watch method

Stream<DtoBackground?> watch(
  1. UserId id
)

Returns the Stream of real-time changes happening with the DtoBackground identified by the provided id.

Implementation

Stream<DtoBackground?> watch(UserId id) {
  return stream((db) {
    final stmt = db.select(db.background)
      ..where((u) => u.userId.equals(id.val));

    StreamController<DtoBackground?>? controller = _controllers[id];
    if (controller == null) {
      controller = StreamController<DtoBackground?>.broadcast(sync: true);
      _controllers[id] = controller;
    }

    return StreamGroup.merge([
      controller.stream,
      stmt.watch().map(
        (e) => e.isEmpty ? null : _BackgroundDb.fromDb(e.first),
      ),
    ]);
  });
}