block-messenger

block-messenger

Simplifies message exchange between pipeline blocks.

Factory Pattern simplifies replacement of Client.

MQTT Client is Implemented based on NPM mqtt package

To Create a MQTT Client using the BlockMessenger Factory

type = 'mqtt'

To receive messages, listen to event 'message' (topic, message) To publish a message, messenger.publish(some_data, callback);

Usage example:

'use strict';

const Messenger = require('block-messenger');

const options = {
    clientId: 'test',
    host: process.env.MQTT_HOST || '127.0.0.1',
    port: process.env.MQTT_PORT || 1883,
    username: process.env.MQTT_USERNAME,
    password: process.env.MQTT_PASSWORD,
    qos: 1
};

const mqtt = Messenger.mqtt(options);

console.log(options);

mqtt.on('subscribed', (granted) => {
    console.log(granted);
});

mqtt.on('message', (topic, message) => {
    console.log(`new message in topic ${topic}:`, message.toString());
});


mqtt.subscribe('aigent/test/in');

setInterval(() => {
    mqtt.publish('aigent/test/out', {data: 'test data'})
        .then(data => {
            console.log('data published');
        }).catch(err => {
        console.error(err);
    });

}, 1000);

The MQTT Client also emits the following events:

• connect

• reconnect

• close

• offline

• error

• end

• packetsend

• packetreceive

• message

• subscribed

Run Tests

npm test
npm run-script test-cov

TO DO:

• Implement kafka-messenger.js (type = 'kafka')

Dev:

Transpile TypeScript into Javascript:

npm install
npm run-script build
npm publish