# File lib/action_view/helpers/form_helper.rb, line 530 def fields_for(record_or_name_or_array, *args, &block) raise ArgumentError, "Missing block" unless block_given? options = args.extract_options! case record_or_name_or_array when String, Symbol object_name = record_or_name_or_array object = args.first else object = record_or_name_or_array object_name = ActiveModel::Naming.singular(object) end builder = options[:builder] || ActionView::Base.default_form_builder capture(builder.new(object_name, object, self, options, block), &block) end