This section describes the transaction of the retrieval of the FHIR® resources referenced in the input field of the Notification or Workflow Task.
These input fields contain valueString with either the generic type code “search-resource” or a LOINC or SNOMED CT code.

1. Scope

Open

This transaction supports the request of resources by the Requesting System to the Resource Server.

2. Use Case Roles

Actor: Receiving GtK

Role: Sends a request for resources on behalf of a retrieving user.

Actor: Sending GtK (Resource Server)

Role: Processes the request and responds with the requested resources.

3. Referenced Standards

• HL7® FHIR® standard STU3 https://hl7.org/fhir/stu3

4. Messages

4.1. Request message

The requesting system wants to obtain the resources that were referenced in the Task. These resources are retrieved using a FHIR® search interaction, i.e. executing an HTTP GET request to the resource servers FHIR® endpoint. If there is a relative path, the input valueString must be appended to the FHIR® base-url.

The requesting system may provide the HTTP Accept header. Valid values for this header are application/fhir+json or application/fhir+xml. If none is set, the resource server will use its default.

4.2. Response message

The resource server returns the resource(s) that are requested.

The payload of this message consists of a FHIR® Bundle resource that contains the requested resource(s). This message is returned to the Receiving System.

The media type of the HTTP body must be either application/fhir+json or application/fhir+xml, based on the Accept header or default response content type.

When an error occurs an OperationOutcome resource must be returned with more details on the reason.

The HTTP response must be accompanied with the correct HTTP status code, e.g.:

• 200 OK - The search was processed and a valid response was returned

• 400 Bad Request - The search could not be processed or failed basic FHIR® validation rules

• 401 Not Authorized - Authorization is required for the interaction that was attempted

• 404 Not Found - The resource type not supported

The requesting system processes the response according to application defined rules.