hide_namespace.diff

diff --git a/railties/lib/rails/generators.rb b/railties/lib/rails/generators.rb
index 8794392..03c97bc 100644
--- a/railties/lib/rails/generators.rb
+++ b/railties/lib/rails/generators.rb
@@ -168,38 +168,52 @@ module Rails
 
     def self.hidden_namespaces
       @hidden_namespaces ||= begin
-        orm      = options[:rails][:orm]
-        test     = options[:rails][:test_framework]
-        template = options[:rails][:template_engine]
-
-        [
-          "rails",
-          "#{orm}:migration",
-          "#{orm}:model",
-          "#{orm}:observer",
-          "#{orm}:session_migration",
-          "#{test}:controller",
-          "#{test}:helper",
-          "#{test}:integration",
-          "#{test}:mailer",
-          "#{test}:model",
-          "#{test}:observer",
-          "#{test}:scaffold",
-          "#{test}:view",
-          "#{test}:performance",
-          "#{test}:plugin",
-          "#{template}:controller",
-          "#{template}:scaffold",
-          "#{template}:mailer"
-        ]
+        hidden = ["rails"]
+
+        hide_namespace(:orm, options[:rails][:orm]).each do |orm|
+          hidden.concat [
+            "#{orm}:migration",
+            "#{orm}:model",
+            "#{orm}:observer",
+            "#{orm}:session_migration"
+          ]
+        end
+
+        hide_namespace(:test_framework, options[:rails][:test_framework]).each do |test|
+          hidden.concat [
+            "#{test}:controller",
+            "#{test}:helper",
+            "#{test}:integration",
+            "#{test}:mailer",
+            "#{test}:model",
+            "#{test}:observer",
+            "#{test}:scaffold",
+            "#{test}:view",
+            "#{test}:performance",
+            "#{test}:plugin"
+          ]
+        end
+
+        hide_namespace(:template_engine, options[:rails][:template_engine]).each do |template|
+          hidden.concat [
+            "#{template}:controller",
+            "#{template}:scaffold",
+            "#{template}:mailer"
+          ]
+        end
+
+        hidden
       end
     end
 
-    class << self
-      def hide_namespaces(*namespaces)
-        hidden_namespaces.concat(namespaces)
-      end
-      alias hide_namespace hide_namespaces
+    def self.hide_namespace(kind, name=nil)
+      @hide_namespace ||= Hash.new { |h,k| h[k] = [] }
+      @hide_namespace[kind] << name if name
+      @hide_namespace[kind]
+    end
+
+    def self.show_namespace(kind, name)
+      hide_namespace(kind).delete(name)
     end
 
     # Show help message with available generators.