Question about notification contexts per FHIRCast specs

[gkustas]

@lbergnehr,
I'm about to add code in our prototype to send an open-study notification to the hub.

I notice in the sandbox that when you send notification events to a subscriber, you create your context like this:
notification.Event.Context = new object[] {
clientEvent.UserIdentifier,
clientEvent.PatientIdentifier,
clientEvent.PatientIdIssuer,
clientEvent.AccessionNumber,
clientEvent.AccessionNumberGroup,
clientEvent.StudyId,
};
...whereas in http://fhircast.org/#event-catalog the context looks something like this (in json of course):

 "context": [
    {
      "key": "patient",
      "resource": {
        "resourceType": "Patient",
        "id": "ewUbXT9RWEbSj5wPEdgRaBw3",
        "identifier": [
          {
            "system": "urn:oid:1.2.840.114350",
            "value": "185444"
          },
          {
            "system": "urn:oid:1.2.840.114350.1.13.861.1.7.5.737384.27000",
            "value": "2667"
          }
        ]
      }
    },
    {
      "key": "study",
      "resource": {
        "resourceType": "ImagingStudy",
        "id": "8i7tbu6fby5ftfbku6fniuf",
        "uid": "urn:oid:2.16.124.113543.6003.1154777499.30246.19789.3503430045",
        "identifier": [
          {
            "system": "7678",
            "value": "185444"
          }
        ],
        "patient": {
          "reference": "Patient/ewUbXT9RWEbSj5wPEdgRaBw3"
        }
      }
    }
  ]

The questions are:

1. Can I assume that the publishers notification to the hub should be formatted in the same way that the hub sends the notification to the subscribers?

2. Can I also assume that our hub [eventually] will need to send the notifications formatted per the FHIRCast spec?

3. If so, where would I properly specify the patient MRN and the study's accession number?

4. Should have asked before... Is the FHIRCast spec solidified enough to try and follow the format provided on the previously referenced web site?

[lbergnehr]

Can I assume that the publishers notification to the hub should be formatted in the same way that the hub sends the notification to the subscribers?

Not necessarily.

Can I also assume that our hub [eventually] will need to send the notifications formatted per the FHIRCast spec?

Yes, that's the goal. Discrepancies are bugs in the sandbox (or the spec, but that's more unlikely).

If so, where would I properly specify the patient MRN and the study's accession number?

In a FHIR resource object I'd say, much like what's exemplified in the event cataloge.

Should have asked before... Is the FHIRCast spec solidified enough to try and follow the format provided on the previously referenced web site?

Hard to say how much it could change, but it surely feels like it would be more on the detail-level rather than complete re-haul.