mapOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? mapOrNull<TResult extends Object?>({
  1. TResult? dataField(
    1. PassportElementErrorDataField value
    )?,
  2. TResult? frontSide(
    1. PassportElementErrorFrontSide value
    )?,
  3. TResult? reverseSide(
    1. PassportElementErrorReverseSide value
    )?,
  4. TResult? selfie(
    1. PassportElementErrorSelfie value
    )?,
  5. TResult? file(
    1. PassportElementErrorFile value
    )?,
  6. TResult? files(
    1. PassportElementErrorFiles value
    )?,
  7. TResult? translationFile(
    1. PassportElementErrorTranslationFile value
    )?,
  8. TResult? translationFiles(
    1. PassportElementErrorTranslationFiles value
    )?,
  9. TResult? unspecified(
    1. PassportElementErrorUnspecified value
    )?,
})

A variant of map that fallback to returning null.

It is equivalent to doing:

switch (sealedClass) {
  case final Subclass value:
    return ...;
  case _:
    return null;
}

Implementation

@optionalTypeArgs
TResult? mapOrNull<TResult extends Object?>({
  TResult? Function(PassportElementErrorDataField value)? dataField,
  TResult? Function(PassportElementErrorFrontSide value)? frontSide,
  TResult? Function(PassportElementErrorReverseSide value)? reverseSide,
  TResult? Function(PassportElementErrorSelfie value)? selfie,
  TResult? Function(PassportElementErrorFile value)? file,
  TResult? Function(PassportElementErrorFiles value)? files,
  TResult? Function(PassportElementErrorTranslationFile value)?
  translationFile,
  TResult? Function(PassportElementErrorTranslationFiles value)?
  translationFiles,
  TResult? Function(PassportElementErrorUnspecified value)? unspecified,
}) {
  final _that = this;
  switch (_that) {
    case PassportElementErrorDataField() when dataField != null:
      return dataField(_that);
    case PassportElementErrorFrontSide() when frontSide != null:
      return frontSide(_that);
    case PassportElementErrorReverseSide() when reverseSide != null:
      return reverseSide(_that);
    case PassportElementErrorSelfie() when selfie != null:
      return selfie(_that);
    case PassportElementErrorFile() when file != null:
      return file(_that);
    case PassportElementErrorFiles() when files != null:
      return files(_that);
    case PassportElementErrorTranslationFile() when translationFile != null:
      return translationFile(_that);
    case PassportElementErrorTranslationFiles() when translationFiles != null:
      return translationFiles(_that);
    case PassportElementErrorUnspecified() when unspecified != null:
      return unspecified(_that);
    case _:
      return null;
  }
}