我发现这有点混乱。旧的教程和代码已经没有意义了。
您可以使用Heroku + Facebook OmniAuth example来执行服务器端Facebook(以及其他许多)身份验证的外部网站(而不是画布应用)。
当你这样做时,OmniAuth会为你提供你需要传递给fb_graph的令牌。在提供的例子中,你可以添加另一个网址:
get '/me' do
me = FbGraph::User.me(session['fb_token']).fetch
"Hello " + me.name
end
画布应用程序,添加以下代码为“机架Facebook的request.rb”我回购基于this gist
require 'base64'
require 'openssl'
require 'json'
# This is inspired by [rack-facebook-signed-request](https://github.com/gamesthatgive/rack-facebook-signed-request)
#
# Usage
#
# use Rack::FBSignedRequest, :secret => 'SECRET'
#
class Rack::FBSignedRequest
def initialize(app, options)
@app = app
@options = options
end
def call(env)
@request = Rack::Request.new(env)
if @request.POST['signed_request']
if facebook_params = parse_signed_request(@request.params['signed_request'])
@request.params['facebook_params'] = facebook_params
env['rack.request.query_hash'] = @request.params
env['REQUEST_METHOD'] = 'GET'
puts 'Valid signed request. Changed REQUEST_METHOD to GET.'
if facebook_params['user_id']
env['fb_user_id'] = facebook_params['user_id']
env['fb_access_token'] = facebook_params['oauth_token']
puts 'Request has been authorized.'
else
puts 'Request is not authorized.'
end
else
puts 'Not a valid signed request'
end
else
puts 'Not a signed_request'
end
@app.call(env)
end
private
# The following code from omniauth
def parse_signed_request(value)
signature, encoded_payload = value.split('.')
decoded_hex_signature = base64_decode_url(signature)
decoded_payload = JSON(base64_decode_url(encoded_payload))
unless decoded_payload['algorithm'] == 'HMAC-SHA256'
raise NotImplementedError, "unkown algorithm: #{decoded_payload['algorithm']}"
end
if valid_signature?(@options[:secret], decoded_hex_signature, encoded_payload)
decoded_payload
end
end
def valid_signature?(secret, signature, payload, algorithm = OpenSSL::Digest::SHA256.new)
OpenSSL::HMAC.digest(algorithm, secret, payload) == signature
end
def base64_decode_url(value)
value += '=' * (4 - value.size.modulo(4))
Base64.decode64(value.tr('-_', '+/'))
end
end
这如果您的应用获得授权,将会为您提供当前的fb_user_id和fb_access_token。请记住,在这种情况下您必须使用javascript or a link in the iFrame to request app authorisation。