Validation¶

Validate C-CDA documents using XSD schemas and Schematron rules.

XSD Validation¶

Setup¶

Download C-CDA schemas from HL7:

# Visit: https://www.hl7.org/implement/standards/product_brief.cfm?product_id=492
# Download and extract to schemas/ directory

Basic Validation¶

from ccdakit.validators import XSDValidator

validator = XSDValidator()
result = validator.validate(xml_string)

if result.is_valid:
    print("✅ Valid C-CDA!")
else:
    print("❌ Validation errors:")
    for issue in result.issues:
        print(f"  - {issue.message} at {issue.location}")

Validation Result¶

class ValidationResult:
    is_valid: bool
    issues: List[ValidationIssue]

class ValidationIssue:
    level: ValidationLevel  # ERROR, WARNING, INFO
    message: str
    code: str
    location: Optional[str]

Schematron Validation¶

More advanced rule-based validation for business rules and template conformance.

Automatic Setup¶

The official HL7 C-CDA R2.1 Schematron files are automatically downloaded and cleaned on first use:

from ccdakit.validators import SchematronValidator

# Files auto-download on first use (~63MB one-time download)
# Automatically uses cleaned version compatible with lxml
validator = SchematronValidator()
result = validator.validate(xml_string)

if result.is_valid:
    print("✅ Passes Schematron validation!")
else:
    for error in result.errors:
        print(f"  - {error.message}")

Note: The official HL7 Schematron file contains IDREF errors that prevent lxml from loading it. ccdakit automatically cleans these files during download, removing invalid pattern references while preserving all validation rules.

Custom Schematron Files¶

You can also use your own Schematron files:

validator = SchematronValidator(
    schematron_path="path/to/custom.sch"
)
result = validator.validate(xml_string)

Custom Validation Rules¶

Create custom business rules:

from ccdakit.validators import ValidationRule, ValidationIssue, ValidationLevel
from lxml import etree

class CustomRule(ValidationRule):
    def validate(self, document: etree._Element) -> List[ValidationIssue]:
        issues = []

        # Your validation logic
        if condition_not_met:
            issues.append(ValidationIssue(
                level=ValidationLevel.ERROR,
                message="Custom validation failed",
                code="custom_rule_01",
                location="//element/path",
            ))

        return issues

# Use it
rule = CustomRule()
issues = rule.validate(doc)

Schema Manager¶

Manage XSD schemas:

from ccdakit.validators.utils import SchemaManager

manager = SchemaManager()

# Check if schemas installed
if not manager.schemas_installed():
    print("Please install C-CDA schemas")

# Get schema directory
schema_dir = manager.get_schema_directory()

Validation During Build¶

Enable validation during document generation:

from ccdakit import configure, CDAConfig

configure(CDAConfig(
    validate_on_build=True  # Validate as you build
))