Whitelist all attribute assignment by default.

Change the default for newly generated applications to whitelist all attribute assignment.  Also update the generated model classes so users are reminded of the importance of attr_accessible.

activerecord/lib/rails/generators/active_record/model/model_generator.rb

@@ -30,6 +30,10 @@ def attributes_with_index
         attributes.select { |a| a.has_index? || (a.reference? && options[:indexes]) }
       end
 
+      def accessible_attributes
+        attributes.reject(&:reference?)
+      end
+
       hook_for :test_framework
 
       protected

activerecord/lib/rails/generators/active_record/model/templates/model.rb

@@ -3,5 +3,10 @@ class <%= class_name %> < <%= parent_class_name.classify %>
 <% attributes.select  {|attr| attr.reference? }.each do |attribute| -%>
   belongs_to :<%= attribute.name %>
 <% end  -%>
+<% if  !accessible_attributes.empty? -%>
+  attr_accessible <%= accessible_attributes.map {|a| ":#{a.name}" }.sort.join(', ') %>
+<% else  -%>
+  # attr_accessible :title, :body
+<% end  -%>
 end
 <% end  -%>

railties/lib/rails/generators/rails/app/templates/config/application.rb

@@ -54,7 +54,7 @@ class Application < Rails::Application
     # This will create an empty whitelist of attributes available for mass-assignment for all models
     # in your app. As such, your models will need to explicitly whitelist or blacklist accessible
     # parameters by using an attr_accessible or attr_protected declaration.
-    # config.active_record.whitelist_attributes = true
+    config.active_record.whitelist_attributes = true
 
     # Specifies wether or not has_many or has_one association option :dependent => :restrict raises
     # an exception. If set to true, then an ActiveRecord::DeleteRestrictionError exception would be

railties/test/generators/model_generator_test.rb

@@ -317,4 +317,14 @@ def test_index_is_skipped_for_references_association
       end
     end
   end
+
+  def test_attr_accessible_added_with_non_reference_attributes
+    run_generator
+    assert_file 'app/models/account.rb', /attr_accessible :age, :name/
+  end
+
+  def test_attr_accessible_added_with_comments_when_no_attributes_present
+    run_generator ["Account"]
+    assert_file 'app/models/account.rb', /# attr_accessible :title, :body/
+  end
 end