XSD2RDF

A tool to convert XML Schema (XSD) files into various RDF formats (SHACL, OWL, SKOS) with integrated validation capabilities.

Overview

XSD2RDF allows you to convert XML Schema definitions into:

• SHACL (Shapes Constraint Language) for RDF data validation
• OWL (Web Ontology Language) for ontology representation
• SKOS (Simple Knowledge Organization System) for concept schemes and taxonomies

Features

• Convert XSD to SHACL, OWL, and SKOS based on integrated principles
• SHACL shape constraints are linked to SKOS concept schemes when applicable
• Handle complex XSD structures (choices, unions, complex types, enumerations, etc.)
• SHACL shapes are validated according to SHACL-SHACL

This repository also includes a validation script to check RDF data against the generated SHACL shapes and SKOS concepts.

Current usage

This tool is currently used by ERA for the purpose of generating the telematics ontology in preparation to be merged with ERA ontology.

Installation

From PyPI

pip install xsd2rdf

From Source

git clone https://github.com/YourUsername/xsd2rdf.git
cd xsd2rdf
python -m pip install poetry
poetry install

Basic Usage

Convert an XSD file to all RDF formats (SHACL, OWL, SKOS):

python -m xsd2rdf -x path/to/schema.xsd

This generates the following files:

• schema.xsd.shape.ttl (SHACL shapes)
• schema.xsd.owl.ttl (OWL ontology)
• schema.xsd.*.skos.ttl (SKOS concept schemes, one file per enumeration)

Command Line Parameters

• -x, --XSD_FILE: XSD file to be converted
• -f, --FOLDER: Folder containing non-related XSD files to be converted
• -o, --OUTPUT_DIR: Output directory for generated files (default: same as XSD file)
• -a, --ABBREVIATIONS_FILE: File containing custom abbreviations, one per line
• -d, --debug: Enable debug output
• -nc, --namespaced-concepts: Use namespaced IRIs for SKOS concepts
• -un, --use-namespace: Override the XSD targetNamespace for generated SHACL, OWL and SKOS resources
• -ssv, --skipShaclValidation: Skip SHACL-SHACL validation
• -pkqi, --property-kind-qualified-iris: Append DP or OP to every property IRI according to its OWL property kind

Either -x or -f must be specified, but not both. If both are specified, -x takes precedence.

SKOS IRI Options

By default, SKOS concept IRIs are created using a flat structure:

targetnamespace/concepts/conceptschemename_conceptname

With the --namespaced-concepts flag, concepts use a hierarchical structure:

targetnamespace/concepts/conceptschemename/conceptname

Release new version CI/CD

The CI/CD script will automatically push a new version of the library to PyPi when a new Gitlab tag is created. As the tag name, use semantic versioning with 3 digits, examples: v1.2.3.

For user's convenience, best also add human readable release notes.

Examples

With custom output directory:

python -m xsd2rdf  -x path/to/schema.xsd -o output/directory

With folder containing multiple unrelated XSD files:

python -m xsd2rdf -f path/to/folder

Using a custom abbreviations file:

python -m xsd2rdf -x path/to/schema.xsd -a path/to/abbreviations.txt

A practical way to generate a list of abbreviations on a Windows machine using Powershell is with this command:

 Select-String -Path "c:\Users\mathi\Git\era\xsd2rdf\debug\SFERA_v3.00.xsd" -Pattern "\b[A-Z]{2,}\b" -AllMatches | ForEach-Object { $_.Matches } | ForEach-Object { $_.Value } | Where-Object { $_ -cmatch "^[A-Z]{2,}$" } | Sort-Object -Unique | Where-Object { $_.Length -ge 2 -and $_.Length -le 10 }

Using namespaced concept IRIs:

python -m xsd2rdf -x path/to/schema.xsd --namespaced-concepts

The abbreviations file should contain one abbreviation per line. These abbreviations will be preserved as uppercase when creating human-readable labels from camelCase or PascalCase strings.

Using a custom namespace instead of the XSD targetNamespace:

python -m xsd2rdf -x path/to/schema.xsd --use-namespace http://data.europa.eu/949/

Skipping SHACL-SHACL validation:

python -m xsd2rdf -x path/to/schema.xsd -ssv

Property-kind-qualified IRIs

Use --property-kind-qualified-iris to give every generated property IRI an explicit suffix based on its OWL property kind:

• datatype properties receive the DP suffix;
• object properties receive the OP suffix.

This is a global opt-in mode. It changes all generated property IRIs, not only IRIs that would otherwise be used as both datatype and object properties. The default mode remains unchanged for backwards compatibility.

For example, consider two complex types that both use an author element in the same xsd file, but with a different structure. A Book has an author name (simple string), while an Article references an author as a complete person object:

<xsd:complexType name="Book">
  <xsd:sequence>
    <xsd:element name="title" type="xsd:string"/>
    <xsd:element name="author" type="xsd:string"/>
  </xsd:sequence>
</xsd:complexType>

<xsd:complexType name="Article">
  <xsd:sequence>
    <xsd:element name="title" type="xsd:string"/>
    <xsd:element name="author" type="PersonType"/>
  </xsd:sequence>
</xsd:complexType>

<xsd:complexType name="PersonType">
  <xsd:sequence>
    <xsd:element name="firstName" type="xsd:string"/>
    <xsd:element name="lastName" type="xsd:string"/>
  </xsd:sequence>
</xsd:complexType>

With property-kind qualification enabled, their SHACL paths and OWL property IRIs are distinct:

sh:path ex:authorDP .
ex:authorDP a owl:DatatypeProperty .

sh:path ex:authorOP .
ex:authorOP a owl:ObjectProperty .

Enable the mode with:

python -m xsd2rdf \
  -x path/to/schema.xsd \
  --property-kind-qualified-iris

Development validation

This feature is only available from source as it is meant for development purposes.

Prerequisites:

• Create sample data for validation schema.xsd.shape.ttl in the same directory as the xsd file

To validate RDF data against SHACL shapes with SKOS concepts:

python shacl-validation.py path/to/schema.xsd

This result will:

1. Load the data from schema.xsd.sample.ttl
2. Include all related SKOS files (schema.xsd.*.skos.ttl)
3. Perform validation using the generated SHACL shapes (schema.xsd.shape.ttl)
4. Report results in the command line

Wiki Pages

Some wiki pages explain the inner workings of the convertor and the list of mapping rules implemented within the tool.

License

EUPL 1.2