row->getDestinationProperty('module'))) {
            return parent::import($row, $old_destination_id_values);
        }
        $msg = sprintf("Search module '%s' is not enabled on this site.", $row->getDestinationProperty('module'));
        throw new MigrateException($msg, 0, NULL, MigrationInterface::MESSAGE_INFORMATIONAL, MigrateIdMapInterface::STATUS_IGNORED);
    }
    
    /**
     * Updates the entity with the contents of a row.
     *
     * @param \Drupal\Core\Entity\EntityInterface $entity
     *   The search page entity.
     * @param \Drupal\migrate\Row $row
     *   The row object to update from.
     */
    protected function updateEntity(EntityInterface $entity, Row $row) {
        parent::updateEntity($entity, $row);
        $entity->setPlugin($row->getDestinationProperty('plugin'));
        // The user_search plugin does not have a setConfiguration() method.
        $plugin = $entity->getPlugin();
        if ($plugin instanceof ConfigurableSearchPluginBase) {
            $plugin->setConfiguration($row->getDestinationProperty('configuration'));
        }
    }

}