# HKCDADocumentSample A Clinical Document Architecture (CDA) sample that stores a single document. ``` class HKCDADocumentSample ``` ## Overview The sample’s `document` property contains an [`HKCDADocument`](/documentation/HealthKit/HKCDADocument) object, representing the underlying XML document. The [`HKCDADocumentSample`](/documentation/HealthKit/HKCDADocumentSample) class is a concrete subclass of the [`HKDocumentSample`](/documentation/HealthKit/HKDocumentSample) class. Document samples are immutable. HealthKit assigns the document’s properties when the sample is created. They cannot change. If you need to update a document in HealthKit, create a new document sample with the updated CDA document. ## Topics ### Creating CDA Samples [`init(data:start:end:metadata:)`](/documentation/HealthKit/HKCDADocumentSample/init(data:start:end:metadata:)) Returns a CDA document sample containing the provided XML document and metadata. [`HKDetailedCDAValidationErrorKey`](/documentation/HealthKit/HKDetailedCDAValidationErrorKey) A key for accessing validation error information from an error object’s user information dictionary. ### Accessing the Document [`document`](/documentation/HealthKit/HKCDADocumentSample/document) The CDA document. [`HKCDADocument`](/documentation/HealthKit/HKCDADocument) An object representing a Clinical Document Architecture (CDA) document in HealthKit. ### Accessing Validation Errors [`HKDetailedCDAValidationErrorKey`](/documentation/HealthKit/HKDetailedCDAValidationErrorKey) A key for accessing validation error information from an error object’s user information dictionary. ### Specifying Predicate Key Paths [`HKPredicateKeyPathCDAAuthorName`](/documentation/HealthKit/HKPredicateKeyPathCDAAuthorName) The key path for accessing the author’s name inside a predicate format string. [`HKPredicateKeyPathCDACustodianName`](/documentation/HealthKit/HKPredicateKeyPathCDACustodianName) The key path for accessing the custodian’s name inside a predicate format string. [`HKPredicateKeyPathCDAPatientName`](/documentation/HealthKit/HKPredicateKeyPathCDAPatientName) The key path for accessing the patient’s name inside a predicate format string. [`HKPredicateKeyPathCDATitle`](/documentation/HealthKit/HKPredicateKeyPathCDATitle) The key path for accessing the document’s title inside a predicate format string. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)