saveFileWithDialog function

Future<String?> saveFileWithDialog({ required String fileName, required Uint8List bytes, required String mimeType, String? dialogTitle, })

Asks the user where to save bytes with the system save dialog, then writes them there.

On Linux the dialog goes through the XDG desktop portal, so it also works inside a Flatpak sandbox; on Android it is the system "create document" picker. No initial folder is passed: Windows, macOS and the portals remember the last folder by themselves.

Returns the name (or path, where there is one) of the saved file, or null when the user cancels.

Implementation

Future<String?> saveFileWithDialog({
  required String fileName,
  required Uint8List bytes,
  required String mimeType,
  String? dialogTitle,
}) async {
  final saved = await FilePicker.saveFile(
    dialogTitle: dialogTitle,
    fileName: fileName,
    bytes: bytes,
    mimeType: mimeType,
  );
  if (saved == null) return null;
  if (saved.scheme == 'file') return saved.toFilePath();
  // Content URIs (Android) only carry a document id such as
  // "primary:Download/labels.pdf": show its last part.
  final last = Uri.decodeComponent(
    saved.pathSegments.isEmpty ? '' : saved.pathSegments.last,
  );
  final name = last.split(RegExp(r'[/:]')).last;
  return name.isEmpty ? fileName : name;
}