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: Target path

Official URL: http://hl7.org/fhir/StructureDefinition/targetPath Version: 5.2.0-ballot
Standards status: Trial-use Maturity Level: 2 Computable Name: TargetPath
Other Identifiers: OID:2.16.840.1.113883.4.642.5.1670

Indicates that the reference has a particular focus in the target resource, a particular element of interest, identified by a FHIRPath statement. The FHIRPath expression is limited to a the simple subset with the additional limitation that .resolve() that is not allowed. This is a more sophisticated mechanism of referring to an element than [[[http://hl7.org/fhir/StructureDefinition/targetElement]]] but does require the system resolving the item to be able to use at least FHIRPath. If the author of the reference has the ability to ensure an id will be present on the target [[[http://hl7.org/fhir/StructureDefinition/targetElement]]] might be more widely useable.

Context of Use

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

Usage info

Usage:

Changes since version 1.0.0:

  • The resource metadata has changed (description)
  • 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 string: Indicates that the reference has a particular focus in the target resource, a particular element of interest, identified by a FHIRPath statement. The FHIRPath expression is limited to a the simple subset with the additional limitation that .resolve() that is not allowed. This is a more sophisticated mechanism of referring to an element than Target element but does require the system resolving the item to be able to use at least FHIRPath. If the author of the reference has the ability to ensure an id will be present on the target Target element might be more widely useable.

    Maturity: 2

    This structure is derived from Extension

    NameFlagsCard.TypeDescription & Constraintsdoco
    .. Extension 0..* Extension A particular element of interest in the target resource (by limited FHIRPath)
    ... extension 0..0
    ... url 1..1 uri "http://hl7.org/fhir/StructureDefinition/targetPath"
    ... value[x] 1..1 string Value of extension

    doco Documentation for this format
    NameFlagsCard.TypeDescription & Constraintsdoco
    .. Extension 0..* Extension A particular element of interest in the target resource (by limited FHIRPath)
    ... id 0..1 id Unique id for inter-element referencing
    ... extension 0..0
    ... url 1..1 uri "http://hl7.org/fhir/StructureDefinition/targetPath"

    doco Documentation for this format

    This structure is derived from Extension

    Summary

    Simple Extension of type string: Indicates that the reference has a particular focus in the target resource, a particular element of interest, identified by a FHIRPath statement. The FHIRPath expression is limited to a the simple subset with the additional limitation that .resolve() that is not allowed. This is a more sophisticated mechanism of referring to an element than Target element but does require the system resolving the item to be able to use at least FHIRPath. If the author of the reference has the ability to ensure an id will be present on the target Target element might be more widely useable.

    Maturity: 2

    Differential View

    This structure is derived from Extension

    NameFlagsCard.TypeDescription & Constraintsdoco
    .. Extension 0..* Extension A particular element of interest in the target resource (by limited FHIRPath)
    ... extension 0..0
    ... url 1..1 uri "http://hl7.org/fhir/StructureDefinition/targetPath"
    ... value[x] 1..1 string Value of extension

    doco Documentation for this format

    Snapshot View

    NameFlagsCard.TypeDescription & Constraintsdoco
    .. Extension 0..* Extension A particular element of interest in the target resource (by limited FHIRPath)
    ... id 0..1 id Unique id for inter-element referencing
    ... extension 0..0
    ... url 1..1 uri "http://hl7.org/fhir/StructureDefinition/targetPath"

    doco Documentation for this format

     

    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()

    R4B

    The extension is unchanged in R4B

    R4

    The extension is unchanged in R4

    R3

    The extension is represented a little differently in R3:

    • Remove the extension context canonical
    • 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 0..* Extension A particular element of interest in the target resource (by limited FHIRPath)
    . . . extension 0 .. 0
    . . . url 1 .. 1 uri "http://hl7.org/fhir/StructureDefinition/targetPath"
    . . . value[x] 1.. 1 string Value of extension

    doco Documentation for this format

    Search Parameters for this Extension

    (none found)