From: Raj Sahae <rajsahae@...>
Date: 2007-03-01T16:42:46+09:00
Subject: problem with DRb

I'm going to try to explain this problem without posting huge amounts of 
code, so please stick with me.

Imagine you have an object, GameServer, that contains an instance of 
some object, Game.
Game has many objects it owns too, Player's, Deck's, Card's, and all 
these objects have methods.
Then, I start a DRb service, passing in GameServer.game.  This isn't 
what the code actually is, but a
basic skeleton would be something like:

Class GameServer
    def initialize
       @game = Game.new
     end
end

Class Game
    def initialize
       @players = Array.new #holds Player.new instances
     end
end

Class Player
    def initialize
       @name
       @hand = Array.new # holds Cards
       @deck = Array.new # holds Cards
    end

    def draw
       @hand << @deck.shift
    end
end

DRb.start service etc etc


I have a client that starts a DRb service, creating a DRbObject game.  I 
wasn't successfull in using DRbUndumped, so I have all the classes 
defined on both the server and the client(probably related to the 
problem but I can't get DRbUndumped to work).  I know the connection 
works because I have accessed data through the connection, but at some 
point, the client calls a method on the DRbObject, and nothing happens.  
It's a Player.draw method, that takes a Card from Deck, and puts it in 
Player.hand.  I threw some prints in there, so I know the method is 
being called, but it's not having the desired effect.  I want the object 
on the server to change, but apparently the intuitive way to go about 
that isn't the correct way.  When I call the method, the prints show up 
in the clients prompt.  How do I activate the method on the server, from 
the client, thereby manipulating the object on the server?

I know that paragraph can be quite confusing.  Please ask for 
clarification where needed.

Raj Sahae