class TemporaryJsonapiFileFieldUploader in JSON:API 8.2

Reads data from an upload stream and creates a corresponding file entity.

This is implemented at the field level for the following reasons:

Validation for uploaded files is tied to fields (allowed extensions, max size, etc..).
The actual files do not need to be stored in another temporary location, to be later moved when they are referenced from a file field.
Permission to upload a file can be determined by a user's field- and entity-level access.

@internal This will be removed once https://www.drupal.org/project/drupal/issues/2940383 lands.

Hierarchy

class \Drupal\jsonapi\Controller\TemporaryJsonapiFileFieldUploader

Expanded class hierarchy of TemporaryJsonapiFileFieldUploader

1 string reference to 'TemporaryJsonapiFileFieldUploader'

jsonapi.services.yml in ./jsonapi.services.yml: jsonapi.services.yml

1 service uses TemporaryJsonapiFileFieldUploader

jsonapi.file.uploader.field in ./jsonapi.services.yml: Drupal\jsonapi\Controller\TemporaryJsonapiFileFieldUploader

File

src/Controller/TemporaryJsonapiFileFieldUploader.php, line 42

Namespace

Drupal\jsonapi\Controller

View source

class TemporaryJsonapiFileFieldUploader {

  /**
   * The regex used to extract the filename from the content disposition header.
   *
   * @var string
   */
  const REQUEST_HEADER_FILENAME_REGEX = '@\\bfilename(?<star>\\*?)=\\"(?<filename>.+)\\"@';

  /**
   * The amount of bytes to read in each iteration when streaming file data.
   *
   * @var int
   */
  const BYTES_TO_READ = 8192;

  /**
   * A logger instance.
   *
   * @var \Psr\Log\LoggerInterface
   */
  protected $logger;

  /**
   * The file system service.
   *
   * @var \Drupal\Core\File\FileSystemInterface
   */
  protected $fileSystem;

  /**
   * The MIME type guesser.
   *
   * @var \Symfony\Component\HttpFoundation\File\MimeType\MimeTypeGuesserInterface
   */
  protected $mimeTypeGuesser;

  /**
   * The token replacement instance.
   *
   * @var \Drupal\Core\Utility\Token
   */
  protected $token;

  /**
   * The lock service.
   *
   * @var \Drupal\Core\Lock\LockBackendInterface
   */
  protected $lock;

  /**
   * System file configuration.
   *
   * @var \Drupal\Core\Config\ImmutableConfig
   */
  protected $systemFileConfig;

  /**
   * Constructs a FileUploadResource instance.
   *
   * @param \Psr\Log\LoggerInterface $logger
   *   A logger instance.
   * @param \Drupal\Core\File\FileSystemInterface $file_system
   *   The file system service.
   * @param \Symfony\Component\HttpFoundation\File\MimeType\MimeTypeGuesserInterface $mime_type_guesser
   *   The MIME type guesser.
   * @param \Drupal\Core\Utility\Token $token
   *   The token replacement instance.
   * @param \Drupal\Core\Lock\LockBackendInterface $lock
   *   The lock service.
   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
   *   The config factory.
   */
  public function __construct(LoggerInterface $logger, FileSystemInterface $file_system, MimeTypeGuesserInterface $mime_type_guesser, Token $token, LockBackendInterface $lock, ConfigFactoryInterface $config_factory) {
    $this->logger = $logger;
    $this->fileSystem = $file_system;
    $this->mimeTypeGuesser = $mime_type_guesser;
    $this->token = $token;
    $this->lock = $lock;
    $this->systemFileConfig = $config_factory
      ->get('system.file');
  }

