html_options_for_form_with

# File actionview/lib/action_view/helpers/form_helper.rb, line 1573
        def html_options_for_form_with(url_for_options = nil, model = nil, html: {}, local: !form_with_generates_remote_forms,
          skip_enforcing_utf8: nil, **options)
          html_options = options.slice(:id, :class, :multipart, :method, :data, :authenticity_token).merge!(html)
          html_options[:remote] = html.delete(:remote) || !local
          html_options[:method] ||= :patch if model.respond_to?(:persisted?) && model.persisted?
          if skip_enforcing_utf8.nil?
            if options.key?(:enforce_utf8)
              html_options[:enforce_utf8] = options[:enforce_utf8]
            end
          else
            html_options[:enforce_utf8] = !skip_enforcing_utf8
          end
          html_options_for_form(url_for_options.nil? ? {} : url_for_options, html_options)
        end