Reference namespace in same XSLT - xslt

Question

Trying to reference namespace to the same xslt with document('') but I get :
SystemID: file:/c:/intersystems/cache/mgr/samples/; Line#: 1; Column#: 1
net.sf.saxon.trans.XPathException: Error reported by XML parser
....
Caused by: org.xml.sax.SAXParseException; systemId: file:/c:/intersystems/cache/mgr/samples/; lineNumber: 1; columnNumber: 1; Content is not allowed in prolog.
at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(Unknown Source)
So it seems can not reference the same xslt? Is there some way to do this
<?xml version="1.0"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:fo="http://www.w3.org/1999/XSL/Format"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:fn="http://www.w3.org/2005/xpath-functions"
xmlns:xdt="http://www.w3.org/2005/xpath-datatypes" xmlns:csv="csv:csv">
<!-- <xsl:output method="text" version="4.0" encoding="iso-8859-1" indent="yes"/> -->
<xsl:strip-space elements="*" />
<xsl:output method="text" encoding="utf-8" />
<xsl:variable name="delimiter" select="','"/>
<csv:columns>
<column>GlobalID</column>
<column>ServicePointName</column>
</csv:columns>
<xsl:template match="/Report">
<!-- Output the CSV header -->
****<xsl:for-each select="document('')/*/csv:columns/*">****
<xsl:value-of select="."/>
<xsl:if test="position() != last()">
<xsl:value-of select="$delimiter"/>
</xsl:if>
</xsl:for-each>
<xsl:text>
</xsl:text>
<!-- Output rows for each matched Report -->
<xsl:apply-templates select="*" />
</xsl:template>
<xsl:template match="/Report/CLI">
<xsl:for-each select="//CLI">
<xsl:value-of select="GlobalID"/>
<xsl:value-of select="$delimiter"/>
<xsl:value-of select="ServicePointName"/>
<!-- Add a newline at the end of the record -->
<xsl:text>
</xsl:text>
</xsl:for-each>
</xsl:template>
</xsl:stylesheet>

Answer 1

Saxon 9 is an XSLT 2.0 processor - so you can easily do:
XSLT 2.0
<xsl:stylesheet version="2.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="text" encoding="UTF-8"/>
<xsl:variable name="delimiter" select="','"/>
<xsl:variable name="columns">
<column>GlobalID</column>
<column>ServicePointName</column>
</xsl:variable>
<xsl:template match="/">
<xsl:for-each select="$columns/*">
<xsl:value-of select="."/>
<xsl:if test="position() != last()">
<xsl:value-of select="$delimiter"/>
</xsl:if>
</xsl:for-each>
<xsl:text>
</xsl:text>
<!-- the rest -->
</xsl:template>
</xsl:stylesheet>
I don't see that you're using the columns further on in your stylesheet. If so, why don't you simplify the whole thing to:
<xsl:stylesheet version="2.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="text" encoding="UTF-8"/>
<xsl:template match="/">
<xsl:text>GlobalID,ServicePointName
</xsl:text>
<!-- the rest -->
</xsl:template>
</xsl:stylesheet>
(which is also XSLT 1.0 compatible).
None of this explains why your attempt to use an internal node wouldn't work.

Answer 2

I've never tried to do this, but just looking at the documentation for the document() function it says this:
document() Used to access the nodes in an external XML document
Edit: I jumped the gun as pointed out by comments below. There is another question facing the same problems:
XSLT document('') function doesn't work