when<TResult extends Object?> method

  1. @optionalTypeArgs
TResult when<TResult extends Object?>({
  1. required TResult empty(),
  2. required TResult sp(
    1. String type,
    2. SpView model
    ),
  3. required TResult ping(
    1. String type
    ),
})

A switch-like method, using callbacks.

As opposed to map, this offers destructuring. It is equivalent to doing:

switch (sealedClass) {
  case Subclass(:final field):
    return ...;
  case Subclass2(:final field2):
    return ...;
}

Implementation

@optionalTypeArgs
TResult when<TResult extends Object?>({
  required TResult Function() empty,
  required TResult Function(@JsonKey(name: "type") String type,
          @JsonKey(name: "jsonString", toJson: modelToString) SpView model)
      sp,
  required TResult Function(@JsonKey(name: "type") String type) ping,
}) {
  final _that = this;
  switch (_that) {
    case SocketSendModelEmpty():
      return empty();
    case SpViewSendModel():
      return sp(_that.type, _that.model);
    case PingViewSendModel():
      return ping(_that.type);
  }
}