Support itemWeight (replacing deprecated ordinalValue) in calculated expressions

[patrick-werner]

Description:
LHC Forms currently only supports the deprecated ordinalValue extension for scoring calculations in sdc-questionnaire-calculatedExpression.
In the FHIR Extension pack, http://hl7.org/fhir/StructureDefinition/ordinalValue has been replaced by http://hl7.org/fhir/StructureDefinition/itemWeight. (

As a result, questionnaires using itemWeight (as per the latest FHIR spec) fail to compute calculated scores in LHC Forms, while identical forms using ordinalValue work correctly.

lforms/src/fhir/common/sdc-import-common.js

Lines 53 to 54 in 4c75455

	'R4': "http://hl7.org/fhir/StructureDefinition/ordinalValue",
	'R5': "http://hl7.org/fhir/StructureDefinition/itemWeight"

shows that itemWeight is used in a FHIR R5 context, this should be changed to support both extensions in all R4 and R5.

Expected behavior:
LHC Forms should support itemWeight in the same way as ordinalValue when processing calculated expressions. Ideally, both should be accepted for backward compatibility.

Proposed fix:

• Recognize and process itemWeight as equivalent to ordinalValue in the internal normalization logic.
• Maintain backward compatibility for existing forms still using ordinalValue.

[plynchnlm]

I think when we implemented this itemWeight was only valid for R5+, and ordinalValue for R4. Now I see that ordinalValue is included in the new extensions pack as a deprecated extension, and changes have been made to make the extensions pack usable with any version of FHIR. We will plan to make changes to support itemWeight and ordinalValue for any version of FHIR.

[jcy1225]

Hi @patrick-werner ,

Can you provide a simplest example form that fails on the calculated expression?

[lhcye]

This has been fixed in v38.7.2. Please give it a try and let us know if there is a problem. Thanks for reporting the issue.