HAPI FHIR ValueSet $expand operation - Text 'filter' param not supporting language designations display filtering

[Aitor Pérez Pellitero]

Hi,


Currently I'm using HAPI FHIR as a terminology server. Exploring ValueSet operation "$expand" I found that a ValueSet can be expanded to obtain all the displays it is referencing (from CodeSystem resources).

Apart from that there is an option to perform some text filtering on ValueSet expansion (seems applies the text filter on the 'display' field) using the parameter "filter":


From FHIR official docs:


http://hl7.org/fhir/valueset-operation-expand.html#examples

Request: Expanding a value set that is already registered on the server as "23", with a text filter of "abdo"

GET [base]/ValueSet/23/$expand?filter=abdo



This is working fine, the issue comes when introducing to the terminology some language traslations.

Seems that language translations should be defined as a language "designation" array containg the different display translations.

Check an extract from a HL7 CodeSystem "resource-types"



            {
                            "code": "BodyStructure",
                            "display": "BodyStructure",
                            "definition": "Record details about an anatomical structure.  This resource may be used when a coded concept does not provide the necessary detail needed for the use case.",
                            "designation": [
                                {
                                    "language": "en",
                                    "use": {
                                        "system": "http://terminology.hl7.org/CodeSystem/designation-usage",
                                        "code": "display"
                                    },
                                    "value": "BodyStructure"
                                },
                                {
                                    "language": "it",
                                    "use": {
                                        "system": "http://terminology.hl7.org/CodeSystem/designation-usage",
                                        "code": "display"
                                    },
                                    "value": "StrutturaDelCorpo"
                                },
                                {
                                    "language": "fr",
                                    "use": {
                                        "system": "http://terminology.hl7.org/CodeSystem/designation-usage",
                                        "code": "display"
                                    },
                                    "value": "MorphologieDeCorps"
                                }
                                    ...
                       



The issue is that when applying text filtering with the parameter "filter", this filter is never applied to other language designations displays, so a ValueSet can never be filtered by a text in other language (only can be filtered in the default language used outside designations)


Should be nice if Hibernate Search can index the text content of this language designations displays in order to support search capabilities in different languages for a ValueSet.

Not sure if there is another option to manage different languages in ValueSet/CodeSystem.

Thanks in advance