The XML module of the DataType Utility allows you to take an XML document and convert it to a string.
To output an XML document as a string, simply call the format() function of the DataType.XML class:
YUI().use("datatype-xml", function(Y) {
var xmlString =
'<myroot>' +
'<item type="foo">' +
'<name>Abc</name>' +
'<rank>1</rank>' +
'</item>' +
'<item type="bar">' +
'<name>Def</name>' +
'<rank>2</rank>' +
'</item>' +
'<item type="bat">' +
'<name>Ghhi</name>' +
'<rank>3</rank>' +
'</item>' +
'</myroot>';
var myXMLDoc = Y.DataType.XML.parse(xmlString);
alert(Y.DataType.XML.format(myXMLDoc));
});