Stream: implementers
Topic: Forge 22.0 for R4 Extension
Aleksi Aho (Jul 24 2019 at 08:57):
Hello, I'm having problems with the extensions. I am trying to extend Observation.value[x] (type Quantity) so I can have alternative Quantity in the value. When I click value[x] Extend-button is disabled. Extending this value was possible in stu3. Is this something that is no longer possible or is the issue in Forge?
Michel Rutten (Jul 25 2019 at 10:12):
Hi @Aleksi Aho, type slicing has changed in R4.
Forge does not support extensions on sliced elements, but you can add an extension to named slices.
To create a type slice, slice the value[x] element, then add a named slice and constrain it to a single type (e.g. Quantity). Forge then renames the type slice to valueQuantity and allows you to put an extension on there.
Note that In R4, the valueQuantity type slice introduces specific constraints for Quantity values but does NOT constrain the list of allowed types. To actually disallow other types, constrain the types of the sliced value[x] parent element to only Quantity. Also note that Forge R4 will NOT rename the sliced value[x] parent element, even if constrained to a single type.
Last updated: Apr 12 2022 at 19:14 UTC
