require 'bundler/setup'
require 'sinatra/base'
require 'omniauth-facebook'
SCOPE = 'email,read_stream'
class App < Sinatra::Base
# turn off sinatra default X-Frame-Options for FB canvas
set :protection, :except => :frame_options
# server-side flow
get '/' do
# NOTE: you would just hit this endpoint directly from the browser
# in a real app. the redirect is just here to setup the root
# path in this example sinatra app.
redirect '/auth/facebook'
end
# client-side flow
get '/client-side' do
content_type 'text/html'
# NOTE: when you enable cookie below in the FB.init call
# the GET request in the FB.login callback will send
# a signed request in a cookie back the OmniAuth callback
# which will parse out the authorization code and obtain
# the access_token. This will be the exact same access_token
# returned to the client in response.authResponse.accessToken.
<<-END
Client-side Flow Example
Connect to FB
END
end
# auth via FB canvas and signed request param
post '/canvas/' do
# we just redirect to /auth/facebook here which will parse the
# signed_request FB sends us, asking for auth if the user has
# not already granted access, or simply moving straight to the
# callback where they have already granted access.
redirect "/auth/facebook?signed_request=#{request.params['signed_request']}"
end
get '/auth/:provider/callback' do
content_type 'application/json'
MultiJson.encode(request.env)
end
get '/auth/failure' do
content_type 'application/json'
MultiJson.encode(request.env)
end
end
use Rack::Session::Cookie
use OmniAuth::Builder do
provider :facebook, ENV['APP_ID'], ENV['APP_SECRET'], :scope => SCOPE
end
run App.new