Hello everybody,
I had been searching the web but I can’t find a way to add a new
abstract data type to AR using a composed_of. To put this in context
let me explain what I want to do:
In a rails app I had developed a Money Class that use to
attr :amount, :currency. I had add functionality to have Factories for
creating Money in different currencies, arithmetical operations,
comparisons, and several financial calculations (interest, expected
values, amortized payments, etc.) . I had been using this in my models
as
composed_of :price_money,
:class_name => Money,
:mapping =>
[ # database ruby
[ :price, :amount ],
[ :currency, :currency ]
]
I have also a Bank Class were I kept the exchange rates among
currencies
After talking in RailsConf2008 with several railers they told me that
will be good if I can deploy this as a plugin or a gem. I had been
working in extracting this as a plugin, but I would like to be able to
add a new abstract data type to AR for money, then we can use in
migrations something like this as example:
create_table “prices”, :force => true do |t|
t.money “price”, :precision => 16, :scale => 4. :default_currency
=> “USD”
end
Rather than
create_table “prices”, :force => true do |t|
t.decimal “price”, :precision => 16, :scale => 4
t.string “currency”, :limit => 3, :default => “USD”, :null =>
false
end
And get out also the need for the composed_of declaration.
I will appreciate very much any suggestion how to tackle this.
Best regards,
Manuel Vidaurre