machbase-neo
JSH
@jsh/mqtt

@jsh/mqtt

Since v8.0.52

Client

The MQTT client.

Usage example
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const mqtt = require("@jsh/mqtt");

const client = new mqtt.Client({
        serverUrls: ["tcp://127.0.0.1:1236"],
        keepAlive: 30,
        cleanStart: true,
        onConnect: (ack) => {
            println("connected.");
        },
        onConnectError: (err) => {
            println("connect error", err);
        },
    });

try {    
    client.connect();
    client.awaitConnection(1000);
    client.publish("test/topic", "Hello, MQTT!", 0)
} catch(e) {
    console.log("Error:", e);
} finally {
    client.disconnect();
}
Creation
ConstructorDescription
new Client(options)Instantiates a MQTT client object with an options
Options
OptionTypeDefaultDescription
serverUrls[]Stringserver addresses
keepAliveNumber10
cleanStartBooleanfalseclean session
usernameString
passwordString
clientIDStringrandom id
onClientErrorfunction(err) => {}
onConnectfunction(ack) => {}
onConnectErrorfunction(err) => {}
onDisconnectfunction(disconnect) => {}
onMessagefunction(msg) => {}

connect()

Syntax
connect()
Parameters

None.

Return value

None.

disconnect()

Syntax
disconnect()
Parameters

None.

Return value

None.

awaitConnection()

Syntax
awaitConnection()
Parameters

None.

Return value

None.

subscribe()

Syntax
subscribe(opts)
Parameters
Return value

None.

publish()

Syntax
publish()
Parameters

None.

Return value

None.

SubscriptionOption

Properties
PropertyTypeDescription
subscriptionsObject[]Array of Subscription
userPropertiesObjectkey-value object

Subscription

Properties
PropertyTypeDescription
topicString
qosNumber0, 1, 2
retainHandlingNumber
noLocalBoolean
retainAsPublishedBoolean

onMessage()

On publish message callback.

Syntax
funciton (msg) { }
Parameters
Return value

None.

Message

Properties
PropertyTypeDescription
packetIDNumber
qosNumber
retainBoolean
topicString
payloadObjectPayload
propertiesObjectMessageProperties
userObjectUserProperties

Payload

bytes()

Syntax
bytes()
Parameters

None.

Return value

Array of bytes.

string()

Syntax
string()
Parameters

None.

Return value

String

MessageProperties

PropertyTypeDescription
correlationData
contentType
responseTopic
payloadFormat
messageExpiry
subscriptionIdentifier
topicAlias

UserProperties

PropertyTypeDescription

onConnect()

On connect callback.

Syntax
funciton (ack) { }
Parameters
  • ack Object
Return value

None.

onConnectError()

On connect error callback.

Syntax
funciton (err) { }
Parameters
  • error String
Return value

None.

onDisconnect()

On disconnect callback

Syntax
funciton (disconn) { }
Parameters
  • disconn Object
Return value

None.

onClientError()

On client error callback

Syntax
funciton (err) { }
Parameters
  • err String
Return value

None.

Last updated on
@jsh/db@jsh/http