Ruby MVC from scratch with Rack

Ruby MVC from scratch with Rack

I

Marco Schaden | @donschado | 23.08.2014RedFrog Conf

there was a rack applicationhandling 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

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) { }


# config.rurun [ ]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



! ->(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


SHIP IT


, read it: https://github.com/rack/rack

How does it work?

seriously

https://github.com/rack/rack

HTML + ERB

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

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

# config.rurun -> 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


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>


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>

MVC

froscon-rack-mvc

frack-mvc

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


source "https://rubygems.org"!gem 'rack'gem 'thin'gem 'tilt'


<html> <head> <title>Frack MVC</title> </head> <body> <h1>application#layout</h1> <%= yield %> </body></html>


<h2>users#index</h2>


$LOAD_PATH << '.'require 'rack'require 'tilt'!module Frack class Application class << self def call(env) # Your code goes here... end end endend!use Rack::CommonLoggeruse Rack::ContentLengthrun Frack::Application

*use adds a middleware to the rack application stack created by Rack::Builder.


$LOAD_PATH << '.'require 'rack'require 'tilt'!module Frack class Application class << self def call(env) end end endend!use Rack::CommonLoggeruse Rack::ContentLengthrun 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>]


$LOAD_PATH << '.'require 'rack'require 'tilt'!module Frack class Application class << self def call(env) Rack::Response.new( ) end end endend!use Rack::CommonLoggeruse Rack::ContentLengthrun Frack::Application

env


$LOAD_PATH << '.'require 'rack'require 'tilt'!module Frack class Application class << self def call(env) Rack::Response.new(render 'users/index') end end endend!use Rack::CommonLoggeruse Rack::ContentLengthrun Frack::Application

$LOAD_PATH << '.'require 'rack'require 'tilt'!module Frack class Application class << self def call(env) Rack::Response.new( ) end!!!!!!!!!! !!!!!

end endend!use Rack::CommonLoggeruse Rack::ContentLengthrun Frack::Application




render 'users/index'





def render(view)






def render(view)render_template('layouts/application') do







render_template(view)end

end








end

def render_template(path, &block)








end

def render_template(path, &block)Tilt.new("app/views/#{path}.html.erb").render(&block)

end



application#layout!!users#index

application#layout!!users#index

but can I haz style?


$LOAD_PATH << '.'require 'rack'require 'tilt'!module Frack class Application class << self def call(env) Rack::Response.new( ) end!!!!!!!!!! end endend!use Rack::CommonLoggeruse Rack::ContentLengthrun 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


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

http://config.ru


$LOAD_PATH << '.'require 'rack'require 'tilt'!module Frack class Application class << self def call(env) Rack::Response.new( ) end!!!!!!!!!! end endend!use Rack::CommonLoggeruse Rack::ContentLengthrun Frack::Application




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

#$ public" #$ css" " &$ style.css" #$ images" &$ js

http://config.ru

frack-mvc"#$ Gemfile#$ app" &$ views" #$ 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; }

http://config.ru


<html> <head> <title>Frack MVC</title>! </head> <body> <h1>application#layout</h1> <%= yield %> </body></html>

http://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">

http://config.ru


$LOAD_PATH << '.'require 'rack'require 'tilt'!module Frack class Application class << self def call(env) Rack::Response.new( ) end!!!!!!!!!! end endend!!use Rack::CommonLoggeruse Rack::ContentLengthrun Frack::Application





http://config.ru


$LOAD_PATH << '.'require 'rack'require 'tilt'!module Frack class Application class << self def call(env) Rack::Response.new( ) end!!!!!!!!!! end endend!!use Rack::CommonLoggeruse Rack::ContentLengthrun Frack::Application




use Rack::Static, root: 'public', urls: ['/images', '/js', '/css']


http://config.ru

application#layout !users#index

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?

