acts_as_euro is a minimal module I've written to handle currencies stored in a db as integers. Given a parameter such as price it will create a couple accessor methods to work with the whole and cents part of the price. To use it just put it in lib/ and then require the file in your application.rb. In your model add something like this:

class CardItemPrice < ActiveRecord::Base
  include ActsAsEuro
  acts_as_euro :price
end

The module will create these methods:

• price_whole
• price_whole=
• price_cents
• price_cents=

That will extract the cents and whole parts from the main price attribute. They will be added to the attr_accessible list.

A simple test:

describe Product do
  it { should validate_presence_of :price }

  it "should deal correctly with cents and whole euros" do
    p = Product.new
    p.price = 123
    p.price_whole.should == 1
    p.price_cents.should == "23"

    p.price_whole = 2
    p.price_cents = 99
    p.price.should == 299
  end
end

I'm sure it can be improved, it was written in 5 minutes.