Stream: implementers
Topic: must support and cardinality
Brian Reinhold (May 05 2017 at 19:51):
I have always found it a little difficult understanding the semantics of 'must support' versus cardinality. Is it possible to have 'must support' on an element with a minimum cardinality of 0?
Lloyd McKenzie (May 05 2017 at 19:53):
Absolutely. E.g. Patient.deceasedDate
Elliot Silver (May 05 2017 at 19:53):
If I recall correctly, "must support" means "you need to understand what to do with this element if it is there." Cardinality just says whether it needs to be there.
Lloyd McKenzie (May 05 2017 at 19:54):
Cardinality is 0 - we allow you to send patient's who aren't deceased and don't require you to make them so before sending data. However, if they are deceased, we expect you to be able to capture/send/understand/display/include in decision support logic/report based on/whatever that data element.
Lloyd McKenzie (May 05 2017 at 19:54):
(The specific meaning of mustSupport is dictated by the IG or profile that uses it as "support" means different things in different contexts.)
Brian Reinhold (May 05 2017 at 19:58):
I see. I guess its trying to understand what it means when one requires "you need to understand what to do with this element if it is there". I assume it doesn't matter to the server but only to the consumer of the resource.
Lloyd McKenzie (May 05 2017 at 20:24):
Well, it matters for servers too - for example not throwing it away. (Servers aren't required to support all element they receive - they may throw away certain extensions and might also throw away core elements in some cases.)
Lloyd McKenzie (May 05 2017 at 20:24):
But it's not something you can test by looking at an instance, you can only check "mustSupport" by looking at the behavior of the system.
Last updated: Apr 12 2022 at 19:14 UTC
