Inspired by @JEG2's talk at Rubyconf... Any ruby object, as a webapp! 'Cause we can. :-)

webapp.rb

require 'rubygems'
require 'rack'

class Object
  def webapp
    class << self
       define_method :call do |env|
         func, *attrs = env['PATH_INFO'].split('/').reject(&:empty?)
         [200, {}, send(func, *attrs)]
       end
    end
    self
  end
end

Rack::Handler::Mongrel.run [].webapp, :Port => 9292
#                         ^^^^^^^^^^^
#                              |          (x)
#                         ROFLSCALE DB ---/
#


# http://localhost:9292/push/1  -> 1
# http://localhost:9292/push/2  -> 12
# http://localhost:9292/push/3  -> 123

# http://localhost:9292/to_a    -> 123

# http://localhost:9292/pop     -> 3
# http://localhost:9292/shift   -> 1

# Implementations in other languages (thanks guys!):
# Node.js: https://gist.github.com/700995
# Groovy: https://gist.github.com/702337
# Python: https://gist.github.com/702001
# Perl w/ plack: https://gist.github.com/703620
# Perl w/ continuity: https://gist.github.com/703651
# Io: https://gist.github.com/703431

# Great explanation of how this works in Ruby on Stackoverflow:
# http://stackoverflow.com/questions/4198883/exposing-any-ruby-object-over-the-web

Yep, 1.8.7 should work. What does your console output when you run the server and make that request?

hmmm, you'r right, it's talking about the each method... but I'm running ruby 1.8.7

config.ru:1:in new' config.ru:1 Wed Nov 24 16:03:46 +0100 2010: Read error: #<NoMethodError: undefined methodeach' for Array:Class>
/Library/Ruby/Gems/1.8/gems/rack-1.2.1/lib/rack/chunked.rb:37:in each' /Library/Ruby/Gems/1.8/gems/rack-1.2.1/lib/rack/handler/mongrel.rb:80:inprocess'
/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:159:in process_client' /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:158:ineach'
/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:158:in `process_cli

Right, you're seeing the problem I described below. You need to convert everything to a StringIO and then you're good to go.

So I updated it a bit in my fork; it removes url encoding and returns json serialization of results

https://gist.github.com/737959

@danny: nice!

How come you didn’t settle with def self.call(env) instead?

require 'rack'

class Object
  def to_webapp
    def self.call(env)
      func, *attrs = env['PATH_INFO'].split('/').reject(&:empty?)
      [200, {}, send(func || :inspect, *attrs)]
    end
    self
  end
end

Rack::Handler::WEBrick.run [].to_webapp, :Port => 9292