Ruby MVC from scratch with Rack

Ruby MVC from scratch with Rack I Marco Schaden |
@donschado | 23.08.2014 RedFrog Conf

there was a rack application handling 10.000+ req/sec once upon
a time http://www.madebymarket.com/blog/dev/ruby-web-benchmark-report.html

DISCLAIMER no live coding: but we write and refactor a
lot of code! simple codez: examples try to be more obvious than "SOLID"! • a newbie will learn some cool tricks! • a pro will ﬁnd a lot to complain ;)! !seriously: this presentation contains all the memes, sorry

Rack is the foundation of all modern Ruby web frameworks

the future?

(this was less than a week before my talk @froscon)

https://groups.google.com/forum/#!topic/rack-devel/P8oOycVBaH0

no worries

Rack 2.0, or Rack for the Future https://gist.github.com/raggi/11c3491561802e573a47 https://docs.google.com/document/d/  1Ltwk-NJeJHIZy7yqLi5XBxAnclRqWwOQBOzb4EYJGO4/
https://gist.github.com/rkh/d99f0bf820de79b8d59b https://github.com/tenderlove/the_metal http://tenderlovemaking.com/2011/03/03/rack-api-is-awkward.html

status quo

http://chneukirchen.org/talks/euruko-2007/neukirchen07introducingrack.pdf • speciﬁcation! • implementation! • minimal abstract API for
HTTP! • Request: CGI environment! • Response: status, headers, body common interface between server and application

Write once, run "everywhere" WEBrick! Thin! Puma! Unicorn! Passenger! Torqbox
/ Torquebox! Trinidad! Mongrel! Pow! CGI! SCGI! FastCGI! Ebb! Fuzed! Litespeed! …

RackApp +call(env) A rack application is any Ruby object that
responds to call. ! ! It takes the environment hash as argument! and returns an array of exactly three values: ! the status, the headers and the body*! ! *which must respond to each

<<"show"me"the"code">>

! ->(env) { }

! ->(env) { } [ ]

! ->(env) { } [ ] 200, {'Content-Type' => 'text/html'},
['Hello World!']

! ->(env) { } *run means "call that object for
each request" run [ ] 200, {'Content-Type' => 'text/html'}, ['Hello World!']

! ->(env) { } *run means "call that object for
each request" # config.ru run [ ] 200, {'Content-Type' => 'text/html'}, ['Hello World!']

! ->(env) { } $ rackup 127.0.0.1 - - [23/Aug/2014
10:50:07] "GET / HTTP/1.1" 200 - 0.0007 [2014-08-23 10:50:00] INFO WEBrick 1.3.1 [2014-08-23 10:50:00] INFO ruby 2.1.1 (2014-02-24) [x86_64-darwin13.0] [2014-08-23 10:50:00] INFO WEBrick::HTTPServer#start: pid=11802 port=9292 *run means "call that object for each request" # config.ru run [ ] 200, {'Content-Type' => 'text/html'}, ['Hello World!']

! ->(env) { } $ rackup 127.0.0.1 - - [23/Aug/2014
10:50:07] "GET / HTTP/1.1" 200 - 0.0007 [2014-08-23 10:50:00] INFO WEBrick 1.3.1 [2014-08-23 10:50:00] INFO ruby 2.1.1 (2014-02-24) [x86_64-darwin13.0] [2014-08-23 10:50:00] INFO WEBrick::HTTPServer#start: pid=11802 port=9292 *run means "call that object for each request" SHIP IT # config.ru run [ ] 200, {'Content-Type' => 'text/html'}, ['Hello World!']

, read it: https://github.com/rack/rack How does it work? seriously

HTML + ERB

# config.ru run -> e { [200, {'Content-Type' => 'text/html'},
['Hello World!']] }

# config.ru run -> e { Rack::Response.new('Hello World!') }

# config.ru run -> e { Rack::Response.new(view) }

# config.ru ! ! ! ! ! ! ! !
! ! ! ! ! ! ! ! run -> e { Rack::Response.new(view) } view = <<-HTML <!DOCTYPE html> <html> <head> <title>Rack with HTML</title> </head> <body> <div> <h1>Hello World!</h1> </div> </body> </html> HTML

# config.ru ! ! ! ! ! ! ! !
! ! ! ! ! ! ! ! run -> e { Rack::Response.new(view) } require 'erb' view = <<-HTML <!DOCTYPE html> <html> <head> <title>Rack with </head> <body> <div> <h1>Hello World!</h1> </div> </body> </html> HTML ERB</title> <h1>Current time: <%= Time.now %></h1>

# config.ru ! ! ! ! ! ! ! !
! ! ! ! ! ! ! ! run -> e { Rack::Response.new(view) } require 'erb' view = <<-HTML <!DOCTYPE html> <html> <head> <title>Rack with </head> <body> <div> <h1>Hello World!</h1> </div> </body> </html> HTML ERB</title> <h1>Current time: <%= Time.now %></h1> ERB.new(view).result) }

Current time: 2014-08-23 10:54:29 +0200

</introduction>

froscon-rack-mvc

frack-mvc

frack-mvc " #$ Gemfile #$ app " &$ views "
#$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb &$ config.ru

#$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb &$ config.ru source "https://rubygems.org" ! gem 'rack' gem 'thin' gem 'tilt'

#$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb &$ config.ru <html> <head> <title>Frack MVC</title> </head> <body> <h1>application#layout</h1> <%= yield %> </body> </html>

#$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb &$ config.ru <h2>users#index</h2>

#$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb &$ config.ru $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) # Your code goes here... end end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application *use adds a middleware to the rack application stack created by Rack::Builder.

