mqtt reset

(mqtt-reset t . args)

mqtt-reset resets an existing MQTT instance.

Parameter	Description
t	MQTT instance
args	Optional: Subscription arguments (below)

Attribute	Description
clean-session	Broker to clean all messages/subscriptions on disconnect (Default: 0)
host	Hostname or IP (Default: "127.0.0.1")
port	Port number (Default: 1883)
keepalive	Interval of keepalive [sec] (Default: 10)
timeout	Timeout [sec] (Default: 10)
max-packets	(Default: 100)
handler	Handler of type (lambda (topic val) ...) (Default: #f)
will	Message to be send by broker if client disconnects '("topic" "msg" qos retain) (Default: #f)
username	Username as string (Default: #f)
password	Password as string (Default: #f)
tls-version	TLS version (Default: "tlsv1.2")
tls-insecure	Disable server certificate verification (Default: #f)
psk	pre-shared-key in hex format (Default: #f)
psk_identity	identity/username of this client (Default: #f)
id	Id tag of host (Default: #f, which makes it LN/IP-pid)

Example

Example 1: Make a connection to a mosquitto broker running on localhost:1883, reset instance to connect to broker on 168.1.1.2:1882, subscribe to two topics, publish some data to them and wait for the results to show. Then unsubscribe from one topic and show that it's handler is no longer called. Finally close the connection properly.

> (define m (make-mqtt 'host "127.0.0.1" 'port 1883 
                       'handler (lambda (topic val) 
                          (for-each display (list topic ": " val "\n")))))
> (mqtt-reset m 'host "168.1.1.2" 'port 1882 'handler (lambda (topic val) 
                          (for-each display (list topic " = " val "\n")))))
> (thread-sleep! 0.5)
> (mqtt-subscribe m "Test1" 2)
#t
> (mqtt-subscribe m "Test2" 2)
#t
> (mqtt-publish m "Test1" 123 2 0)
#t
> (mqtt-publish m "Test2" 123456 2 0)
#t
> (thread-sleep! 1.)
Test1: 123
Test2: 123456
> (mqtt-unsubscribe m "Test1")
#t
> (mqtt-publish m "Test1" "blah" 2 0)
#t
> (mqtt-publish m "Test2" "LN1" 2 0)
#t
> (thread-sleep! 1.)
Test2: LN1
> (mqtt-destroy m)
#t