Reference to FHIR binary resource used in messaging paradigm

Question

I am using Document Reference resource to contain some meta data about the document returned via query response with in Atom Feed. The document is itself a blob and therefore needs to be in binary resource referenced with document reference resource. I am not clear how I will reference binary resource with in document resource.

My best guess is to use location element to point to XPATH to binary object with in Atom Feed.

<location value="/feed/entry/content/Binary/@28BEE6CC-28F4-11E2-B493-B2916188709B"/>

where "28BEE6CC-28F4-11E2-B493-B2916188709B" is the masteridentifier for the document.

Please if anyone shed more light on binary resource as used with in messaging paradigm?

Answer 1

The location in the document reference is a URL that refers to the direct address of the resource. If that URL referred to a literal server that could be accessed, it would be an absolute URL. If you then packaged that binary resource in the bundle, the id of the resource would be that literal URL, and when you find the location, you look through the atom feed looking for an entry with that URL. If you don't find it, then you look at the original source URL ( http://hl7.org/implement/standards/fhir/references.html#atom-refs ).

In your case, the binary need not exist on a RESTful server, but the resolution is the same - look through the bundle for an entry id that matches the url of the location. So if the location is

<location value="urn:uuid:28bee6cc-28f4-11e2-b493-b2916188709b"/>

then the process will look through the bundle looking for an entry with the id:

  <entry>
    <id>urn:uuid:28bee6cc-28f4-11e2-b493-b2916188709b</id>
    ...
  </entry>

Note: in the URI form, UUIDs have to be lowercase. I recommend always using lowercase to avoid confusion