Twitter OAuth in sinatra

oauthsinatra.rb

require 'sinatra'
require 'twitter_oauth'

enable :sessions

before do
	key = '**app**consumer**key**'
	secret = '**app**consumer**secret**'
	@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}"
	"#{request.scheme}://#{request.host}#{port}"
end

get "/request_token/?" 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
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 => @exception
		return erb :authorize_fail
	end

	session[:access_token] = @access_token.token
	session[:secret_token] = @access_token.secret
	session[:user_id] = @twitter.info['user_id']
	session[:screen_name] = @twitter.info['screen_name']
	session[:profile_image] = @twitter.info['profile_image_url_https']

	redirect '/'
end

get "/?" do
	@title = 'TwitterOAuth認証'
	erb :index
end