添加类到表格单元格


AJAX Add Class to Table Cell

我的表单上有两个选择菜单:类型和类别。当用户从类型菜单中选择一些东西时,我希望它然后执行一个PHP脚本,该脚本查询数据库并返回所选类型的匹配类别列表,以便他们从类别菜单中进行选择。

这工作得很好,但我现在想更新它,以便它添加一个类到categoryGroup("成功"或"错误"取决于AJAX的结果)。这是我的表格,有两个单元格:

<div class="form-group">
  <label for="title" class="control-label col-sm-3">Type</label>
  <div class="input-group col-xs-8">
    <select class="form-control" name="type" id="type" onchange="getCategories(this.value)">
      <option value="" selected></option>
      <option value="Business">Business</option>
      <option value="Commercial">Commercial</option>
      <option value="Commercial Land">Commercial Land</option>
      <option value="Land">Land</option>
      <option value="Rental">Rental</option>
      <option value="Residential">Residential</option>
      <option value="Rural">Rural</option>
    </select>
  </div>
</div>
<div class="form-group" id="categoryGroup">
  <label for="title" class="control-label col-sm-3">Category</label>
  <div class="input-group col-xs-8" class="" id="categoryList">
    <select class="form-control" name="category" id="category">
      <option value="" selected></option>
    </select>
  </div>
</div>

,这里是我的脚本,正在工作,以取代类别选择菜单与适当的选项从AJAX调用:

<script type="text/javascript">
  function getCategories(str) {
    if (str == "") {
      document.getElementById("categoryList").innerHTML = "";
      return;
    }
    if (window.XMLHttpRequest) { // code for IE7+, Firefox, Chrome, Opera, Safari
      xmlhttp = new XMLHttpRequest();
    } else { // code for IE6, IE5
      xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
    }
    xmlhttp.onreadystatechange = function() {
      if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
        document.getElementById("categoryList").innerHTML = xmlhttp.responseText;
      }
    }
    xmlhttp.open("POST", "getPropertyCategories.php?type=" + str, true);
    xmlhttp.send();
  }
</script>

我不知道如何更新这也添加一个类到categoryGroup id

很基本,但我想你已经明白了要点:

 xmlhttp.onreadystatechange = function() {
     if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
         document.getElementById("categoryList").innerHTML = xmlhttp.responseText;
     }
     var status = xmlhttp.status == 200 ? 'success' : 'error'
     var group = document.getElementById("categoryGroup")
     group.classList.add(status)
}