How to use randomCode Functions with Flexporter

[Sharath314e]

I want to use ValuesetURL to load code, system and display into Flexporter fields using the provided randomCode function. When I try to use this I get Error or NullPointerException. Can anyone help me to fix this issue.

[dehall]

Can you share the mapping file that you're using? I can take a look and see where it's going wrong. The flexporter is still very experimental so it's possible the feature may need to be improved

[Sharath314e]

`applicability: true
actions:

• name: DenominatorExclusion1
  set_values:
  • applicability: Encounter
    fields:
    • location: Encounter.type.coding
      value: $randomCode("https://r4.ontoserver.csiro.au/fhir/ValueSet/2.16.840.1.113883.3.666.5.307")
    • location: period
      value:
      start: "2023-01-28T03:37:51+00:00"
      end: "2023-01-29T03:37:51+00:00"`

Here I am trying to populate the values for encounter.type.coding from the valueset, but I get a nullpointerException.

[dehall]

Ah ok thanks, that all looks like it should work but as I debug this I see some ways we need to improve our documentation and could potentially make some things simpler.

The short version is, you will need to make sure the generate.terminology_service_url setting is set, either by uncommenting it in src/main/resources/synthea.properties or by providing the argument on the command line --generate.terminology_service_url "https://r4.ontoserver.csiro.au/fhir", and then use the following mapping:

 - name: DenominatorExclusion1
   set_values:
     - applicability: Encounter
       fields:
         - location: Encounter.type.coding
           value: $randomCode([http://cts.nlm.nih.gov/fhir/ValueSet/2.16.840.1.113883.3.666.5.307])
         - location: period
           value:
              start: "2023-01-28T03:37:51+00:00"
              end: "2023-01-29T03:37:51+00:00"

The necessary changes were as follows:

• Arguments to value functions such as $randomCode need to be wrapped in square braces [] even if only a single value
• Arguments to value functions should not have quotes
• The URL to provide here should be the official URL of the ValueSet, not the url on terminology server to fetch from. (In this case I just went to the URL https://r4.ontoserver.csiro.au/fhir/ValueSet/2.16.840.1.113883.3.666.5.307 and found the URL property in the description)

In the short term I'll update our documentation to make these clearer. I'll also put a note to simplify some of these requirements, for example the quotes shouldn't be an issue and the [] maybe shouldn't be necessary.