modifyData method

Future<T?> modifyData(FutureOr<T> onChange(T?))

Similar to updateData but provide current current data in Manager as param. return updated data result once completed.

Implementation

Future<T?> modifyData(FutureOr<T> Function(T?) onChange) async {
  T? data = await onChange(_data);
  updateData(data);
  return data;
}