View source  
  <?php
namespace Drupal\webform_submission_export_import\Controller;
use Drupal\Core\Controller\ControllerBase;
use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
use Drupal\Core\Entity\EntityTypeManagerInterface;
use Drupal\Core\Serialization\Yaml;
use Drupal\webform\WebformRequestInterface;
use Drupal\webform\WebformSubmissionGenerateInterface;
use Drupal\webform_submission_export_import\WebformSubmissionExportImportImporterInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;
use Symfony\Component\HttpFoundation\StreamedResponse;
class WebformSubmissionExportImportController extends ControllerBase implements ContainerInjectionInterface {
  
  protected $entityTypeManager;
  
  protected $webformSubmissionStorage;
  
  protected $requestHandler;
  
  protected $generate;
  
  protected $importer;
  
  public function __construct(EntityTypeManagerInterface $entity_type_manager, WebformRequestInterface $request_handler, WebformSubmissionGenerateInterface $submission_generate, WebformSubmissionExportImportImporterInterface $importer) {
    $this->entityTypeManager = $entity_type_manager;
    $this->webformSubmissionStorage = $entity_type_manager
      ->getStorage('webform_submission');
    $this->requestHandler = $request_handler;
    $this->generate = $submission_generate;
    $this->importer = $importer;
    
    $webform = $this->requestHandler
      ->getCurrentWebform();
    $source_entity = $this->requestHandler
      ->getCurrentSourceEntity();
    $this->importer
      ->setWebform($webform);
    $this->importer
      ->setSourceEntity($source_entity);
  }
  
  public static function create(ContainerInterface $container) {
    return new static($container
      ->get('entity_type.manager'), $container
      ->get('webform.request'), $container
      ->get('webform_submission.generate'), $container
      ->get('webform_submission_export_import.importer'));
  }
  
  public function view() {
    return $this
      ->createResponse(FALSE);
  }
  
  public function download() {
    return $this
      ->createResponse(TRUE);
  }
  
  protected function createResponse($download = FALSE) {
    $webform = $this->importer
      ->getWebform();
    
    $response = new StreamedResponse(function () {
      $handle = fopen('php://output', 'r+');
      $header = $this->importer
        ->exportHeader();
      fputcsv($handle, $header);
      for ($i = 1; $i <= 3; $i++) {
        $webform_submission = $this
          ->generateSubmission($i);
        $record = $this->importer
          ->exportSubmission($webform_submission);
        fputcsv($handle, $record);
      }
      fclose($handle);
    });
    $response->headers
      ->set('Content-Type', $download ? 'text/csv' : 'text/plain');
    $response->headers
      ->set('Content-Disposition', ($download ? 'attachment' : 'inline') . '; filename=' . $webform
      ->id() . '.csv');
    return $response;
  }
  
  protected function generateSubmission($index) {
    $webform = $this->requestHandler
      ->getCurrentWebform();
    $source_entity = $this->requestHandler
      ->getCurrentSourceEntity();
    $users = $this->entityTypeManager
      ->getStorage('user')
      ->getQuery()
      ->execute();
    $uid = array_rand($users);
    $url = $webform
      ->toUrl();
    if ($source_entity && $source_entity
      ->hasLinkTemplate('canonical')) {
      $url = $source_entity
        ->toUrl();
    }
    return $this->webformSubmissionStorage
      ->create([
      'sid' => $index,
      'serial' => $index,
      'webform_id' => $webform
        ->id(),
      'entity_type' => $source_entity ? $source_entity
        ->getEntityTypeId() : '',
      'entity_id' => $source_entity ? $source_entity
        ->id() : '',
      'uid' => $uid,
      'remote_addr' => mt_rand(0, 255) . '.' . mt_rand(0, 255) . '.' . mt_rand(0, 255) . '.' . mt_rand(0, 255),
      'uri' => preg_replace('#^' . base_path() . '#', '/', $url
        ->toString()),
      'data' => Yaml::encode($this->generate
        ->getData($webform)),
      'created' => strtotime('-1 year'),
      'completed' => rand(strtotime('-1 year'), time()),
      'changed' => time(),
    ]);
  }
}