$LOAD_PATH << '.'require 'rack'require 'tilt'!module Frack 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 endend!use Rack::Static, root: 'public', urls: ['/images', '/js', '/css']use Rack::CommonLoggeruse Rack::ContentLengthrun Frack::Application


http://config.ru

$LOAD_PATH << '.'require 'rack'require 'tilt'!module Frack 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 endend!use Rack::Static, root: 'public', urls: ['/images', '/js', '/css']use Rack::CommonLoggeruse Rack::ContentLengthrun Frack::Application

if env['PATH_INFO'] == '/'


http://config.ru

$LOAD_PATH << '.'require 'rack'require 'tilt'!module Frack 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 endend!use Rack::Static, root: 'public', urls: ['/images', '/js', '/css']use Rack::CommonLoggeruse Rack::ContentLengthrun Frack::Application


elseRack::Response.new('Not found', 404)

end


http://config.ru

$LOAD_PATH << '.'require 'rack'require 'tilt'!module Frack 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 endend!use Rack::Static, root: 'public', urls: ['/images', '/js', '/css']use Rack::CommonLoggeruse Rack::ContentLengthrun Frack::Application


else Rack::Response.new('Not found', 404)end

&block)


http://config.ru




@users = ['Anthony Stark', 'Peter Parker', 'Bruce Wayne']

&block)


http://config.ru




@users = ['Anthony Stark', 'Peter Parker', 'Bruce Wayne']

&block)self,


http://config.ru

<h2>users#index</h2>!!!!!


http://config.ru

<h2>users#index</h2>!!!!!

<ul><% @users.each do |user| %>

<li><%= user %></li><% end %>

</ul>


http://config.ru

not sure if MVC…


$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 endend!use Rack::Static, root: 'public', urls: ['/images', '/js', '/css']use Rack::CommonLoggeruse Rack::ContentLengthrun Frack::Application

render 'users/index')@users = ['Anthony Stark', 'Peter Parker', 'Bruce Wayne']

Rack::Response.new( else Rack::Response.new('Not found', 404) end end

http://config.ru




http://config.ru




UsersController.new.index)

http://config.ru

$LOAD_PATH << '.'require 'rack'require 'tilt'!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!!!!!!!!!!!! endend!use Rack::Static, root: 'public', urls: ['/images', '/js', '/css']use Rack::CommonLoggeruse Rack::ContentLengthrun Frack::Application


endend

class BaseControllerdef render(view) render_template('layouts/application') do render_template(view) endend!def render_template(path, &block) Tilt.new("app/views/#{path}.html.erb").render(self, &block)end

http://config.ru

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 endend!!!!!!!!!!!!!!!use Rack::Static, root: 'public', urls: ['/images', '/js', '/css']use Rack::CommonLoggeruse Rack::ContentLengthrun Frack::Application


class UsersController < Frack::BaseControllerdef index

@users = User.allrender 'users/index'

endend

http://config.ru

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 endend!!!!!!!!!!!!!!!use Rack::Static, root: 'public', urls: ['/images', '/js', '/css']use Rack::CommonLoggeruse Rack::ContentLengthrun Frack::Application


class UsersController < Frack::BaseControllerdef index

@users = User.allrender 'users/index'

endend

class Userdef self.all

['Anthony Stark', 'Peter Parker', 'Bruce Wayne']end

end

http://config.ru

PROVE IT!

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!!!!!!!!!!!!!!!!!!


#$ 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!!!!!!!!!!!!!!!!!!


#$ spec" #$ integration" " &$ user_spec.rb" &$ spec_helper.rb

describe 'users#index' dobefore { visit '/' }

it 'renders layout' doexpect(page).to have_content('application#layout')

end

it 'renders index view' doexpect(page).to have_content('users#index')

end

it 'shows a list of users' doexpect(page).to have_selector('li',text: /Stark|Parker|Wayne/, count: 3)

endend

&$ 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 endend!class UsersController < Frack::BaseController def index @users = User.all render 'users/index' endend!class User def self.all ['Anthony Stark', 'Peter Parker', 'Bruce Wayne'] endend

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

http://config.ru

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

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 endend!class UsersController < Frack::BaseController def index @users = User.all render 'users/index' endend!class User def self.all ['Anthony Stark', 'Peter Parker', 'Bruce Wayne'] endend

