form_for (ActionView::Helpers::FormHelper)

    # File lib/action_view/helpers/form_helper.rb, line 232
          def form_for(record_or_name_or_array, *args, &proc)
            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
            when Array
              object = record_or_name_or_array.last
              object_name = ActionController::RecordIdentifier.singular_class_name(object)
              apply_form_for_options!(record_or_name_or_array, options)
              args.unshift object
            else
              object = record_or_name_or_array
              object_name = ActionController::RecordIdentifier.singular_class_name(object)
              apply_form_for_options!([object], options)
              args.unshift object
            end

            concat(form_tag(options.delete(:url) || {}, options.delete(:html) || {}), proc.binding)
            fields_for(object_name, *(args << options), &proc)
            concat('</form>', proc.binding)
          end