how to convert json to xml with saxonjs? - node.js

Question

I need to convert a json to xml with saxonjs, I don't know how to match keys to xml nodes, I'm looking for some examples for none of them work for me, this is my code
const issue = {
id: 1,
details: {
type: 'urgent',
description: 'Description of issue comes here',
date: '2021-12-12',
}
};
saxonJS.transform({
stylesheetLocation: './issue.sef.json',
sourceType: 'json',
sourceText: issue,
destination: 'serialized',
}, 'async').then(data => {
fs.open('output.xml', 'w', function(err, fd) {
fs.write(fd, data.principalResult, (err2, bytes) => {
if(err2) {
console.log(err2);
}
});
});
res.status(200).send('Ok');
})
.catch(err => {
console.log(err);
res.status(500).send('error');
});
And this is the output I'm trying to achieve
<xml>
<issue id="1">
<description>
<![CDATA[
Description of issue comes here
]]>
</description>
<type>urgent</type>
<date>2021-12-12</date>
</issue>
</xml>
Can you please help me with the xslt template?

Answer 1

Your shown input is a JavaScript object, it is not JSON in the strict syntax rules of the JSON spec.
So I would think it is better to use JSON.stringify to create JSON and pass that to the XPath 3.1 function parse-json to create JSON or to make use of the Saxon-JS 2.3 feature to take JSON text, just make sure you have correctly JSON.stringifyed that object.
As for a sample XSLT, that looks easy, for readability of the XSLT the below sample just uses a JavaScript string with the XSLT source code and runs it through the Saxon API:
const SaxonJS = require("saxon-js");
const issue = {
id: 1,
details: {
type: 'urgent',
description: 'Description of issue comes here',
date: '2021-12-12',
}
};
const xslt = `<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="3.0" expand-text="yes">
<xsl:output indent="yes" cdata-section-elements="description"/>
<xsl:template match=".">
<xml>
<issue id="{?id}">
<description>{?details?description}</description>
<type>{?details?type}</type>
<date>{?details?date}</date>
</issue>
</xml>
</xsl:template>
</xsl:stylesheet>`;
const result = SaxonJS.XPath.evaluate(`transform(map {
'stylesheet-text' : $xslt,
'initial-match-selection' : parse-json($json),
'delivery-format' : 'serialized'
})?output`,
[],
{ params :
{
json : JSON.stringify(issue),
xslt : xslt
}
});
Of course, in the end you can first compile the XSLT to SEF/JSON and then run it as you tried.
To give you an example XSLT that uses two different templates and apply-templates, the following, instead of processing the nested object/map with inline code pushes processing it to a different template:
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="3.0" expand-text="yes" xmlns:map="http://www.w3.org/2005/xpath-functions/map" exclude-result-prefixes="#all">
<xsl:output indent="yes" cdata-section-elements="description"/>
<xsl:template match=".[. instance of map(*) and map:contains(., 'id')]">
<xml>
<issue id="{?id}">
<xsl:apply-templates select="?details"/>
</issue>
</xml>
</xsl:template>
<xsl:template match=".[. instance of map(*) and map:contains(., 'description')]">
<description>{?description}</description>
<type>{?type}</type>
<date>{?date}</date>
</xsl:template>
</xsl:stylesheet>