IncomingMessageTopicAlias Property

An integer used to identify the topic instead of the full topic filter in order to reduce the size of the publish packet.

Syntax

• C++
• Objective-C
• C

ANSI (Cross Platform)
int GetIncomingMessageTopicAlias(int iIncomingMessageIndex);

Unicode (Windows)
INT GetIncomingMessageTopicAlias(INT iIncomingMessageIndex);

- (int)incomingMessageTopicAlias:(int)incomingMessageIndex;

#define PID_MQTT_INCOMINGMESSAGETOPICALIAS 24

IPWORKSMQ_EXTERNAL void* IPWORKSMQ_CALL IPWorksMQ_MQTT_Get(void *lpObj, int propid, int arridx, int *lpcbVal, int64 *lpllVal);

IPWORKSMQ_EXTERNAL int IPWORKSMQ_CALL IPWorksMQ_MQTT_CheckIndex(void *lpObj, int propid, int arridx);

Default Value

0

Remarks

An integer used to identify the topic instead of the full topic filter in order to reduce the size of the publish packet.

If a non-zero topic alias is received, the client should establish a new topic alias mapping or use an existing mapping, depending on whether the IncomingMessageTopic string is empty.

For details on setting topic aliases for outgoing messages, see the TopicAlias configuration setting.

Valid only for MQTT 5.

The IncomingMessageIndex parameter specifies the index of the item in the array. The size of the array is controlled by the IncomingMessageCount property.

This property is read-only and not available at design time.

Data Type

Integer