Refactor au-core-medreq-03 (FHIR-46498, FHIR-48362)

[JayMurdoch]

FHIR-46498: medreq-03 allows non-precise date if Data Absent Reason is present
FHIR-48362: correct to require min length of 10

• Refactored au-core-medreq-03 for precise date or DAR, increased min length to 10

[dt-r]

The PR should include both technical corrections on this invariant.

[dt-r]

See inline comments.

[dt-r]

See continued conversation

[dbojicic]

Changes requested.

[dbojicic]

please update xpath to match the updated expression.

[dbojicic]

I am not convinced this is the solution. Could not get it to work with FHIRPath Lab either.
I've raised a question in Zulip: MedicationRequest.authoredOn allow precise date or DAR ext; @JayMurdoch, could you please follow up if there is no response by early next week?

[dbojicic]

Please see inline comments

[dbojicic]

@JayMurdoch
based on the feedback in Zulip, here is a refined expression that seem to be working:

<expression value ="($this.hasValue().not() and extension('http://hl7.org/fhir/StructureDefinition/data-absent-reason').value.exists()) or ($this.hasValue() and $this.toString().length() >= 10 and extension('http://hl7.org/fhir/StructureDefinition/data-absent-reason').value.exists().not())"/>

@heathfrankel provided a simplified version of this:
<expression value ="$this.hasValue() implies (extension('http://hl7.org/fhir/StructureDefinition/data-absent-reason').value.exists().not() and $this.toString().length() >= 10)"/>

Initial test in Fhirpath-lab using HAPI validator passed, see
🧪 Test with FHIRPath-Lab

Could you please test both expressions?

[JayMurdoch]

@dbojicic Test results - behaved as expected

<expression value ="($this.hasValue().not() and extension('http://hl7.org/fhir/StructureDefinition/data-absent-reason').value.exists()) or ($this.hasValue() and $this.toString().length() >= 10 and extension('http://hl7.org/fhir/StructureDefinition/data-absent-reason').value.exists().not())"/>

Test	Outcome
Valid DAR	pass
Valid date (to day)	pass
Valid date (to day) + DAR	fail
Valid date (to seconds)	pass
Valid date (to seconds) + DAR	fail
Invalid date (to month)	fail
Invalid date (to month) + DAR	fail

Test results - behaved as expected

<expression value ="$this.hasValue() implies (extension('http://hl7.org/fhir/StructureDefinition/data-absent-reason').value.exists().not() and $this.toString().length() >= 10)"/>

Test	Outcome
Valid DAR	pass
Valid date (to day)	pass
Valid date (to day) + DAR	fail
Valid date (to seconds)	pass
Valid date (to seconds) + DAR	fail
Invalid date (to month)	fail
Invalid date (to month) + DAR	fail

Proceeding with 2nd option as discussed with @dbojicic, @brettesler-ext, @johnscarter

[dbojicic]

Thanks @JayMurdoch , just a few minor changes.

[dbojicic]

One minor change