test.html

<script type="text/javascript">
  RED.nodes.registerType('googlehome-config-node-offline', {
    category: 'config',
    defaults: {
      ipaddress: {
        value: "",
        required: true
      },
      name: {
        value: ""
      },
      language: {
        value: "en"
      },
      notificationLevel: {
        value: 50
      }
    },
    label: function () {
      return this.name || this.ipaddress;
    },
    oneditprepare: function () {
      var node = this;
      var options = $("#node-input-language");

      //Calling the API built by NodeJS code
      $.getJSON('/languages', function (languages) {
        $.each(languages, function (l, language) {
          options.append($("<option />").val(language.key).text(language.value));
          options.val(node.language);
        });
      });

      try {
        $("#node-config-input-ipaddress").autocomplete("destroy");
      } catch (err) { }
      $("#node-config-lookup-ipaddress").click(function () {
        $("#node-config-lookup-ipaddress-icon").removeClass('fa-search');
        $("#node-config-lookup-ipaddress-icon").addClass('spinner');
        $("#node-config-lookup-ipaddress").addClass('disabled');
        $.getJSON('ipaddresses', function (data) {
          $("#node-config-lookup-ipaddress-icon").addClass('fa-search');
          $("#node-config-lookup-ipaddress-icon").removeClass('spinner');
          $("#node-config-lookup-ipaddress").removeClass('disabled');
          var ipaddresses = [];
          $.each(data, function (i, ip) {
            ipaddresses.push(ip);
          });
          $("#node-config-input-ipaddress").autocomplete({
            source: ipaddresses,
            minLength: 0,
            close: function (event, ui) {
              $("#node-config-input-ipaddress").autocomplete("destroy");
            }
          }).autocomplete("search", "");
        });
      });

    },
    oneditsave: function () {
      var node = this;
      node.language = $("#node-input-language").val();
    }
  });
</script>

<script type="text/x-red" data-template-name="googlehome-config-node-offline">
  <div class="form-row">
    <label for="node-config-input-ipaddress"><i class="icon-bookmark"></i> IP Adress</label>
    <input type="text" id="node-config-input-ipaddress" style="width:60%;" placeholder="192.168.xxx.xxx"/>
    <a id="node-config-lookup-ipaddress" class="btn"><i id="node-config-lookup-ipaddress-icon" class="fa fa-search"></i></a>
  </div>
  <div class="form-row">
    <label for="node-config-input-name"><i class="icon-tag"></i> Name</label>
    <input type="text" id="node-config-input-name" style="width:60%;" placeholder="Google Home Mini"/>
  </div>
  <div class="form-row">
    <label for="node-input-language"><i class="fa fa-globe"></i>  Language</label>
    <select id="node-input-language" style="width:60%;">
          <option value="en"> English</option>
      </select>
  </div>
  <div class="form-row">
    <label for="node-input-language" style="width:40%;"><i class="fa fa-volume-up" ></i> Default notification level (%)</label>
    <input type="text" id="node-config-input-notificationLevel" style="width:10%;" placeholder="50"/>
    <label for="node-config-input-name" ><i class="icon-tag"></i> Overridable</label>
    <input type="checkbox" checked data-toggle="toggle" class="red-ui-tab-link-button">
  </div>
  <div class="form-row">
    <label for="node-input-language"><i class="fa fa-volume-up"></i> <span data-i18n="node-red:tcpin.label.type">Default notification level (%)</span></label>
    <select id="node-input-language" style="width:120px; margin-right:5px;">
        <option value="server" data-i18n="node-red:tcpin.type.listen">Listen on</option>
        <option value="client" data-i18n="node-red:tcpin.type.connect">Connect to</option>
    </select>
    <span data-i18n="node-red:tcpin.label.port">port</span> <input type="text" id="node-input-port" style="width:65px" autocomplete="disable" dir="" class="input-error">
</div> 
</script>