XSLT 3.0 extract transformed nodes as multiple documents - xslt

Question

I have this XML structure
<doc>
<Bundle>
<entry>
<Observation>
<id value="o1-3" />
<subject>
<reference value="Subject/1" />
</subject>
<valueQuantity>
<value value="400" />
<unit value="U" />
</valueQuantity>
<referenceRange>
<low>
<value value="0" />
<unit value="U" />
</low>
<high>
<value value="45" />
<unit value="U" />
</high>
</referenceRange>
</Observation>
</entry>
<entry>
<Observation>
<id value="o8-3" />
<subject>
<reference value="Subject/1" />
</subject>
<valueQuantity>
<value value="0.39" />
<unit value="L" />
</valueQuantity>
<referenceRange>
<low>
<value value="0.14" />
<unit value="L" />
</low>
<high>
<value value="0.35" />
<unit value="L" />
</high>
</referenceRange>
</Observation>
</entry>
</Bundle>
<Bundle>
<entry>
<Observation>
<id value="o3-4" />
<subject>
<reference value="Subject/2" />
</subject>
<valueQuantity>
<value value="10" />
<unit value="U" />
</valueQuantity>
<referenceRange>
<low>
<value value="3" />
<unit value="U" />
</low>
<high>
<value value="30" />
<unit value="U" />
</high>
</referenceRange>
</Observation>
</entry>
<entry>
<Observation>
<id value="o15-4" />
<subject>
<reference value="Subject/2" />
</subject>
<valueQuantity>
<value value="7.1" />
<unit value="m" />
</valueQuantity>
<referenceRange>
<low>
<value value="3.5" />
<unit value="m" />
</low>
<high>
<value value="5.0" />
<unit value="m" />
</high>
</referenceRange>
</Observation>
</entry>
</Bundle>
</doc>
I am developing below mechanism:
Interpret if the valueQuantity is deviated from the referenceRange, if yes, transform the entry
Extract the Observation node grouped by Observation/subject as separate document.
A correctly interpreted Observation and extracted document is below:
<?xml version="1.0" encoding="UTF-8"?>
<Interpretation xmlns="http://intelli.org/interpretation">
<Subject>Subject/1</Subject>
<Observations>
<id value="o1-3"/>
<subject>
<reference value="Subject/1"/>
</subject>
<valueQuantity>
<value value="400"/>
<unit value="U"/>
</valueQuantity>
<referenceRange>
<low>
<value value="0"/>
<unit value="U"/>
</low>
<high>
<value value="45"/>
<unit value="U"/>
</high>
</referenceRange></Observations></Interpretation>
My XSLT:
<!-- Interpretation Starts -->
<xsl:template match="valueQuantity">
<xsl:param name="value" as="xs:double*" select="value/#value" />
<xsl:param name="low" as="xs:double*" select="following::referenceRange[1]/low/value/#value" />
<xsl:param name="high" as="xs:double*" select="following::referenceRange[1]/high/value/#value" />
<xsl:if test="$value lt $low or $value gt $high">
<xsl:element name="Interpretation">
</xsl:element>
</xsl:if>
<!-- Interpretation Ends -->
<!-- Identity Transform -->
<xsl:copy-of select="." />
<!-- Extraction Starts: Locality? -->
<xsl:for-each select="parent::Observation">
<xsl:result-document include-content-type="no" href="/interpret&extract/deviation/{concat('interpretation/', id/#value, '.xml')}">
<xsl:copy-of select="." />
</xsl:result-document>
</xsl:for-each>
</xsl:template>

Answer 1

I guess (because you haven't explained it clearly) that you're trying to write all the entry/valueQuantity elements that have the same value for entry/subject/reference to the same output file. The spec doesn't allow that (for a number of reasons: the results would depend on order of execution, parallel execution would become very difficult, and the resulting XML document would have no outer wrapper element).
Instead, do a separate pass over the input to generate this output file, using something like
<xsl:for-each-group select="entry" group-by="subject/reference/#value">
<xsl:result-document href="{...}">
<wrapper>
<xsl:copy-of select="current-group()"/>
</wrapper>
</xsl:result-document>
</xsl:for-each-group>