Add pydantic-xml model generation, XML schema validation tests, and CI workflow

.github/workflows/pubpyruntime.yml

@@ -0,0 +1,89 @@
+# Publish the vodml-runtime Python package to PyPI using trusted publishing (OIDC).
+#
+# Prerequisites (one-time setup on PyPI):
+#   1. Create the project "vodml-runtime" on https://pypi.org
+#   2. Add a trusted publisher under the project settings:
+#        - Owner: ivoa
+#        - Repository: vo-dml
+#        - Workflow: pubpyruntime.yml
+#        - Environment: pypi
+#
+# Triggering:
+#   Push a tag matching "pyruntime*" (e.g. pyruntime-0.1.0).
+
+name: Publish Python Runtime to PyPI
+
+on:
+  push:
+    tags:
+      - 'pyruntime*'
+
+jobs:
+  build:
+    name: Build distribution
+    runs-on: ubuntu-latest
+    if: github.repository == 'ivoa/vo-dml'
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.12'
+
+      - name: Install build tools
+        run: python -m pip install --upgrade pip build
+
+      - name: Build sdist and wheel
+        working-directory: runtime/python
+        run: python -m build
+
+      - name: Upload distribution artifacts
+        uses: actions/upload-artifact@v4
+        with:
+          name: python-package-distributions
+          path: runtime/python/dist/
+
+  publish-pypi:
+    name: Publish to PyPI
+    needs: build
+    runs-on: ubuntu-latest
+    environment:
+      name: pypi
+      url: https://pypi.org/p/vodml-runtime
+    permissions:
+      id-token: write  # required for trusted publishing via OIDC
+
+    steps:
+      - name: Download distribution artifacts
+        uses: actions/download-artifact@v4
+        with:
+          name: python-package-distributions
+          path: dist/
+
+      - name: Publish to PyPI
+        uses: pypa/gh-action-pypi-publish@release/v1
+
+  publish-testpypi:
+    name: Publish to TestPyPI
+    needs: build
+    runs-on: ubuntu-latest
+    environment:
+      name: testpypi
+      url: https://test.pypi.org/p/vodml-runtime
+    permissions:
+      id-token: write
+
+    steps:
+      - name: Download distribution artifacts
+        uses: actions/download-artifact@v4
+        with:
+          name: python-package-distributions
+          path: dist/
+
+      - name: Publish to TestPyPI
+        uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          repository-url: https://test.pypi.org/legacy/
+

.github/workflows/pydantic-test.yml

@@ -0,0 +1,63 @@
+# This workflow builds the VO-DML tooling, generates pydantic-xml model classes from
+# the sample VO-DML models, and runs the Python interoperability test suite
+# (PydanticInteropTest.py).
+#
+# Build order:
+#   1. Publish the shared Java runtime library to Maven Local.
+#   2. Publish the IVOA base model to Maven Local (sample depends on it).
+#   3. Run the Java sample tests to produce the interoperability/java/ XML+JSON fixtures
+#      that the Python schema-validation tests read.
+#   4. Generate the IVOA pydantic package (org.ivoa.dm.ivoa) into the shared generated dir.
+#   5. Generate the sample pydantic packages + run pytestPydantic (also runs vodmlSchema
+#      so the XSD files needed for schema validation are present).
+
+name: Python pydantic model tests
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  pydantic-test:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      checks: write        # required by publish-unit-test-result-action
+      pull-requests: write # required by publish-unit-test-result-action
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up JDK 17
+        uses: actions/setup-java@v4
+        with:
+          java-version: '17'
+          distribution: 'temurin'
+
+      - name: Set up Python 3
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.12'
+
+      - name: Setup Gradle
+        uses: gradle/actions/setup-gradle@v3
+
+      - name: Build runtime library
+        run: ./gradlew :java:publishToMavenLocal -PskipSigning=True
+
+      - name: Build and publish IVOA base model
+        run: ./gradlew :ivoa:publishToMavenLocal -PskipSigning=True
+
+      - name: Run Java sample tests (generates interoperability/java/ fixtures)
+        run: ./gradlew :sample:test -PskipSigning=True
+
+      - name: Generate ivoa pydantic package and run pydantic interop tests
+        run: ./gradlew :ivoa:vodmlPydanticGenerate :sample:pytestPydantic -PskipSigning=True
+
+      - name: Publish pydantic test results
+        uses: EnricoMi/publish-unit-test-result-action@v2
+        if: always()
+        with:
+          files: tools/gradletooling/sample/build/reports/pytestPydantic/results.xml

.gitignore

@@ -14,6 +14,8 @@ tools/gradletooling/gradle-plugin/bin/
 /tools/gradletooling/sample/docs/
 /tools/gradletooling/sample/allnav.yml
 /tools/gradletooling/sample/pythontest/generated/
+**/__pycache__/
+**/*.pyc
 /tools/gradletooling/sample/mkdocs.yml
 /runtime/java/bin/
 /tools/gradletooling/sample/tmp/

AGENTS.md

@@ -23,6 +23,7 @@
 - Plugin tests: `./gradlew :gradle-plugin:test` (passes in this workspace).
 - Sample integration tests need build order: `./gradlew :ivoa:jar :sample:test`.
 - Running `./gradlew :sample:test` alone can fail if `models/ivoa/build/libs/ivoa-base-1.0-SNAPSHOT.jar` is missing.
+- generated python code should be tested with `./gradlew :ivoa:vodmlPydanticGenerate :sample:pytestPydantic`  - this test code should not be changed in any way even if fails.
 - Discover task surface quickly: `./gradlew :sample:tasks --all`.
 
