Robert Rolls wrote:


> I have some xml that has an IDREFs type holding multiple 
> IDs how do I get back a node list of the items? Do I have to manual parse 
> the attribute an dclaa nodeFromID or can I use an xpath expression 
> id(@hrefs)/* (or something similar)

As you have already seen the DOM in MSXML has nodeFromID to get from an 
ID value to a node but you are right, if you have an IDREFS attribute 
which has a space separated list of ID values then you first need to 
parse/split up that value into ID values to then be able to use 
nodeFromID on a single ID value.

As for XPath there it is indeed simpler, the id function is smart enough 
to process such a list to give you a node list (API) or node set (XSLT) 
back:

Example JScript program testing that feature:

var xmlDocument = new ActiveXObject('Msxml2.DOMDocument.4.0');
xmlDocument.async = false;
xmlDocument.validateOnParse = true;
var valid = xmlDocument.load('test2005070401.xml');
if (valid) {
   var nodeList = xmlDocument.selectNodes('id(/root/y[1]/@names)');
   alert(nodeList.length);
}

when applied to the XML below yields two for the node list length:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE root [
   <!ELEMENT root (x+, y+)>
   <!ELEMENT x EMPTY>
   <!ELEMENT y EMPTY>
   <!ATTLIST x
     name ID #REQUIRED>
   <!ATTLIST y
     names IDREFS #IMPLIED>
]>
<root>
   <x name="x1" />
   <x name="x2" />
   <y names="x1 x2" />
</root>


Only problem is that an XSLT processor is not required to use an XML 
parser reading external DTDs so relying on the use of the id function in 
XPath in XSLT is not portable in general, you need to make sure that the 
XSLT processor gets the information in the DTD.

-- 

	Martin Honnen --- MVP XML
	http://JavaScript.FAQTs.com/