Rails gem to check if an attribute was changed on the last save. Useful in after_save callbacks.

gem install filthy

class Movie < ActiveRecord::Base
  include Filthy
  
  filthy_attributes :title, :director

end

@movie = Movie.find(1)
@movie.title = "28 days later"
@movie.title_filthy?
=> false
@movie.save
=> true
@movie.title_filthy?
=> true
@movie.save
=> true
@movie.title_filthy?
=> false

Filthy is maintained by Mike Taylor and is funded by BookRenter.com. Many of the ideas that have inspired Filthy come from practical usage by the Bookrenter software development team and conversations with Bookrenter developers Andrew Wheeler, Michael Pearce, Philippe Huibonhoa, and Ben Somers.

Copyright (c) 2012 Mike Taylor, Bookrenter.com.