  /**
   * Creates and validates a file entity for a file field from a file stream.
   *
   * @param \Drupal\Core\Field\FieldDefinitionInterface $field_definition
   *   The field definition of the field for which the file is to be uploaded.
   * @param string $filename
   *   The name of the file.
   * @param \Drupal\Core\Session\AccountInterface $owner
   *   The owner of the file. Note, it is the responsibility of the caller to
   *   enforce access.
   *
   * @return \Drupal\file\FileInterface|\Drupal\Core\Entity\EntityConstraintViolationListInterface
   *   The newly uploaded file entity, or a list of validation constraint
   *   violations
   *
   * @throws \Symfony\Component\HttpKernel\Exception\HttpException
   *   Thrown when temporary files cannot be written, a lock cannot be acquired,
   *   or when temporary files cannot be moved to their new location.
   */
  public function handleFileUploadForField(FieldDefinitionInterface $field_definition, $filename, AccountInterface $owner) {
    assert(is_a($field_definition
      ->getClass(), FileFieldItemList::class, TRUE));
    $destination = $this
      ->getUploadLocation($field_definition
      ->getSettings());

    // Check the destination file path is writable.
    // @todo Remove when we stop supporting Drupal 8.5 and 8.6.
    if (floatval(\Drupal::VERSION) < 8.699999999999999) {
      if (!file_prepare_directory($destination, FILE_CREATE_DIRECTORY)) {
        throw new HttpException(500, 'Destination file path is not writable');
      }
    }
    else {
      if (!$this->fileSystem
        ->prepareDirectory($destination, FileSystemInterface::CREATE_DIRECTORY)) {
        throw new HttpException(500, 'Destination file path is not writable');
      }
    }
    $validators = $this
      ->getUploadValidators($field_definition);
    $prepared_filename = $this
      ->prepareFilename($filename, $validators);

    // Create the file.
    $file_uri = "{$destination}/{$prepared_filename}";
    $temp_file_path = $this
      ->streamUploadData();

    // @todo Remove when we stop supporting Drupal 8.5 and 8.6.
    if (floatval(\Drupal::VERSION) < 8.699999999999999) {

      // This will take care of altering $file_uri if a file already exists.
      file_unmanaged_prepare($temp_file_path, $file_uri);
    }
    else {
      $file_uri = $this->fileSystem
        ->getDestinationFilename($file_uri, FileSystemInterface::EXISTS_RENAME);
    }

    // Lock based on the prepared file URI.
    $lock_id = $this
      ->generateLockIdFromFileUri($file_uri);
    if (!$this->lock
      ->acquire($lock_id)) {
      throw new HttpException(503, sprintf('File "%s" is already locked for writing.'), NULL, [
        'Retry-After' => 1,
      ]);
    }

    // Begin building file entity.
    $file = File::create([]);
    $file
      ->setOwnerId($owner
      ->id());
    $file
      ->setFilename($prepared_filename);
    $file
      ->setMimeType($this->mimeTypeGuesser
      ->guess($prepared_filename));
    $file
      ->setFileUri($file_uri);

    // Set the size. This is done in File::preSave() but we validate the file
    // before it is saved.
    $file
      ->setSize(@filesize($temp_file_path));

    // Validate the file entity against entity-level validation and field-level
    // validators.
    $violations = $this
      ->validate($file, $validators);
    if ($violations
      ->count() > 0) {
      return $violations;
    }

    // Move the file to the correct location after validation. Use
    // FILE_EXISTS_ERROR as the file location has already been determined above
    // in FileSystem::getDestinationFilename().
    // @todo Remove when we stop supporting Drupal 8.5 and 8.6.
    if (floatval(\Drupal::VERSION) < 8.699999999999999) {
      if (!file_unmanaged_move($temp_file_path, $file_uri, FILE_EXISTS_ERROR)) {
        throw new HttpException(500, 'Temporary file could not be moved to file location.');
      }
    }
    else {
      try {
        $this->fileSystem
          ->move($temp_file_path, $file_uri, FileSystemInterface::EXISTS_ERROR);
      } catch (FileException $e) {
        throw new HttpException(500, 'Temporary file could not be moved to file location');
      }
    }
    $file
      ->save();
    $this->lock
      ->release($lock_id);
    return $file;
  }

  /**
   * Validates and extracts the filename from the Content-Disposition header.
   *
   * @param \Symfony\Component\HttpFoundation\Request $request
   *   The request object.
   *
   * @return string
   *   The filename extracted from the header.
   *
   * @throws \Symfony\Component\HttpKernel\Exception\BadRequestHttpException
   *   Thrown when the 'Content-Disposition' request header is invalid.
   */
  public function validateAndParseContentDispositionHeader(Request $request) {

