mqtt-typedi

About

An elegant way to use publisher/consumer pattern with MQTT in Typedi container. Project is dependent on typedi container & mqtt

Installation

• peer dependencies

npm install mqtt typedi --save

• package

npm install mqtt-typedi --save

Enable decorators/metadata options in tsconfig.json

{
  "experimentalDecorators": true,
  "emitDecoratorMetadata": true
}

Usage

Create client and set it into Typedi container under Client type key

import { Container } from 'typedi';
import * as mqtt from 'mqtt';
import { Client } from 'mqtt';

const client = mqtt.connect('mqtt://localhost', {
    username: 'admin',
    password: 'public',
});

Container.set(Client, client);

Publisher.ts

import { Service } from 'typedi';
import { Publisher, PublisherInterface } from 'mqtt-typedi';

@Service()
@Publisher('cool')
export class CoolPublisher implements PublisherInterface {
    publish(message: string): any {
    	return message;
    }
}

another_file.ts

import { CoolPublisher } from './CoolPublisher';
import { Container } from 'typedi';

const publisher = Container.get<CoolPublisher>(CoolPublisher);
publisher.publish('Hello mqtt-typedi');

Consumer.ts

import { Service } from 'typedi';
import { Consumer, ConsumerInterface } from 'mqtt-typedi';

@Service()
@Consumer('cool')
export class CoolConsumer implements ConsumerInterface {
    consume(topic: string, message: string): any {
        console.log({ topic, message }); // method will be called when new message appears on `cool` topic
    }
}

another_file.ts

import { CoolConsumer } from './CoolConsumer';

const consumer = new CoolConsumer(); //initialize consumer

Subscribe options

In Publisher/Consumer decorators is available to pass subscribe options, however this is not mandatory, default QoS is 0

to pass options

@Publisher('cool', {
    qos: 2,
    rh: true,
    ...
})

same for consumer