#$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb &$ config.ru $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) end end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application Rack::Response.new(env) *use adds a middleware to the rack application stack created by Rack::Builder.

["SERVER_SOFTWARE",."thin.1.6.2.codename.Doc.Brown"] ["SERVER_NAME",."localhost"]["rack.input",. #<Rack::Lint::InputWrapper:0x007fc0421e1ea0. @input=#<StringIO:0x007fc0421fb940>>]["rack.version",.[1,. 0]]["rack.errors",.#<Rack::Lint::ErrorWrapper: 0x007fc0421e1cc0.@error=#<IO:<STDERR>>>] ["rack.multithread",.false]["rack.multiprocess",.false] ["rack.run_once",.false]["REQUEST_METHOD",."GET"] ["REQUEST_PATH",."/"]["PATH_INFO",."/"]["REQUEST_URI",."/"] ["HTTP_VERSION",."HTTP/1.1"]["HTTP_USER_AGENT",."curl/
7.30.0"]["HTTP_HOST",."localhost:9292"]["HTTP_ACCEPT",."*/ *"]["GATEWAY_INTERFACE",."CGI/1.2"]["SERVER_PORT",."9292"] ["QUERY_STRING",.""]["SERVER_PROTOCOL",."HTTP/1.1"] ["rack.url_scheme",."http"]["SCRIPT_NAME",.""] ["REMOTE_ADDR",."127.0.0.1"]["async.callback",.#<Method:. Thin::Connection#post_process>]["async.close",. #<EventMachine::DefaultDeferrable:0x007fc0421fab08>]

#$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb &$ config.ru $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) Rack::Response.new( ) end end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application env

#$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb &$ config.ru $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) Rack::Response.new(render 'users/index') end end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) Rack::Response.new( ) end ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application

#$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb &$ config.ru $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) Rack::Response.new(render 'users/index') end end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) Rack::Response.new( ) end ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! render 'users/index' end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application

#$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb &$ config.ru $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) Rack::Response.new(render 'users/index') end end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) Rack::Response.new( ) end ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! def render(view) render 'users/index' end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application

#$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb &$ config.ru $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) Rack::Response.new(render 'users/index') end end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) Rack::Response.new( ) end ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! def render(view) render_template('layouts/application') do render 'users/index' end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application

#$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb &$ config.ru $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) Rack::Response.new(render 'users/index') end end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) Rack::Response.new( ) end ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! def render(view) render_template('layouts/application') do render_template(view) end end render 'users/index' end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application

#$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb &$ config.ru $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) Rack::Response.new(render 'users/index') end end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) Rack::Response.new( ) end ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! def render(view) render_template('layouts/application') do render_template(view) end end def render_template(path, &block) render 'users/index' end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application

#$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb &$ config.ru $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) Rack::Response.new(render 'users/index') end end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) Rack::Response.new( ) end ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! def render(view) render_template('layouts/application') do render_template(view) end end def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render(&block) end render 'users/index' end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application

application#layout! ! users#index

application#layout! ! users#index but can I haz style?

#$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb &$ config.ru $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) Rack::Response.new(render 'users/index') end end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) Rack::Response.new( ) end ! ! ! ! ! ! ! ! ! ! end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application def render(view) render_template('layouts/application') do render_template(view) end end def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render(&block) end render 'users/index'

$LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack
class Application class << self def call(env) Rack::Response.new(render 'users/index') end end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) Rack::Response.new( ) end ! ! ! ! ! ! ! ! ! ! end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application def render(view) render_template('layouts/application') do render_template(view) end end def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render(&block) end render 'users/index' frack-mvc " #$ Gemfile #$ app " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb ! ! ! ! ! &$ config.ru

class Application class << self def call(env) Rack::Response.new(render 'users/index') end end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) Rack::Response.new( ) end ! ! ! ! ! ! ! ! ! ! end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application def render(view) render_template('layouts/application') do render_template(view) end end def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render(&block) end render 'users/index' frack-mvc " #$ Gemfile #$ app " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb ! ! ! ! ! &$ config.ru #$ public " #$ css " " &$ style.css " #$ images " &$ js

#$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js &$ config.ru html { font-family: sans-serif; } h1 { color: #008040; } h2 { color: #ff0080; }

#$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js &$ config.ru <html> <head> <title>Frack MVC</title> ! </head> <body> <h1>application#layout</h1> <%= yield %> </body> </html>

#$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js &$ config.ru <html> <head> <title>Frack MVC</title> ! </head> <body> <h1>application#layout</h1> <%= yield %> </body> </html> <link rel="stylesheet" type="text/css" href="css/style.css">

class Application class << self def call(env) Rack::Response.new(render 'users/index') end end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) Rack::Response.new( ) end ! ! ! ! ! ! ! ! ! ! end end end ! ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application def render(view) render_template('layouts/application') do render_template(view) end end def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render(&block) end render 'users/index' frack-mvc " #$ Gemfile #$ app " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js &$ config.ru

class Application class << self def call(env) Rack::Response.new(render 'users/index') end end end end ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) Rack::Response.new( ) end ! ! ! ! ! ! ! ! ! ! end end end ! ! use Rack::CommonLogger use Rack::ContentLength run Frack::Application def render(view) render_template('layouts/application') do render_template(view) end end def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render(&block) end render 'users/index' use Rack::Static, root: 'public', urls: ['/images', '/js', '/css'] frack-mvc " #$ Gemfile #$ app " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js &$ config.ru

application#layout ! users#index

application#layout ! users#index what about simple routing?

application#layout ! users#index what about simple routing? and list some
users?

