UUID generation function on FHIR expression

[ekigamba]

Is your feature request related to a problem? Please describe. Definition-based extraction does not support use-cases of multiple resource extraction where references to the main resource are required during extraction. This requires the main resource to have an ID

Describe the solution you'd like Support for FHIRPath expression uuid() which generates a UUID string. This support should be prioritised in initialExpression and calculatedExpression

Describe alternatives you've considered Use https://www.hl7.org/fhir/mapping-language.html with StructureMap-based extraction since it provides a uuid function that generates a UUID

Additional context This issue originates from the discussion here https://github.com/google/android-fhir/issues/504#issuecomment-856920877

Would you like to work on the issue? Yes

[jingtang10]

@santosh-pingle FYI

[jingtang10]

FHIR chat link: https://chat.fhir.org/#narrow/stream/179266-fhirpath/topic/Creating.20a.20Coding.20in.20FHIRPath/near/241785622

@ekigamba it doesn't seem to me there is concensus yet - can you provde a link as in https://github.com/google/android-fhir/issues/504#issuecomment-856920877 you mentioned the syntax $UUID.generate()?

[ekigamba]

@jingtang10 Yea, there isn't a conclusion or any progress on this issue. I'll follow up and update this whenever I get an update

[ekigamba]

Jira request change being tracked here https://jira.hl7.org/browse/FHIR-33070

Based on my guess and unrelated chats,

• It might take weeks or months before it gets to the change committee

[fredhersch]

@ekigamba I saw that Bryn had provided a comment on the JIRA request suggesting that we explore other ways to implement this outside of FHIRPath. Please take a look.