modifyData method

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

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? data) onChange) async {
  T? data = await onChange(value.data);
  return updateData(data);
}