["SERVER_SOFTWARE",."thin.1.6.2.codename.Doc.Brown"] ["SERVER_NAME",."localhost"]["rack.input",. #<Rack::Lint::InputWrapper:0x007fc0421e1ea0. @input=#<StringIO:0x007fc0421fb940>>]["rack.version",.[1,. 0]]["rack.errors",.#<Rack::Lint::ErrorWrapper: 0x007fc0421e1cc0.@error=#<IO:<STDERR>>>] ["rack.multithread",.false]["rack.multiprocess",.false] ["rack.run_once",.false]["REQUEST_METHOD",."GET"] ["REQUEST_PATH",""/"]["PATH_INFO",""/"]["REQUEST_URI",."/"] ["HTTP_VERSION",."HTTP/1.1"]["HTTP_USER_AGENT",."curl/
7.30.0"]["HTTP_HOST",."localhost:9292"]["HTTP_ACCEPT",."*/ *"]["GATEWAY_INTERFACE",."CGI/1.2"]["SERVER_PORT",."9292"] ["QUERY_STRING",.""]["SERVER_PROTOCOL",."HTTP/1.1"] ["rack.url_scheme",."http"]["SCRIPT_NAME",.""] ["REMOTE_ADDR",."127.0.0.1"]["async.callback",.#<Method:. Thin::Connection#post_process>]["async.close",. #<EventMachine::DefaultDeferrable:0x007fc0421fab08>] remember env?

class Application class << self def call(env) Rack::Response.new(render 'users/index') end ! def render(view) render_template('layouts/application') do render_template(view) end end ! def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render(&block) end end end end ! use Rack::Static, root: 'public', urls: ['/images', '/js', '/css'] use Rack::CommonLogger use Rack::ContentLength run Frack::Application frack-mvc " #$ Gemfile #$ app " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js &$ config.ru

class Application class << self def call(env) Rack::Response.new(render 'users/index') ! ! ! end ! def render(view) render_template('layouts/application') do render_template(view) end end ! def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render(&block) end end end end ! use Rack::Static, root: 'public', urls: ['/images', '/js', '/css'] use Rack::CommonLogger use Rack::ContentLength run Frack::Application frack-mvc " #$ Gemfile #$ app " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js &$ config.ru

class Application class << self def call(env) Rack::Response.new(render 'users/index') ! ! ! end ! def render(view) render_template('layouts/application') do render_template(view) end end ! def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render(&block) end end end end ! use Rack::Static, root: 'public', urls: ['/images', '/js', '/css'] use Rack::CommonLogger use Rack::ContentLength run Frack::Application if env['PATH_INFO'] == '/' frack-mvc " #$ Gemfile #$ app " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js &$ config.ru

class Application class << self def call(env) Rack::Response.new(render 'users/index') ! ! ! end ! def render(view) render_template('layouts/application') do render_template(view) end end ! def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render(&block) end end end end ! use Rack::Static, root: 'public', urls: ['/images', '/js', '/css'] use Rack::CommonLogger use Rack::ContentLength run Frack::Application if env['PATH_INFO'] == '/' else Rack::Response.new('Not found', 404) end frack-mvc " #$ Gemfile #$ app " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js &$ config.ru

class Application class << self def call(env) ! Rack::Response.new(render 'users/index') ! ! ! end ! def render(view) render_template('layouts/application') do render_template(view) end end ! def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render( end end end end ! use Rack::Static, root: 'public', urls: ['/images', '/js', '/css'] use Rack::CommonLogger use Rack::ContentLength run Frack::Application if env['PATH_INFO'] == '/' else Rack::Response.new('Not found', 404) end &block) frack-mvc " #$ Gemfile #$ app " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js &$ config.ru

class Application class << self def call(env) ! Rack::Response.new(render 'users/index') ! ! ! end ! def render(view) render_template('layouts/application') do render_template(view) end end ! def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render( end end end end ! use Rack::Static, root: 'public', urls: ['/images', '/js', '/css'] use Rack::CommonLogger use Rack::ContentLength run Frack::Application if env['PATH_INFO'] == '/' else Rack::Response.new('Not found', 404) end @users = ['Anthony Stark', 'Peter Parker', 'Bruce Wayne'] &block) frack-mvc " #$ Gemfile #$ app " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js &$ config.ru

class Application class << self def call(env) ! Rack::Response.new(render 'users/index') ! ! ! end ! def render(view) render_template('layouts/application') do render_template(view) end end ! def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render( end end end end ! use Rack::Static, root: 'public', urls: ['/images', '/js', '/css'] use Rack::CommonLogger use Rack::ContentLength run Frack::Application if env['PATH_INFO'] == '/' else Rack::Response.new('Not found', 404) end @users = ['Anthony Stark', 'Peter Parker', 'Bruce Wayne'] &block) self, frack-mvc " #$ Gemfile #$ app " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js &$ config.ru

<h2>users#index</h2> ! ! ! ! ! frack-mvc " #$ Gemfile
#$ app " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js &$ config.ru

