kotlin-fhir-workflow

Kotlin Multiplatform library for implementing workflow patterns and logic

Resolving knowledge artifacts

FhirOperator looks knowledge artifacts up through a CanonicalResolver, a single-method interface over "give me the resource of this type published under this canonical URL":

fun interface CanonicalResolver {
  suspend fun resolve(type: ResourceType, canonical: String): Resource?
}

It is deliberately not limited to the PlanDefinitions and ActivityDefinitions that PlanDefinition/$apply needs today. A Library, ValueSet or StructureDefinition resolves the same way, so the CQL and validation work still to come needs no further API. From Kotlin, use the reified form and let the type argument name the resource:

val plan = resolver.resolve<PlanDefinition>("http://example.org/PlanDefinition/anc|0.3.0")
val library = resolver.resolve<Library>("http://example.org/Library/FHIRHelpers")

The default is RepositoryCanonicalResolver, which reads the artifacts back out of the same WorkflowRepository that holds the patient data — nothing to wire up if that is where you keep them:

val operator = FhirOperator(repository)

Backing it with the knowledge library

Pass your own implementation to keep the artifacts somewhere else. This is how kotlin-fhir-knowledge plugs in — it installs versioned FHIR NPM packages and indexes them by canonical URL, which is exactly what the resolver asks for. Neither library depends on the other; the adapter lives in your application:

class KnowledgeCanonicalResolver(private val knowledgeManager: KnowledgeManager) :
  CanonicalResolver {

  override suspend fun resolve(type: ResourceType, canonical: String): Resource? =
    knowledgeManager.loadResources(canonical).firstOrNull { it::class.simpleName == type.getCode() }
}

val knowledgeManager = KnowledgeManager.create(platformContext = context)
knowledgeManager.install(FhirNpmPackage("anc-cds", "0.3.0"))

val operator = FhirOperator(repository, resolver = KnowledgeCanonicalResolver(knowledgeManager))
val carePlan =
  operator.generateCarePlan(
    planDefinitionCanonical = "http://fhir.org/guides/who/anc-cds/PlanDefinition/anc|0.3.0",
    subject = patient,
    today = today,
  )

loadResources accepts the |version suffix directly, so a versioned canonical resolves to that exact version and an unversioned one to every version indexed.