PushRadar Node.js Server Library

PushRadar is a realtime API service for the web. The service uses a simple publish-subscribe model, allowing you to broadcast "messages" on "channels" that are subscribed to by one or more clients. Messages are pushed in realtime to those clients.

This is PushRadar's official Node.js server library.

Prerequisites

In order to use this library, please ensure that you have the following:

• Node.js and npm installed on your server
• A PushRadar account - you can sign up at pushradar.com

Installation

The easiest way to get up and running is to install the library using the npm dependency manager. Run the following command in your console:

$ npm install pushradar --save

Broadcasting Messages

const radar = require("pushradar")("your-secret-key");
radar.broadcast("channel-1", {message: 'Hello world!'});

Receiving Messages

<script src="https://js.pushradar.com/v3/pushradar.min.js"></script>
<script>
    var radar = new PushRadar('your-public-key');
    radar.subscribe.to('channel-1', function (data) {
        console.log(data.message);
    });
</script>

Private Channels

Private channels require authentication and start with the prefix private-. We recommend that you use private channels by default to prevent unauthorised access to channels.

You will need to set up an authentication endpoint that returns a token using the auth(...) method if the user is allowed to subscribe to the channel. For example:

const radar = require("pushradar")("your-secret-key");
const channelName = request.query.channelName;
const socketID = request.query.socketID;
if (/* is user allowed to access channel? */ true) {
    radar.auth(channelName, socketID, (err, authResponse) => {
        if (!err) {
            response.send({token: authResponse.token});
        } else {
            response.status(403);
        }
    });
}

Then register your authentication endpoint by calling the auth(...) method client-side:

radar.auth('/auth');

Presence Channels

Presence channels require authentication and start with the prefix presence-. Presence channels are eligible for 'presence messages' containing information about channel subscribers.

You will need to set up an authentication endpoint as with private channels (see above). You should then register a onPresence(...) callback which will be called periodically. Your callback should accept two parameters: subscriber count and subscriber data. For example:

radar.auth('/auth');
radar.call.on.connection('/connected');

radar.subscribe.to('presence-channel-1', function (data) {
    console.log(data.message);
}).onPresence(function (count, clientData) {
    console.log(count);
});

If you wish to pass through subscriber (client) data, you can set up an endpoint and pass its URL to the call.on.connection(...) method. Your endpoint will be called when a user first connects to the service. From your endpoint you can register client data as follows:

const radar = require("pushradar")("your-secret-key");
const socketID = request.body.socketID;
radar.registerClientData(socketID, {'##uniqueID': 1, 'name': 'James Smith'});

Complete Documentation

Complete documentation for PushRadar's Node.js server library can be found at: https://pushradar.com/docs/3.x/node

License

Copyright © 2021, PushRadar. PushRadar's Node.js server library is licensed under the MIT license: https://opensource.org/licenses/mit-license.php