oauth_helper.rb

module OAuthHelper
  enable :sessions

  get '/oauth/auth' do
    consumer = OAuth::Consumer.new(
      settings.oauth_consumer_key,
      settings.oauth_consumer_secret,
      {
        :site => settings.oauth_site,
      })
    request_token = consumer.get_request_token(:oauth_callback => url('/oauth/cb'))
    session[:request_token] = request_token
    redirect request_token.authorize_url
  end

  get '/oauth/cb' do
    session[:access_token] = session[:request_token].get_access_token
    session.delete(:request_token)
    redirect to(settings.oauth_redirect_to)
  end
end