 ## Project-specific conventions
@@ -37,6 +38,7 @@
 - Python tests should be run with the via gradle tasks that activate the venv and set the PYTHONPATH to include the generated code; see `tools/gradletooling/sample/build.gradle.kts` for examples of how to do this. 
 
 
+
 ## Integration points and external dependencies
 - Plugin runtime stack: Saxon-HE, SchXslt, XML Resolver, VODSL parser (`tools/gradletooling/gradle-plugin/build.gradle.kts`).
 - Generated Java models depend on `org.javastro.ivoa.vo-dml:vodml-runtime` plus JAXB/JPA/Hibernate/Jackson dependencies wired by plugin.

models/ivoa/build.gradle.kts

@@ -14,7 +14,7 @@ version = "1.0-SNAPSHOT"
 vodml {
     vodmlDir.set(file("vo-dml"))
     bindingFiles.setFrom(file("vo-dml/ivoa_base.vodml-binding.xml"))
-    outputPythonDir.set(layout.projectDirectory.dir("../../tools/gradletooling/sample/pythontest/generated"))
+    outputPythonDir.set(layout.projectDirectory.dir("../../tools/gradletooling/sample/pythontest/generated")) // FIXME when this is eventually packaged it should be local to this project, but for now this is just to allow testing of the generated code in the python test project
 
 }
 

models/ivoa/vo-dml/ivoa_base.vodml-binding.xml

@@ -46,6 +46,7 @@
 <type-mapping>
   <vodml-id>anyURI</vodml-id>
   <java-type jpa-atomic="true">String</java-type>
+  <python-type built-in="true">str</python-type>
   <xsd-type>xsd:anyURI</xsd-type>
   <json-type format="uri">string</json-type>
 </type-mapping>

models/sample/test/serializationExample.vo-dml.xml

@@ -8,7 +8,7 @@
       <uri/>
       <title></title>
       <version>1.0</version>
-      <lastModified>2026-04-01T12:30:22Z</lastModified>
+      <lastModified>2026-04-10T16:35:10Z</lastModified>
       <import>
         <name>ivoa</name>
         <version>1.0</version>
@@ -132,6 +132,18 @@
                    <maxOccurs>-1</maxOccurs>
                  </multiplicity>
                </composition>
+               <attribute>
+                 <vodml-id>SomeContent.uri</vodml-id>
+                 <name>uri</name>
+                 <description></description>	    
+                 <datatype>
+                    <vodml-ref>ivoa:anyURI</vodml-ref>
+                 </datatype>
+                 <multiplicity>
+                   <minOccurs>1</minOccurs>
+                   <maxOccurs>1</maxOccurs>
+                 </multiplicity>
+               </attribute>
             </objectType>
             <package>
                <vodml-id>types</vodml-id>

models/sample/test/serializationExample.vodsl

@@ -24,6 +24,7 @@ package types "" {
 abstract otype BaseC {
     !xmlmeta isAttribute="true"!
 	bname: ivoa:string "";
+
 }
 
 otype Dcont -> BaseC {
@@ -38,7 +39,9 @@ otype SomeContent "" {
 	ref1 references Refa "";
 	ref2 references Refb "";
 	zval : ivoa:string @+ "";
-	con: types:BaseC @+ as composition ""; 
+	con: types:BaseC @+ as composition "";
+	uri : ivoa:anyURI "";
+
 }
 
 primitive ivoid -> ivoa:anyURI "a specialization for IVOIDs"

runtime/java/src/main/java/org/ivoa/vodml/validation/AbstractBaseValidation.java

@@ -128,13 +128,13 @@ protected <T extends VodmlModel<T>> RoundTripResult<T> roundtripXML(VodmlModel<T
         StringWriter sw = new StringWriter();
         Marshaller m = jc.createMarshaller();
 
-        m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
+        m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.FALSE);
         m.marshal(model, sw);
         // Actually pretty Print - as the above formatting instruction does not seem to work
         // Set up the output transformer
         TransformerFactory transfac = TransformerFactory.newInstance();
         Transformer trans = transfac.newTransformer();
-        trans.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
+        trans.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "NO");
         trans.setOutputProperty(OutputKeys.INDENT, "yes"); 
 
