Migrating from older SDK versions

The parsing classes have been renamed twice over the SDK’s lifetime, so older code and tutorials use names that are now obsolete. This page maps those names onto the current API. If you are writing new code, you do not need it — start from Deserialization and Serialization.

Two naming changes account for almost everything:

  • “Parser” became “Deserializer”. The original FhirXmlParser / FhirJsonParser (SDK 3) are obsolete in favour of FhirXmlDeserializer / FhirJsonDeserializer.

  • The Poco infix was dropped. The SDK 5 *Poco* classes (e.g. BaseFhirXmlPocoDeserializer) are obsolete; the current classes drop Poco from the name (BaseFhirXmlDeserializer).

A short history of the classes

The diagrams below show the XML deserialization and serialization classes and how they relate. The JSON classes mirror them exactly (FhirJsonDeserializer, BaseFhirJsonSerializer, and so on).

classDiagram BaseFhirXmlDeserializer <|-- FhirXmlDeserializer BaseFhirXmlDeserializer <|-- BaseFhirXmlPocoDeserializer FhirXmlDeserializer <|-- FhirXmlParser BaseFhirXmlPocoDeserializer <|-- FhirXmlPocoDeserializer class BaseFhirXmlDeserializer { <<current>> } class FhirXmlDeserializer { <<current>> } class FhirXmlParser { <<obsolete>> } class BaseFhirXmlPocoDeserializer { <<obsolete>> } class FhirXmlPocoDeserializer { <<obsolete>> }
classDiagram BaseFhirXmlSerializer <|-- FhirXmlSerializer BaseFhirXmlSerializer <|-- BaseFhirXmlPocoSerializer BaseFhirXmlPocoSerializer <|-- FhirXmlPocoSerializer class BaseFhirXmlSerializer { <<current>> } class FhirXmlSerializer { <<current>> } class BaseFhirXmlPocoSerializer { <<obsolete>> } class FhirXmlPocoSerializer { <<obsolete>> }

FhirXmlParser dates back to SDK 3, the *Poco* classes to SDK 5, and the current names to SDK 6. All the obsolete classes still work — they are thin subclasses of the current ones — but new code should use the current names.

Class name mapping

Obsolete

Use instead

FhirXmlParser / FhirJsonParser

FhirXmlDeserializer / FhirJsonDeserializer

BaseFhirXmlPocoDeserializer / BaseFhirJsonPocoDeserializer

BaseFhirXmlDeserializer / BaseFhirJsonDeserializer

FhirXmlPocoDeserializer / FhirJsonPocoDeserializer

FhirXmlDeserializer / FhirJsonDeserializer

BaseFhirXmlPocoSerializer / BaseFhirJsonPocoSerializer

BaseFhirXmlSerializer / BaseFhirJsonSerializer

FhirXmlPocoSerializer / FhirJsonPocoSerializer

FhirXmlSerializer / FhirJsonSerializer

Method changes

  • Parse<T>(…) → Deserialize<T>(…).

  • The …Async methods (ParseAsync, SerializeToStringAsync, …) are gone: the current (de)serializers are synchronous. Call the synchronous method directly.

Settings and options

Old

Now

ParserSettings { AcceptUnknownMembers, AllowUnrecognizedEnums, PermissiveParsing }

DeserializerSettings with a mode (Recoverable / BackwardsCompatible); AcceptUnknownMembers and AllowUnrecognizedEnums also remain as shortcuts

FhirJsonPocoDeserializerSettings / FhirXmlPocoDeserializerSettings

DeserializerSettings (or FhirJsonConverterOptions for System.Text.Json)

JsonSerializerOptions.ForFhir(Assembly)

ForFhir(ModelInspector)

option to skip base64 decoding

automatic — base64 is kept as a string and decoded only when you read .Value

DataAnnotationDeserializationValidator

FhirAttributeValidator

The bigger picture

Beyond the renames, SDK 6 changed how the deserializer treats imperfect data: rather than rejecting anything that does not fit the POCO, it captures everything — using overflow for what does not fit — and reports only genuine problems. If you previously relied on AcceptUnknownMembers or permissive parsing to get data in, read Error handling and deserialization modes to see how modes and overflow replace that.