SaxonJS - Prevent Server Reloading When Stylesheet Changes - node.js

Question

I am using Saxon-JS to convert an XML file to an XSL-fo. I follow the documentation and leverage the xslt3 command to first compile an XSL file to a sef file such as:
"compile": "xslt3 -xsl:./src/styles/sample.xsl -export:sef/sample.sef.json -t -nogo -ns:##html5"
However, this causes an issue that the server needs to reload and compile the stylesheet whenever there is a change in stylesheet.
My question is: how to prevent the server from reloading when a change is made? Thank you in advance.

Answer 1

Using SaxonJS.XPath.evaluate('transform(...)', ..., { ... }) it is also possible to run XSLT directly. Whether that works and performs for you is something you would need to test, I don't know how complex your XSLT is, whether it has includes or imports, how large the input XML and how large the resulting XSL-FO is. But if the target format is XSL-FO and not HTML in the browser (although that way I don't understand the use of -ns:##html5) you might not need the interactive Saxon extensions that the xslt3 compilation supports and adds.
Simple example:
const SaxonJS = require("saxon-js")
const xml = `<root>
<item>a</item>
<item>b</item>
</root>`;
const xslt = `<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
version="3.0"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:fo="http://www.w3.org/1999/XSL/Format"
exclude-result-prefixes="xs"
expand-text="yes">
<xsl:output method="xml" indent="yes"/>
<xsl:mode on-no-match="shallow-copy"/>
<xsl:template match="/" name="xsl:initial-template">
<fo:root>
<fo:layout-master-set>
<fo:simple-page-master master-name="sample">
<fo:region-body/>
</fo:simple-page-master>
</fo:layout-master-set>
<fo:page-sequence master-reference="sample">
<fo:flow flow-name="xsl-region-body">
<fo:block>
<xsl:apply-templates/>
</fo:block>
</fo:flow>
</fo:page-sequence>
</fo:root>
</xsl:template>
<xsl:template match="root">
<fo:list-block>
<xsl:apply-templates/>
</fo:list-block>
</xsl:template>
<xsl:template match="item">
<fo:list-item>
<fo:list-item-label end-indent="label-end()">
<fo:block>
<xsl:number format="1."/>
</fo:block>
</fo:list-item-label>
<fo:list-item-body start-indent="body-start()">
<fo:block>
<xsl:apply-templates/>
</fo:block>
</fo:list-item-body>
</fo:list-item>
</xsl:template>
</xsl:stylesheet>`;
const result = SaxonJS.XPath.evaluate(
`transform(
map {
'stylesheet-text' : $xslt,
'source-node' : parse-xml($xml),
'delivery-format' : 'serialized'
}
)?output`,
[],
{ params : { 'xml' : xml, 'xslt' : xslt } }
);
console.log(result);