Release 4B

Extension: expression

FHIR Infrastructure Work Group

Maturity Level: 1

Informative

Use Context: Any

URL for this extension:

http://hl7.org/fhir/StructureDefinition/cqf-expression

Status: draft. Extension maintained by: Health Level Seven, Inc. - CDS WG

An expression that, when evaluated, provides the value for the element on which it appears.

Context of Use: Use on Element ID Element

Summary

Name	Flags	Card.	Type	Description & Constraints
expression		0..*	Expression	URL = http://hl7.org/fhir/StructureDefinition/cqf-expression expression: An expression that, when evaluated, provides the value for the element on which it appears. Use on Element ID Element
Documentation for this format

Full Structure

Name	Card.	Type	Description & Constraints
extension	0..*	Extension	URL = http://hl7.org/fhir/StructureDefinition/cqf-expression expression: An expression that, when evaluated, provides the value for the element on which it appears. Use on Element ID Element
extension	0..0
url	1..1	uri	"http://hl7.org/fhir/StructureDefinition/cqf-expression"
value[x]	1..1	Expression	Value of extension
Documentation for this format

XML Template

<!-- expression -->

<extension xmlns="http://hl7.org/fhir"
     url="http://hl7.org/fhir/StructureDefinition/cqf-expression" >
  <!-- from Element: extension -->
 <valueExpression><!--  1..1 Expression Value of extension --></valueExpression>
</extension>

JSON Template

{ // expression
  // from Element: extension
    "extension" : [ //  sliced by value:url  in the specified order, Open ]
    "url" : "http://hl7.org/fhir/StructureDefinition/cqf-expression", // R! 
    "valueExpression" : { Expression } // C? R! Value of extension
  }

Summary

Name	Flags	Card.	Type	Description & Constraints
expression		0..*	Expression	URL = http://hl7.org/fhir/StructureDefinition/cqf-expression expression: An expression that, when evaluated, provides the value for the element on which it appears. Use on Element ID Element
Documentation for this format

Full Structure

Name	Card.	Type	Description & Constraints
extension	0..*	Extension	URL = http://hl7.org/fhir/StructureDefinition/cqf-expression expression: An expression that, when evaluated, provides the value for the element on which it appears. Use on Element ID Element
extension	0..0
url	1..1	uri	"http://hl7.org/fhir/StructureDefinition/cqf-expression"
value[x]	1..1	Expression	Value of extension
Documentation for this format

XML Template

<!-- expression -->

<extension xmlns="http://hl7.org/fhir"
     url="http://hl7.org/fhir/StructureDefinition/cqf-expression" >
  <!-- from Element: extension -->
 <valueExpression><!--  1..1 Expression Value of extension --></valueExpression>
</extension>

JSON Template

{ // expression
  // from Element: extension
    "extension" : [ //  sliced by value:url  in the specified order, Open ]
    "url" : "http://hl7.org/fhir/StructureDefinition/cqf-expression", // R! 
    "valueExpression" : { Expression } // C? R! Value of extension
  }

Constraints

ele-1: All FHIR elements must have a @value or children unless an empty Parameters resource (xpath: @value|f:*|h:div|self::f:Parameters)
ext-1: Must have either extensions or value[x], not both (xpath: exists(f:extension)!=exists(f:*[starts-with(local-name(.), 'value')]))
ele-1: On Extension.extension: All FHIR elements must have a @value or children (xpath on Extension.extension: @value|f:*|h:div)
ext-1: On Extension.extension: Must have either extensions or value[x], not both (xpath on Extension.extension: exists(f:extension)!=exists(f:*[starts-with(local-name(.), "value")]))
ele-1: On Extension.value[x]: All FHIR elements must have a @value or children (xpath on Extension.value[x]: @value|f:*|h:div)