unsubscribe method

void unsubscribe(
  1. String topic, {
  2. dynamic expectAcknowledge = false,
})

Unsubscribe from a topic. Some brokers(AWS for instance) need to have each un subscription acknowledged, use the expectAcknowledge parameter for this, default is false.

Implementation

void unsubscribe(String topic, {expectAcknowledge = false}) {
  final unsubscribeMsg = MqttUnsubscribeMessage()
      .withMessageIdentifier(
          messageIdentifierDispenser.getNextMessageIdentifier())
      .fromTopic(topic);
  if (expectAcknowledge) {
    unsubscribeMsg.expectAcknowledgement();
  }
  connectionHandler!.sendMessage(unsubscribeMsg);
  pendingUnsubscriptions[unsubscribeMsg.variableHeader!.messageIdentifier] =
      topic;
}