maybeWhen<TResult extends Object?> method

@optionalTypeArgs TResult maybeWhen<TResult extends Object?>({ TResult file(File file)?, TResult network(String url)?, required TResult orElse(), })

A variant of when that fallback to an orElse callback.

It is equivalent to doing:

switch (sealedClass) {
  case Subclass(:final field):
    return ...;
  case _:
    return orElse();
}

Implementation

@optionalTypeArgs
TResult maybeWhen<TResult extends Object?>({
  TResult Function(File file)? file,
  TResult Function(String url)? network,
  required TResult orElse(),
}) {
  final _that = this;
  switch (_that) {
    case XXFile() when file != null:
      return file(_that.file);
    case XXImage() when network != null:
      return network(_that.url);
    case _:
      return orElse();
  }
}