xsl-list
[Top] [All Lists]

copy-of "canonicalization" behavior in Xalan (Java)

2004-07-22 23:04:26
The copy-of element when processed by Xalan (Java) appears to canonicalize the 
output, rather than output the source tree exactly.

For specific nodes in the source tree I would like to create an identical copy 
in the result tree, including redundant namespace
declarations.

Assume a source document like:

<foo:root xmlns:foo="http://abc.org/foo#"; xmlns:xyz="http://xyzinc.com/xyz#";>
        <foo:parent xmlns:foo="http://abc.org/foo#";>
                <foo:child xmlns:foo="http://abc.org/foo#";>more text</foo:child>
                <xyz:child xmlns:xyz="http://xyzinc.com/xyz#";>yet more 
text</xyz:child>
        </xyz:parent>
</foo:root>

The namespace declarations on the parent and child nodes are redundant (their 
namespace prefixes have been bound to a namespace on
the root node).

When I use copy-of, such as in the simple template below, in XML Spy using its 
built in XSLT processor the result tree is an exact
and complete copy of the source tree, redundant namespace declarations and all, 
as I would expect.

<xsl:template match ="/">
  <xsl:copy-of select="(.)"/>
</xsl:template>

(I have simplified the template in the extreme to make it clear.)

When I run the same template with the Xalan (Java) XSLT processor, which uses a 
SAX parser, I get a "cleaned", canonical form of the
source tree as my result, with all redundant namespace declarations removed.

This may appear to be a benefit, but I later manipulate parts of the result 
tree (which is much more complex than the simple
example) as separate XML fragments and at that point the namespace declarations 
are in fact no longer redundant but critical.

I have not been able to find anything in the Xalan documentation which suggests 
a way to avoid this canonicalization - perhaps its a
SAX issue? Is there a way to force Xalan to make an exact copy of the source 
tree, warts and all?


Thanks