HL7/fhirpath.js

impossible to use attribute name that starts with a capitalized letter

ruscoder opened this issue · 3 comments

ruscoder commented

Hello!

I'm using fhirpath.js library with a FHIR server that allows using first-class extensions with custom name and there is an issue with accessing attributes that starts with a capitalized letter, e.g.

fhirpath.evaluate({"resourceType": "Patient", "CustomField": "value"}, "Patient.CustomField", {})

returns []

What is the reason for having this restriction?

Thanks.

plynchnlm commented

I think the code is assuming that any identifier starting with a capital letter is a resource type. It is a simplification, but on other hand, I am not aware of any case in FHIR where a property of a resource also starts with a capital letter. Why would you not follow that pattern for your custom property names?

Anyway, I agree that identifiers starting with a capital letter should work, and I will add it to our list of things to address.

  • 👍1
ruscoder commented

Why would you not follow that pattern for your custom property names?

I'm using Aidbox FHIR server that has own format for union type where valueQuantity: {...} becomes {value: {Quantity: {...}}} and currently it's impossible to extract value.Quantity.unit, so, I'm using workaround value.children().unit.

ruscoder commented

Thanks for fixing it! It works well in the latest release