<h2>users#index</h2> ! ! ! ! ! <ul> <% @users.each do
|user| %> <li><%= user %></li> <% end %> </ul> frack-mvc " #$ Gemfile #$ app " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js &$ config.ru

not sure if MVC…

#$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js &$ config.ru $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) if env['PATH_INFO'] == '/' ! ! ! ! ! def render(view) render_template('layouts/application') do render_template(view) end end ! def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render(self, &block) end end end end ! use Rack::Static, root: 'public', urls: ['/images', '/js', '/css'] use Rack::CommonLogger use Rack::ContentLength run Frack::Application render 'users/index') @users = ['Anthony Stark', 'Peter Parker', 'Bruce Wayne'] Rack::Response.new( else Rack::Response.new('Not found', 404) end end

#$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js &$ config.ru $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) if env['PATH_INFO'] == '/' ! ! ! ! ! def render(view) render_template('layouts/application') do render_template(view) end end ! def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render(self, &block) end end end end ! use Rack::Static, root: 'public', urls: ['/images', '/js', '/css'] use Rack::CommonLogger use Rack::ContentLength run Frack::Application Rack::Response.new( else Rack::Response.new('Not found', 404) end end

#$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js &$ config.ru $LOAD_PATH << '.' require 'rack' require 'tilt' ! module Frack class Application class << self def call(env) if env['PATH_INFO'] == '/' ! ! ! ! ! def render(view) render_template('layouts/application') do render_template(view) end end ! def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render(self, &block) end end end end ! use Rack::Static, root: 'public', urls: ['/images', '/js', '/css'] use Rack::CommonLogger use Rack::ContentLength run Frack::Application Rack::Response.new( else Rack::Response.new('Not found', 404) end end UsersController.new.index)

class Application class << self def call(env) if env['PATH_INFO'] == '/' Rack::Response.new(UsersController.new.index) else Rack::Response.new('Not found', 404) end end ! ! ! ! ! ! ! ! ! ! ! ! end end ! use Rack::Static, root: 'public', urls: ['/images', '/js', '/css'] use Rack::CommonLogger use Rack::ContentLength run Frack::Application frack-mvc " #$ Gemfile #$ app " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js &$ config.ru end end class BaseController def render(view) render_template('layouts/application') do render_template(view) end end ! def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render(self, &block) end

Rack::Response.new('Not found', 404) end end end end ! class BaseController
def render(view) render_template('layouts/application') do render_template(view) end end ! def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render(self, &block) end end end ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! use Rack::Static, root: 'public', urls: ['/images', '/js', '/css'] use Rack::CommonLogger use Rack::ContentLength run Frack::Application frack-mvc " #$ Gemfile #$ app " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js &$ config.ru class UsersController < Frack::BaseController def index @users = User.all render 'users/index' end end

Rack::Response.new('Not found', 404) end end end end ! class BaseController
def render(view) render_template('layouts/application') do render_template(view) end end ! def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render(self, &block) end end end ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! use Rack::Static, root: 'public', urls: ['/images', '/js', '/css'] use Rack::CommonLogger use Rack::ContentLength run Frack::Application frack-mvc " #$ Gemfile #$ app " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js &$ config.ru class UsersController < Frack::BaseController def index @users = User.all render 'users/index' end end class User def self.all ['Anthony Stark', 'Peter Parker', 'Bruce Wayne'] end end

PROVE IT!

#$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js ! ! ! ! &$ config.ru

#$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js ! ! ! ! #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru

require 'spec_helper' ! Capybara.app = Rack::Builder.new do eval(File.read(File.expand_path('./config.ru'))) end !
! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js ! ! ! ! #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru

require 'spec_helper' ! Capybara.app = Rack::Builder.new do eval(File.read(File.expand_path('./config.ru'))) end !
! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js ! ! ! ! #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb describe 'users#index' do before { visit '/' } it 'renders layout' do expect(page).to have_content('application#layout') end it 'renders index view' do expect(page).to have_content('users#index') end it 'shows a list of users' do expect(page).to have_selector('li', text: /Stark|Parker|Wayne/, count: 3) end end &$ config.ru

$ rspec ! users#index renders layout renders index view shows
a list of users ! Finished in 0.02326 seconds 3 examples, 0 failures ! Randomized with seed 13626

module Frack class Application class << self def call(env) if
env['PATH_INFO'] == '/' Rack::Response.new(UsersController.new.index) else Rack::Response.new('Not found', 404) end end end end ! class BaseController def render(view) render_template('layouts/application') do render_template(view) end end ! def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render(self, &block) end end end ! class UsersController < Frack::BaseController def index @users = User.all render 'users/index' end end ! class User def self.all ['Anthony Stark', 'Peter Parker', 'Bruce Wayne'] end end frack-mvc " #$ Gemfile #$ app " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru

#$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru module Frack class Application class << self def call(env) if env['PATH_INFO'] == '/' Rack::Response.new(UsersController.new.index) else Rack::Response.new('Not found', 404) end end end end ! class BaseController def render(view) render_template('layouts/application') do render_template(view) end end ! def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render(self, &block) end end end ! class UsersController < Frack::BaseController def index @users = User.all render 'users/index' end end ! class User def self.all ['Anthony Stark', 'Peter Parker', 'Bruce Wayne'] end end REFACTOR ALL THE FRACK

! " &$ views " #$ layouts " " &$
application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru frack-mvc " #$ Gemfile #$ app