    // First, check the header exists.
    if (!$request->headers
      ->has('content-disposition')) {
      throw new BadRequestHttpException('"Content-Disposition" header is required. A file name in the format "filename=FILENAME" must be provided.');
    }
    $content_disposition = $request->headers
      ->get('content-disposition');

    // Parse the header value. This regex does not allow an empty filename.
    // i.e. 'filename=""'. This also matches on a word boundary so other keys
    // like 'not_a_filename' don't work.
    if (!preg_match(static::REQUEST_HEADER_FILENAME_REGEX, $content_disposition, $matches)) {
      throw new BadRequestHttpException('No filename found in "Content-Disposition" header. A file name in the format "filename=FILENAME" must be provided.');
    }

    // Check for the "filename*" format. This is currently unsupported.
    if (!empty($matches['star'])) {
      throw new BadRequestHttpException('The extended "filename*" format is currently not supported in the "Content-Disposition" header.');
    }

    // Don't validate the actual filename here, that will be done by the upload
    // validators in validate().
    // @see \Drupal\file\Plugin\rest\resource\FileUploadResource::validate()
    $filename = $matches['filename'];

    // Make sure only the filename component is returned. Path information is
    // stripped as per https://tools.ietf.org/html/rfc6266#section-4.3.
    return $this->fileSystem
      ->basename($filename);
  }

  /**
   * Checks if the current user has access to upload the file.
   *
   * @param \Drupal\Core\Session\AccountInterface $account
   *   The account for which file upload access should be checked.
   * @param \Drupal\Core\Field\FieldDefinitionInterface $field_definition
   *   The field definition for which to get validators.
   * @param \Drupal\Core\Entity\EntityInterface $entity
   *   (optional) The entity to which the file is to be uploaded, if it exists.
   *   If the entity does not exist and it is not given, create access to the
   *   file will be checked.
   *
   * @return \Drupal\Core\Access\AccessResultInterface
   *   The file upload access result.
   */
  public static function checkFileUploadAccess(AccountInterface $account, FieldDefinitionInterface $field_definition, EntityInterface $entity = NULL) {
    assert(is_null($entity) || $field_definition
      ->getTargetEntityTypeId() === $entity
      ->getEntityTypeId() && $field_definition
      ->getTargetBundle() === $entity
      ->bundle());
    $entity_type_manager = \Drupal::entityTypeManager();
    $entity_access_control_handler = $entity_type_manager
      ->getAccessControlHandler($field_definition
      ->getTargetEntityTypeId());
    $bundle = $entity_type_manager
      ->getDefinition($field_definition
      ->getTargetEntityTypeId())
      ->hasKey('bundle') ? $field_definition
      ->getTargetBundle() : NULL;
    $entity_access_result = $entity ? $entity_access_control_handler
      ->access($entity, 'update', $account, TRUE) : $entity_access_control_handler
      ->createAccess($bundle, $account, [], TRUE);
    $field_access_result = $entity_access_control_handler
      ->fieldAccess('edit', $field_definition, NULL, NULL, TRUE);
    return $entity_access_result
      ->andIf($field_access_result);
  }

  /**
   * Streams file upload data to temporary file and moves to file destination.
   *
   * @return string
   *   The temp file path.
   *
   * @throws \Symfony\Component\HttpKernel\Exception\HttpException
   *   Thrown when input data cannot be read, the temporary file cannot be
   *   opened, or the temporary file cannot be written.
   */
  protected function streamUploadData() {

    // 'rb' is needed so reading works correctly on Windows environments too.
    $file_data = fopen('php://input', 'rb');
    $temp_file_path = $this->fileSystem
      ->tempnam('temporary://', 'file');
    $temp_file = fopen($temp_file_path, 'wb');
    if ($temp_file) {
      while (!feof($file_data)) {
        $read = fread($file_data, static::BYTES_TO_READ);
        if ($read === FALSE) {

