From: Joe Van Dyk <joevandyk@...>
Date: 2005-06-26T06:22:56+09:00
Subject: Re: DSL question

On 6/25/05, Joel VanderWerf <vjoel@path.berkeley.edu> wrote:
> Joe Van Dyk wrote:
> > Hi,
> >
> > require 'traits'
> > $applications = {}
> >
> > class Application
> >   has %w{ application_id title executable options}
> > end
> >
> > def application(application_id, &block)
> >   a = Application.new
> >   ###### What goes here?   #############
> >   $applications[application_id] = a
> > end
> >
> > application :joe_app do
> >   title       "Joe's Application"
> >   executable  "My executable"
> >   options     "my options"
> > end
> >
> > application :another_app do
> >   title       "Another App"
> >   executable  "another exec"
> >   options     "the options"
> > end
> >
> >
> > It should be pretty apparent to what I'm trying to do.  Any ideas?
> > Can I restructure this better somehow?
> 
> instance_eval can help:
> 



Ooh, thanks.  I forgot about that one.  Revised code:

joe@ubuntu:~ $ cat test.rb
require 'traits'
$applications = {}

class Application
    has %w{ application_id title executable options }
end

def application(application_id, &block)
    a = Application.new
    a.instance_eval(&block)
    $applications[application_id] = a
end

application :joe_app do
    title       "Joe's Application"
    executable  "My executable"
    options     "my options"
end

application :another_app do
    title       "Another App"
    executable  "another exec"
    options     "the options"
end

puts $applications[:joe_app].title


joe@ubuntu:~ $ ruby test.rb
Joe's Application