feat: Schematron validation using Saxon Home Edition (Java)

.gitattributes

@@ -3,13 +3,14 @@
 /.gitignore export-ignore
 /CHANGELOG.md export-ignore
 /CONTRIBUTING.md export-ignore
-/doc export-ignore
+/docs export-ignore
 /tools export-ignore
-/Makefile export-ignore
 /phpunit.xml.dist export-ignore
+/phpunit.xml export-ignore
 /tests export-ignore
 /VERSIONING.md export-ignore
 /.php-cs-fixer.php export-ignore
 /rector.php export-ignore
 /phpstan.neon.dist export-ignore
-/phpstan-baseline.neon export-ignore
+/phpstan-baseline.neon export-ignore
+/Dockerfile export-ignore

.github/workflows/tests.yml

@@ -21,6 +21,32 @@ jobs:
               with:
                   php-version: ${{ matrix.php-versions }}
 
+            - name: Cache Saxon HE
+              uses: actions/cache@v5
+              id: saxon-cache
+              with:
+                  path: saxon
+                  key: saxon-he-12.9
+
+            - name: Download Saxon HE 12.9
+              id: saxon_download
+              if: steps.saxon-cache.outputs.cache-hit != 'true'
+              run: |
+                  SAXON_ZIP_URL="https://github.com/Saxonica/Saxon-HE/releases/download/SaxonHE12-9/SaxonHE12-9J.zip"
+                  curl -L -o saxon.zip "$SAXON_ZIP_URL"
+                  unzip -q saxon.zip -d saxon
+                  rm saxon.zip
+
+            - name: Set Saxon JAR path
+              run: |
+                  SAXON_JAR=$(find saxon -type f -name "saxon-he-12.9.jar" | head -n 1)
+                  if [ -z "$SAXON_JAR" ]; then
+                    echo "⚠️ JAR Saxon not found!"
+                    exit 1
+                  fi
+                  echo "SAXON_JAR=$SAXON_JAR" >> $GITHUB_ENV
+                  echo "Saxon JAR path: $SAXON_JAR"
+
             - uses: "ramsey/composer-install@v3"
 
             - name: Run test suite

Dockerfile

@@ -0,0 +1,36 @@
+# Use PHP 8.3 CLI as base image
+FROM php:8.3-cli
+
+# Install system dependencies and PHP extensions
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends \
+        git \
+        unzip \
+        curl \
+        ca-certificates \
+        libzip-dev \
+        libicu-dev \
+        libxml2-dev \
+        default-jre \
+        wget \
+    && docker-php-ext-install intl zip dom xml \
+    && rm -rf /var/lib/apt/lists/*
+
+# Install Composer
+COPY --from=composer:2 /usr/bin/composer /usr/bin/composer
+
+# Set working directory
+WORKDIR /app
+
+# Install Saxon Home edition for Java
+RUN wget -nv "https://github.com/Saxonica/Saxon-HE/releases/download/SaxonHE12-9/SaxonHE12-9J.zip" -O /tmp/saxon.zip && \
+    unzip /tmp/saxon.zip -d /opt/saxon && \
+    rm /tmp/saxon.zip
+
+ENV PATH="/opt/saxon/bin:${PATH}"
+
+ENV SAXON_JAR="/opt/saxon/saxon-he-12.9.jar"
+
+
+
+

composer.json

@@ -22,7 +22,8 @@
         "friendsofphp/php-cs-fixer": "^3.93",
         "phpunit/phpunit": "^12.5",
         "ext-libxml": "*",
-        "ext-dom": "*"
+        "ext-dom": "*",
+        "symfony/process": "^7.4"
     },
     "scripts": {
         "cs-fix": "php-cs-fixer fix",

