canvas app work, need to write tests for it

README

@@ -36,7 +36,7 @@ shared login partial.
 <%= fb_connect_async_js %>
 <% if current_facebook_user %>
    <%= "Welcome #{current_facebook_user.first_name} #{current_facebook_user.last_name}!" %>
-   or 
+   or
    <%= "Hello #{fb_name(current_facebook_user, :useyou => false)}!" # link to facebook profile
     %>
   <%= fb_logout_link("Logout of fb", request.url) %><br />
@@ -48,4 +48,41 @@ shared login partial.
   <%= fb_login_and_redirect('<your URL here>', :perms => 'email,user_birthday') %>
 <% end %>
 
+Using with Canvas Applications
+==============================
+
+To improve integration with Facebook and iframe canvas applications, the primary goal
+being things like FB.ui work as a dialog rather than a popup, the application
+needs to be authenticated against the user's account via OAuth before use.
+
+0. Prerequisite: You need a Facebook app. Have your canvas page name handy.
+
+1. Install facebooker2.
+
+2. Create config/facebooker.yml as above, but add the following key:
+
+production:
+  canvas_page_name: <your canvas page name>
+
+3. Add the following lines to your app/controllers/application_controller.rb
+
+include Facebooker2::Rails::Controller::CanvasOAuth
+
+ensure_canvas_connected_to_facebook :oauth_url, 'publish_stream'
+create_facebook_oauth_callback :oauth
+
+rescue_from Facebooker2::OAuthException do |exception|
+  redirect_to 'http://www.facebook.com/'
+end
+
+4. Create a route that generates a URL for the OAuth callback and calls the appropriate
+action on your controller:
+
+map.oauth '/oauth', :controller => :application, :action => :oauth
+
+5. Your canvas application will now ensure that the current user has authorized
+the application before anything else is allowed.  The authorization and FB.ui dialogs
+will appear inline instead of as popups, improving user experience.
+
 Copyright (c) 2010 Mike Mangino, released under the MIT license
+Copyright (c) 2010 John Bintz, released under the MIT license

lib/facebooker2.rb

@@ -1,35 +1,37 @@
 # Facebooker2
 require "mogli"
+
 module Facebooker2
   class NotConfigured < Exception; end
   class << self
-    attr_accessor :api_key, :secret, :app_id
+    attr_accessor :api_key, :secret, :app_id, :canvas_page_name
   end
-    
+
   def self.secret
-    @secret || raise_unconfigured_exception    
+    @secret || raise_unconfigured_exception
   end
-  
+
   def self.app_id
     @app_id || raise_unconfigured_exception
   end
-  
+
   def self.raise_unconfigured_exception
     raise NotConfigured.new("No configuration provided for Facebooker2. Either set the app_id and secret or call Facebooker2.load_facebooker_yaml in an initializer")
   end
-  
+
   def self.configuration=(hash)
     self.api_key = hash[:api_key]
     self.secret = hash[:secret]
     self.app_id = hash[:app_id]
+    self.canvas_page_name = hash[:canvas_page_name]
   end
-  
+
   def self.load_facebooker_yaml
     config = YAML.load(File.read(File.join(::Rails.root,"config","facebooker.yml")))[::Rails.env]
     raise NotConfigured.new("Unable to load configuration for #{::Rails.env} from facebooker.yml. Is it set up?") if config.nil?
     self.configuration = config.with_indifferent_access
   end
-  
+
   def self.cast_to_facebook_id(object)
     if object.kind_of?(Mogli::Profile)
       object.id
@@ -43,8 +45,10 @@ end
 
 
 require "facebooker2/rails/controller"
+require "facebooker2/rails/controller/canvas_oauth"
 require "facebooker2/rails/helpers/facebook_connect"
 require "facebooker2/rails/helpers/javascript"
 require "facebooker2/rails/helpers/request_forms"
 require "facebooker2/rails/helpers/user"
-require "facebooker2/rails/helpers"
+require "facebooker2/rails/helpers"
+require "facebooker2/oauth_exception"

lib/facebooker2/oauth_exception.rb

@@ -0,0 +1,4 @@
+module Facebooker2
+  class OAuthException < StandardError; end
+end
+