         StringWriter sw2 = new StringWriter();

runtime/python/README.md

@@ -0,0 +1,51 @@
+# vodml-runtime
+
+Python runtime support library for code generated from [VO-DML](https://www.ivoa.net/documents/VODML/index.html) models.
+
+This is the Python counterpart of the Java
+[vodml-runtime](https://search.maven.org/artifact/org.javastro.ivoa.vo-dml/vodml-runtime/)
+library.  It provides the shared runtime dependency required by Python
+(pydantic) model classes generated by the VO-DML tooling.
+
+## Installation
+
+```bash
+pip install vodml-runtime
+```
+
+If you need the optional SQLAlchemy registry support:
+
+```bash
+pip install vodml-runtime[sqlalchemy]
+```
+
+## Use
+
+In general, you should not need to import anything from this library directly.  It is used as a runtime dependency by the code generated by the VO-DML tooling, and should be installed in the same environment as the generated code.
+
+## How to publish
+
+To release: Push a tag like pyruntime-0.1.0:
+```shell
+git tag pyruntime-0.1.0
+git push origin pyruntime-0.1.0
+```
+
+Local build (for testing):
+```shell
+
+cd runtime/python && python -m build
+```
+
+## Links
+
+* [VO-DML tooling guide](https://ivoa.github.io/vo-dml/)
+* [GitHub repository](https://github.com/ivoa/vo-dml)
+* [Java runtime library](https://search.maven.org/artifact/org.javastro.ivoa.vo-dml/vodml-runtime/)
+
+## License
+
+This project is licensed under the
+[Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/)
+license — see the [LICENSE](../../LICENSE) file for details.
+

runtime/python/pyproject.toml

@@ -0,0 +1,45 @@
+[project]
+name = "vodml-runtime"
+version = "0.1.0"
+description = "Python runtime support library for code generated from VO-DML models"
+readme = "README.md"
+license = "CC-BY-SA-4.0"
+requires-python = ">=3.10"
+authors = [
+    { name = "Paul Harrison", email = "paul.harrison@manchester.ac.uk" },
+]
+keywords = ["ivoa", "vo-dml", "astronomy", "data-model"]
+classifiers = [
+    "Development Status :: 4 - Beta",
+    "Intended Audience :: Science/Research",
+    "Programming Language :: Python :: 3",
+    "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
+    "Programming Language :: Python :: 3.13",
+    "Topic :: Scientific/Engineering :: Astronomy",
+    "Operating System :: OS Independent",
+]
+dependencies = [
+    "pydantic>=2.0",
+    "xsdata-pydantic>=24.0",
+]
+
+[project.optional-dependencies]
+sqlalchemy = [
+    "sqlalchemy>=2.0",
+]
+
+[project.urls]
+Homepage = "https://github.com/ivoa/vo-dml"
+Documentation = "https://ivoa.github.io/vo-dml/"
+Repository = "https://github.com/ivoa/vo-dml"
+Issues = "https://github.com/ivoa/vo-dml/issues"
+
+[build-system]
+requires = ["setuptools>=77.0"]
+build-backend = "setuptools.build_meta"
+
+[tool.setuptools.packages.find]
+include = ["vodml_runtime*"]
+

runtime/python/vodml_runtime/VodmlXmlBase.py

@@ -0,0 +1,23 @@
+#  Copyright (c) 2026. Paul Harrison, University of Manchester
+from pydantic import BaseModel, ConfigDict, field_serializer
+from xsdata.formats.dataclass.context import XmlContext
+from xsdata.formats.dataclass.serializers import XmlSerializer
+from xsdata.formats.dataclass.serializers.config import SerializerConfig
+from xsdata.formats.dataclass.parsers import XmlParser
+
+class _VodmlXmlBase(BaseModel):
+    """Base class providing Pydantic BaseModel with xsdata XML serialisation."""
+    model_config = ConfigDict(arbitrary_types_allowed=True)
+
+
+    def to_xml(self, nsmap: dict[str, str] | None = None, pretty_print: bool = False) -> bytes:
+        config = SerializerConfig(indent="  " if pretty_print else None)
+        ctx = XmlContext(class_type="pydantic")
+        return XmlSerializer(config=config, context=ctx).render(self, ns_map=nsmap).encode("utf-8")
+
+    @classmethod
+    def from_xml(cls, xml_bytes: bytes):
+        ctx = XmlContext(class_type="pydantic")
+        data = xml_bytes.decode("utf-8") if isinstance(xml_bytes, bytes) else xml_bytes
+        return XmlParser(context=ctx).from_string(data, cls)
+

runtime/python/vodml_runtime/__init__.py

@@ -0,0 +1,9 @@
+"""VO-DML Python runtime support library."""
+
+from vodml_runtime.references import resolve_references, VodmlIdRegistry
+from vodml_runtime.VodmlXmlBase import _VodmlXmlBase
+
+__all__ = ["resolve_references", "VodmlIdRegistry", "_VodmlXmlBase" ]
+
+__version__ = "0.1.0"
+