XSLT (Extensible Stylesheet Language Transformations)¶

XSLT (Extensible Stylesheet Language Transformations) is a language used to transform and manipulate XML data. With XSLT, you have the capability to create rules and transformations that convert data documents into different formats or structures.

Example¶

Here's an example of an XML file, an XSLT stylesheet, and the resulting output in RDF format after applying the XSLT transformation. In this example, we'll transform a simple XML representation of books into RDF triples.

Input XML file (books.xml)¶

<?xml version="1.0" encoding="UTF-8"?>
<library>
  <book>
    <title>The Great Gatsby</title>
    <author>F. Scott Fitzgerald</author>
  </book>
  <book>
    <title>1984</title>
    <author>George Orwell</author>
  </book>
</library>

XSLT Stylesheet (books-to-rdf.xsl)¶

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:template match="/">
    <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
      <xsl:for-each select="library/book">
        <rdf:Description>
          <rdf:type rdf:resource="http://example.org/book" />
          <rdf:Description>
            <rdf:type rdf:resource="http://example.org/author" />
            <rdf:value>
              <xsl:value-of select="author" />
            </rdf:value>
          </rdf:Description>
          <rdf:title>
            <xsl:value-of select="title" />
          </rdf:title>
        </rdf:Description>
      </xsl:for-each>
    </rdf:RDF>
  </xsl:template>
</xsl:stylesheet>

Output RDF (result.rdf) after applying XSLT¶

<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
  <rdf:Description>
    <rdf:type rdf:resource="http://example.org/book" />
    <rdf:Description>
      <rdf:type rdf:resource="http://example.org/author" />
      <rdf:value>F. Scott Fitzgerald</rdf:value>
    </rdf:Description>
    <rdf:title>The Great Gatsby</rdf:title>
  </rdf:Description>
  <rdf:Description>
    <rdf:type rdf:resource="http://example.org/book" />
    <rdf:Description>
      <rdf:type rdf:resource="http://example.org/author" />
      <rdf:value>George Orwell</rdf:value>
    </rdf:Description>
    <rdf:title>1984</rdf:title>
  </rdf:Description>
</rdf:RDF>

Using XSLT in TriplyETL¶

In TriplyETL, XSLT processing is supported in the fromXML() and loadRdf() middlewares by providing an optional Source.file() to the stylesheet parameter that uses an XSL-XML Stylesheet. Below we will explain in steps how it can be used:

1. Create your XSLT stylesheet:

First, you need to create an XSLT stylesheet. This stylesheet defines the rules for transforming your XML data. It should have a .xslt or .xsl file extension. You can create this stylesheet using any text editor or XML/XSLT development tool.

2. Load the data and apply XSLT transformation using either fromXml() or loadRdf():

• fromXml() is used to load and transform xml to xml with different structure:

fromXml(Source.file(xml), {
  selectors: 'rdf:RDF.sdo:Person',
  stylesheet: Source.file(stylesheet),
})

• loadRdf() is used to load and transform xml to xml/rdf to internal store:

loadRdf(Source.file(xml), {
  contentType: 'application/rdf+xml',
  stylesheet: Source.file(xsl),
}),