How to access nested params

Question

I would like to get some nested params. I have an Order that has many Items and these Items each have a Type. i would like to get the type_id parameter from the controllers create method.

@order = Order.new(params[:order])
@order.items.each do |f|
  f.item_type_id = Item_type.find_by_name(f.item_type_id).id
end

The reason is that i want the user to be able to create new item_types in the view. When they do that i use an AJAX call add them to the db. When they post the form i get names of the item_type in the item_type_id parameter and i want to find the correct item_type and set the id to that

Answer 1

To access the nested fields from params do the following:

params[:order][:items_attributes].values.each do |item|
  item[:type_id]
end if params[:order] and params[:order][:items_attributes]

Above solution will work ONLY if you have declared the correct associations and accepts_nested_attributes_for.

class Order < ActiveRecord::Base
  has_many :items
  accepts_nested_attributes_for :items, :allow_destroy => true
end

class Item < ActiveRecord::Base
  belongs_to :order
end