sinatra-session-flash.rb

# Demonstrates a secure usage of sessions in Sinatra
# for authentication and notices.
require 'rubygems'
require 'sinatra'

configure :production, :test do
  use Rack::Session::Cookie,
    :key => 'rack.session',
    :domain => '.example.com', # use a wildcard with leading
                               # dot and at least two dots in total
    :path => '/',
    :expire_after => 10*60*60, # in seconds - for persistent cookies -
                               # survives browser restart
    :secret => 'd81ca50470b5bc80e9' # please change this secret; you i
       # can use the same secret in your multiple applications to share
       # the state between all your applications, that run in the same
       # wildcard defined domain group
end

configure :development do
  use Rack::Session::Cookie,
    :key => 'rack.session',
    # do not use the localhost domain here, wildcard '.localhost' also
    # does not work (likely) because of 'two dots rule'
    # :domain => 'localhost', # localhost for development
    :path => '/',
    :expire_after => 10*60*60, # In seconds
    :secret => '93b7e7ef35bc0b08d'
end

get '/' do
  "<form method='post'>
    <h2>Please type in your name</h2>
    <input name='username' type='text'>
    <input type='submit' value='submit'>
  </form>"
end

post '/' do
  puts params[:username]
  # The Rails like flash notice will be stored in a cookie on the client
  # side and will survive the redirect
  session[:notice] = "Hello #{params[:username]}"
  puts 'in post / ' + session.inspect
  redirect '/next_step'
end

get '/next_step' do
  puts 'in next_step ' + session.inspect
  "<h1>Next step</h1><div>Flash: #{session[:notice]}</div>"
end