XSL - Make element mandatory based on other element availability - xslt

Question

I am creating a XSD based on the below Xml using a XSL file. Actually I want to make Element2 block mandatory (minOccurs=1) only when Element1 block is available in each node (Sample, Sample1, etc..). If Element1 block is not available then Element2 block should become optional (minOccurs=0). I tried ancestor::[], match etc., but nothing is working. Please help.
Xml
<Root>
<Sample>
<Element1>
<SubElement1>0</SubElement1>
</Element1>
<Element2>
<X>1</X>
<Y>2</Y>
</Element2>
</Sample>
<Sample1>
<Element2>
<X>1</X>
<Y>2</Y>
</Element2>
</Sample1>
</Root>
XSL
<xsl:choose>
<xsl:when test="(local-name() = 'Element2' and //*[matches(local-name(), 'Element1')])">
<xs:element name="{local-name()}" minOccurs="1">
<xsl:call-template name="renderChildElements" />
</xs:element>
</xsl:when>
<xsl:otherwise>
<xs:element name="{local-name()}" minOccurs="0">
<xsl:call-template name="renderChildElements" />
</xs:element>
</xsl:otherwise>
</xsl:choose>
<xsl:template name="renderChildElements">
<xs:complexType>
<xs:all minOccurs="0">
<xsl:apply-templates select="*"/>
</xs:all>
<xsl:apply-templates select="#*"/>
</xs:complexType>
</xsl:template>

Answer 1

It sounds as if you only want to make Element2 have minOccurs="1" when it has an Element1 sibling?
The XPath //*[matches(local-name(), 'Element1')]) is using the descendant axis, so it is jumping up to the top of the XML tree and looking through the entire document to test whether there is an Element1 element.
Instead, you want to constrain it to just the elements under the Element2 parent: ..//*[local-name() eq 'Element1'] or if you just care about the children of the parent of Element2 you could use: ../*[local-name() eq 'Element1']
I think you can further simplify and consolidate, and move the conditional logic inside of the minOccurs attribute, using an attribute value template to compute the value of either 1 or 0:
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="2.0" xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xsl:output indent="yes"/>
<xsl:template match="*">
<xs:element name="{local-name()}"
minOccurs="{if (local-name() = 'Element2' and ..//*[local-name() eq 'Element1']) then 1 else 0}">
<xsl:call-template name="renderChildElements" />
</xs:element>
</xsl:template>
<xsl:template name="renderChildElements">
<xs:complexType>
<xs:all minOccurs="0">
<xsl:apply-templates select="*"/>
</xs:all>
<xsl:apply-templates select="#*"/>
</xs:complexType>
</xsl:template>
</xsl:stylesheet>