XSL Transform to Convert a WordPress Page/Post export XML to separate files and build a _data.json file (e.g. for converting sites to HarpJs / EJS)

convertWPtoEJS.xsl

<?xml version="1.0"?>
<!--
    Basic XSL transform to convert a WordPress "export" file into a set of separate files, one for each WordPress Page (or Post). This uses
    xsl:result-document and so needs an XSL 3.0 processor such as
    Michael Kay's SaxonHE. A typical command line would be:
    java -jar saxon9HE.jar <WORDPRESS-EXPORT-FILE>.xml convertWPtoEJS.xsl > _data.json
-->
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:content="http://purl.org/rss/1.0/modules/content/" version="2.0">
    <!-- The content is enclosed in CDATA, we want to output the raw text -->
    <xsl:output method="text" cdata-section-elements="content:encoded"/>

    <xsl:template match="/rss/channel">
        <xsl:text>{</xsl:text> <!-- start JSON standard output -->
        <xsl:for-each select="item">
            <!-- If the link element is not in a useful format consider the guid element instead-->
            <xsl:variable name="linkString" select="link" />
            <xsl:variable name="contentString" select="content:encoded" />
            <xsl:variable name="titleString" select="title" />
            <!-- This regex can be anything that you want to pick out of the 
                  link element, just make sure that it will be unique -->
            <xsl:analyze-string select="$linkString" regex="http://your-web-site.com/(.*)/$">
                <xsl:matching-substring>
                    <!-- You can add other parts to the (unique) filename here -->
                    <xsl:variable name="fileName">_<xsl:value-of select="regex-group(1)"/>.ejs</xsl:variable>     
                    <!-- This section copies the WP page content to a separate file -->
                    <xsl:result-document href="{$fileName}"  method="text">
                        <xsl:value-of select="$contentString"/>
                        <!-- You can also output other WordPress elements as required here, wrapping them in HTML if necessary, for
                        example dc:creator or wp:post_date. If these fields
                        are CDATA encoded remember to add them to the xsl:output
                        attribute above. -->
                    </xsl:result-document>
                    <!-- The following lines write a basic Harp JSON entry to standard output -->
                    <xsl:text>"</xsl:text>
                    <xsl:value-of select="$fileName" />
                    <xsl:text>": {</xsl:text>
                    <xsl:text>"pageTitle": "</xsl:text>
                    <xsl:value-of select="$titleString" />
                    <xsl:text>"},</xsl:text> <!-- PROBLEM! - need to remove final comma! -->
                </xsl:matching-substring>
            </xsl:analyze-string>
        </xsl:for-each>
        <!-- CHEAT SOLUTION! Add a final, dummy entry to the JSON -->
        <xsl:text>{"_dummy": ""}</xsl:text>
        <xsl:text>}</xsl:text> <!-- close JSON standard output -->
    </xsl:template>
</xsl:stylesheet>