Stream: conformance
Topic: How to handle missing StructureDefinition.derivation?
Michel Rutten (Feb 14 2019 at 10:05):
Like most other elements, the StructureDefinition.derivation element is optional:
http://hl7.org/fhir/structuredefinition-definitions.html#StructureDefinition.derivation
However the value is critical for the correct interpretation of a StructureDefinition.
How should systems interpret a StructureDefinition that does not explicitly define derivation?
Richard Townley-O'Neill (Feb 15 2019 at 03:46):
If elements are added it is specialization, otherwise it is constraint?
If the definition is a specialization, then it adds new elements in the differential, and the snapshot includes the inherited elements. If the definition is a constraint, then it cannot define new elements, it can only make new rules about existing content
Grahame Grieve (Feb 17 2019 at 13:33):
it should be present if there's a baseDefinition. If it's not present, I would treat it as an error. And we should at least say that, if not make a constraint, in R5. Make a task
Michel Rutten (Feb 19 2019 at 10:25):
Done: GF#20403 (for target release R5).
For earlier FHIR releases, can we clarify that StructureDefinitions w/o derivation should be treated as an error?
Last updated: Apr 12 2022 at 19:14 UTC
