## RequestForInformation **RequestForInformation** interaction should be implemented by defined FHIR messaging context in HL7 FHIR. It supports further communication based on the the ServiceRequest initiated by the submitting system to an eReferral server or vice versa. In FHIR messaging, a "request message" is sent from a source application to a destination application when an event happens. Events mostly correspond to things that happen in the real world. The request message consists of a Bundle identified by the type "message", with the first resource in the bundle being a MessageHeader resource. The MessageHeader resource has a code - the message event - that identifies the nature of the request message, and it also carries additional request metadata. The other resources in the bundle depend on the type of the request. The events supported in this specification , along with the resources that are included in them are mentioned in MessageHeader. The destination application processes the request and returns one or more response messages which are also a bundle of resources identified by the type "message", with the first resource in each bundle being a **MessageHeader resource** with a response section that reports the outcome of processing the message and any additional response resources required. ### Scope These transactions involves a request/response by an FHIR Client Application for the submission/receiving of referrals communication.These are sent via a /Bundle POST to an endpoint hosted by the eReferral server. ### Interaction Diagrams The following diagram illustrates the high-level interaction between an FHIR submitting and receiving system which are involved in further communication. {{render:eReferral-Ontario/RequestForInfo-jpg}} **Actor:** FHIR requester Application **Role:** Requests communication bundle based on a known identifier-ServiceRequest ID. **Actor:** FHIR Receiving Application **Role:** Returns communication bundle containing the service ID for the single patient ### RequestForInformation Operation This operation supports an HTTP POST specifying the allowed identifiers( e.g. ServiceRequest identifiers) of a single patient instance from the FHIR requester application to send the communication to receiving application. **Trigger Events** 1. When an FHIR requester application initiates the request for communication for a patient, it invokes a communication request and send it to the receiving system. 2. When an FHIR receiving system recieves new communication bundle from an eReferral server,it invokes the response and send it to the requester system. **Summary of Supported Operations** The table below shows the allowed transactions for each profile and how they support FHIR endpoints, resources and their corresponding HTTP operations (https://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html): |Resource | Transaction | HTTP Operations|URL|Request Body Resource|Response Body Resource |- |Communication|POST|POST|[base]/Communication?|[Communication](https://simplifier.net/guide/eReferraldraftiGuide/Communication)|[Communication]( https://simplifier.net/guide/eReferraldraftiGuide/Communication)| | The interaction summary table below lists the HTTP status codes that may be returned for the POST operations for referral communication |Interaction|Content-Type|Body|Location|Versioning|HTTP Status Codes|Comments |- |POST|R|R: Communication|Bundle|N/A|200,400,500(**TBD**)| | **Expected Behavior** Referral requester System SHALL send the request bundle containing Communication and associated resources along with ServiceRequest ID generated for serviceRequest provided by the FHIR requesting application. eReferral receiving system SHALL respond with a bundle containing Communication and associated resources that contains a ServiceRequest identifier received in the request, or an http error if an internal error occurs. ### Resource Profiles This eReferral FHIR operation is based on the HL7 FHIR STU R4 POST operation. **RequestForInformation** **eReferral Requester Systems** will submit a FHIR Bundle containing a Communication + other relevant resources to the endpoint of a pre-selected target HealthcareService, hosted by an eReferral server. On successful submission, the sending system will receive a response bundle. **Sending an eReferral has following key components: 1. Build a /Bundle including the /Communication and other relevant resources 2. POST to the target service's /Endpoint ***'POST [endpoint.address]'*** **RequestForInformation Reponse** The response from an eReferral request operation is a bundle containing Communication and other relevant resources along with the serviceID received by the requester System . If eReferral does not found any serviceRequest based on the specified ID in Search Request, it will return an empty search result with no error, but may include an OperationOutcome with further advice. **Examples**