Where would this logic go in Rails?

If the options aren't coming from a database table, I would put them
in a constant array inside the model, such as:


               [ "Canada", "CAN" ],
               [ "United States", "US" ],
               [ "England", "UK" ],
               [ "Other", "OT" ],

and then just use this array as the source for your select menu. If
these select objects are related to your model, you can then validate
by using something like:

validates_presence_of :country_name

or use a custom validation if it's more complicated.