Problem with Sending XML Requests
Question
Writing a basic XML file reader into an HTML page. I am having trouble reading from the XML file. Here's my set up: I have three text fields and a button. When the button is pressed, the request is put in to grab three pieces of XML and to populate the three text fields. However, I am running into trouble with the status of the request. I am getting the status code 0, instead of 200. According to my research (http://www.daniweb.com/web-development/javascript-dhtml-ajax/threads/282972), I think it has to do with cross domain blocking. I have tried putting the source XML both locally and on a server.
<html>
<head>
<script type="text/javascript">
function displayQuotes()
{
var xmlhttp;
xmlhttp=new XMLHttpRequest();
xmlhttp.onreadystatechange=function()
{
//if (xmlhttp.readyState==4 && xmlhttp.status==200)
//{
document.getElementById("quote1").innerHTML=xmlhttp.status;
//}
}
xmlhttp.open("GET","http://filebox.vt.edu/users/yiuleung/project5/letter.xml",true);
xmlhttp.send();
xmlDoc=xmlhttp.responseXML;
document.getElementById("quote1").innerHTML=
xmlDoc.getElementsByTagName("to")[0].childNodes[0].nodeValue;
document.getElementById("quote2").innerHTML=
xmlDoc.getElementsByTagName("from")[0].childNodes[0].nodeValue;
document.getElementById("quote3").innerHTML=
xmlDoc.getElementsByTagName("body")[0].childNodes[0].nodeValue;
}
</script>
</head>
<body>
<div id="quote1" style="margin:0;padding:0;position:absolute;left:65px;top:319px;width:250px;height:16px;text-align:left;z-index:2;">
<font style="font-size:13px" color="#000000" face="Arial">Quote 1</font></div>
<div id="quote2" style="margin:0;padding:0;position:absolute;left:65px;top:389px;width:250px;height:16px;text-align:left;z-index:3;">
<font style="font-size:13px" color="#000000" face="Arial">Quote 2</font></div>
<div id="quote3" style="margin:0;padding:0;position:absolute;left:65px;top:458px;width:250px;height:16px;text-align:left;z-index:4;">
<font style="font-size:13px" color="#000000" face="Arial">Quote 3</font></div>
<input type="button" id="shuffle_button" name="" value="Shuffle" onClick=displayQuotes() style="position:absolute;left:316px;top:228px;width:96px;height:25px;font-family:Arial;font-size:13px;z-index:10">
</body>
</html>
1 answers
solution1
2 2011-09-20 06:31:02
You use xmlhttp.open("GET","letter.xml",true); - it open XMLHttpRequest in async mode. But next two lines of your code expected to work in sync mode. You need to switch to sync mode: xmlhttp.open("GET","letter.xml",false); or (better) to modify code for work in async mode, as in example below:
function displayQuotes()
{
var xmlhttp;
xmlhttp=new XMLHttpRequest();
xmlhttp.open("GET","letter.xml",true);
xmlhttp.onreadystatechange=function() {
console.info(xmlhttp.readyState,"|",xmlhttp.status,"|",xmlhttp.statusText); // for debugging only
if(xmlhttp.readyState===4&&xmlhttp.status===200) {
// HTTP OK
xmlDoc=xmlhttp.responseXML; // maybe var xmlDoc ???
document.getElementById("quote1").innerHTML=
xmlDoc.getElementsByTagName("to")[0].childNodes[0].nodeValue;
document.getElementById("quote2").innerHTML=
xmlDoc.getElementsByTagName("from")[0].childNodes[0].nodeValue;
document.getElementById("quote3").innerHTML=
xmlDoc.getElementsByTagName("body")[0].childNodes[0].nodeValue;
}
};
xmlhttp.send(null);
}
Using XMLHttpRequest in MDN: https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest/Using_XMLHttpRequest
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