[SOLVED] XSLT 3.0 stylesheet compilation error with accumulator

XSLT 3.0 stylesheet compilation error with accumulator

I'm trying to transform my XML so I can easily convert it to JSON in a sap integration process. I'm getting a stylesheet compilation error and I cant figure out why. Here is my XML:

<groups>
        <UserGroup>
                <integrationKey>xxa</integrationKey>
                <uid>001</uid>]
        </UserGroup>
        <UserGroup>
                <integrationKey>xxb</integrationKey>
                <uid>002</uid>
        </UserGroup>
</groups>

Here is my XSLT:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="3.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:accumulator name="UserGroupCounter" as="xs:integer" initial-value="0">
        <xsl:accumulator-rule match="//groups" select="0"/>
        <xsl:accumulator-rule match="//groups/UserGroup" select="$value + 1"/>
    </xsl:accumulator>
  
    <xsl:template match="UserGroup">
        <xsl:copy>
            <xsl:attribute name="userGroupIndex" select="accumulator-before('UserGroupCounter')"/>
            <xsl:apply-templates/>
        </xsl:copy>
    </xsl:template>

    <xsl:mode on-no-match="shallow-copy" use-accumulators="UserGroupCounter"/>
</xsl:stylesheet>

I get an error even when I try only declare the accumulator. Here is the error text:

[CAMEL][IFLOW][EXCEPTION] : org.apache.camel.FailedToCreateRouteException: Failed to create route Process_817351: Route(Process_817351)[[From[direct:Process_817351]] -> [To[o... because of net.sf.saxon.s9api.SaxonApiException: Errors were reported during stylesheet compilation
  [CAMEL][IFLOW][CAUSE] : Cause: javax.xml.transform.TransformerConfigurationException: net.sf.saxon.s9api.SaxonApiException: Errors were reported during stylesheet compilation
    [CAMEL][IFLOW][CAUSE] : Cause: net.sf.saxon.s9api.SaxonApiException: Errors were reported during stylesheet compilation
      [CAMEL][IFLOW][CAUSE] : Cause: net.sf.saxon.trans.XPathException: Errors were reported during stylesheet compilation

I have tried changing the pattern to things like //groups/UserGroup etc but nothing seems to work. I've tried limiting the XSLT to just:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="3.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:accumulator name="UserGroupCounter" as="xs:integer" initial-value="0">
    </xsl:accumulator>

Still erroring. What should I do?

Solution

You need to declare the schema namespace for the xs prefix that is used for the integer type declaration:

xmlns:xs="http://www.w3.org/2001/XMLSchema"

Either add to the xsl:accumulator element or above on the xsl:stylesheet element.