sendWaitWhere method

Future<Message> sendWaitWhere(Message message, Filter filter, { Duration? timeout, })

Sends a message to another side of channel and waits for the response.

Recognition of the response message is performed by the given filter function. See Filters for some useful filter implementations.

If timeout is given and there's no suitable response message within the timeout, method fails with TimeoutException.

Implementation

Future<Message> sendWaitWhere(Message message, Filter filter,
    {Duration? timeout}) {
  var comp = Completer<Message>();

  var lsid = listener.prependListener((e) {
    try {
      var msg = Message.fromJson(assertTyped(e));
      if (filter(msg)) {
        comp.complete(msg);
        return false;
      }
    } on TypeAssertionError {
      return true;
    }

    return true;
  });

  var future = comp.future.then((value) {
    listener.removeListener(lsid);
    return value;
  });

  sendSignal(message);

  return (timeout != null) ? future.timeout(timeout) : future;
}