rails validation contigent on multiple elements

Question

I've been using accepts_nested_attributes_for for a few different models and I've got an odd situation.

I can skip creation blanks thru the top model, and I can validate_presence of individual records thru the bottom, but is it possible to do a most complex validation on a set of records?

I have the models Rooms and Rates. Rooms has_many Rates and accepts_nested_attributes_for Rates.

I can weed out blanks with

accepts_nested_attributes_for :room_rates, :reject_if => lambda { |a| a[:price].blank? }

but for each Room there are 7 different records (rates).. always 7 and submitted at once from the same form. Currently if they enter only 1 day it will allow it. However I would like to validate that all 7 must exist. Either they enter all 7 and it accepts it or it gives them an error for entering only 1 or 2. And does nothing at all if they leave all 7 completely blank.

I haven't seen anything like this yet for nested_attirbutes so i'm wondering if it's possible.

Answer 1

I'm not sure this would work, but can you not check the size of the rates in your Room class, something like:

class Room < ActiveRecord::Base
  validate :all_rates_present

...

private
def all_rates_present
  unless rates.size == 7
    errors.add(:rates, "must all be filled in.")
  end
end