Examples for the Cookie-based Sessions in Sinatra published by RubyLearning.com blog on Sep 30, 2009.

first_example.rb

require 'rubygems'
require 'sinatra'

enable :sessions

get '/' do
  session["value"] ||= "Hello world!"
  
  "The cookie you've created contains the value: #{session["value"]}"
end

second_example.rb

require 'rubygems'
require 'sinatra'
require 'haml'

enable :sessions

get '/' do
  session["user"] ||= nil
  
  haml :index
end

get '/introduction' do
  haml :introduction
end

post '/introduction' do
  session["user"] = params[:name]
  
  redirect '/'
end

get '/bye' do
  session["user"] = nil
  
  haml :bye
end

__END__

@@ layout
%html
  %head
    %title Introduce Yourself | 2nd Cookie-based sessions example in Sinatra
  %body
    = yield
  
@@ index
- name = session["user"].nil? ? "Stranger" : session["user"].capitalize
%h1= "Howdy #{name}!"
%p
  - if session["user"].nil?
    %a{:href => '/introduction'} What is your name?
  - else
    Man! Long time no see!!! :)
- unless session["user"].nil?
  %p Well... I <a href="/bye">gotta go</a> now. See ya!
  
@@ introduction
%h1 Hi there!
%form{:method => 'post'}
  My name is 
  %input{:type => 'text', :name => 'name'}
  %input{:type => 'submit', :value => 'Introduce Myself'}

@@ bye
%h1 Bye!
%p See you <a href="/">next time</a>!

third_example.rb

require 'rubygems'
require 'sinatra'
require 'haml'

get '/' do
  @@expiration_date = Time.now + (60 * 2) \
    unless request.cookies.key?('some_options') && request.cookies.key?('other_options')
  
  haml :index
end

get '/some_options' do
  @some_cookie = request.cookies["some_options"]
  
  haml :some_options
end

post '/some_options' do  
  response.set_cookie('some_options', :value => cookie_values(params), :expires => @@expiration_date)
  
  redirect '/'
end

get '/other_options' do
  @other_cookie = request.cookies["other_options"]
  
  haml :other_options
end

post '/other_options' do
  response.set_cookie('other_options', :value => cookie_values(params),:expires => @@expiration_date)
  
  redirect '/'
end

helpers do
  def cookie_values(parameters)
    values = {}
    
    parameters.each do |key, value|
      case key
      when 'options'
        values[value] = true
      else
        values[key] = true
      end
    end
    
    values
  end
end

__END__

@@ layout
%html
  %head
    %title Session Tests | 3rd Cookie-based sessions in Sinatra
  %body
    = yield
    
@@ index
%h1 Configuration Cookies
%p= request.cookies.to_s
%ul
  - action = request.cookies.has_key?('some_options') ? "Modify" : "Create" 
  %li<
    %a{:href => '/some_options'}= "#{action} some options"
  - action = request.cookies.has_key?('other_options') ? "Modify" : "Create"
  %li<
    %a{:href => '/other_options'}= "#{action} other options"

@@ some_options
%h1 Some Options
%p Choose one or more options.
%form{:method => 'post'}
  %ul
    %li<
      - value = @some_cookie.nil? ? false : @some_cookie['first_option']
      %input{:type => 'checkbox', :name => 'first_option', :checked => value} First Option
    %li<
      - value = @some_cookie.nil? ? false : @some_cookie['second_option']
      %input{:type => 'checkbox', :name => 'second_option', :checked => value} Second Option
    %li<
      - value = @some_cookie.nil? ? false : @some_cookie['third_option']
      %input{:type => 'checkbox', :name => 'third_option', :checked => value} Third Option
    %li<
      - value = @some_cookie.nil? ? false : @some_cookie['fourth_option']
      %input{:type => 'checkbox', :name => 'fourth_option', :checked => value} Fourth Option
    %li<
      - value = @some_cookie.nil? ? false : @some_cookie['fifth_option']
      %input{:type => 'checkbox', :name => 'fifth_option', :checked => value} Fifth Option
  - action = @some_cookie.nil? ? "Set" : "Modify"
  %input{:type => 'submit', :value => "#{action} Options"}

@@ other_options
%h1 Other Options
%p Choose only one of the options available.
%form{:method => 'post'}
  %ul
    %li<
      - value = @other_cookie.nil? ? false : @other_cookie['first_option']
      %input{:type => 'radio', :name => 'options', :value => 'first_option', :checked => value} First Option
    %li<
      - value = @other_cookie.nil? ? false : @other_cookie['second_option']
      %input{:type => 'radio', :name => 'options', :value => 'second_option', :checked => value} Second Option
    %li<
      - value = @other_cookie.nil? ? false : @other_cookie['third_option']
      %input{:type => 'radio', :name => 'options', :value => 'third_option', :checked => value} Third Option
    %li<
      - value = @other_cookie.nil? ? false : @other_cookie['fourth_option']
      %input{:type => 'radio', :name => 'options', :value => 'fourth_option', :checked => value} Fourth Option
    %li<
      - value = @other_cookie.nil? ? false : @other_cookie['fifth_option']
      %input{:type => 'radio', :name => 'options', :value => 'fifth_option', :checked => value} Fifth Option
  - action = @other_cookie.nil? ? "Set" : "Modify"
  %input{:type => 'submit', :value => "#{action} Options"}