Stream: shorthand
Topic: Proposed Syntax Change for Extensions
Chris Moesel (Feb 27 2020 at 17:11):
@David Hay raised an issue a while ago about our current approach for adding inline extensions (mostly relevant to complex extensions). The problem is that when you say something like extension contains maxSize, SUSHI assumes you mean to reference the existing maxSize extension from FHIR core -- which you might mean, but you also might mean to declare a new inline extension called maxSize. See FHIR/sushi#86 for details.
To remove the ambiguity, we propose the following changes for declaring extensions:
- For declaring inline extensions, the syntax remains the same:
Extension: CapacityDetails * extension contains maxSize 0..1 * extension[maxSize].value[x] only integer // ...
SUSHI would always recognize this style as an inline extension.
- For declaring use of an externally defined extension (defined inside or outside the IG, but not inline), you must declare a slicename and the reference to the extension:
Alias: MaxSizeExtension = http://hl7.org/fhir/StructureDefinition/maxSize Extension: CapacityDetails * extension contains MaxSizeExtension named maxSize 0..1 * extension[maxSize].value[x] only integer
@David Hay (and others), what do you think of this approach? It will be a breaking change, but we're early on in FSH/SUSHI, so now is the time to make breaking changes!
Chris Moesel (Feb 27 2020 at 17:13):
NOTE: This would apply to extensions wherever you declare them, so it would also apply to profiles, e.g.:
Alias: USCoreRaceExtension = http://hl7.org/fhir/us/core/StructureDefinition/us-core-race Profile: MyPatient Parent: Patient * extension contains USCoreRaceExtension named race 0..1
David Hay (Feb 27 2020 at 18:43):
works for me!
Last updated: Apr 12 2022 at 19:14 UTC
