XOM API for Processing XML with Java

[Wolfgang Hoschek <whoschek AT lbl.gov>]

On Jul 9, 2005, at 12:04 AM, Michael Kay wrote:

> > For the W3C XQuery Serialization spec, all result sequence nodes to
> > be serialized may be parentless, except attributes and namespaces.
> > Should be easy to fix as far as I can see...
>
> Actually, the restriction on serializing attribute nodes and  
> namespace nodes
> in that spec applies whether or not they have a parent.
>
> Essentially the spec says that if you want to serialize anything  
> other than
> a document, you wrap a document node around it, as in
> <xsl:document><xsl:copy-of select="$seq"/></xsl:document>; and this  
> throws
> an error if $seq contains attribute or namespace nodes.

Right. Already the sequence normalization algorithm throws  
appropriate exceptions for attributes and namespace nodes:

            if (node instanceof Attribute) {
                throw new XMLException(
                "SE0001: W3C XQuery Serialization spec forbids top- 
level attributes");
            }
            if (node instanceof Namespace) {
                throw new XMLException(
                "SE0001: W3C XQuery Serialization spec forbids top- 
level namespaces");
            }

I'm of course not wrapping a real document around the nodes; For  
efficiency I'm directly writing the normalized sequence via

        private void write(Nodes nodes) throws IOException {
            writeXMLDeclaration();

            int size = nodes.size();
            for (int i=0; i < size; i++) {
                writeChild(nodes.get(i));
                if (getIndent() > 0) breakLine();
            }

            flush();
        }

Everything works like a charm here. (For parentless text nodes, I had  
to add the parent == null check in Serializer.isBoundaryWhitespace as  
discussed previously.)