Transport Pattern Mapping

FHIR-MHD Transport Pattern Mapping Notes

• FHIR REST API (in least in theory) is based on OMG Health RESTful specification
  • http://www.omg.org/spec/HData/1.0/PDF/
  • on first inspection, it does not seem to cause incompatibility issues with existing use of REST in MHD.
• the recommendation of using CORS has impact on HTTP level: http://enable-cors.org/. Discussed in http://www.hl7.org/implement/standards/fhir/security.html

HTTP verbs used for basic operations on resources in FHIR

• POST - create
• PUT - update
• DELETE - delete
• GET - read

There are some exceptions to this scheme: the "transaction" operation utilizes POST to create or update a set of resources (resource bundle) atomically.

Mapping of FHIR operations to existing XDS transactions

Transaction

This operation can facilitate Provide & Register Document Set-b (ITI-41, ITI-42) and "Update Document Set" (ITI-57) transactions. It can create and update a set of resources (authors, documents) in one transaction:

• If entry.content is omitted, the resulting operation is closer to Register (ITI-42).
• If entry.id refers to an existing resource, it mimicks "Update Document Set"

Open issue: there is a note about the ability to delete resources, but I couldn't figure out how a delete would be implemented.

Delete

This operation can be mapped to Delete Document Set, but only works for individual resources.