Re: [xsl] Inconsistency between XPath 1.0 and XSLT 1.0 treatment of processing instruction initial whitespace

[David Carlisle <davidc@xxxxxxxxx>]

[I killed xsl-list as you're not supposed to cc this list and another (and
  I got ticked off by our esteemed list owner last time I tried:-) ]

> In other words, the xsl:processing-instruction element appears able to 
> create processing instructions that are not legal in the XPath 1.0 data 
> model.

I don't think that's necessarily a problem for 1.0, it just means that

  <xsl:processing-instruction name="testcase">
This is the content of a PI
   </xsl:processing-instruction>


generates

<?testcase 
This is the content of a PI
   ?>

which if re-parsed produces some input equvalent to

<?testcase This is the content of a PI
   ?>

At no point is an inconsistent set of data produced, as XSLT 1
(unextended) can't query into the result tree fragment generated by the
xsl:processing-instruction.

However for xsl2 2...


<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"; version="2.0">

<xsl:template match="/">
<xsl:variable name="x">
   <xsl:processing-instruction name="testcase">
    This is the content of a PI
   </xsl:processing-instruction>
</xsl:variable>

[[<xsl:value-of select="$x//processing-instruction()"/>]]
</xsl:template>


</xsl:stylesheet>



$ saxon8 pi.xsl pi.xsl
<?xml version="1.0" encoding="UTF-8"?>

[[
    This is the content of a PI
   ]]


so it's generated a PI with leading white space, which again can't come
from parsing an XML file, but it doesn't seem to break any of the
constraints in:

http://www.w3.org/TR/xpath-datamodel/#ProcessingInstructionNode

(as there are no constraints:-)

so even here, this seems to be OK, I think, although it's not common in
xslt to be able to generate a result tree that can't be generated by
parsing an xml file.

The alternative I suppose would be for xsl:proccing-instruction to strip
any leading white space from its supplied content.


David

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