如何从onFailure事件中删除警报？

Question

我在Ajax/JSON函数上遇到了一点问题......我想用这个函数从下拉框中获取值，并使用一个锚标记来设置它的值。

我一直以为使用onClick事件将字符串传递给用于下拉框的函数是很容易的，而且数据也被成功添加到了MySQL中，但是我却在JSON onFailure事件中得到了警报。我试着从onFailure事件中删除警报，但是它就不添加数据了。没有警报的时候，下拉框会继续工作，且运行正常。(注意，删除警报也破坏了我的下拉框)。

第一，添加onClick事件…

<a href="<?php echo Settings::get('app.webroot'); ?>?view=schedule&action=questions" onmouseout="MM_swapImgRestore();" onmouseover="MM_swapImage('bre','','template/images/schedule/bre_f2.gif',1)" onclick="assignCallType('testing')";>

第二，检查main.js.php：

function assignCallType(type) {
  alert(type);
  new Request.JSON({
    url: "ajax.php",
    onSuccess: function(rtndata, txt) {
      if (rtndata['STATUS'] != 'OK')
        alert('Status was not okay');
    },
    onFailure: function() {
      alert("onFailure")
    }
  }).get({
    'action': 'assignCallType',
    'call_type': type
  });
}

第3，Ajax.php：变量返回PHP，值被添加到MySQL中，但我在JSON onFailure事件中得到了警报：

if ($_GET['action'] == "assignCallType") {
    if ($USER->isInsideSales()) {
        $call_type = $_GET['call_type'];
        $_SESSION['callinfo']->setCallType($call_type);
        $_SESSION['callinfo']->save($callid);
        echo json_encode(array('STATUS'=>'OK'));
    } else {
        echo json_encode(array('STATUS'=>'DENIED'));
    }
}

究竟哪里出错了？这与工作下拉列表之间唯一的区别是在函数调用上，我使用的是onchange="assignCallType(this.value)"。

Answer 1

Does the callback for onFailure provide any arguments? For example in jQuery there are 3 arguments that can give you information about the error. I ran into a similar problem where the error callback kept getting called even though there was no connection error. The problem turned out to be badly-formed JSON. Can you confirm that your JSON is well-formed?

UPDATE

I just checked out the documentation for Request and noticed that onFailure can have xhr in its signature. Try taking a look at the status, statusText, and responseText attributes of the XMLHttpRequest object. That will give you a clue as to what's going wrong.

Try this:

onFailure: function(xhr) {
   console.log(xhr.status, xhr.statusText, xhr.responseText);
}