From: Andre Nathan <andre@...>
Date: 2003-12-23T11:11:30+09:00
Subject: Using DRbObservable

Hi

I'm trying to find out how to use the DRbObservable module. This is
what I have so far:

--[ Server ]--
require 'drb/drb'
require 'drb/observer'

class Foo
  include DRb::DRbObservable
  def run
    changed
    puts 'Notifying observer'
    notify_observers('foo message')
  end
end

DRb::start_service("druby://localhost:8888", Foo.new)
DRb::thread.join

--[ Client ]--
require 'drb/drb'
require 'drb/observer'

class Warner
  def initialize(obj)
    obj.add_observer(self)
  end
  def update(msg)
    puts "Update message: #{msg}"
  end
end

DRb.start_service
obj = DRbObject.new(nil, 'druby://localhost:8888')
Warner.new(obj)
obj.run


This is the error I get when I run the client after starting the
server:

$ ruby client.rb
(druby://localhost:8888) /usr/local/lib/ruby/1.8/observer.rb:126:in
`add_observer': observer needs to respond to `update' (NoMethodError)
        from b.rb:6:in `initialize'
        from b.rb:15:in `new'
        from b.rb:15

I don't understand it, since I've defined an 'update' method... can
anyone help me on that?

Thanks
Andre