" #$ controllers " " &$ users_controller.rb " #$ models
" " &$ user.rb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb ! " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru frack-mvc " #$ Gemfile #$ app

frack-mvc " #$ Gemfile #$ app " #$ controllers "
" &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! class UsersController < Frack::BaseController def index @users = User.all render 'users/index' end end class User def self.all ['Anthony Stark', 'Peter Parker', 'Bruce Wayne'] end end module Frack ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! end class Application class << self def call(env) if env['PATH_INFO'] == '/' Rack::Response.new(UsersController.new.index) else Rack::Response.new('Not found', 404) end end end end class BaseController def render(view) render_template('layouts/application') do render_template(view) end end ! def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render(self, &block) end end

" &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! class UsersController < Frack::BaseController def index @users = User.all render 'users/index' end end class User def self.all ['Anthony Stark', 'Peter Parker', 'Bruce Wayne'] end end require 'app/controllers/users_controller' module Frack ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! end class Application class << self def call(env) if env['PATH_INFO'] == '/' Rack::Response.new(UsersController.new.index) else Rack::Response.new('Not found', 404) end end end end class BaseController def render(view) render_template('layouts/application') do render_template(view) end end ! def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render(self, &block) end end

" &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! class UsersController < Frack::BaseController def index @users = User.all render 'users/index' end end class User def self.all ['Anthony Stark', 'Peter Parker', 'Bruce Wayne'] end end require 'app/models/user' require 'app/controllers/users_controller' module Frack ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! end class Application class << self def call(env) if env['PATH_INFO'] == '/' Rack::Response.new(UsersController.new.index) else Rack::Response.new('Not found', 404) end end end end class BaseController def render(view) render_template('layouts/application') do render_template(view) end end ! def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render(self, &block) end end

" &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! class UsersController < Frack::BaseController def index @users = User.all render 'users/index' end end class User def self.all ['Anthony Stark', 'Peter Parker', 'Bruce Wayne'] end end require 'app/models/user' require 'app/controllers/users_controller' require 'lib/frack' module Frack ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! end class Application class << self def call(env) if env['PATH_INFO'] == '/' Rack::Response.new(UsersController.new.index) else Rack::Response.new('Not found', 404) end end end end class BaseController def render(view) render_template('layouts/application') do render_template(view) end end ! def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render(self, &block) end end

" &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru $LOAD_PATH << '.' ! require 'lib/frack' require 'app/controllers/users_controller' require 'app/models/user' ! use Rack::Static, root: 'public', urls: ['/images', '/js', '/css'] use Rack::CommonLogger use Rack::ContentLength run Frack::Application

" &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru $LOAD_PATH << File.expand_path(File.dirname(__FILE__)) ! require 'rack' require 'tilt' ! module Frack autoload :Application, 'frack/application' autoload :BaseController, 'frack/base_controller' end

module Frack class BaseController def render(view) render_template('layouts/application') do render_template(view) end
end ! def render_template(path, &block) Tilt.new( end ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru "app/views/#{ }.html. ).render(self, &block) end end erb" path

end ! def render_template(path, &block) Tilt.new( end ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru "app/views/#{ }.html. ).render(self, &block) end end *" path

end ! def render_template(path, &block) Tilt.new( end ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru ).render(self, &block) end end path

end ! def render_template(path, &block) Tilt.new( end ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru ).render(self, &block) end end file( ) path

end ! def render_template(path, &block) Tilt.new( end ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru ).render(self, &block) end end def file(path) Dir[ ] end file( ) path

end ! def render_template(path, &block) Tilt.new( end ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru ).render(self, &block) end end def file(path) Dir[ ] end File.join('app', 'views', "#{path}.html.*") file( ) path

end ! def render_template(path, &block) Tilt.new( end ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru ).render(self, &block) end end def file(path) Dir[ ] end File.join('app', 'views', "#{path}.html.*") .first file( ) path

end ! def render_template(path, &block) Tilt.new( end ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru ).render(self, &block) end end def file(path) Dir[ ] end File.join('app', 'views', "#{path}.html.*") .first file( ) path AWESOME!  support all the template engines

better routing? MVC

better routing? magic? MVC

What if the router could be middleware?

Middleware Stack *a middleware is a rack application that wraps
up an inner application.

Middleware Stack HTTP request *a middleware is a rack application
that wraps up an inner application.

Middleware Stack use Rack::Static use Rack::CommonLogger use Rack::ContentLength run Frack::Application
HTTP request *a middleware is a rack application that wraps up an inner application.

HTTP request HTTP response *a middleware is a rack application that wraps up an inner application.

HTTP request HTTP response module Rack class ContentLength def initialize(app) @app = app end ! def call(env) status, headers, body = @app.call(env) # [...] # headers['Content-Length'] = length.to_s # [...] [status, headers, body] end end end *a middleware is a rack application that wraps up an inner application.