lib/facebooker2/rails/controller.rb

@@ -3,31 +3,31 @@ require "hmac-sha2"
 module Facebooker2
   module Rails
     module Controller
-      
+
       def self.included(controller)
         controller.helper Facebooker2::Rails::Helpers
         controller.helper_method :current_facebook_user
         controller.helper_method :current_facebook_client
         controller.helper_method :facebook_params
       end
-      
+
       def current_facebook_user
         fetch_client_and_user
         @_current_facebook_user
       end
-      
+
       def current_facebook_client
         fetch_client_and_user
         @_current_facebook_client
       end
-      
+
       def fetch_client_and_user
         return if @_fb_user_fetched
         fetch_client_and_user_from_cookie
         fetch_client_and_user_from_signed_request unless @_current_facebook_client
         @_fb_user_fetched = true
       end
-      
+
       def fetch_client_and_user_from_cookie
         app_id = Facebooker2.app_id
         if (hash_data = fb_cookie_hash_for_app_id(app_id)) and
@@ -35,20 +35,20 @@ module Facebooker2
           fb_create_user_and_client(hash_data["access_token"],hash_data["expires"],hash_data["uid"])
         end
       end
-      
+
       def fb_create_user_and_client(token,expires,userid)
         client = Mogli::Client.new(token,expires.to_i)
         user = Mogli::User.new(:id=>userid)
-        fb_sign_in_user_and_client(user,client)        
+        fb_sign_in_user_and_client(user,client)
       end
-            
+
       def fb_sign_in_user_and_client(user,client)
         user.client = client
         @_current_facebook_user = user
         @_current_facebook_client = client
         @_fb_user_fetched = true
       end
-      
+
       def fb_cookie_hash_for_app_id(app_id)
         return nil unless fb_cookie_for_app_id?(app_id)
         hash={}
@@ -59,15 +59,15 @@ module Facebooker2
         end
         hash
       end
-      
+
       def fb_cookie_for_app_id?(app_id)
         !fb_cookie_for_app_id(app_id).nil?
       end
-      
+
       def fb_cookie_for_app_id(app_id)
         cookies["fbs_#{app_id}"]
       end
-      
+
       def fb_cookie_signature_correct?(hash,secret)
         sorted_keys = hash.keys.reject {|k| k=="sig"}.sort
         test_string = ""
@@ -77,13 +77,13 @@ module Facebooker2
         test_string += secret
         Digest::MD5.hexdigest(test_string) == hash["sig"]
       end
-      
+
       def fb_signed_request_json(encoded)
         chars_to_add = 4-(encoded.size % 4)
         encoded += ("=" * chars_to_add)
         Base64.decode64(encoded)
       end
-      
+
       def facebook_params
         @facebook_param ||= fb_load_facebook_params
       end
@@ -93,20 +93,21 @@ module Facebooker2
         sig,encoded_json = params[:signed_request].split(".")
         return {} unless fb_signed_request_sig_valid?(sig,encoded_json)
         ActiveSupport::JSON.decode(fb_signed_request_json(encoded_json)).with_indifferent_access
-      end  
+      end
-      
+
-      def fb_signed_request_sig_valid?(sig,encoded) 
+      def fb_signed_request_sig_valid?(sig,encoded)
         base64 = Base64.encode64(HMAC::SHA256.digest(Facebooker2.secret,encoded))
         #now make the url changes that facebook makes
         url_escaped_base64 = base64.gsub(/=*\n?$/,"").tr("+/","-_")
         sig ==  url_escaped_base64
       end
-      
+
       def fetch_client_and_user_from_signed_request
         if facebook_params[:oauth_token]
           fb_create_user_and_client(facebook_params[:oauth_token],facebook_params[:expires],facebook_params[:user_id])
         end
       end
+
     end
   end
 end

lib/facebooker2/rails/controller/canvas_oauth.rb

@@ -0,0 +1,55 @@
+module Facebooker2
+  module Rails
+    module Controller
+      module CanvasOAuth
+        def self.included(controller)
+          controller.extend(CanvasOAuthClass)
+
+          class << controller
+            attr_accessor :_facebooker_oauth_callback_url, :_facebooker_scope
+          end
+        end
+
+        protected
+          def canvas_oauth_connect
+            raise "Canvas page name not defined! Define it in config/facebooker.yml as #{::Rails.env}: canvas_page_name: <your url>." if !Facebooker2.canvas_page_name
+            if params[:error]
+              raise Facebooker2::OAuthException.new(params[:error][:message])
+            else
+              redirect_to ('http://apps.facebook.com/' + Facebooker2.canvas_page_name) if params[:code]
+            end
+            return false
+          end
+
+          def ensure_canvas_connected
+            case self.class._facebooker_oauth_callback_url
+              when Symbol
+                callback_url = send(self.class._facebooker_oauth_callback_url)
+            end
+
+            if current_facebook_user == nil && !params[:code] && !params[:error]
+              render :text => "<script>top.location.href = 'https://graph.facebook.com/oauth/authorize?client_id=#{Facebooker2.app_id}&redirect_uri=#{callback_url}&scope=#{[ self.class._facebooker_scope ].flatten * ','}'</script>"
+              return false
+            end
+          end
+      end
+
+      module CanvasOAuthClass
+        def ensure_canvas_connected_to_facebook(oauth_callback_url, *scope)
+          self._facebooker_oauth_callback_url = oauth_callback_url
+          self._facebooker_scope = scope
+
+          before_filter :ensure_canvas_connected
+        end
+
+        def create_facebook_oauth_callback(method_name)
+          self.class_eval(<<-EOT)
+            def #{method_name}
+              return canvas_oauth_connect
+            end
+          EOT
+        end
+      end
+    end
+  end
+end