Facebook OAuth2.0 sample for Ruby

#!/usr/bin/env ruby
# coding: utf-8

require 'rubygems'
require 'oauth2'
require 'sinatra'
require 'json'

API_KEY = your_api_key
API_SECRET = your_api_secret

class Facebook
  def initialize(key, secret)
    @key, @secret = key, secret
  end

  def client
    OAuth2::Client.new(@key, @secret, :site => "https://graph.facebook.com")
  end

  def redirect_uri
    uri = URI.parse(request.url)
    uri.path = '/auth/facebook/callback'
    uri.query = nil
    uri.to_s
  end
end

get '/auth/facebook' do
  client = Facebook.new(API_KEY, API_SECRET)
  redirect client.web_server.authorize_url(:redirect_uri => redirect_uri)
end

get '/auth/facebook/callback' do
  access_token = client.web_server.access_token(params[:code], :redirect_uri => redirect_uri)
  user = JSON.parse(access_token.get('/me'))

  user.inspect
end

試しに書いてみた。多分動かない。