Question

22

responseXML is null

rated 0 times [ 26] [ 4] / answers: 1 / hits: 19602 / 13 Years ago, sun, august 7, 2011, 12:00:00

url = http://localhost/xml.php?type=xml;

if (window.XMLHttpRequest) {

      xmlhttp = new XMLHttpRequest();

      xmlhttp.open(GET, url, true);

      xmlhttp.setRequestHeader('Content-Type', 'application/xml');

      xmlhttp.send(null);

}

else if (window.ActiveXObject)  {

    xmlhttp=new ActiveXObject(Microsoft.XMLHTTP);

    if (xmlhttp) {

        xmlhttp.open(GET, url, true);

        xmlhttp.setRequestHeader('Content-Type', 'application/xml');

        xmlhttp.send();

    }

}



alert(xmlhttp.responseXML); //returns null

XML file

<?xml version=1.0 encoding=UTF-8 ?>

<main>

    <food>

        <type>6</type>

        <region>5676</region>

    </food>

    <food>

        <type>6</type>

        <region>5676</region>

    </food>



</main>

Anyone has idea why xmlhttp.responseXML is returning as null?

Answers

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brianaclaras

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4 Years ago

answered 13 Years ago dequant · Accepted Answer

Your HTTP request is asynchronous. xmlhttp.responseXML won't have some value until xmlhttp.readyState has the value of 4.

var url = http://localhost/xml.php?type=xml;

var xmlhttp;

if (window.XMLHttpRequest) {

      xmlhttp = new XMLHttpRequest();

}

else if (window.ActiveXObject)  {

    xmlhttp=new ActiveXObject(Microsoft.XMLHTTP);

}

if (xmlhttp) {

    xmlhttp.open(GET, url, true);

    xmlhttp.setRequestHeader('Content-Type', 'text/xml');

    xmlhttp.onreadystatechange = function () {

        if (xmlhttp.readyState == 4) {

            alert(xmlhttp.responseXML);

        }

    };

    xmlhttp.send();

}

Additionaly, I don't think you need the setRequestHeader line. XML MIME type is required for response, not for request. Also, please respect good coding practices (don't forget var, DRY, etc.)