XPTY0004: An empty sequence is not allowed as the value of variable while loading xslt using saxon templatefactory - xslt-1.0

Question

I updated the provided xslt to accept a param "multiplexpaths" from my source and assignin enter code here`g this to nodes variable in xslt to below:
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
exclude-result-prefixes="#all"
version="3.0">
<xsl:param name="multiplexpaths" as="xs:string" static="yes" />
<!-- xsl:param name="copy" as="xs:string" static="yes" select="'//other[. = 1345], //more[. = 2]'"/-->
<xsl:variable name="nodes" _select="{$multiplexpaths}"/>
<xsl:variable name="ancestors" select="$nodes/ancestor::*"/>
<xsl:mode on-no-match="shallow-skip"/>
<xsl:output method="xml" indent="yes"/>
<xsl:template match="$nodes">
<xsl:sequence select="."/>
</xsl:template>
<xsl:template match="$ancestors">
<xsl:copy>
<xsl:copy-of select="#*"/>
<xsl:apply-templates/>
</xsl:copy>
</xsl:template>
</xsl:stylesheet>

Answer 1

For the xsl:evaluate example, you would need to use Saxon 10 HE, 9.9 HE doesn't support xsl:evaluate.
As for setting a static parameter with Saxon 9.9 and s9api, a simple example is
String paths = "catalog/cd1,catalog/Test/value/a1";
Processor processor = new Processor(true);
XsltCompiler xsltCompiler = processor.newXsltCompiler();
xsltCompiler.setParameter(new QName("copy"), new XdmAtomicValue(paths));
XsltExecutable xsltExecutable = xsltCompiler.compile(new StreamSource("static-param-example2.xsl"));
Xslt30Transformer xslt30Transformer = xsltExecutable.load30();
xslt30Transformer.transform(new StreamSource("input-sample1.xml"), xslt30Transformer.newSerializer(System.out));
with the input-sample1.xml being
<catalog>
<cd1>
<name>abc</name>
<Stext>1234</Stext>
<Tag>uuuu</Tag>
</cd1>
<cd2>
<name>abc</name>
<Stext>1234</Stext>
<Tag>uuuu</Tag>
</cd2>
<Test>
<value>
<a1>123</a1>
<b1>77474</b1>
</value>
</Test>
</catalog>
and the XSLT
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
exclude-result-prefixes="#all"
version="3.0">
<xsl:param name="copy" as="xs:string" static="yes" select="'()'"/>
<xsl:variable name="nodes" _select="{$copy}"/>
<xsl:variable name="ancestors" select="$nodes/ancestor::*"/>
<xsl:mode on-no-match="shallow-skip"/>
<xsl:output method="xml" indent="yes"/>
<xsl:template match="$nodes">
<xsl:sequence select="."/>
</xsl:template>
<xsl:template match="$ancestors">
<xsl:copy>
<xsl:copy-of select="#*"/>
<xsl:apply-templates/>
</xsl:copy>
</xsl:template>
</xsl:stylesheet>
this outputs
<catalog>
<cd1>
<name>abc</name>
<Stext>1234</Stext>
<Tag>uuuu</Tag>
</cd1>
<Test>
<value>
<a1>123</a1>
</value>
</Test>
</catalog>
So the main point is to set the parameter on the XsltCompiler and not after compilation on the transformer.