sinatra oauth(authenticate) sample

sinatra_oauth.rb

#encoding: UTF-8

require 'rubygems'
require 'sinatra'
require 'erb'
require 'pp'
require 'twitter_oauth'


set :sessions, true

helpers do
    include Rack::Utils 
    alias_method :h, :escape_html
end

configure do
    use Rack::Session::Cookie, :secret => Digest::SHA1.hexdigest(rand.to_s)
    KEY = "YOUR KEY"
    SECRET = "YOUR SECRET"
end


before do
    @twitter = TwitterOAuth::Client.new(
        :consumer_key => KEY,
        :consumer_secret => SECRET,
        :token => session[:access_token],
        :secret => session[:secret_token]
    )
end

def base_url
    default_port = (request.scheme == "http") ? 80 : 443
    port = (request.port == default_port) ? "" : ":#{request.port.to_s}"
    return  "#{request.scheme}://#{request.host}#{port}"
end

get '/' do
    if session[:login]
        @screen_name = @twitter.info['screen_name']
        @image_url = @twitter.info['profile_image_url_https']
        erb :login, :layout => false
    else
        erb :notlogin, :layout => false
    end
end

get '/login' do
    callback_url = "#{base_url}/access_token"
    request_token = @twitter.request_token(
        :oauth_callback => callback_url
    )
    session[:request_token] = request_token.token
    session[:request_token_secret] = request_token.secret
    redirect request_token.authorize_url.gsub('authorize', 'authenticate')
end

get '/access_token' do
    begin
        @access_token = @twitter.authorize(
            session[:request_token],
            session[:request_token_secret],
            :oauth_verifier => params[:oauth_verifier]
        )
    rescue OAuth::Unauthorized
    end

    if @twitter.authorized?
        session[:access_token] = @access_token.token
        session[:secret_token] = @access_token.secret
        session[:login] = true
        redirect '/'
    else
        erb :error, :layout => false
    end   
end

get '/logout' do
    @twitter=nil
    session.clear
    redirect '/'
end

__END__

@@ login
<div><%= @screen_name %></div>
<div><img src="<%= @image_url %>" alt="" /></div>

@@ notlogin
<a href="/login">OAuth Login</a>

@@ error
<strong>error occured</strong>