canvas app work, need to write tests for it

README

@@ -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

@@ -1,9 +1,10 @@
 # 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
@@ -22,6 +23,7 @@ module Facebooker2
     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
@@ -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/oauth_exception"

lib/facebooker2/oauth_exception.rb

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

lib/facebooker2/rails/controller.rb

@@ -107,6 +107,7 @@ module Facebooker2
           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