          // Close the file streams.
          fclose($temp_file);
          fclose($file_data);
          $this->logger
            ->error('Input data could not be read');
          throw new HttpException(500, 'Input file data could not be read.');
        }
        if (fwrite($temp_file, $read) === FALSE) {

          // Close the file streams.
          fclose($temp_file);
          fclose($file_data);
          $this->logger
            ->error('Temporary file data for "%path" could not be written', [
            '%path' => $temp_file_path,
          ]);
          throw new HttpException(500, 'Temporary file data could not be written.');
        }
      }

      // Close the temp file stream.
      fclose($temp_file);
    }
    else {

      // Close the input file stream since we can't proceed with the upload.
      // Don't try to close $temp_file since it's FALSE at this point.
      fclose($file_data);
      $this->logger
        ->error('Temporary file "%path" could not be opened for file upload.', [
        '%path' => $temp_file_path,
      ]);
      throw new HttpException(500, 'Temporary file could not be opened');
    }

    // Close the input stream.
    fclose($file_data);
    return $temp_file_path;
  }

  /**
   * Validates the file.
   *
   * @param \Drupal\file\FileInterface $file
   *   The file entity to validate.
   * @param array $validators
   *   An array of upload validators to pass to file_validate().
   *
   * @return \Drupal\Core\Entity\EntityConstraintViolationListInterface
   *   The list of constraint violations, if any.
   */
  protected function validate(FileInterface $file, array $validators) {
    $violations = $file
      ->validate();

    // Remove violations of inaccessible fields as they cannot stem from our
    // changes.
    $violations
      ->filterByFieldAccess();

    // Validate the file based on the field definition configuration.
    $errors = file_validate($file, $validators);
    if (!empty($errors)) {
      $translator = new DrupalTranslator();
      foreach ($errors as $error) {
        $violation = new ConstraintViolation($translator
          ->trans($error), $error, [], EntityAdapter::createFromEntity($file), '', NULL);
        $violations
          ->add($violation);
      }
    }
    return $violations;
  }

  /**
   * Prepares the filename to strip out any malicious extensions.
   *
   * @param string $filename
   *   The file name.
   * @param array $validators
   *   The array of upload validators.
   *
   * @return string
   *   The prepared/munged filename.
   */
  protected function prepareFilename($filename, array &$validators) {
    if (!empty($validators['file_validate_extensions'][0])) {

      // If there is a file_validate_extensions validator and a list of
      // valid extensions, munge the filename to protect against possible
      // malicious extension hiding within an unknown file type. For example,
      // "filename.html.foo".
      $filename = file_munge_filename($filename, $validators['file_validate_extensions'][0]);
    }

    // Rename potentially executable files, to help prevent exploits (i.e. will
    // rename filename.php.foo and filename.php to filename.php.foo.txt and
    // filename.php.txt, respectively). Don't rename if 'allow_insecure_uploads'
    // evaluates to TRUE.
    if (!$this->systemFileConfig
      ->get('allow_insecure_uploads') && preg_match(FILE_INSECURE_EXTENSION_REGEX, $filename) && substr($filename, -4) != '.txt') {

      // The destination filename will also later be used to create the URI.
      $filename .= '.txt';

      // The .txt extension may not be in the allowed list of extensions. We
      // have to add it here or else the file upload will fail.
      if (!empty($validators['file_validate_extensions'][0])) {
        $validators['file_validate_extensions'][0] .= ' txt';
      }
    }
    return $filename;
  }

  /**
   * Determines the URI for a file field.
   *
   * @param array $settings
   *   The array of field settings.
   *
   * @return string
   *   An un-sanitized file directory URI with tokens replaced. The result of
   *   the token replacement is then converted to plain text and returned.
   */
  protected function getUploadLocation(array $settings) {
    $destination = trim($settings['file_directory'], '/');

    // Replace tokens. As the tokens might contain HTML we convert it to plain
    // text.
    $destination = PlainTextOutput::renderFromHtml($this->token
      ->replace($destination, [], [], new BubbleableMetadata()));
    return $settings['uri_scheme'] . '://' . $destination;
  }

