<?php

abstract class PhabricatorExportEngineExtension extends Phobject {

  private $viewer;

  final public function getExtensionKey() {
    return $this->getPhobjectClassConstant('EXTENSIONKEY');
  }

  final public function setViewer($viewer) {
    $this->viewer = $viewer;
    return $this;
  }

  final public function getViewer() {
    return $this->viewer;
  }

  abstract public function supportsObject($object);
  abstract public function newExportFields();
  abstract public function newExportData(array $objects);

  final public static function getAllExtensions() {
    return id(new PhutilClassMapQuery())
      ->setAncestorClass(self::class)
      ->setUniqueMethod('getExtensionKey')
      ->execute();
  }

}