subscribe method

Future subscribe(
  1. String topic,
  2. Map<String, dynamic> options,
  3. IMqttMessageListener listener
)

Implementation

Future subscribe(String topic, Map<String, dynamic> options,
    IMqttMessageListener listener) async {
  // Check for open connection
  checkOpen();

  // Subscribe to topic
  await Future(() {
    var res = connection_!.subscribe(
      topic,
      options['qos']!,
    );
    if (res == null) throw Exception('Subscribe error');
  });

  // Determine if messages shall be filtered (topic without wildcarts)
  var filter = !topic.contains('*');

  // Add the subscription
  var subscription = MqttSubscription(
      topic: topic, options: options, filter: filter, listener: listener);
  subscriptions_.add(subscription);
}