Allow scaffold controller to load action_orm files on demand.

railties/lib/generators.rb

@@ -12,7 +12,6 @@ require 'rails/version' unless defined?(Rails::VERSION)
 
 require 'generators/base'
 require 'generators/named_base'
-require 'generators/active_record' # We will need ActionORM from ActiveRecord, but just it.
 
 module Rails
   module Generators

railties/lib/generators/named_base.rb

@@ -129,13 +129,24 @@ module Rails
         #
         def orm_class
           @orm_class ||= begin
+            # Raise an error if the class_option :orm was not defined.
             unless self.class.class_options[:orm]
               raise "You need to have :orm as class option to invoke orm_class and orm_instance" 
             end
 
             action_orm = "#{options[:orm].to_s.classify}::Generators::ActionORM"
-            action_orm.constantize
-          rescue NameError => e
+
+            # If the orm was not loaded, try to load it at "generators/orm",
+            # for example "generators/active_record" or "generators/sequel".
+            begin
+              klass = action_orm.constantize
+            rescue NameError
+              require "generators/#{options[:orm]}"
+            end
+
+            # Try once again after loading the file with success.
+            klass ||= action_orm.constantize
+          rescue Exception => e
             raise Error, "Could not load #{action_orm}, skipping controller. Error: #{e.message}."
           end
         end

railties/test/generators/scaffold_controller_generator_test.rb

@@ -100,7 +100,7 @@ class ScaffoldControllerGeneratorTest < GeneratorsTestCase
   def test_error_is_shown_if_orm_does_not_provide_interface
     error = capture(:stderr){ run_generator ["User", "--orm=unknown"] }
     assert_equal "Could not load Unknown::Generators::ActionORM, skipping controller. " <<
-                 "Error: uninitialized constant Unknown.\n", error
+                 "Error: no such file to load -- generators/unknown.\n", error
   end
 
   protected