  /**
   * Retrieves the upload validators for a field definition.
   *
   * This is copied from \Drupal\file\Plugin\Field\FieldType\FileItem as there
   * is no entity instance available here that that a FileItem would exist for.
   *
   * @param \Drupal\Core\Field\FieldDefinitionInterface $field_definition
   *   The field definition for which to get validators.
   *
   * @return array
   *   An array suitable for passing to file_save_upload() or the file field
   *   element's '#upload_validators' property.
   */
  protected function getUploadValidators(FieldDefinitionInterface $field_definition) {
    $validators = [
      // Add in our check of the file name length.
      'file_validate_name_length' => [],
    ];
    $settings = $field_definition
      ->getSettings();

    // Cap the upload size according to the PHP limit.
    // @todo Remove when we stop supporting Drupal 8.5 and 8.6.
    $max_bytes = floatval(\Drupal::VERSION) < 8.699999999999999 ? file_upload_max_size() : Environment::getUploadMaxSize();
    $max_filesize = Bytes::toInt($max_bytes);
    if (!empty($settings['max_filesize'])) {
      $max_filesize = min($max_filesize, Bytes::toInt($settings['max_filesize']));
    }

    // There is always a file size limit due to the PHP server limit.
    $validators['file_validate_size'] = [
      $max_filesize,
    ];

    // Add the extension check if necessary.
    if (!empty($settings['file_extensions'])) {
      $validators['file_validate_extensions'] = [
        $settings['file_extensions'],
      ];
    }
    return $validators;
  }

  /**
   * Generates a lock ID based on the file URI.
   *
   * @param string $file_uri
   *   The file URI.
   *
   * @return string
   *   The generated lock ID.
   */
  protected static function generateLockIdFromFileUri($file_uri) {
    return 'file:jsonapi:' . Crypt::hashBase64($file_uri);
  }

}

Members

Name	Modifiers	Type	Description
TemporaryJsonapiFileFieldUploader::$fileSystem	protected	property	The file system service.
TemporaryJsonapiFileFieldUploader::$lock	protected	property	The lock service.
TemporaryJsonapiFileFieldUploader::$logger	protected	property	A logger instance.
TemporaryJsonapiFileFieldUploader::$mimeTypeGuesser	protected	property	The MIME type guesser.
TemporaryJsonapiFileFieldUploader::$systemFileConfig	protected	property	System file configuration.
TemporaryJsonapiFileFieldUploader::$token	protected	property	The token replacement instance.
TemporaryJsonapiFileFieldUploader::BYTES_TO_READ		constant	The amount of bytes to read in each iteration when streaming file data.
TemporaryJsonapiFileFieldUploader::checkFileUploadAccess	public static	function	Checks if the current user has access to upload the file.
TemporaryJsonapiFileFieldUploader::generateLockIdFromFileUri	protected static	function	Generates a lock ID based on the file URI.
TemporaryJsonapiFileFieldUploader::getUploadLocation	protected	function	Determines the URI for a file field.
TemporaryJsonapiFileFieldUploader::getUploadValidators	protected	function	Retrieves the upload validators for a field definition.
TemporaryJsonapiFileFieldUploader::handleFileUploadForField	public	function	Creates and validates a file entity for a file field from a file stream.
TemporaryJsonapiFileFieldUploader::prepareFilename	protected	function	Prepares the filename to strip out any malicious extensions.
TemporaryJsonapiFileFieldUploader::REQUEST_HEADER_FILENAME_REGEX		constant	The regex used to extract the filename from the content disposition header.
TemporaryJsonapiFileFieldUploader::streamUploadData	protected	function	Streams file upload data to temporary file and moves to file destination.
TemporaryJsonapiFileFieldUploader::validate	protected	function	Validates the file.
TemporaryJsonapiFileFieldUploader::validateAndParseContentDispositionHeader	public	function	Validates and extracts the filename from the Content-Disposition header.
TemporaryJsonapiFileFieldUploader::__construct	public	function	Constructs a FileUploadResource instance.

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class TemporaryJsonapiFileFieldUploader in JSON:API 8.2

Hierarchy

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