" &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru $LOAD_PATH << '.' ! require 'lib/frack' require 'app/controllers/users_controller' require 'app/models/user' ! use Rack::Static, root: 'public', urls: ['/images', '/js', '/css'] use Rack::CommonLogger use Rack::ContentLength ! run Frack::Application

" &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru $LOAD_PATH << '.' ! require 'lib/frack' require 'app/controllers/users_controller' require 'app/models/user' ! use Rack::Static, root: 'public', urls: ['/images', '/js', '/css'] use Rack::CommonLogger use Rack::ContentLength ! run Frack::Application use Frack::Router

" &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru $LOAD_PATH << File.expand_path(File.dirname(__FILE__)) ! require 'rack' require 'tilt' ! module Frack ! autoload :Application, 'frack/application' autoload :BaseController, 'frack/base_controller' end

" &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru $LOAD_PATH << File.expand_path(File.dirname(__FILE__)) ! require 'rack' require 'tilt' ! module Frack ! autoload :Application, 'frack/application' autoload :BaseController, 'frack/base_controller' end autoload :Router, 'frack/router'

" &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru module Frack class Router attr_reader :app ! def initialize(app) @app = app end ! def call(env) app.call(env) end end end

module Frack class Router attr_reader :app ! ! ! !
! def initialize(app) @app = app end ! def call(env) ! ! ! ! ! end end end frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru app.call(env)

! def initialize(app) @app = app end ! def call(env) ! ! ! ! ! end end end frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru ROUTES = { '/' => } app.call(env)

! def initialize(app) @app = app end ! def call(env) ! ! ! ! ! end end end frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru ROUTES = { '/' => } app.call(env) { 'controller' => 'users', 'action' => 'index' },

! def initialize(app) @app = app end ! def call(env) ! ! ! ! ! end end end frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru if (mapping = ROUTES[env['PATH_INFO']]) ROUTES = { '/' => } app.call(env) { 'controller' => 'users', 'action' => 'index' },

! def initialize(app) @app = app end ! def call(env) ! ! ! ! ! end end end frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru if (mapping = ROUTES[env['PATH_INFO']]) env.merge!(mapping) ROUTES = { '/' => } app.call(env) { 'controller' => 'users', 'action' => 'index' },

! def initialize(app) @app = app end ! def call(env) ! ! ! ! ! end end end frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru if (mapping = ROUTES[env['PATH_INFO']]) env.merge!(mapping) else Rack::Response.new('Not found', 404) end ROUTES = { '/' => } app.call(env) { 'controller' => 'users', 'action' => 'index' },

! def initialize(app) @app = app end ! def call(env) ! ! ! ! ! end end end frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru if (mapping = ROUTES[env['PATH_INFO']]) env.merge!(mapping) else Rack::Response.new('Not found', 404) end ROUTES = { '/' => } app.call(env) 'users#index'

! def initialize(app) @app = app end ! def call(env) ! ! ! ! ! end ! ! ! ! end end frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru if (mapping = ROUTES[env['PATH_INFO']]) env.merge!( else Rack::Response.new('Not found', 404) end ROUTES = { '/' => } app.call(env) 'users#index' mapping)

! def initialize(app) @app = app end ! def call(env) ! ! ! ! ! end ! ! ! ! end end frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru if (mapping = ROUTES[env['PATH_INFO']]) env.merge!( else Rack::Response.new('Not found', 404) end ROUTES = { '/' => } app.call(env) 'users#index' def controller_action(mapping) mapping)

! def initialize(app) @app = app end ! def call(env) ! ! ! ! ! end ! ! ! ! end end frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru if (mapping = ROUTES[env['PATH_INFO']]) env.merge!( else Rack::Response.new('Not found', 404) end ROUTES = { '/' => } app.call(env) 'users#index' def controller_action(mapping) controller_action( ) mapping)

! def initialize(app) @app = app end ! def call(env) ! ! ! ! ! end ! ! ! ! end end frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru if (mapping = ROUTES[env['PATH_INFO']]) env.merge!( else Rack::Response.new('Not found', 404) end ROUTES = { '/' => } app.call(env) 'users#index' def controller_action(mapping) Hash[ %w(controller action).zip mapping.split('#') ] end controller_action( ) mapping)

! def initialize(app) @app = app end ! def call(env) ! ! ! ! ! end ! ! ! ! end end frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru if (mapping = ROUTES[env['PATH_INFO']]) env.merge!( else Rack::Response.new('Not found', 404) end ROUTES = { '/' => } app.call(env) 'users#index' def controller_action(mapping) Hash[ %w(controller action).zip mapping.split('#') ] end controller_action( ) mapping) def controller_action(mapping) ! ! end or keep it simple…

! def initialize(app) @app = app end ! def call(env) ! ! ! ! ! end ! ! ! ! end end frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru if (mapping = ROUTES[env['PATH_INFO']]) env.merge!( else Rack::Response.new('Not found', 404) end ROUTES = { '/' => } app.call(env) 'users#index' def controller_action(mapping) Hash[ %w(controller action).zip mapping.split('#') ] end controller_action( ) mapping) def controller_action(mapping) ! ! end or keep it simple… controller, action = mapping.split('#')

! def initialize(app) @app = app end ! def call(env) ! ! ! ! ! end ! ! ! ! end end frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru if (mapping = ROUTES[env['PATH_INFO']]) env.merge!( else Rack::Response.new('Not found', 404) end ROUTES = { '/' => } app.call(env) 'users#index' def controller_action(mapping) Hash[ %w(controller action).zip mapping.split('#') ] end controller_action( ) mapping) def controller_action(mapping) ! ! end or keep it simple… controller, action = mapping.split('#') { 'controller' => controller, 'action' => action }

module Frack class Application class << self ! ! !
! ! ! ! ! ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru if env['PATH_INFO'] == '/' else Rack::Response.new('Not found', 404) end UsersController.new.index) Rack::Response.new( end end end def call(env) end

! ! ! ! ! ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru UsersController.new.index) Rack::Response.new( end end end def call(env) end

! ! ! ! ! ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru Rack::Response.new( end end end def call(env) end

! ! ! ! ! ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru *dispatch) Rack::Response.new( end end end def call(env) end

! ! ! ! ! ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru *dispatch) Rack::Response.new( end end end def call(env) attr_accessor :env self.env = env end

! ! ! ! ! ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru *dispatch) Rack::Response.new( end end end def call(env) attr_accessor :env self.env = env end def dispatch controller.new.public_send(env['action']) end

! ! ! ! ! ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru *dispatch) Rack::Response.new( end end end def call(env) attr_accessor :env self.env = env end def dispatch controller.new.public_send(env['action']) end def controller

! ! ! ! ! ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru *dispatch) Rack::Response.new( end end end def call(env) attr_accessor :env self.env = env end def dispatch controller.new.public_send(env['action']) end def controller Object.const_get(env['controller'].capitalize + 'Controller') end

What if the router could take a block?

