Q:

Can you use strong parameters and whitelist attributes together in Rails 3? 

We're on Rails 3.   We'd like to switch to strong parameters through the strong_parameters gem. 
The documentation of the gem says that to use this gem, the following value needs to be changed from true to false in the config/application.rb file
config.active_record.whitelist_attributes = false

We have many models and controllers in our application.   Making this change means we have to migrate ALL our models and controllers to strong parameters? 
Ideally we'd like to migrate gradually.   That is, start using strong parameters for the new models and controllers, and then gradually update all the models and controllers. 
So can you use strong parameters for some models/controllers and whitelist attributes for others? 
Thank you. 

A:

I just started doing this.  My experience is that I can leave the auto-whitelist enabled:
config.active_record.whitelist_attributes = true

Then I need to explicitly disable the whitelist in models I'm migrating to strong params using attr_protected:
class Widget < ActiveRecord::Base
  attr_protected # disable whitelist in this model
  include ActiveModel::ForbiddenAttributesProtection
  ...
end

