Adding a :cast option to text_field in order to facilitate displaying data in a form in a more human friendly form

Adding a :cast option to text_field in order to facilitate displaying data in a form in a more human friendly form.

For example:

text_field(:shopping_cart, :price, :cast => lambda {|v| number_to_currency v})

=> <input type="text" id="shopping_cart_price" name="shopping_cart[price]" value="#{number_to_currency(@shopping_cart.price)}" />