Chrome extension:Cannot call method 'getElementsByTagName' of null
- by T_t
Hi,i am beginner with chrome extension.There is simple problem.
There is the code in my extension,but it do not work.I don't know how to figure it out.
In my extension, i used a xml file to stroe some data.There is the
code in my background.html,but it do not work,i don't know how to
figure it out...
<!DOCTYPE html>
<html>
<head>
</head>
<body>
<script>
function loadXmlFile(){
var xmlDom = null;
var xmlhttp = new XMLHttpRequest();
if( xmlhttp ){
xmlhttp.onreadystatechange = function(){
if( xmlhttp.readyState == 4 ){
if( xmlhttp.status == 200 ){
xmlDom = xmlhttp.responseXML;
}
}
}
xmlhttp.open( "GET",chrome.extension.getURL("/xml/123.xml"),true);
xmlhttp.send( null );
}
return xmlDom;
}
var xmlDom = loadXmlFile();
var s = xmlDom.getElementsByTagName( "to" );
alert( s[0].nodeType );
</script>
</body>
</html>
I used developer tools to debug,but it says " Cannot call method
'getElementsByTagName' of null"...
who can help me?