@aws-amplify/pubsub

What is @aws-amplify/pubsub?

@aws-amplify/pubsub is a part of the AWS Amplify library that provides a simple and powerful way to work with real-time messaging and event-driven architectures. It allows you to publish and subscribe to messages using AWS IoT, AWS AppSync, and other supported providers.

What are @aws-amplify/pubsub's main functionalities?

Publishing Messages

This feature allows you to publish messages to a specific topic. In this example, a message is published to 'myTopic' with the content 'Hello to all subscribers!'.

const { PubSub } = require('@aws-amplify/pubsub');

async function publishMessage() {
  await PubSub.publish('myTopic', { msg: 'Hello to all subscribers!' });
}

publishMessage();

Subscribing to Messages

This feature allows you to subscribe to a specific topic and receive messages. In this example, the subscription listens to 'myTopic' and logs any received messages.

const { PubSub } = require('@aws-amplify/pubsub');

PubSub.subscribe('myTopic').subscribe({
  next: data => console.log('Message received:', data),
  error: error => console.error(error),
  close: () => console.log('Done'),
});

Using AWS IoT

This feature allows you to use AWS IoT as a provider for PubSub. In this example, the AWS IoT provider is configured and used to subscribe to 'iotTopic'.

const { PubSub } = require('@aws-amplify/pubsub');
const { AWSIoTProvider } = require('@aws-amplify/pubsub/lib/Providers');

PubSub.addPluggable(new AWSIoTProvider({
  aws_pubsub_region: 'us-west-2',
  aws_pubsub_endpoint: 'wss://your-endpoint.iot.us-west-2.amazonaws.com/mqtt',
}));

PubSub.subscribe('iotTopic').subscribe({
  next: data => console.log('Message received:', data),
  error: error => console.error(error),
  close: () => console.log('Done'),
});

Other packages similar to @aws-amplify/pubsub

mqtt

The 'mqtt' package is a client library for the MQTT protocol, which is a lightweight messaging protocol for small sensors and mobile devices. It provides similar publish/subscribe functionality but requires more manual setup compared to @aws-amplify/pubsub.

socket.io

The 'socket.io' package is a library for real-time web applications. It enables real-time, bidirectional communication between web clients and servers. While it offers similar real-time messaging capabilities, it is more focused on web sockets and less on integration with AWS services.

paho-mqtt

The 'paho-mqtt' package is an MQTT client library for JavaScript. It provides similar publish/subscribe functionality and is part of the Eclipse Paho project. Like 'mqtt', it requires more manual setup and does not integrate as seamlessly with AWS services as @aws-amplify/pubsub.

README

This package contains the AWS Amplify PubSub category. For more information on using PubSub in your application please reference the Amplify Dev Center.