REFACTOR ALL THE FRACK

http://config.ru

!" &$ 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

http://config.ru

" #$ 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

http://config.ru

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' endend

class User def self.all ['Anthony Stark', 'Peter Parker', 'Bruce Wayne'] endend

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

http://config.ru


!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!



require 'app/controllers/users_controller'

module Frack!! !!!!!!!!!!!!!!!!!!!!end



http://config.ru


!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!



require 'app/models/user'require 'app/controllers/users_controller'

module Frack!! !!!!!!!!!!!!!!!!!!!!end



http://config.ru


!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!



require 'app/models/user'require 'app/controllers/users_controller'require 'lib/frack'

module Frack!! !!!!!!!!!!!!!!!!!!!!end



http://config.ru


!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!




module Frack!! !!!!!!!!!!!!!!!!!!!!end



http://config.ru


!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!




module Frack!! !!!!!!!!!!!!!!!!!!!!end



http://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::CommonLoggeruse Rack::ContentLengthrun Frack::Application

http://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

http://config.ru

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!!!!!


"app/views/#{ }.html. ).render(self, &block)

endend

erb"path

http://config.ru



"app/views/#{ }.html. ).render(self, &block)

endend

*"path

http://config.ru



).render(self, &block)

endend

path

http://config.ru




endend

file( )path

http://config.ru




endend

def file(path)Dir[ ]

end

file( )path

http://config.ru




endend


endFile.join('app', 'views', "#{path}.html.*")

file( )path

http://config.ru




endend


endFile.join('app', 'views', "#{path}.html.*") .first

file( )path

http://config.ru




endend


endFile.join('app', 'views', "#{path}.html.*") .first

file( )path

AWESOME!support all the template engines

http://config.ru

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

HT

TP

requ

est


Middleware Stack

use Rack::Static

use Rack::CommonLogger

use Rack::ContentLength

run Frack::Application

HT

TP

requ

est


Middleware Stack

use Rack::Static




HT

TP

requ

est

HT

TP

resp

onse


Middleware Stack

use Rack::Static




HT

TP

requ

est

HT

TP

resp

onse

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 endend



$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::CommonLoggeruse Rack::ContentLength!run Frack::Application

http://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::CommonLoggeruse Rack::ContentLength!run Frack::Applicationuse Frack::Router

http://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

http://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'

http://config.ru


module Frack class Router attr_reader :app! def initialize(app) @app = app end! def call(env) app.call(env) end endend

http://config.ru

module Frack class Router attr_reader :app!!!!! def initialize(app) @app = app end! def call(env) !!!!! end endend


app.call(env)

http://config.ru



ROUTES = {'/' =>

}

app.call(env)

http://config.ru



ROUTES = {'/' =>

}

app.call(env)

{ 'controller' => 'users', 'action' => 'index' },

http://config.ru



if (mapping = ROUTES[env['PATH_INFO']])

ROUTES = {'/' =>

}

app.call(env)


http://config.ru



if (mapping = ROUTES[env['PATH_INFO']])env.merge!(mapping)

ROUTES = {'/' =>

}

app.call(env)


http://config.ru





end

ROUTES = {'/' =>

}

app.call(env)


http://config.ru





end

ROUTES = {'/' =>

}

app.call(env)

'users#index'

http://config.ru

module Frack class Router attr_reader :app!!!!! def initialize(app) @app = app end! def call(env) !!!!! end!!!! endend


if (mapping = ROUTES[env['PATH_INFO']]) env.merge!( else Rack::Response.new('Not found', 404) end

ROUTES = { '/' => }

app.call(env)

'users#index'

mapping)

http://config.ru




ROUTES = { '/' => }

app.call(env)

'users#index'

def controller_action(mapping)

mapping)

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ROUTES = { '/' => }

app.call(env)

'users#index'

def controller_action(mapping)

controller_action( )mapping)

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ROUTES = { '/' => }

app.call(env)

'users#index'

def controller_action(mapping)Hash[ %w(controller action).zip mapping.split('#') ]

end


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module Frack class Application class << self!! !! !!!!!!!!!




