What is pubnub?
PubNub is a real-time communication platform that allows developers to build applications with real-time messaging, presence, and data synchronization capabilities. It is commonly used for chat applications, live updates, IoT device communication, and more.
What are pubnub's main functionalities?
Real-time Messaging
This feature allows you to send real-time messages to a specific channel. The code sample demonstrates how to publish a message to a channel using PubNub.
const PubNub = require('pubnub');
const pubnub = new PubNub({
publishKey: 'your-publish-key',
subscribeKey: 'your-subscribe-key'
});
pubnub.publish({
channel: 'my_channel',
message: { text: 'Hello, World!' }
}, (status, response) => {
if (status.error) {
console.log('Publish failed: ', status);
} else {
console.log('Message published with timetoken', response.timetoken);
}
});
Real-time Subscription
This feature allows you to subscribe to a channel and receive real-time messages. The code sample demonstrates how to listen for new messages on a subscribed channel.
const PubNub = require('pubnub');
const pubnub = new PubNub({
publishKey: 'your-publish-key',
subscribeKey: 'your-subscribe-key'
});
pubnub.addListener({
message: function(event) {
console.log('New message received: ', event.message);
}
});
pubnub.subscribe({
channels: ['my_channel']
});
Presence Detection
This feature allows you to detect the presence of users in a channel. The code sample demonstrates how to listen for presence events such as join, leave, and timeout.
const PubNub = require('pubnub');
const pubnub = new PubNub({
publishKey: 'your-publish-key',
subscribeKey: 'your-subscribe-key'
});
pubnub.addListener({
presence: function(event) {
console.log('Presence event: ', event);
}
});
pubnub.subscribe({
channels: ['my_channel'],
withPresence: true
});
History
This feature allows you to retrieve the message history of a channel. The code sample demonstrates how to fetch the last 10 messages from a channel's history.
const PubNub = require('pubnub');
const pubnub = new PubNub({
publishKey: 'your-publish-key',
subscribeKey: 'your-subscribe-key'
});
pubnub.history({
channel: 'my_channel',
count: 10
}, (status, response) => {
if (status.error) {
console.log('History retrieval failed: ', status);
} else {
console.log('Message history: ', response.messages);
}
});
Other packages similar to pubnub
socket.io
Socket.IO is a library that enables real-time, bidirectional, and event-based communication between web clients and servers. It is commonly used for chat applications, live updates, and real-time analytics. Compared to PubNub, Socket.IO is more focused on web sockets and may require more server-side setup.
pusher
Pusher is a hosted service that makes it easy to add real-time data and functionality to web and mobile applications. It offers features like real-time messaging, presence, and webhooks. Pusher is similar to PubNub in terms of functionality but is a hosted service with a different pricing model.
ably
Ably is a real-time messaging service that provides pub/sub messaging, presence, and data synchronization. It is designed for high scalability and reliability. Ably offers similar features to PubNub but emphasizes performance and global data distribution.