react-native-paho-mqtt

Eclipse Paho JavaScript client forked for React Native

A fork of paho-client, this project exists to provide an ES6-ready, Promise-based, react-native compatible version of the Eclipse Paho client

Compatibility note

Due to a React Native binary websocket bug, this library will not work with React Native 0.46.0 on Android, but should be ok on other platforms. RN 0.47 and RN<=0.45 are fine on all platforms as far as I know.

Documentation

Reference documentation (for the base Paho client) is online at: http://www.eclipse.org/paho/files/jsdoc/index.html

Getting Started

The included code below is a very basic sample that connects to a server using WebSockets and subscribes to the topic World, once subscribed, it then publishes the message Hello to that topic. Any messages that come into the subscribed topic will be printed to the Javascript console.

This requires the use of a broker that supports WebSockets natively, or the use of a gateway that can forward between WebSockets and TCP.

import { Client, Message } from 'react-native-paho-mqtt';

//Set up an in-memory alternative to global localStorage
const myStorage = {
  setItem: (key, item) => {
    myStorage[key] = item;
  },
  getItem: (key) => myStorage[key],
  removeItem: (key) => {
    delete myStorage[key];
  },
};

// Create a client instance
const client = new Client({ uri: 'ws://iot.eclipse.org:80/ws', clientId: 'clientId', storage: myStorage });

// set event handlers
client.on('connectionLost', (responseObject) => {
  if (responseObject.errorCode !== 0) {
    console.log(responseObject.errorMessage);
  }
});
client.on('messageReceived', (message) => {
  console.log(message.payloadString);
});

// connect the client
client.connect()
  .then(() => {
    // Once a connection has been made, make a subscription and send a message.
    console.log('onConnect');
    return client.subscribe('World');
  })
  .then(() => {
    const message = new Message('Hello');
    message.destinationName = 'World';
    client.send(message);
  })
  .catch((responseObject) => {
    if (responseObject.errorCode !== 0) {
      console.log('onConnectionLost:' + responseObject.errorMessage);
    }
  })
;