Release 4

This page is part of the FHIR Specification (v4.0.1: R4 - Mixed Normative and STU) in it's permanent home (it will always be available at this URL). The current version which supercedes this version is 5.0.0. For a full list of available versions, see the Directory of published versions . Page versions: R4B R4

Extension hierarchy - Detailed Descriptions

FHIR Infrastructure Work Group Maturity Level: 1InformativeUse Context: Any

Detailed Descriptions for the elements in the extension.

Extension
Element IdExtension
Definition

For circular references (references back to the same type of resource): whether they are allowed to transitively point back to the same instance (false), or whether the relationship must be a strict one-way hierarchy (true).

Cardinality0..1 This element is affected by the following invariants: ele-1
Invariants
Inherited by this element
ele-1RuleAll FHIR elements must have a @value or childrenhasValue() or (children().count() > id.count())
ext-1RuleMust have either extensions or value[x], not bothextension.exists() != value.exists()
Extension.id
Element IdExtension.id
Definition

Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

Cardinality0..1
Typestring
Extension.extension
Element IdExtension.extension
Definition

An Extension

Cardinality0..0
TypeExtension
Invariants
Inherited by this element
ele-1RuleAll FHIR elements must have a @value or childrenhasValue() or (children().count() > id.count())
ext-1RuleMust have either extensions or value[x], not bothextension.exists() != value.exists()
SlicingThis element introduces a set of slices. The slicing rules are:
  • unordered
  • Open
  • discriminators: value:url
Extension.url
Element IdExtension.url
Definition

Source of the definition for the extension code - a logical name or a URL.

Cardinality1..1
Typeuri
Comments

The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.

Fixed Valuehttp://hl7.org/fhir/StructureDefinition/structuredefinition-hierarchy
Extension.value[x]
Element IdExtension.value[x]
Definition

Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).

Cardinality1..1
Typeboolean
[x] NoteSee Choice of Data Types for further information about how to use [x]
Invariants
Inherited by this element
ele-1RuleAll FHIR elements must have a @value or childrenhasValue() or (children().count() > id.count())