MQTTAsync_willOptions Struct Reference

MQTTAsync_willOptions defines the MQTT "Last Will and Testament" (LWT) settings for the client. More...

#include <MQTTAsync.h>

Data Fields
char	struct_id [4]
	The eyecatcher for this structure. More...
int	struct_version
	The version number of this structure. More...
const char *	topicName
	The LWT topic to which the LWT message will be published.
const char *	message
	The LWT payload.
int	retained
	The retained flag for the LWT message (see MQTTAsync_message.retained).
int	qos
	The quality of service setting for the LWT message (see MQTTAsync_message.qos and qos).
struct {
int   len
	binary payload length
const void *   data
	binary payload data
}	payload
	The LWT payload in binary form. More...

Detailed Description

MQTTAsync_willOptions defines the MQTT "Last Will and Testament" (LWT) settings for the client.

In the event that a client unexpectedly loses its connection to the server, the server publishes the LWT message to the LWT topic on behalf of the client. This allows other clients (subscribed to the LWT topic) to be made aware that the client has disconnected. To enable the LWT function for a specific client, a valid pointer to an MQTTAsync_willOptions structure is passed in the MQTTAsync_connectOptions structure used in the MQTTAsync_connect() call that connects the client to the server. The pointer to MQTTAsync_willOptions can be set to NULL if the LWT function is not required.

Field Documentation

payload

struct { ... } MQTTAsync_willOptions::payload

The LWT payload in binary form.

This is only checked and used if the message option is NULL

struct_id

char MQTTAsync_willOptions::struct_id[4]

The eyecatcher for this structure.

must be MQTW.

struct_version

int MQTTAsync_willOptions::struct_version

The version number of this structure.

Must be 0 or 1 0 indicates no binary will message support

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The documentation for this struct was generated from the following file:

• MQTTAsync.h