Feature: model_name overridden in form_object module

The model_name class method is part of the ActiveModel::Naming module.

Typically Form Objects want to override the self.model_name method,
as this method is used by form_for to determine the URL that the form is
submitted to.

The FormObject module uses the resource part of the concrete form-object
Class name as the name attribute of the ActiveModel::Name instance
returned from model_name.

lib/active_model/form_object.rb

@@ -19,6 +19,10 @@ def new(*args, &block)
         allocate_and_init(*args, &block)
       end
 
+      def model_name
+        ActiveModel::Name.new(self, nil, self.name.split(/(?=[A-Z])/).first)
+      end
+
       private
 
       def create_accessors(*args)

spec/dummy/app/form_objects/user_signup.rb

@@ -8,10 +8,6 @@ class UserSignup
 
   validates :name, :length => { :minimum => 2 }
 
-  def self.model_name
-    ActiveModel::Name.new(self, nil, "User")
-  end
-
   def persist!
     @user = User.create!(:name => name)
   end