TCPSocket: Sockets in the browser

Michael Carter of Orbited has written about how he now likes to call Comet sockets in the browser, and has an implementation available that looks like this:

PLAIN TEXT JAVASCRIPT:

var conn = new TCPSocket(hostname, port)

conn.onopen = function() { alert('connection opened!') }

conn.onread = function(data) { alert('RECEIVE: ' + data) }

conn.onclose = function(data) { alert('connection closed!') }

conn.send('Hello World');

The above code code is all you need to know. It will open a TCP connection to hostname:port, and will send the data Hello World. Any data the server sends back will be alerted with the onread handler.

The exact mechanism behind this innovation is pretty straightforward: Orbited is a router and firewall for incoming TCPSocket connections from the browser. It uses Comet techniques to establish bi-directional communication with the browser, then forwards all data over a raw TCP socket to the end point. Configuration allows access control enforcement so that the TCPSocket can only be connected to pre-approved end-points, so that the Orbited server isnt an open relay.

While this presents a paradigm shift in the way developers are tackling real-time, web-based applications today, its actually a return to the original method of writing network applications. Instead of writing applications based on web frameworks and throwing a Comet server in the mix, you can simply use the client-server architecture where the browser is the client, and the server is an arbitrary TCP server.