" &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru $LOAD_PATH << '.' ! require 'lib/frack' require 'app/controllers/users_controller' require 'app/models/user' ! use Rack::Static, root: 'public', urls: ['/images', '/js', '/css'] use Rack::CommonLogger use Rack::ContentLength ! ! ! ! use Frack::Router run Frack::Application

" &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru $LOAD_PATH << '.' ! require 'lib/frack' require 'app/controllers/users_controller' require 'app/models/user' ! use Rack::Static, root: 'public', urls: ['/images', '/js', '/css'] use Rack::CommonLogger use Rack::ContentLength ! ! ! ! use Frack::Router do match '/' => 'users#index' end run Frack::Application

! ! ! end ! def call(env) ! ! ! ! ! end ! ! ! ! ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru if (mapping = [env['PATH_INFO']]) env.merge!( else Rack::Response.new('Not found', 404) end ROUTES = { '/' => } app.call(env) 'users#index' def controller_action(mapping) Hash[ %w(controller action).zip mapping.split('#') ] end controller_action( ) mapping) def initialize(app) @app = app end end ROUTES

! ! ! end ! def call(env) ! ! ! ! ! end ! ! ! ! ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru if (mapping = [env['PATH_INFO']]) env.merge!( else Rack::Response.new('Not found', 404) end ROUTES = { '/' => } app.call(env) 'users#index' def controller_action(mapping) Hash[ %w(controller action).zip mapping.split('#') ] end controller_action( ) mapping) , :routes def initialize(app) @app = app end end ROUTES

! ! ! end ! def call(env) ! ! ! ! ! end ! ! ! ! ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru if (mapping = [env['PATH_INFO']]) env.merge!( else Rack::Response.new('Not found', 404) end app.call(env) def controller_action(mapping) Hash[ %w(controller action).zip mapping.split('#') ] end controller_action( ) mapping) , :routes routes def initialize(app) @app = app end end

! ! ! end ! def call(env) ! ! ! ! ! end ! ! ! ! ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru if (mapping = [env['PATH_INFO']]) env.merge!( else Rack::Response.new('Not found', 404) end app.call(env) def controller_action(mapping) Hash[ %w(controller action).zip mapping.split('#') ] end controller_action( ) mapping) , :routes routes def initialize(app) @app = app end end , &block)

! ! ! end ! def call(env) ! ! ! ! ! end ! ! ! ! ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru if (mapping = [env['PATH_INFO']]) env.merge!( else Rack::Response.new('Not found', 404) end app.call(env) def controller_action(mapping) Hash[ %w(controller action).zip mapping.split('#') ] end controller_action( ) mapping) , :routes @routes = {} routes def initialize(app) @app = app end end , &block)

! ! ! end ! def call(env) ! ! ! ! ! end ! ! ! ! ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru if (mapping = [env['PATH_INFO']]) env.merge!( else Rack::Response.new('Not found', 404) end app.call(env) def controller_action(mapping) Hash[ %w(controller action).zip mapping.split('#') ] end controller_action( ) mapping) , :routes @routes = {} instance_eval(&block) if block_given? routes def initialize(app) @app = app end end , &block)

! ! ! end ! def call(env) ! ! ! ! ! end ! ! ! ! ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru if (mapping = [env['PATH_INFO']]) env.merge!( else Rack::Response.new('Not found', 404) end app.call(env) def controller_action(mapping) Hash[ %w(controller action).zip mapping.split('#') ] end controller_action( ) mapping) , :routes @routes = {} instance_eval(&block) if block_given? routes def match(route) def initialize(app) @app = app end end , &block)

! ! ! end ! def call(env) ! ! ! ! ! end ! ! ! ! ! ! ! ! ! frack-mvc " #$ Gemfile #$ app " #$ controllers " " &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru if (mapping = [env['PATH_INFO']]) env.merge!( else Rack::Response.new('Not found', 404) end app.call(env) def controller_action(mapping) Hash[ %w(controller action).zip mapping.split('#') ] end controller_action( ) mapping) , :routes @routes = {} instance_eval(&block) if block_given? routes def match(route) self.routes.merge!(route) end def initialize(app) @app = app end end , &block)

what do we have now?

