Building a Threaded Ruby Socket Server for Flash CS4

I haven’t seen many examples of connecting Adobe’s Flash to a Ruby socket server. I’ve seen several examples in Java, Python, Perl, etc. but not Ruby. Today I’m going to build a very simple threaded socket server that will work with Flash CS4 (it should also work with Flash CS3).

For this project I used Ruby 1.8.7 and Flash CS4 (ActionScript 3.0). I ran the socket server on Ubuntu 10.04 (Beta 1) inside of VMWare Player 7 hosted on Windows Vista.

Here is the Ruby code:

require 'socket'

socketServer = TCPServer.open(843)

puts "Starting the socket server"

while true
	Thread.new(socketServer.accept) do |connection|

		puts "Accepting connection from: #{connection.peeraddr[2]}"

		begin
			while connection
			  	incomingData = connection.gets("\0")
			  	if incomingData != nil
					incomingData = incomingData.chomp
				end

				puts "Incoming: #{incomingData}"

				if incomingData == "DISCONNECT\0"
					puts "Received: DISCONNECT, closed connection"
					connection.close
					break
				else
					connection.puts "You said: #{incomingData}"
					connection.flush
				end
			end
		rescue Exception => e
		  puts "#{ e } (#{ e.class })"
		ensure
		  connection.close
		  puts "ensure: Closing"
		end
	end
end

Here is the ActionScript code to connect to the socket server on port 843:

var xmlSocket:XMLSocket = new XMLSocket();
// Adjust this to the IP address of your Linux machine/vm
xmlSocket.connect("192.168.1.100", 843);

xmlSocket.addEventListener(DataEvent.DATA, onIncomingData);
send_btn.addEventListener(MouseEvent.CLICK, clickHandler);
disconnect_btn.addEventListener(MouseEvent.CLICK, disconnectHandler);

function clickHandler(event:MouseEvent):void
{
    xmlSocket.send(input_txt.text);
    input_txt.text = "";
}

function disconnectHandler(event:MouseEvent):void
{
    xmlSocket.send("DISCONNECT");

	// You could use this if you wanted to but I
	// wanted the socket server the do the disconnect
	//xmlSocket.close();
    send_btn.enabled = false;
}

function onIncomingData(event:DataEvent):void
{
    trace("[" + event.type + "] " + event.data);
    output_txt.text += event.data + "\n";
    output_txt.verticalScrollPosition = output_txt.maxVerticalScrollPosition;
}

I named the interface components as such:
textarea – output_txt
textinput – input_txt
button (send) – send_btn
button (disconnect) – disconnect_btn

Keep in mind if you run this outside of the Flash IDE environment you will need to implement code to serve the Flash security policy file.