Choice elements are not handled properly

[jsdebruin1981]

According to the FHIR specification:

2.9.1.1 Polymorphism in FHIR
For choice elements, where elements can be one of multiple types, e.g. Patient.deceased[x]. In actual instances these will be present as either Patient.deceasedBoolean or Patient.deceasedDateTime. In FHIRPath, choice elements are labeled according to the name without the '[x]' suffix, and children can be explicitly treated as a specific type using the as operation:

(Observation.value as Quantity).unit

The implementation does not handle those, the FHIRpath path only recognizes the actual fieldname, e.g. valueQuantity etc....

[ir4y]

Hi @jsdebruin1981

This feature is supported.
You need to specify a version of FHIR to emable this feature.
Here is a related unit test https://github.com/beda-software/fhirpath-py/blob/master/tests/cases/fhir-quantity.yaml#L64