AU eRequesting Implementation Guide, published by HL7 Australia. This guide is not an authorized publication; it is the continuous build for version 0.2.0-ci-build built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/hl7au/au-fhir-erequesting/ and changes regularly. See the Directory of published versions

General Guidance

Read/Search Syntax

Searching resources is defined by the FHIR RESTful API and included here for informative purposes. The AU eRequesting CapabilityStatements document the server and client rules for the RESTful interactions described in this guide.

All the search interactions in this guide use the GET command with the following syntax:

GET [base]/[Resource-type]?[parameter1]{:m1|m2|...}={c1|c2|...}[value1{,value2,...}]{&[parameter2]{:m1|m2|...}={c1|c2|...}[value1{,value2,...}]&...}

• GET is the HTTP verb used for fetching a resource
• Variables surrounded by “[]” are mandatory for the client to supply and will be replaced by the string literal identified.
• Variables surrounded by “{}” are optional for the client to supply and will be replaced by the string literal identified.
• Variables:
  • base: The Service Root URL (e.g., “https://fhir-open-api-dstu2.smarthealthit.org”)
  • Resource-type: The name of a resource type (e.g., “Patient”)
  • parameter: the search parameters as defined for the particular interaction (e.g.,”?patient=Patient/123”)
  • value: the search parameter value for a particular search
    • When searching using the token type SearchParameter (how to search by token), the syntax {system|}[code] means that the system value is optional for the client to supply.:
    • When searching using the reference type SearchParameter (how to search by reference), the syntax {Type/}[id] means that the Type value is optional for the client to supply:
    • When searching using the date type SearchParameter (how to search by date), the syntax {gt|lt|ge|le}[date] means the date comparators “gt”, “lt”, “ge”, and “le” are optional. Date type searches without a comparator prefix are equivalent to searches with the “eq” comparator even if a server does not support the comparator.
  • {:m1|m2|…}: The list of supported search parameter modifiers
  • {c1|c2|…}: The list of supported search parameter comparators
  • {,value2,…}: Optional multiple ‘OR’ Values
  • {&parameter2={:m1|m2|…}={c1|c2|…}[value1{,value2,…}&…}: Optional multiple ‘AND’ search parameters

In the simplest case, a search is executed by performing a GET operation in the RESTful framework:

GET [base]/[Resource-type]?name=value&...

For this RESTful search, the parameters are a series of name=[value] pairs encoded in the URL. The search parameter names are defined for each resource. For example, the Observation resource has the name “code” for searching on the LOINC or SNOMED CT-AU code. For more information, see the FHIR RESTful Search API.