docs/SaxonJarSchematronValidator.md

@@ -0,0 +1,80 @@
+# SaxonJarSchematronValidator
+
+The `SaxonJarSchematronValidator` is a Schematron validator implementation that uses the Saxon XSLT processor (Java edition) to validate XML documents against Schematron rules compiled as XSLT stylesheets.
+
+## Overview
+
+Schematron is a rule-based validation language for XML documents. Unlike XSD (XML Schema Definition), which validates structure, Schematron validates business rules and constraints using XPath expressions.
+
+In this implementation:
+1. Schematron rules are pre-compiled into an XSLT stylesheet
+2. Saxon XSLT processor transforms the XML document using the XSLT rules
+3. The output is an SVRL (Schematron Validation Report Language) document
+4. Failed assertions are extracted and reported as validation errors
+
+## Requirements
+
+### System Requirements
+
+- **Java Runtime Environment (JRE)** 8 or higher
+  - The `java` command must be available in your system PATH
+  - Check with: `java -version`
+
+- **Saxon-HE JAR file** (Home Edition, version 9.x or higher)
+  - Download from: [Saxonica Downloads](https://www.saxonica.com/download/java.xml)
+
+### PHP Requirements
+
+- **PHP 8.3** or higher
+- **Required PHP extensions:**
+  - `dom` - for parsing SVRL XML output
+  - `libxml` - for XML handling
+
+### Composer Dependencies
+
+```bash
+composer require symfony/process
+```
+
+The `symfony/process` component is used to execute the Java Saxon processor as a subprocess.
+
+## Usage
+
+### Basic Usage
+
+```php
+<?php
+
+use TiimePDP\CrossDomainAcknowledgementAndResponse\Schematron\SaxonJarSchematronValidator;
+use TiimePDP\CrossDomainAcknowledgementAndResponse\Schematron\ValidationFailedException;
+
+// Create validator instance with path to Saxon JAR
+$validator = new SaxonJarSchematronValidator(
+    saxonJar: '/usr/local/lib/saxon-he.jar'
+);
+
+try {
+    // Validate XML file against Schematron XSLT rules
+    $validator->validate(
+        xmlFilepath: '/path/to/document.xml',
+        xsltFilepath: '/path/to/schematron-rules.xsl'
+    );
+
+    echo "Validation successful!\n";
+
+} catch (ValidationFailedException $e) {
+    echo "Validation failed: " . $e->getMessage() . "\n";
+
+    // Access validation errors
+    foreach ($e->errors as $error) {
+        echo sprintf(
+            "Error [%s]: %s\n  Location: %s\n  Test: %s\n",
+            $error->getId(),
+            $error->getText(),
+            $error->getLocation(),
+            $error->getTest()
+        );
+    }
+}
+```
+

