A presentation on Shanghai on Rails, March 14 2009, includes rack middelware introduction, one-file application using sinatra and sequel, and sinatra program running under Rails Metal.

1. Ruby off Rails Rack, Sinatra and Sequel Jiang Wu 2009.3.14

3. rack http://rack.rubyforge.net/ Rack aims to provide a minimal API for connecting web servers and web frameworks.

4. Rack SPEC {"HTTP_USER_AGENT"=>"curl/7.12.2 ...", "REQUEST_URI"=>"http://ruby-lang.org/", "QUERY_STRING"=>"", "HTTP_ACCEPT"=>"*/*", "REQUEST_METHOD"=>"GET", "rack.input" => '...', ... } call(env) [status, headers, body] to_i each each [String,String] String yields yields

5. Rack middleware: process RESP RESP RESP Rack Middleware 1 Rack Middleware 3 Rack Middleware 2

8. sinatra http://www.sinatrarb.com/

10. sequel The Database Toolkit for Ruby sequel postgres://localhost/blog Your database is stored in DB... >> DB.tables => [:blogs, :tags] >> require 'logger' >> DB.logger = Logger.new(STDOUT) >> DB[:tags].filter(:count > 100).order( :name.desc).limit(5).all INFO -- : SELECT * FROM &quot;tags&quot; WHERE (&quot;count&quot; > 150) ORDER BY &quot;name&quot; DESC LIMIT 5 >> class Tag < Sequel::Model;end >> Tag.filter(:count > 150).order(:name.desc).limit(5).all

11. sinatra + sequel: a simple note ruby notes.rb Just ONE file to run!

19. Questions?