Question

我正在观看关于Ajax培训的新波士顿教程，我编写了与课程导师相同的代码。但是代码在我的电脑中不起作用。

在Google Chrome中

Uncaught TypeError: Cannot read property 'documentElement' of null
message = xmlHttp.responseXML.documentElement.firstChild.data;

在Firefox中

not-well formed bookname.php:5:8
echo '<response>';

的index.html

<body onload="process()">
    <h1>Users information</h1>
    Enter user_name you would want to know about:
    <input type="text" id="userInput" />
    <div id="underInput" />
</body>

bookname.php

<?php 
  header('Content-Type: text/xml');
  echo '<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>';

  echo '<response>';

  $name = $_GET['userName'];
  $nameArray = array('Mehrshad', 'Alex', 'Tom', 'Aydin');

  if(in_array($name, $nameArray)
  {
      echo 'I do know '. $name . '!';
  }
  else if($name == '')
  {
      echo 'Enter a name you want to know about';
  }
  else
  {
      echo 'Sorry we don\'t have user "'. $name . '" '
  }

  echo '</response>';

?>

bookname.js

var xmlHttp = createXmlHttpRequestObject();

function createXmlHttpRequestObject()
{
    var xmlHttp;

    if(window.ActiveXObject)
    {
        try {
            xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
        } catch(e) {
            xmlHttp = false;        
        }
    }
    else
    {
        try{
            xmlHttp = new XMLHttpRequest();     
        } catch(e) {
            xmlHttp = false;
        }   
    }

    if(!xmlHttp)
    {
        alert('can\'t create that object hoss!')
    }
    else
    {
        return xmlHttp;
    }

}

function process()
{
    if(xmlHttp.readyState == 4 || xmlHttp.readyState == 0)
    {
        username = encodeURIComponent(document.getElementById('userInput').value);
        xmlHttp.open("GET", "bookname.php?userName=" + username, true);
        xmlHttp.onreadystatechange = handleServerResponse;
        xmlHttp.send(null);
    }
    else
    {
        setTimeout('process()', 1000);
    }
}

function handleServerResponse()
{
    if(xmlHttp.readyState == 4)
    {
        if(xmlHttp.status == 200)
        {
            message = xmlHttp.responseXML.documentElement.firstChild.data;
            document.getElementById("underInput").innerHTML =
                '<span style="color: blue"' + message  + '</span>';
                setTimeout('process()', 1000);
        }
        else
        {
            alert('Something went wrong!');
        }
    }

}

Answer 1

你的php代码无效，因为：

您在;

echo 'Sorry we don\'t have user "'. $name . '" ';

)

if(in_array($name, $nameArray))

>

document.getElementById("underInput").innerHTML = '<span style="color: blue">' + message + '</span>';

Answer 2

我也正在运行相同的代码，但是显示了与上述相同的错误。请提出解决方案，因为我仍然没有犯上述错误，但仍然显示Uncaught TypeError：无法读取XMLHttpRequest.handleServerResponse的null属性'documentElement'。

Answer 3

http_request.overrideMimeType（'application / xml'）;当IAm在IE和chrome迁移之间进行修复时，为我工作了

Ajax，无法读取null的属性'documentElement'

3 个答案: