Query Processing

EAP

This page describes how the HL7 v2.x Listening Endpoint module handles inbound HL7 v2.x query transactions. For supported query types, see Transactions.

Processing

When a query message is received, the HL7 v2.x Listening Endpoint module validates the request, searches the FHIR repository, and builds an HL7 v2.x response.

Identifier Mapping

The map_identifiers_using_namingsystem_inbound property controls how HL7 v2.x Assigning Authorities are resolved to FHIR Identifier.system URIs in the query, and how FHIR systems are mapped back to Assigning Authorities in the response. See NamingSystem Mapping for Query Processing for details and examples.

Callback Scripts

The query processing pipeline supports two callback scripts:

• onPreConvertHl7V2ToFhir — called after the message is logged to the transaction log and before query processing begins. It can be used to manipulate the incoming query message.
• onPreQueryResponse — called after the RSP^K23 response has been built and before it is logged in the ENDPOINT_REPLY step. It can be used to customize the outgoing response (e.g. override assigning authorities or convert AE to NF).

The following diagram shows where the callback scripts are invoked during query processing: