Module jls.net.mqtt
This module provides classes to work with MQTT.
Message Queuing Telemetry Transport
Class MqttClient
| MqttClient:new () | Creates a new MQTT client. |
| mqttClient:connect ([addr[, port]]) | Connects this MQTT client. |
| mqttClient:close () | Closes this MQTT client. |
| mqttClient:onMessage (topicName, payload) | Called when a message has been published on a subscribed topic. |
| mqttClient:publish (topicName, payload[, options]) | Publishes a message payload on a topic. |
| mqttClient:subscribe (topicName, qos) | Subscribes to a topic. |
| mqttClient:unsubscribe (topicName) | Unubscribes from a topic. |
Class MqttServer
| MqttServer:new () | Creates a new MQTT server. |
| mqttServer:bind (node[, port[, backlog[, callback]]]) | Binds this server to the specified address and port number. |
| mqttServer:close ([callback]) | Closes this server. |
Class MqttClient
The MqttClient class enables to Publish and Subscribe to Application Messages.
Usage:
local event = require('jls.lang.event') local mqtt = require('jls.net.mqtt') local topicName, payload = 'test', 'Hello world!' local mqttClient = mqtt.MqttClient:new() mqttClient:connect():next(function() return mqttClient:publish(topicName, payload) end):next(function() mqttClient:close() end) event:loop()
- MqttClient:new ()
-
Creates a new MQTT client.
Returns:
-
a new MQTT client
- mqttClient:connect ([addr[, port]])
-
Connects this MQTT client.
Parameters:
- addr string the address to connect to, could be an IP address or a host name. (optional)
- port number the port to connect to, default is 1883. (optional)
Returns:
-
a promise that resolves once the client is connected.
- mqttClient:close ()
-
Closes this MQTT client.
Returns:
-
a promise that resolves once the client is closed.
- mqttClient:onMessage (topicName, payload)
-
Called when a message has been published on a subscribed topic.
Parameters:
- mqttClient:publish (topicName, payload[, options])
-
Publishes a message payload on a topic.
Parameters:
- topicName string The name of the topic.
- payload string The message payload.
- options the options.
- qos number Quality of Service, 0: At most once delivery, 1: At least once delivery, 2: Exactly once delivery (optional)
- retain boolean Retain flag, will be delivered to future subscribers (optional)
Returns:
-
a promise that resolves once the message is sent.
- mqttClient:subscribe (topicName, qos)
-
Subscribes to a topic.
Parameters:
- topicName string The name of the topic.
- qos number The QoS.
Returns:
-
a promise that resolves once the message is sent.
- mqttClient:unsubscribe (topicName)
-
Unubscribes from a topic.
Parameters:
- topicName string The name of the topic.
Returns:
-
a promise that resolves once the message is sent.
Class MqttServer
The MqttServer class enables clients to exchange Application Messages using publish and subscribe.
Usage:
local event = require('jls.lang.event') local mqtt = require('jls.net.mqtt') local mqttServer = mqtt.MqttServer:new() mqttServer:bind() event:loop()
- MqttServer:new ()
-
Creates a new MQTT server.
Returns:
-
a new MQTT server
- mqttServer:bind (node[, port[, backlog[, callback]]])
-
Binds this server to the specified address and port number.
Parameters:
- node string the address, the address could be an IP address or a host name.
- port number the port number, 0 to let the system automatically choose a port, default is 1883. (optional)
- backlog number the accept queue size, default is 32. (optional)
- callback function an optional callback function to use in place of promise. (optional)
Returns:
-
jls.lang.Promise
a promise that resolves once the server is bound.
- mqttServer:close ([callback])
-
Closes this server.
Parameters:
- callback function an optional callback function to use in place of promise. (optional)
Returns:
-
jls.lang.Promise
a promise that resolves once the server is closed.