src/Schematron/SaxonJarSchematronValidator.php

@@ -0,0 +1,95 @@
+<?php
+
+declare(strict_types=1);
+
+namespace TiimePDP\CrossDomainAcknowledgementAndResponse\Schematron;
+
+use Symfony\Component\Process\Process;
+
+final readonly class SaxonJarSchematronValidator implements SchematronValidatorInterface
+{
+    /**
+     * @throws \LogicException
+     */
+    public function __construct(private string $saxonJar)
+    {
+        if (false === class_exists(Process::class)) {
+            throw new \LogicException('Symfony Process component is required to use SaxonJarSchematronValidator. Run "composer require symfony/process"');
+        }
+
+        if (false === extension_loaded('dom') || false === extension_loaded('libxml')) {
+            throw new \LogicException('DOM and Libxml extensions are required to validate business rules.');
+        }
+    }
+
+    public function validate(string $xmlFilepath, string $xsltFilepath): void
+    {
+        $process = new Process([
+            'java',
+            '-jar',
+            $this->saxonJar,
+            '-s:'.$xmlFilepath,
+            '-xsl:'.$xsltFilepath,
+        ]);
+
+        $process->setTimeout(3600);
+        $process->run();
+
+        if (false === $process->isSuccessful()) {
+            throw new ValidationFailedException(message: $process->getErrorOutput(), code: $process->getExitCode() ?? 1);
+        }
+
+        $output = trim($process->getOutput());
+
+        $doc = new \DOMDocument();
+
+        try {
+            if (false === $doc->loadXML($output)) {
+                throw new ValidationFailedException(message: 'Failed to parse Schematron validation output: invalid XML.');
+            }
+        } catch (\Throwable $throwable) {
+            throw new ValidationFailedException(message: 'Failed to parse Schematron validation output: '.$throwable->getMessage(), previous: $throwable);
+        }
+
+        $xpath = new \DOMXPath($doc);
+        $xpath->registerNamespace('svrl', 'http://purl.oclc.org/dsdl/svrl');
+
+        $failedAsserts = $xpath->query('//svrl:failed-assert');
+
+        if (false === $failedAsserts) {
+            throw new ValidationFailedException(message: 'Failed to parse Schematron validation output');
+        }
+
+        $errors = [];
+
+        /** @var \DOMNode $fa */
+        foreach ($failedAsserts as $fa) {
+            if (!$fa instanceof \DOMElement) {
+                continue;
+            }
+
+            $location = $fa->getAttribute('location');
+            $test = $fa->getAttribute('test');
+
+            $text = null;
+            $textElements = $fa->getElementsByTagName('text');
+            if (0 !== $textElements->length && $textElements->item(0) instanceof \DOMElement) {
+                $text = $textElements->item(0)->nodeValue;
+            }
+
+            $errors[] = new ValidationError(
+                test: $test,
+                id: $fa->getAttribute('id'),
+                flag: $fa->getAttribute('flag'),
+                location: $location,
+                text: $text,
+            );
+        }
+
+        if ([] === $errors) {
+            return;
+        }
+
+        throw new ValidationFailedException(errors: $errors, message: 'Schematron validation failed');
+    }
+}

src/Schematron/SchematronValidatorInterface.php

@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace TiimePDP\CrossDomainAcknowledgementAndResponse\Schematron;
+
+interface SchematronValidatorInterface
+{
+    /**
+     * @param string $xmlFilepath  the path to the XML file to validate against the business rules
+     * @param string $xsltFilepath the path to the Schematron XSLT file to use for validation
+     *
+     * @throws ValidationFailedException
+     */
+    public function validate(string $xmlFilepath, string $xsltFilepath): void;
+}

src/Schematron/ValidationError.php

@@ -0,0 +1,57 @@
+<?php
+
+declare(strict_types=1);
+
+namespace TiimePDP\CrossDomainAcknowledgementAndResponse\Schematron;
+
+final readonly class ValidationError
+{
+    private string $test;
+
+    private string $id;
+
+    private string $flag;
+
+    private string $location;
+
+    private ?string $text;
+
+    public function __construct(
+        string $test,
+        string $id,
+        string $flag,
+        string $location,
+        ?string $text,
+    ) {
+        $this->test = $test;
+        $this->id = $id;
+        $this->flag = $flag;
+        $this->location = $location;
+        $this->text = $text;
+    }
+
+    public function getTest(): string
+    {
+        return $this->test;
+    }
+
+    public function getId(): string
+    {
+        return $this->id;
+    }
+
+    public function getFlag(): string
+    {
+        return $this->flag;
+    }
+
+    public function getLocation(): string
+    {
+        return $this->location;
+    }
+
+    public function getText(): ?string
+    {
+        return $this->text;
+    }
+}

src/Schematron/ValidationFailedException.php

@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+namespace TiimePDP\CrossDomainAcknowledgementAndResponse\Schematron;
+
+final class ValidationFailedException extends \RuntimeException
+{
+    /**
+     * @param ValidationError[] $errors
+     */
+    public function __construct(
+        public readonly array $errors = [],
+        string $message = '',
+        int $code = 0,
+        ?\Throwable $previous = null,
+    ) {
+        parent::__construct($message, $code, $previous);
+    }
+}