Saxon » SaxonJS

DomUtils.nameoOfNode() treats elements in the namespace http://www.w3.org/1999/xhtml as a special case - returning a QName with a blank (@""@) URI. This of course has the advantage that within normal SaxonJS operation XPath expressions automatically apply to either HTML or XHTML elements in the document.

There are however some consequences of this:

1. Using a namespace prefix bound to http://www.w3.org/1999/xhtml within an XPath expression doesn't match elements within that namespace, as their name() is returned in the "" uri namespace, but this is checked against @http://www.w3.org/1999/xhtml@.

2. Setting the xpath-default-namespace="http://www.w3.org/1999/xhtml" has similar effect - no elements in that namespace are now retrieved from unprefixed names in an XPath expression

In cases where the XPath expression is dynamic, such as in xsl:evaluate or in the forthcoming XPath API, this becomes more complicated as it is still not possible to select XHTML elements via a bound prefix.