_server_select.html.erb

<%= fields_for 'host[wds_facet_attributes]', item do |f| %>
  <%-
    wds_servers = WdsServer.all
  -%>
  <%= select_f f, :wds_server_id, wds_servers, :id, :name,
    { include_blank: true },
    { label: _('WDS Server'),
      disabled: f.object.host.operatingsystem.nil? || f.object.host.operatingsystem.family != 'Windows',
      help_inline: :indicator,
      required: true,
      onchange: 'wds_server_selected(this);', :'data-url' => method_path('wds_server_selected'), :'data-type' => controller_name.singularize } %>
<% end %>