Ruby on Rails

Thanks, but I think that I figured it out

In parent AR,

attr_accessible :addresses_attributes
has_many :addresses  ### Pretty sure should be plural for has_many, and singular for has_one
accepts_nested_attributes_for :addresses

Then in the view I have (abbreviated)

form @parent_object do |parent_form|     ### In the controller I just pass @parent_object = Parent_object.new  (AR takes care of all the associations)
... the address sections

parent_form.fields_for :addresses do |primary|
primary.text_field :address_line_1
primary.hidden_field :address_type_id, :value => 'primary'
.... end


parent_form.fields_for :addresses do |alternative|
alternative.text_field :address_line_1
alternative.hidden_field :address_type_id, :value => 'alternative'
.... end

I think this may work.  Haven't looked at the params yet...