FHIR Extensions Pack
5.2.0-ballot - 5.2.0 Ballot - September 2024) International flag

FHIR Extensions Pack, published by HL7 International / FHIR Infrastructure. This guide is not an authorized publication; it is the continuous build for version 5.2.0-ballot built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/HL7/fhir-extensions/ and changes regularly. See the Directory of published versions

Extension: Variable

Official URL: http://hl7.org/fhir/StructureDefinition/variable Version: 5.2.0-ballot
Standards status: Trial-use Maturity Level: 3 Computable Name: Variable
Other Identifiers: OID:2.16.840.1.113883.4.642.5.1528

Variable specifying a logic to generate a variable for use in subsequent logic. The name of the variable will be added to FHIRPath's context when processing descendants of the element that contains this extension as well as extensions within the same element.

Context of Use

This extension may be used on the following element(s):

Usage info

Usage:

  • This Extension is not used by any profiles in this Implementation Guide

Changes since version 1.0.0:

  • The data elements list has changed
  • One or more text definitions, invariants or bindings have changed
  • Formal Views of Extension Content

    Description of Profiles, Differentials, Snapshots, and how the XML and JSON presentations work.

    This structure is derived from Extension

    Summary

    Simple Extension of type Expression: Variable specifying a logic to generate a variable for use in subsequent logic. The name of the variable will be added to FHIRPath's context when processing descendants of the element that contains this extension as well as extensions within the same element.

    Maturity: 3

     

    Other representations of profile: CSV, Excel, Schematron

    Constraints

    IdGradePath(s)DetailsRequirements
    ele-1error**ALL** elementsAll FHIR elements must have a @value or children
    : hasValue() or (children().count() > id.count())
    ext-1error**ALL** extensionsMust have either extensions or value[x], not both
    : extension.exists() != value.exists()
    var-1errorExtensionVariable expressions must have a name
    : value.name.exists()

    R4B

    The extension is represented a little differently in R4B:

    • Adjust the extension context RequestOrchestration to Basic
    • Adjust the extension context RequestOrchestration.action to Basic
    • Note: Extensions that have been modified for R4B are still draft while real-world experience is collected
    Name Flags Card. Type Description & Constraints doco
    . . Extension C 0..* Extension Variable for processing
    var-1: Variable expressions must have a name
    . . . extension 0 .. 0
    . . . url 1 .. 1 uri "http://hl7.org/fhir/StructureDefinition/variable"
    . . . value[x] 1.. 1 Expression Value of extension

    doco Documentation for this format

    R4

    The extension is represented a little differently in R4:

    • Adjust the extension context RequestOrchestration to Basic
    • Adjust the extension context RequestOrchestration.action to Basic
    • Note: Extensions that have been modified for R4 are still draft while real-world experience is collected
    Name Flags Card. Type Description & Constraints doco
    . . Extension C 0..* Extension Variable for processing
    var-1: Variable expressions must have a name
    . . . extension 0 .. 0
    . . . url 1 .. 1 uri "http://hl7.org/fhir/StructureDefinition/variable"
    . . . value[x] 1.. 1 Expression Value of extension

    doco Documentation for this format

    R3

    The extension is represented a little differently in R3:

    • Adjust the extension context RequestOrchestration to Basic
    • Adjust the extension context RequestOrchestration.action to Basic
    • Replace the type Expression with a set of extensions for the content of the type along with the _datatype extension
    • Note: Extensions that have been modified for R3 are still draft while real-world experience is collected
    Name Flags Card. Type Description & Constraints doco
    . . Extension C 0..* Extension Variable for processing
    var-1: Variable expressions must have a name
    . . . Slices for extension 0 ..* Extension Extension
    Slice: Unordered, Open by value:url
    . . . . extension:_datatype 1..1 (Complex) DataType name 'Expression' from R5
    URL: http://hl7.org/fhir/StructureDefinition/_datatype
    . . . . . value[x] 1.. 1 string Value of extension
    Fixed Value: Expression
    . . . . extension:description 0..1 Extension Natural language description of the condition
    . . . . . extension 0 .. 0
    . . . . . url 1 .. 1 uri "description"
    . . . . . value[x] 1.. 1 string Value of extension
    . . . . extension:name 0..1 Extension Short name assigned to expression for reuse
    . . . . . extension 0 .. 0
    . . . . . url 1 .. 1 uri "name"
    . . . . . value[x] 1.. 1 code Value of extension
    . . . . extension:language 0..1 Extension text/cql | text/fhirpath | application/x-fhir-query | etc.
    . . . . . extension 0 .. 0
    . . . . . url 1 .. 1 uri "language"
    . . . . . value[x] 1.. 1 code Value of extension
    Binding: ExpressionLanguage ( extensible ): The media type of the expression language.

    Additional Bindings Purpose
    MimeTypes Max Binding
    . . . . extension:expression 0..1 Extension Expression in specified language
    . . . . . extension 0 .. 0
    . . . . . url 1 .. 1 uri "expression"
    . . . . . value[x] 1.. 1 string Value of extension
    . . . . extension:reference 0..1 Extension Where the expression is found
    . . . . . extension 0 .. 0
    . . . . . url 1 .. 1 uri "reference"
    . . . . . value[x] 1.. 1 uri Value of extension
    . . . url 1 .. 1 uri "http://hl7.org/fhir/StructureDefinition/variable"
    . . . value[x] 0 .. 0

    doco Documentation for this format

    Search Parameters for this Extension

    (none found)