ADHA profile invariants :: enhance to include XPath expression

[dtr-agency]

Prerequisites

• I have searched open and closed issues to make sure it isn't already requested or reported
• I have written a descriptive issue title

The issue / feature

Change description

Invariants in ADHA profiles have the FHIRPath expression of constraint defined but do not have an XPath expression of constraint defined.

Only invariants with XPath expression get included in the Schema+Schematron files generated in an ADHA FHIR NPM package.

This means that there significantly less rule coverage offered by thethe Schema+Schematron files vs the JSON StructureDefinitions.

Noting that JSON StructureDefinitions used in Validator or validate operation provide greater validation capabilities anyway including bindings and questionnaires

What it actually enables people to do

Complete automated Schema+Schematron XML files -

How awesome would it be?

Unclear as the primary expectation of use of ADHA FHIR NPM package in validation remains use of Validator or Validate Operation - these use the JSON StructureDefinitions (FHIRPath expression).

However

Workarounds

N/A

Additional context

Core FHIR standard provides XPath expression for all core FHIR invariants.
US Core provides XPath expression for all US Core invariants.
IPS does not provide XPath expression for all IPS invariants.

[dtr-agency]

1st piece of work to address this is to add conditional cardinality Xpath expresssion e.g. inv-dh-obs-06 The component shall at least have a value or a data absent reason.

This is in progress.

[dtr-agency]

Added Xpath for SNOMED system + conditional reference population via bcd4799

[dtr-agency]

Added Xpath for section entry population that do not require resolve() via 27b1c43

[dtr-agency]

Not all invariants can be checked with Xpath. The following invariants are not addressed with XPath:

• section.code isDistinct
• conformsTo
• resolve

Additionally, invariant on 'valid' identifier only checks for presence of identifier element - the XPath may be added at a later date if desired.

NOTE: At this time XPath expression is not present in HL7 AU Base materials and are therefore not included in generated schema / schematron files.

[dtr-agency]

The introduced XPath expressions are ready for review.

[dtr-agency]

Unit test cases to include XPath expression. Test case development beginning September 19th by @udaychandrupatla & @vikasmittal-dh.