added controller to handle callbacks

controllers/authorization.rb

@@ -0,0 +1,12 @@
+class CustomWizard::AuthorizationController < ::ApplicationController
+  skip_before_action :check_xhr,
+                     :preload_json,
+                     :redirect_to_login_if_required,
+                     :verify_authenticity_token
+
+  def callback
+   # TODO: work out which service it relates to!
+   CustomWizard::Authorization.set_code(service, params[:code])
+   CustomWizard::Authorization.get_access_token(service)
+  end
+end

plugin.rb

@@ -49,6 +49,7 @@ after_initialize do
     get ':wizard_id/steps' => 'wizard#index'
     get ':wizard_id/steps/:step_id' => 'wizard#index'
     put ':wizard_id/steps/:step_id' => 'steps#update'
+    get 'authorization/callback' => "authorization#callback"
   end
 
   require_dependency 'admin_constraint'
@@ -81,6 +82,7 @@ after_initialize do
   load File.expand_path('../controllers/wizard.rb', __FILE__)
   load File.expand_path('../controllers/steps.rb', __FILE__)
   load File.expand_path('../controllers/admin.rb', __FILE__)
+  load File.expand_path('../controllers/authorization.rb', __FILE__)
 
   ::UsersController.class_eval do
     def wizard_path