end

UsersController.new.index)Rack::Response.new(

end endend

def call(env)

end

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UsersController.new.index)Rack::Response.new(

end endend

def call(env)

end

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Rack::Response.new(

end endend

def call(env)

end

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*dispatch)Rack::Response.new(

end endend

def call(env)

end

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end endend

def call(env)

attr_accessor :env

self.env = env

end

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end endend

def call(env)

attr_accessor :env

self.env = env

end

def dispatchcontroller.new.public_send(env['action'])

end

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end endend

def call(env)

attr_accessor :env

self.env = env

end


end

def controller

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end endend

def call(env)

attr_accessor :env

self.env = env

end


end

def controllerObject.const_get(env['controller'].capitalize + 'Controller')

end

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What if the router could take a block?


$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::CommonLoggeruse Rack::ContentLength!!!!

use Frack::Routerrun Frack::Application

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$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::CommonLoggeruse Rack::ContentLength!!!!

use Frack::Router domatch '/' => 'users#index'

end


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module Frack class Router attr_reader :app!!!!!!! end! def call(env) !!!!! end!!!!!!!!!


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


def initialize(app) @app = app

endend

ROUTES

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ROUTES = {'/' =>

}

app.call(env)

'users#index'



, :routes


endend

ROUTES

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app.call(env)



, :routes

routes


endend

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app.call(env)



, :routes

routes


endend

, &block)

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app.call(env)



, :routes

@routes = {}

routes


endend

, &block)

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app.call(env)



, :routes

@routes = {}instance_eval(&block) if block_given?

routes


endend

, &block)

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app.call(env)



, :routes


routes

def match(route)


endend

, &block)

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app.call(env)



, :routes


routes

def match(route)self.routes.merge!(route)

end


endend

, &block)

http://config.ru

in ~ 50-100 LOCMVC

I haven't shown you all of it

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

love the Rails core team for their amazing work

2014.RailsCamp.de

http://2014.RailsCamp.de


kthxbye


Marco @DonSchado - 17 Std.rackup -r rack/lobster -b 'run Rack::Lobster.new'

Backup

Appendix: Rack in the wild

http

://gu

ides

.ruby

onra

ils.o

rg/ra

ils_o

n_ra

ck.ht

ml

\m/ActionController ::Metal

http://api.rubyonrails.org/classes/ActionController/Metal.html

class HelloController < ActionController::Metal def index self.response_body = "Hello World!" endend

get 'hello', to: HelloController.action(:index)

*returns a valid Rack application for the Rails router to dispatch to




OMG WHY?





• maybe to extract lightweight micro services

OMG WHY?





• maybe to extract lightweight micro services • to improve the performance of any API endpoint

OMG WHY?





• 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?





• 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?


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::Instrumentationend

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."

Spoiler Alert!


Ruby 2.1 + Thin + Rack can hit 6301 req/sec

Spoiler Alert!


Ruby 2.1 + Thin + Rack can hit 6301 req/sec=> Sinatra only manages !! ! 2505 req/sec.

Spoiler Alert!


Ruby 2.1 + Thin + Rack can hit 6301 req/sec=> Sinatra only manages !! ! 2505 req/sec.=> Rails only does ! ! ! ! 1455 req/sec

Spoiler Alert!


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!

"Standard Ruby + Thin/Unicorn + Rails !is about the slowest possible combination"



the fastest:


+


the fastest:


On a plain old Rack app it did 10.159 req/sec.

+


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

# hello_world.rbrequire 'rack'!!!!!!!!

app = Rack::Builder.new do !!!end

$ ruby hello_world.rb

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

$ rackup

map '/' do! end

Rack::Handler::WEBrick.run app, :Port => 9292

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


$ ruby -r rack -e 'Rack::Handler::Thin.run lambda { |env| [200, {}, ["ok"]] }'

$ rackup -b 'run proc { [200, {}, [Time.now.to_s]] }'

for the curious:

that’s all

Technology

Ruby MVC from scratch with Rack