CTS2-LE REST API: Resolve Value Set

Operation Signature

REST Call Syntax

http://<host>/WebCts2LE/rest/fhir/ValueSet?_query=expandResource&identifier=<valueset-URI>&stylesheet=<stylesheet-path>

Parameters

identifier: URI-encoded identifier of the requested value set or codesystem (mandatory)

stylesheet: stylesheet that will be referenced within the XML response (optional)

Result

In case of an successful processing of the call, the result will an FHIR Value Set resource as defined in http://www.hl7.org/fhir/valueset.html containing the contents of the requested value set or codesystem.

In case of an error an empty FHIT Value Set resource is returned.

Additional Info

(A) If _query == 'expand' then identifier must be an URI of a value set and the response is the corresponding FHIR expansion. To restrict the expansion to code systems or codes, codeSystemUri and code have to be set accordingly.
(B) If _query == 'expandDefinedCodeSystem' then identifier has no meaning and codeSystemUri must be set. To restrict the expansion to a code, code has to be set accordingly.
(C) If _query == 'expandResource' then identifier must be an URI of a (1) CTS2 value set OR a (2) code system. In case of (1) processing (A) will be performed. In case of (2) processing (B) will be performed where codeSystemUri=identifier.

Example

The main purpose of the method is to resolve value sets in order to allow for

1. display value set items to the user
2. validation of code system/value set references of an electronic health record

In order to reference the value set properly, one has to use its identifier, e.g. http://hl7.org/fhir/vs/administrative-gender

This identifier has to be part of the http-call

http://<host>/WebCts2LE/rest/fhir/ValueSet?_query=expand&identifier=http://hl7.org/fhir/vs/administrative-gender

that will return the following value set expansion

<atom:feed xmlns:atom="http://www.w3.org/2005/Atom" xmlns="http://hl7.org/fhir"
   xmlns:at="http://purl.org/atompub/tombstones/1.0" xmlns:ds="http://www.w3.org/2000/09/xmldsig#"
   xmlns:os="http://a9.com/-/spec/opensearch/1.1/" xmlns:xhtml="http://www.w3.org/1999/xhtml"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
   <atom:title>Value Set Expansion</atom:title>
   <atom:id>urn:uuid:dc9f2f7e-6a1b-4389-9b88-7048787227c2</atom:id>
   <atom:updated>2015-04-05T13:46:55</atom:updated>
   <atom:entry>
      <atom:title>Value Set Resolution</atom:title>
      <atom:id>http://hl7.org/fhir/vs/administrative-gender</atom:id>
      <atom:updated>2015-04-05T13:46:55</atom:updated>
      <atom:content>
         <ValueSet xmlns="http://hl7.org/fhir">
            <name value="..." />
            <description value="..." />
            <status value="draft" />
            <expansion>
               <timestamp />
               <contains xmlns="http://hl7.org/fhir">
                  <system value="urn:oid:2.16.840.1.113883.5.1" />
                  <code value="F" />
                  <display value="Female" />
               </contains>
               <contains xmlns="http://hl7.org/fhir">
                  <system value="urn:oid:2.16.840.1.113883.5.1" />
                  <code value="M" />
                  <display value="Male" />
               </contains>
               <contains xmlns="http://hl7.org/fhir">
                  <system value="urn:oid:2.16.840.1.113883.5.1" />
                  <code value="UN" />
                  <display value="Undifferentiated" />
               </contains>
               <contains xmlns="http://hl7.org/fhir">
                  <system value="urn:oid:2.16.840.1.113883.5.1008" />
                  <code value="UNK" />
                  <display value="unknown" />
               </contains>
            </expansion>
         </ValueSet>
      </atom:content>
   </atom:entry>
</atom:feed>

Appropriate XPATH expressions should select the code list. E.g., the XPATH expression

/atom:feed/atom:entry/atom:content/ValueSet/expansion/contains

retrieves all (code, code system)-pairs with their display name.