Stream: IG creation
Topic: Constraints on Reference
Vikas Mittal (Jul 23 2019 at 06:35):
Does the following text "At least one of reference, identifier and display SHALL be present (unless an extension is provided). " at this page http://build.fhir.org/references.html#Reference has any invariant planned or it is just a text for advice.
A link to the GForge ticket (raised by @Richard Townley-O'Neill) for the same is here https://gforge.hl7.org/gf/project/fhir/tracker/?action=TrackerItemEdit&tracker_item_id=22987
Thanks
Grahame Grieve (Jul 23 2019 at 10:42):
it's enforced by a constraint on Element
Richard Townley-O'Neill (Jul 24 2019 at 01:06):
@Grahame Grieve
Which constraint on element enforces that?
In STU3 it could be enforced by ele-1: Rule (base) All FHIR elements must have a @value or children hasValue() or (children().count() > id.count())
In R4 there is also Reference.type, which means that something more than ele-1 is needed.
R4 does give a warning when a reference has only type, so the warning comes from something other than ele-1.
Grahame Grieve (Jul 24 2019 at 12:00):
I don't know that off the top of my head
Michel Rutten (Jul 25 2019 at 09:10):
ele-1: http://hl7.org/fhir/element.html#definition
Richard Townley-O'Neill (Jul 26 2019 at 02:07):
@Michel Rutten
ele-1 is enough for STU3, but in R4 there is the extra element type. And ele-1 won't object if the only element in a reference is type.
Richard Townley-O'Neill (Jul 26 2019 at 02:08):
But there is a warning (not an error) if the only element is type.
Brian Postlethwaite (Jul 26 2019 at 07:23):
Ele-1 is the same in R4.
Are you referring to the type prop on the identifier datatype?
Bryn Rhodes (Jul 26 2019 at 15:24):
Oops, wrong topic
Last updated: Apr 12 2022 at 19:14 UTC
