etl-broadcast.js

'use strict';
var redis = require('redis');
var client = redis.createClient();

function getOptions(server){
    return {
        onConnection:function(socket){
            console.log('a client just connected', socket.id)
            //retrieve latest message from redis and send it to client
            client.get("broadcast:messages:latest", function(err, reply){
              if(reply){
                socket.send(JSON.parse(reply), function (err) {
                    // console.log('this message (latest) was sent successfully', reply, 'to ' + socket.id);
                });
              } else {
                // console.log('No message or message expired.');
              }
            });
        },
        onDisconnection: function(socket){
            console.log('a client has disconnected', socket.id);
        },
        onMessage:function(socket, message, next){
            // console.log('SOCKET AUTH:', socket.auth)
            console.log('client', socket.id, 'has sent message',message)
            //save the message to redis
            var str = JSON.stringify(message);
            client.RPUSH("broadcast:messages", str); // notification history
            client.LRANGE("broadcast:messages",0 , -1, function(err, data){
                if(data) {
                    var lastElement = data[data.length - 1];
                    var jsonMessage = JSON.parse(lastElement);
                    client.set("broadcast:messages:latest", lastElement, redis.print);
                    client.expire("broadcast:messages:latest", jsonMessage.expire);
                }
            });
            //relay the message to connected clients
            server.broadcast(message);
        },
        auth: {type:'direct'},
        headers: '*'
    }
}
module.exports = {
   getOptions:getOptions
};