Topic Class Reference

Topic is the basic description of data to be published or subscribed. A topic is identified by a name and a type. A Topic is created by calling DomainParticipant.create_topic(). Prior to creating a Topic, the associated data type must be registered with the DomainParticipant via a call to the TypeSupportXYZ.register_type() function. [The register_type() function is auto-generated 'type-specific' code.]. More...

Inheritance diagram for Topic:

Public Member Functions
ReturnCode_t	enable ()
DomainParticipant	get_participant ()
	This operation returns the parent DomainParticipant of the Topic.
String	get_type_name ()
	This operation returns type_name of the Topic.
String	get_name ()
	This operation returns topic_name of the Topic.
ReturnCode_t	set_qos (TopicQos qos)
ReturnCode_t	get_qos (TopicQos qos)
ReturnCode_t	set_listener (TopicListener new_listener, long mask)
TopicListener	get_listener ()
ReturnCode_t	get_inconsistent_topic_status (InconsistentTopicStatus status)
Public Member Functions inherited from Entity
StatusCondition	get_statuscondition ()
int	get_status_changes ()
ReturnCode_t	enable ()
InstanceHandle_t	get_instance_handle ()

Detailed Description

Topic is the basic description of data to be published or subscribed. A topic is identified by a name and a type. A Topic is created by calling DomainParticipant.create_topic(). Prior to creating a Topic, the associated data type must be registered with the DomainParticipant via a call to the TypeSupportXYZ.register_type() function. [The register_type() function is auto-generated 'type-specific' code.].

Member Function Documentation

ReturnCode_t enable

(

)

Enables the Topic. A Topic is created either enabled or not based on the DomainParticipantQos setting entity_factory. When a Topic is not enabled, only the following sub-set of all Topic operations are legal:

• operations to get and set QoS policies,
• get_name(), get_type_name(), get_participant()
• get_statuscondition(),
• get_status_changes(),

Any other operation may return the ReturnCode_t.RETURNCODE_NOT_ENABLED error. Topic.enable() may be called on an already enabled Topic [it will have no effect].

ReturnCode_t get_inconsistent_topic_status

(

InconsistentTopicStatus

status

)

Provides access to the InconsistentTopicStatus of the Topic. As a side-effect, this routine will reset the total_count_change status field to zero.

TopicListener get_listener

(

)

This operation returns the currently installed TopicListener.

ReturnCode_t get_qos

(

TopicQos

qos

)

Returns the current TopicQos settings held in the Topic t. This routine copies the Topic QoS properites into qos.

ReturnCode_t set_listener	(	TopicListener	new_listener,
		long	mask
	)

Installs a TopicListener on Topic t. Only one listener may be attached to a Topic at a time. A call to set_listener() will replace any current listener with a_listener.

a_listener can be NULL, which indicates a listener that does nothing.

The infrastructure will make an internal copy of the listener structure so that it need not be persisted by the application.

See also

DDS for a list of available STATUS constants which may be or'ed together to construct the mask.

ReturnCode_t set_qos

(

TopicQos

qos

)

Sets the TopicQos values. These QoS values affect the behavior of the Topic. This routine may fail if the provided qos argument is not internally consistent. In this case, ReturnCode_t.RETCODE_INCONSISTENT_POLICY will be returned, and no changes will be made to the Topic QoS.