" &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru $LOAD_PATH.unshift '.' ! require 'lib/frack' require 'app/controllers/users_controller' require 'app/models/user' ! # use Rack::CommonLogger use Rack::Static, root: 'public', urls: ['/images', '/js', '/css'] use Rack::ContentLength use Frack::Router do match '/' => 'users#index' end ! run Frack::Application

" &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru $LOAD_PATH.unshift File.expand_path(File.dirname(__FILE__)) ! require 'rack' require 'erb' require 'tilt' ! module Frack autoload :Router, 'frack/router' autoload :Application, 'frack/application' autoload :BaseController, 'frack/base_controller' end

" &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru module Frack class Router attr_reader :app, :routes ! def initialize(app, &block) @app = app @routes = {} instance_eval(&block) if block_given? end ! def call(env) if (mapping = routes[env['PATH_INFO']]) env.merge!(controller_action(mapping)) app.call(env) else Rack::Response.new('Not found', 404) end end ! def controller_action(mapping) controller, action = mapping.split('#') { 'controller' => controller, 'action' => action } end ! def match(route) self.routes.merge!(route) end end end

" &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru module Frack class Application class << self attr_accessor :env ! def call(env) self.env = env Rack::Response.new(*dispatch) end ! def dispatch controller.new(env).public_send(env['action']) end ! def controller Object.const_get(env['controller'].capitalize + 'Controller') end end end end

" &$ users_controller.rb " #$ models " " &$ user.rb " &$ views " #$ layouts " " &$ application.html.erb " &$ users " &$ index.html.erb #$ lib " #$ frack " " #$ application.rb " " #$ base_controller.rb " " &$ router.rb " &$ frack.rb #$ public " #$ css " " &$ style.css " #$ images " &$ js #$ spec " #$ integration " " &$ user_spec.rb " &$ spec_helper.rb &$ config.ru module Frack class BaseController attr_reader :env ! def initialize(env) @env = env end ! def render(view) render_template(layout) do render_template(view) end end ! def render_template(path, &block) Tilt.new(file(path)).render(self, &block) end ! def file(path) Dir[File.join('app', 'views', "#{path}.html.*")].first end ! def layout File.join('layouts', 'application') end end end

in ~ 50-100 LOC MVC

I haven't shown you all of it

Rebuilding Rails features, is a great opportunity to learn how
they work.

Challenges for the curious ones: ! • params! • redirect_to!
• partial rendering! • implicit call to render! • routing with placeholders! • routing with speciﬁc http verbs! • error handling! • session management! • ﬂash messages! • persistence! • security stuff and protection! • different mime types! • url helper! • better class loading / autoloading! • asset management Rebuilding Rails features, is a great opportunity to learn how they work.

YES, you should deﬁnitely do this at home *but maybe
not in production or just <3 the Rails core team deﬁnitely checkout: http://lotusrb.org/ WHY? maybe you come up with the next big framework…

2014.RailsCamp.de

Marco Schaden | @donschado | 23.08.2014 RedFrog Conf kthxbye

Marco Schaden | @donschado | 23.08.2014 RedFrog Conf Marco @DonSchado
- 17 Std.  rackup -r rack/lobster -b 'run Rack::Lobster.new'

Backup

Appendix: Rack in the wild

http://guides.rubyonrails.org/rails_on_rack.html

\m/ ActionController::Metal

http://api.rubyonrails.org/classes/ActionController/Metal.html class HelloController < ActionController::Metal def index self.response_body = "Hello
World!" end end get 'hello', to: HelloController.action(:index) *returns a valid Rack application for the Rails router to dispatch to

World!" end end get 'hello', to: HelloController.action(:index) OMG WHY? *returns a valid Rack application for the Rails router to dispatch to

World!" end end get 'hello', to: HelloController.action(:index) • maybe to extract lightweight micro services OMG WHY? *returns a valid Rack application for the Rails router to dispatch to

World!" end end get 'hello', to: HelloController.action(:index) • maybe to extract lightweight micro services • to improve the performance of any API endpoint OMG WHY? *returns a valid Rack application for the Rails router to dispatch to

World!" end end get 'hello', to: HelloController.action(:index) • maybe to extract lightweight micro services • to improve the performance of any API endpoint • because all beneﬁts of rails are "just a few" includes away OMG WHY? *returns a valid Rack application for the Rails router to dispatch to

World!" end end get 'hello', to: HelloController.action(:index) • maybe to extract lightweight micro services • to improve the performance of any API endpoint • because all beneﬁts of rails are "just a few" includes away OMG WHY? *returns a valid Rack application for the Rails router to dispatch to class HelloController < ActionController::Metal include AbstractController::Rendering include ActionView::Layouts append_view_path "#{Rails.root}/app/views" ! def index render "hello/index" end ! # Ensure ActiveSupport::Notifications events are fired include ActionController::Instrumentation end

Backup Backup

http://www.madebymarket.com/blog/dev/ruby-web-benchmark-report.html "every possible rack server on every possible Ruby, every
possible web framework"

Spoiler Alert!

"The fastest framework is Rack. ! Plain old Rack with
no framework at all." Ruby 2.1 + Thin + Rack can hit 6301 req/sec => Sinatra only manages !! ! 2505 req/sec. => Rails only does ! ! ! ! 1455 req/sec "So, by simply using those frameworks on top of Rack,   you give up over 60% of your maximum possible throughput." Spoiler Alert!

Spoiler spoiler Alert! On a plain old Rack app it
did 10.159 req/sec. + "Standard Ruby + Thin/Unicorn + Rails ! is about the slowest possible combination" the fastest:

*I think these benchmarks are a little bit unfair, !
when you compare a full rails stack vs. a rack one-liner.! But I think the main message is valid:! Do you need the full stack for every request? Logging Sessions Cookies Security Caching Error Handling Routing

that’s all

Ruby MVC from scratch with Rack

Ruby MVC from scratch with Rack

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