XSLT Transformer

The transformer takes as input xml data and the url of a xslt template and transforms the data in RDF. The xml data set must be sent to the transformer via HTTP POST with the url of the XSLT file as parameter. The transformer will return the result RDF data to the client. This transformer is used within FP-209 to transform XML data about events into RDF.

Try it out

The transformer can be started using the latest release that can be downloaded from the releases section. The executable jar file contains all the necessary dependencies. To start an instance of the transformer factory run the command

  java -jar p3-xslt-transformer-v1.0.0-20150505-jar-with-dependencies.jar

An instance of the XSLT transformer factory will be listening at the default port 8307. The port number can be changed, for example to use port number 7100, as follows

 java -jar p3-xslt-transformer-v1.0.0-20150505-jar-with-dependencies.jar -P 7100

Compiling and Running

Compile the Maven project running the command

mvn install

Start the component with

mvn exec:java

The default port number used by the transformer when started with Maven is set in the pom.xml file.

Usage

Some xslt files are bundled with the source code to run test in src/test/resources. The corresponding xslt transformations are available in the same folder and in the project repository on Github. The xslt url must be sent as a query parameter with 'xslt' as the parameter name. As an example we use a foo.xml file with just an element

<?xml version="1.0"?>
<doc>Monte Bondone Hotel</doc>

and an xslt file, foo.xsl, that transforms the xml into RDF/TURTLE

<?xml version="1.0"?>
  <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
  <xsl:output method="text" media-type="text/turtle" encoding="UTF-8"/>
  
  <xsl:template match="doc">
    @prefix rdf: &lt;http://www.w3.org/1999/02/22-rdf-syntax-ns#&gt; .
    @prefix rdfs: &lt;http://www.w3.org/2000/01/rdf-schema#&gt; .

    &lt;http://example.org/res1&gt; rdfs:label "<xsl:value-of select="."/>" .

  </xsl:template>
  
</xsl:stylesheet>

The output format in the xslt should always be specified as in the example. A test can be done with curl. If the xslt file is in a local folder (e.g. /home/user/ ) run the command

curl -i -X POST -H "Content-Type: application/xml" -d @foo.xml http://localhost:7100/?xslt=file:///home/user/foo.xsl

A "Content-Location" header can be passed to the transformer to be used as a parameter in the xsl transformation. The parameter name to use in the xsl is "locationHeader". This parameter can be used as a base for URIs. The curl command will be

curl -i -X POST -H "Content-Type: application/xml" -H "Content-Location: http://example.org" -d @foo.xml http://localhost:7100/?xslt=file:///home/user/foo.xsl 

If the xslt can be put in a web server, just use its http url in place of the file url. The xslt transformation is assumed to be synchronous by default and the result is sent to the client as soon as the transformation is done. In the example the result will be

@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .

<http://example.org/res1> rdfs:label "Monte Bondone Hotel" .