Stream: implementers
Topic: missing modifier - check for support
Paul Lynch (Apr 11 2019 at 16:32):
Is there a way to ask a FHIR server if it supports the "missing" modifier? I was thinking it would be inside a CapabilityStatement, but I haven't found an example of one that says anything about "missing".
Lloyd McKenzie (Apr 11 2019 at 20:25):
in principle, that shoudl be showing up in the CapabilityStatement. What comes back from test.fhir.org?
Paul Lynch (Apr 11 2019 at 20:46):
There is no mention of a missing modifier at http://test.fhir.org/r4/metadata?_format=application/json.
Paul Lynch (Apr 11 2019 at 20:47):
I also did not see anything about modifiers at https://www.hl7.org/fhir/capabilitystatement.html.
Lloyd McKenzie (Apr 11 2019 at 21:00):
@Grahame Grieve ?
Grahame Grieve (Apr 12 2019 at 20:50):
would be on the search parameter
Paul Lynch (Apr 12 2019 at 21:09):
@Grahame Grieve Are you saying that in CapabilityStatement, it would be under rest.resource.searchParam? I don't see a place for modifiers there.
Eric Haas (Apr 13 2019 at 00:01):
you reference the SearchParamter and define what you support in the SearchParameter . Here is an example ...
Eric Haas (Apr 13 2019 at 00:10):
if you click on a link which is a url to a customized search parameter (currently not resolving until GG does his magic ... I think) you get the searhparameter definition: for example Questionnaire publisher : http://build.fhir.org/ig/argonautproject/questionnaire/SearchParameter-Questionnaire-publisher.html
And you can see in the rendered output the supported modifier ( in this case contains )
(note since this is an IG, this is an expectation if you adopt the IG for that actor/server - if an implementation then this would be what you support.)
Eric Haas (Apr 13 2019 at 00:12):
The alternative it simply document in capstatement element as text. ( e.g. "we support the modifiers foo and bar )
Paul Lynch (Apr 15 2019 at 14:37):
@Eric Haas What I am looking for is a way for a client to query a server as to whether it supports the "missing" modifier. For this case, free text or HTML descriptions won't work well.
Eric Haas (Apr 15 2019 at 14:38):
then the first way I describe. point to the custom SP in the CapStatement and define it there.
Eric Haas (Apr 15 2019 at 14:38):
in the SP.
Eric Haas (Apr 15 2019 at 14:40):
For more examples look at VHDIR has a lot of custom search parameter defined too. :
http://build.fhir.org/ig/HL7/VhDir/searchparameters.html
Eric Haas (Apr 15 2019 at 14:42):
The details of the SearchParameter are in the SearchParameter not in the CapStatement. So the Client need to somehow inspect the SearchParameter as well.
Paul Lynch (Apr 15 2019 at 15:28):
I see. So, the client can query like http://test.fhir.org/r4/SearchParameter?base=Observation&code=data-absent-reason&_format=json and check for whether there is "modifier" section under entry[0].resource, and then check whether the modifier section contains the needed modifier (e.g. "missing" in this case.)
Paul Lynch (Apr 15 2019 at 15:29):
I am realizing that writing a client that can talk to random FHIR servers will require a great deal of checking about what can be queried.
Lloyd McKenzie (Apr 15 2019 at 15:56):
The alternative is you run the query you like and then check the 'self' link to see what it actually did.
Last updated: Apr 12 2022 at 19:14 UTC
