Forward data from UDP Socket to HTTP Server Node.js
Question
I am looking to create a Web Service from data that is being retrieved via UDP connection and have decided to use Node.js and Socket.IO but, have come up short in that I think this combination does not give me the result I want. I was hoping someone could point me in the right direction.
Right now, I have the following:
// require http, socket and socket.io
var http = require('http');
var dgram = require('dgram');
var socketio = require('socket.io');
// setup HTTP server, Socket.IO and UDP Socket
var server = http.createServer( handleRequest ),
io = socketio.listen(server),
socket = dgram.createSocket("udp4");
// Every time I receive a UDP Message
socket.on("message", function(msg,rinfo) {
// create a buffer we will store to
var buffer = new Buffer(msg.length);
// copy entire message into buffer
msg.copy(buffer, 0, 0, msg.length);
// if the message has length > 3
if ( buffer.length > 3 ) {
.... take data off the socket ....
// Create an XML document
var xml = "<?xml version=\"1.0\" encoding=\"UTF-8\" ?>\n";
xml += ... ;
xml += ... ;
// emit a udp message event
io.sockets.emit('udp message', xml);
}
});
function handleRequest(req, res) {
res.writeHead(200, {'content-type': 'text/html'});
res.end("<!doctype html> \
<html><head> \
<script src='/socket.io/socket.io.js'></script> \
<script> \
var socket = io.connect('localhost', {port: 8888}); \
socket.on('udp message', function(message) { res.end(message) }); \
</script></head></html>");
}
socket.bind(9876);
server.listen(8888);
Everything works well recv'ing the UDP data stream, creating the XML documents and I can see the XML being sent to the WebSocket but, I cannot retrieve the XML. Basically, I want a to continuously stream the XML once a user connects to the Web Service
Thoughts ? Dennis
1 answers
solution1
1 2013-06-11 17:59:45
This line looks suspiciously to me:
socket.on('udp message', function(message) { res.end(message) });
The client code is run in browser, you can't access res object. You can try to alert instead:
socket.on('udp message', function(message) { alert(message) });
In the real application, you will probably want to process the message and modify HTML of the page accordingly.
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