Extending IValidate for external ontology resources

[Peter Robinson]

Hi everybody,

we are working on a FHIR IG for the Global Alliance for Genomics and Health (GA4GH) Phenopacket (http://phenopackets.org/core-ig/index.html). The rare disease use case will make use of the Human Phenotype Ontology, for which we have extensive Java code for validation. We are profiling Observation, for instance, constraining the code to be Codeablconcept (an HPO term), and I would like to use some of our existing Java code to validate the ontology terms (there are >16000 terms, and making a traditional ValueSet is a little tedious, given that the HPO is frequently updated). 

Is there a recommended way of implementing IValidate to do this? If so, how to I wired things together so that the appropriate resources are checked? Does HAPI FHIR do this automatically? Is there a more idiomatic way?

thanks, Peter