class DestinationBase

abstract class DestinationBase extends PluginBase implements MigrateDestinationInterface, RequirementsInterface {
    
    /**
     * Indicates whether the destination can be rolled back.
     *
     * @var bool
     */
    protected $supportsRollback = FALSE;
    
    /**
     * The rollback action to be saved for the last imported item.
     *
     * @var int
     */
    protected $rollbackAction = MigrateIdMapInterface::ROLLBACK_DELETE;
    
    /**
     * The migration.
     *
     * @var \Drupal\migrate\Plugin\MigrationInterface
     */
    protected $migration;
    
    /**
     * Constructs an entity destination plugin.
     *
     * @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.
     */
    public function __construct(array $configuration, $plugin_id, $plugin_definition, MigrationInterface $migration) {
        parent::__construct($configuration, $plugin_id, $plugin_definition);
        $this->migration = $migration;
    }
    
    /**
     * {@inheritdoc}
     */
    public function rollbackAction() {
        return $this->rollbackAction;
    }
    
    /**
     * {@inheritdoc}
     */
    public function checkRequirements() {
        if (empty($this->pluginDefinition['requirements_met'])) {
            throw new RequirementsException(sprintf("Destination plugin '%s' did not meet the requirements", $this->pluginId));
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function rollback(array $destination_identifier) {
        // By default we do nothing.
    }
    
    /**
     * {@inheritdoc}
     */
    public function supportsRollback() {
        return $this->supportsRollback;
    }
    
    /**
     * For a destination item being updated, set the appropriate rollback action.
     *
     * @param array $id_map
     *   The map row data for the item.
     * @param int $update_action
     *   The rollback action to take if we are updating an existing item.
     */
    protected function setRollbackAction(array $id_map, $update_action = MigrateIdMapInterface::ROLLBACK_PRESERVE) {
        // If the entity we're updating was previously migrated by us, preserve the
        // existing rollback action.
        if (isset($id_map['sourceid1'])) {
            $this->rollbackAction = $id_map['rollback_action'];
        }
        else {
            $this->rollbackAction = $update_action;
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDestinationModule() {
        if (!empty($this->configuration['destination_module'])) {
            return $this->configuration['destination_module'];
        }
        if (!empty($this->pluginDefinition['destination_module'])) {
            return $this->pluginDefinition['destination_module'];
        }
        if (is_string($this->migration->provider)) {
            return $this->migration->provider;
        }
        else {
            return reset($this->migration->provider);
        }
    }

}