Version
=======

Tracks changes on an object through time, no more, no less. Each time a versioned
object has validated and is about to save, the changes provided by 
ActiveRecord::Dirty are stored for later use. Procs may be used to customize the
stored value of each field, allowing diffs or other compress version formats to
be plugged right in.


== A Who?
Don't need to track changes on all of the models fields? No problem! Passing along
field names with :only and :except are here for you, you can even mix and match for
quick hacks!

acts_as_versioned :only => :name
acts_as_versioned :except => :remote_version_cache
acts_as_versioned :only => [:fee, :fi, :foo, :fumb], :except => :fi


== |Old School, Knew School|
By defaut the recorded change is in the format [old_value, new_value], which is great
for strings and other small data types. But what if your tracking changes to a three 
trillion page long document? It would be silly to store the entirety of each version
if a user fixed a typo like 'waht' to 'what'. Customizing the stored value is only
a Proc away.

acts_as_versioned :long_document => Proc.new { |old, knew| Diff(old, knew)  }


== My First Change Is In versions#last? WTH!!?!
It sounds silly, and the order may go away but the thinking is you'll want to view
newer changes before older changes.

Example
=======

class Person < ActiveRecord::Base 

	acts_as_versioned

end


person = Person.new
person.versions.count # => 0

person.update_attribute(:name_first, "Cookie Monster")

person.versions.count # => 1
person.versions # => [{:name_first => [nil, "Cookie Monster"]}]

person.update(:name, "Mr. Crackers")
person.versions.first["name"] # => ["Cookie Monster", "Mr. Crackers"]


Copyright (c) 2009 Jacob Basham, released under the MIT license