Ajax - responseText工作但responseXML为null

I am trying my first AJAX and having a problem with my xml receiving function. I alert responseText and I can see the xml returned from my server, but when I try and get responseXML I get null and the error.

我正在尝试我的第一个AJAX并且我的xml接收功能有问题。我提醒responseText,我可以看到从我的服务器返回的xml,但是当我尝试获取responseXML时,我得到null和错误。

Here is the php function that builds my xml

这是构建我的xml的php函数

  header('Content-type: application/xml');
    echo("<?xml version=\"1.0\" encoding=\"utf-8\"?>");
    echo("<results>");
    echo("<table><![CDATA[tablereererere]]></table>");
    //echo("<ratedTable>".$_POST['ratedTable']."</ratedTable>\n");
    //echo("<table>".$_POST['table']."</table>\n");
    //echo("<post_id>".$_POST['post_id']."</post_id>\n");
    //echo("<user_id>".$_POST['user_id']."</user_id>\n");
    //echo("<rating>".$_POST['rating']."</rating>\n");
    echo("</results>");

And here is my javascript function which is processing the returned xml

这是我的javascript函数,它处理返回的xml

function ajaxReceiver(http_request) {

    //this function continues to run until a result is returned and then it creates the new div
    if(http_request.readyState == 4) {

      response_xml = http_request.responseXML;
      response_text =  http_request.responseText;

      alert(response_text);
      alert(response_xml.getElementsByTagName("table")[0].textContent);
      //document.getElementById('floatingNotification').innerHTML = response_text;
       // alert(http_request.responseXML.getElementsByTagName("table")[0].textContent);
      //ratedTable = responseXML.getElementsByTagName("table").value;
      //alert(ratedTable);
      //message = response.getElementsByTagName('table')[0].textContent;
      //alert(message);
     //alert(message);
//this response contains the xml document that was returned by the php function.You can get any values out of the xml document and 
//use javascript dom to manipulate the contents on the page


    }
}

5 个解决方案

#1

It may be because, even though you're setting the content-type correctly, you need to have an <xml tag in the top of your response. Also, you aren't closing your last tag properly. This should work:

这可能是因为,即使您正确设置了内容类型,也需要在响应顶部添加 标记。此外,您没有正确关闭最后一个标签。这应该工作:

echo("<?xml version='1.0'?>");
echo("<results>");
echo("<ratedTable>".$_POST['ratedTable']."</ratedTable>");
echo("<table>".$_POST['table']."</table>");
echo("<post_id>".$_POST['post_id']."</post_id>");
echo("<user_id>".$_POST['user_id']."</user_id>");
echo("<rating>".$_POST['rating']."</rating>");
echo("<message>$message</message>");
echo("</results>");

For more info on how to define your XML: http://www.w3.org/TR/REC-xml/#sec-prolog-dtd

有关如何定义XML的更多信息:http://www.w3.org/TR/REC-xml/#sec-prolog-dtd

#2

You are closing the parent node improperly (</results> not <results/>) and you should (after sanitizing it) wrap all the POSTDATA in <![CDATA[...]]> tags to be safe. Make sure it's UTF8 encoded, too (see utf8_encode())

您正在不正确地关闭父节点( 而不是 ),您应该(在消毒之后)将 标签中的所有POSTDATA包装起来是安全的。确保它也是UTF8编码的(参见utf8_encode())

EDIT: and what wajiw said about the <?xml version="1.0" encoding="UTF-8" ?> tag at the beginning.

编辑:以及wajiw在开始时对 标记所说的内容。

Edit: Example CDATA Block Usage

<?xml version="1.0" encoding="UTF-8" ?>
<myNode>
    <myData><![CDATA[
        Now I just throw in my data, for fun and profit!
        This way I can use special, reserved characters like <, > and &!
    ]]></myData>
</myNode>

Edit Yet Again:

Why not give Content-Type: text/xml, NOT application/xml, a go?

为什么不给Content-Type:text / xml,not application / xml,go?

#3

The answer is to put the asynchronous property in the function "open()" to false. Like this:

答案是将函数“open()”中的异步属性设置为false。喜欢这个:

ajaxObject.open("POST", "my_XML_Generator.php", false);
ajaxObject.setRequestHeader("Content-type", "text/xml");
ajaxObject.send();

#4

I had the same problem and couldn't solve it until I put my results into subnodes, e.g.

我遇到了同样的问题,直到我把结果放到子节点中才解决它,例如

header("Content-Type: text/xml; charset=utf-8");
echo("<?xml version='1.0' encoding='utf-8'?>\n");
echo("<summary>$summary</summary>\n");
echo("<content>$content</content>\n");

didn't work for me for some weird reason, but this does:

由于一些奇怪的原因,我没有为我工作,但这样做:

header("Content-Type: text/xml; charset=utf-8");
echo("<?xml version='1.0' encoding='utf-8'?>\n");
echo("<page>\n");
echo("    <summary>$summary</summary>\n");
echo("    <content>$content</content>\n");
echo("</page>\n");

My code retrieving the answer is

我的代码检索答案是

function retrieveRequest(title)
{
    if (_xmlRequest.readyState == 4 && _xmlRequest.status == 200)
    {
        var xmlResponse = _xmlRequest.responseXML;
        _divSummary.innerHTML = xmlResponse.getElementsByTagName("summary")[0].textContent;
        _divContent.innerHTML = xmlResponse.getElementsByTagName("content")[0].textContent;
    }
}

#5

I had this error happen to our team once and it took me a long time before we realized that the problem was in our XML data returned from the server. In particular, PHP script that generated return XML string was the culprit.

我有一次这个错误发生在我们的团队之前,我花了很长时间才意识到问题出在我们从服务器返回的XML数据中。特别是,生成返回XML字符串的PHP脚本是罪魁祸首。

My solution was to remove any white space from the beginning of the PHP script. I mean any spaces, new lines, and/or tabs need to be removed from the beginning of the script, so that the first thing in the script is the <?php tag itself. It turned out that the <?PHP tag was not the first thing on the first line of my PHP script; somehow I started my code on the second line and the first script line was simply an empty one.

我的解决方案是从PHP脚本的开头删除任何空格。我的意思是需要从脚本的开头删除任何空格,换行和/或制表符,这样脚本中的第一件事就是

It drove me mad and it took some time for me to figure this out, so I hope someone else can benefit from this solution. It is very simple and easy to try if all else fails.

它让我很生气,我花了一些时间才弄清楚这一点,所以我希望其他人可以从这个解决方案中受益。如果所有其他方法都失败,那么它非常简单易行。