Versioning models with the acts_as_versioned plugin
cd rails/app ./script/plugin install git://github.com/technoweenie/acts_as_versioned.git ./script/generate model post title:string body:text
In your model
class Post < ActiveRecord::Base acts_as_versioned end
In db/migrate/****_create_posts.rb
def self.up
create_table :posts do |t|
t.string :title
t.text :body
t.timestamps
end
Post.create_versioned_table
end
def self.down
drop_table :posts
Post.drop_versioned_table
end
Migrate your db
rake db:migrate
Usage
p = Post.create :body => "hello world" p.body = "HELLO WORLD" p.save p.versions.size p.versions.last p.revert_to(p.versions.first) p.body # => hello world
*Quick Note If you want to revert to an older version in a controller or something, don't do
@post = @post.revert_to(2)
Revert_to method will return a TrueClass, Boolean type. Instead use
@post.revert_to(2)
This method will update the attributes for you and when you call them you'll get that version.
More information is available here http://ar-versioned.rubyforge.org/ and http://www.urbanhonking.com/ideasfordozens/archives/2006/02/learns_to_use_a_1.html
at least not on OS X. Time to do it the hard way. Luckily not too hard. It just can’t find the right path to mysql_config. Sound familiar? http://seanbehan.com/databases/install-do_mysql-ruby-gem-on-mac-os-x/ 
