Socket.io-Stream not sending to Client

Question

I'm am trying to send (relay) a continuous stream of utf-8 data from server to client. While I can eyeball the data arriving on the server, I cannot pipe it into the Socket and forward it to the Client.

Nodejs Server,

var io = require('socket.io')(server);
app.io = io;
var dsteem = require('dsteem')
var es = require('event-stream') 
var client = new dsteem.Client('https://api.steemit.com')
var ss = require('socket.io-stream'); 
var outBoundStream = ss.createStream();
var stream = client.blockchain.getBlockStream();

io.on('connection', function(socket) {
    /* Eyeball the data in the nodejs console */ 
    stream.pipe(es.map(function(block, callback) {
    callback(null, util.inspect(block, {colors: true, depth: null}) + '\n')
    })).pipe(process.stdout);
    /* Send stream data to client */
    ss(socket).on('ready', function(){
        console.log('Here it comes...');
        ss(socket).emit('sending', function(){
            stream.pipe(es.map(function(block, callback) {
            callback(null, util.inspect(block, {colors: true, depth: null}) + '\n')
            }));
        });
    });

    ss(socket).on('disconnect', function(){
        console.log('Disconnected');
    });
});

The data from .getBlockStream() that I can see in the nodejs console looks like something like this snip,

 {['1b3c0394d1146cecdc0b5d38486f0b99a6d7c750',
 '85e3110930f87510b4782d50de86180ecbacf05d',
 '7cbd01b2a9d515736860014eabbc18893707e0c4',
 '307308574fec6336493d0a9713ee98da21bbc1a7',
 '9cb1636cdb2591361b7d7e4c9d04096c1bc93aff',
 '27d22c51a6f3e0d764039b095046ec563e53ae6b',
 '153451e251816823e3342d2f0b1425570d0f3d36',
 '0a17b03e9fddfde49ad632dfe2437d76321c34eb',
 'fdd23d78865d1855b16d171d24199dd4e2fba83a',
 '306e6f2b11e6bd6e2ef37acbe6e593ef2d1c0e1e' ] }

Client,

<script src="/socket.io/socket.io.js"></script>
<script src="/javascripts/socket.io-stream.js"></script>
<script> 
$(function () {
    var socket = io();
    ss(socket).emit('ready', 'Client ready, send me a stream...');
    ss(socket).on('sending', function(stream, d){
            console.log(stream);
  });
});
</script>

In the browser console I'm only seeing this function,

ƒ () {
        var args = slice.call(arguments);
        args = self.encoder.encode(args);
        ack.apply(this, args);
      }

Can anyone help me understand what I'm doing wrong?

Answer 1

The issue happens because you have below code

ss(socket).emit('sending', function(){
   stream.pipe(es.map(function(block, callback) {
   callback(null, util.inspect(block, {colors: true, depth: null}) + '\n')
}))

The second parameter of emit method expects data and your are sending it a function and hence what you receive on client side is a blank function

The fix is simple, just send the data

io.on('connection', function(socket) {
    /* Eyeball the data in the nodejs console */
    /* Send stream data to client */
    ss(socket).on('ready', function(){
        console.log('Here it comes...');
        stream.pipe(es.map(function(block, callback) {
            ss(socket).emit('sending', block);
            callback(null, util.inspect(block, {colors: true, depth: null}) + '\n')

        })).pipe(process.stdout);

    });

    ss(socket).on('disconnect', function(){
        console.log('Disconnected');
    });
});

Once that is done, you can see the data on client side