Topic Use Cases

Working with topics. More...

Working with topics.

Registering a user data type

• Set up participant
• Register user data type of type T under the name "My_Type"

  const char* type_name = "My_Type";
  DDS_ReturnCode_t retcode;
  
  retcode = FooTypeSupport::register_type(participant, type_name);
  if (retcode != DDS_RETCODE_OK) {
      // ... error 
  }

Setting up a topic

• Set up participant
• Ensure user data type is registered
• Create a DDSTopic under the name "my_topic"

  const char* topic_name = "my_topic";
  const char* type_type = "My_Type";   // user data type
  DDS_TopicQos topic_qos;
  DDS_ReturnCode_t retcode;
  
  // MyTopicListener is user defined and 
  // extends DDSTopicListener
  DDSTopicListener* topic_listener = new MyTopicListener(); // or = NULL
  
  retcode = participant->get_default_topic_qos(topic_qos);
  
  if (retcode != DDS_RETCODE_OK) {
      // ... error 
  }
  
  DDSTopic* topic = participant->create_topic(topic_name, type_name,
                                        topic_qos, topic_listener,
                                        DDS_STATUS_MASK_ALL);
  if (topic == NULL) {
      // ... error 
  
  };

Tearing down a topic

• Delete DDSTopic:

  DDS_ReturnCode_t retcode;
  
  retcode = participant->delete_topic(topic);
  
  if (retcode != DDS_RETCODE_OK) {
      // ... check for cause of failure
  }