FHIR Serialization Component

PHP library for FHIR JSON and XML serialization and deserialization, built on top of the Symfony Serializer component.

Features

• FHIR-compliant JSON and XML serialization
• Configurable validation modes (strict/lenient/performance)
• Auto-detection of format and resource type
• Round-trip serialization testing
• Debug information support

Quick Start

use Ardenexal\FHIRTools\Component\Serialization\FHIRSerializationService;

// Serialize to JSON
$json = $service->serializeToJson($patient);

// Serialize to XML
$xml = $service->serializeToXml($patient);

// Deserialize from JSON
$patient = $service->deserializeFromJson($json, FHIRPatient::class);

// Deserialize from XML
$patient = $service->deserializeFromXml($xml, FHIRPatient::class);

// Auto-detect format and resource type
$resource = $service->deserialize($data);

Serialization Contexts

The FHIRSerializationContextFactory provides pre-configured contexts:

use Ardenexal\FHIRTools\Component\Serialization\Context\FHIRSerializationContextFactory;

$factory = new FHIRSerializationContextFactory();

// Default contexts
$jsonContext = $factory->createJsonContext();
$xmlContext = $factory->createXmlContext();

// Strict validation for production
$strictContext = $factory->createStrictContext('json');

// Lenient for development
$lenientContext = $factory->createLenientContext('json');

// Performance-optimized (minimal validation)
$perfContext = $factory->createPerformanceContext('json');

// Debug mode with detailed information
$debugContext = $factory->createDebugContext('json');

Context Options

All contexts support these FHIR-specific options:

Option	Default	Description
fhir_strict_validation	true	Enable strict FHIR validation
fhir_include_extensions	true	Include FHIR extensions
fhir_include_metadata	true	Include metadata elements
fhir_unknown_element_policy	ignore	How to handle unknown elements (ignore, error, preserve)
fhir_validate_references	false	Validate FHIR references

Pass custom overrides to any factory method:

$context = $factory->createJsonContext([
    'fhir_strict_validation' => false,
    'max_depth' => 20,
]);

Round-Trip Testing

Verify serialization integrity:

// Serialize then deserialize, returns the deserialized object
$roundTripped = $service->roundTripTest($patient, 'json');
$roundTripped = $service->roundTripTest($patient, 'xml');

Error Handling

use Ardenexal\FHIRTools\Component\Serialization\Exception\FHIRSerializationException;

try {
    $patient = $service->deserializeFromJson($invalidJson, FHIRPatient::class);
} catch (FHIRSerializationException $e) {
    echo "Serialization error: {$e->getMessage()}";
}

Symfony Integration

When used with the FHIRBundle, the service is automatically registered and available via dependency injection:

use Ardenexal\FHIRTools\Component\Serialization\FHIRSerializationService;

class PatientService
{
    public function __construct(
        private readonly FHIRSerializationService $serializer,
    ) {}

    public function processPatientJson(string $json): object
    {
        return $this->serializer->deserializeFromJson($json, FHIRPatient::class);
    }
}

Requirements

• PHP: 8.3 or higher

License

This component is released under the MIT License. See the LICENSE file for details.