ActiveModel: Mimic a column type datetime

Question

I am using an ActiveModel model DateRange with attributes :from and :to and I want it to behave as follows..

  d = DateRange.new
=> #<DateRange:0x0000010532d3f8>
  d.from = "03/03/2010"
=> Wed, 03 Mar 2010
  d.to  = Date.today
=> Mon, 3 Mar 2014

In other words, whenever an attribute is set, if it is in string format it should be parsed into a date format.
Is there an ActiveModel callback function which will run immediately when an attribute is changed? If not, what would be best practice to do this?

Answer 1

You don't need any callbacks, what you need are custom setter methods:

class DateRange
  attr_reader :from, :to

  def from=(value)
    # implementation
  end

  def to=(value)
    # implementation
  end
end