From: Martin Hart <martin@...>
Date: 2003-01-11T21:53:50+09:00
Subject: Re: [slightly OT] Using Observer pattern in client/server architecture - how?

On 1/10/03, 5:34:39 PM, Tom Sawyer <transami@transami.net> wrote regarding 
Re: [slightly OT] Using Observer pattern in client/server architecture - 
how?:
> i'm not 100% clear on what your trying to achieve. so i'm just throwing 
out
> some basic thoughts and i'm by no means an expert on network coding.

Thanks for sticking with this :-).  I'll explain more clearly exactly 
what I am trying to do.  If anybody thinks this is too OT for the list, 
perhaps we can take it offline?

Server - A ruby program that manages a set of data (we'll call them 
"Things").
Client - A FXRuby application that displays a screen monitoring a 
"Thing".

Many client programs can be started, the client programs can be anywhere 
- so we may have 1 on the same machine as the server, 5 running on 
another machine on the LAN, and lots running somewhere on the Internet.

Each client program can register its interest in a Thing.  If anyone 
decides to change the state of a Thing, then the clients that have 
registered an interest are notified by the server.

That's basically all I want to achieve.  As you say, I could make each 
Client a socket server in its own right, but I shouldn't need to (imho).  
If the server holds open the connection, then it can just send packets 
down it as the "thing" changes.

I know that I can achieve this with a custom protocol - I just wonder 
whether there are open standards for achieving this - without having to 
make each client a server in its own right?

Thanks,
Martin