quotes.rb

require 'bureaucrat/formsets'

class QuoteItemForm < Bureaucrat::Forms::Form
  extend Bureaucrat::Quickfields

  string :id, :required => false
  hide :id
  string :description
  integer :unit_price
  integer :quantity, :required => false

  def save
    if valid?
      QuoteItem.new(cleaned_data)
    end
  end
end

QuoteItemFormSet = Bureaucrat::Formsets.make_formset_class(QuoteItemForm, :extra => 5,  :can_delete => true)
class QuoteItemFormSet
  def clean
    if filled_forms.blank?
      raise Bureaucrat::Fields::FieldValidationError.new("Quote has to contain at least one item.")
    end
  end

  def filled_forms
    forms.reject { |f| f.cleaned_data.blank? }
  end

  def self.from_quote(quote, options = {})
    prefix = options.fetch(:prefix, self.default_prefix)
    params = {}
    quote.items.each_with_index do |item, index|
      [:id, :description, :unit_price, :quantity].each do |f|
        params["%s-%d-%s" % [prefix, index, f]] = item.send(f)
      end
    end
    params["%s-%s" % [prefix, Bureaucrat::Formsets::INITIAL_FORM_COUNT]] = quote.items.count
    params["%s-%s" % [prefix, Bureaucrat::Formsets::TOTAL_FORM_COUNT]] = quote.items.count + options.fetch(:extra, 0)
    self.new(params, options)
  end
end