How do I pass an array to fields_for in Rails?

Question

I want to use fields_for on a subset of records in an association.

I have a Month model, which has_many :payments.

But

Answer 1

You can add additional association for large payments, for example:

class Month < ActiveRecord::Base
  has_many :payments
  has_many :large_payments, :class_name => "Payment", :conditions => "value > 1000000"
end

After that you can use fields_for in common way:

- fields_for :large_payments

I think to encapsulate this logic on a model side is a better approach then in the view.