HL7.FHIR.UV.EXTENSIONS\Target Constraint

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 Constraint

Official URL: http://hl7.org/fhir/StructureDefinition/targetConstraint				Version: 5.2.0-ballot
Standards status: Trial-use		Maturity Level: 2	Responsible: HL7 International / Clinical Decision Support	Computable Name: TargetConstraint

Specifies a constraint that is enforced on instantiated (or target) resources. This extension can be applied to definitional resources (such as ActivityDefinition or Measure) and indicates that the constraint should be enforced on resources that are instantiated from the definition. For example, this extension can be used to define a constraint such as numerator count must be less than or equal to denominator count.

This extension allows constraints to be specified as part of definitional resources as an alternative to having to define a profile to enforce the constraint.

Context of Use

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

Element ID ActivityDefinition
Element ID ActivityDefinition.participant
Element ID ActivityDefinition.dosage
Element ID Measure
Element ID Measure.group
Element ID Measure.group.population
Element ID Measure.group.stratifier
Element ID Measure.supplementalData
Element ID PlanDefinition
Element ID PlanDefinition.goal
Element ID PlanDefinition.goal.target
Element ID PlanDefinition.actor
Element ID PlanDefinition.action
Element ID Questionnaire
Element ID Questionnaire.item

Usage info

Usage:

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

Changes since version 1.0.0:

No changes

Formal Views of Extension Content

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

Text Summary
Differential Table
Snapshot Table
All

This structure is derived from Extension

Summary

Complex Extension: Specifies a constraint that is enforced on instantiated (or target) resources. This extension can be applied to definitional resources (such as ActivityDefinition or Measure) and indicates that the constraint should be enforced on resources that are instantiated from the definition. For example, this extension can be used to define a constraint such as numerator count must be less than or equal to denominator count.

key: id: A unique identifier for the invariant (unique in the context of the resource).
requirements: markdown: A brief description of why the constraint is necessary or appropriate.
severity: code: Whether the constraint indicates an error condition or a warning.
expression: Expression: An expression providing a formal representation of the invariant condition.
human: string: A free text expression of the rule to display to the user if the rule is violated.
location: string: Relative paths to the elements this rule is enforced against.

Maturity: 2

This structure is derived from Extension

Name	Card.	Type	Description & Constraints
Extension	0..*	Extension	A constraint on the target resource
Slices for extension			Content/Rules for all slices
extension:key	1..1	Extension	Unique identifier
extension	0..0
url	1..1	uri	"key"
value[x]	1..1	id	Value of extension
extension:requirements	0..1	Extension	Why the constraint is defined
extension	0..0
url	1..1	uri	"requirements"
value[x]	1..1	markdown	Value of extension
extension:severity	1..1	Extension	error \| warning
extension	0..0
url	1..1	uri	"severity"
value[x]	1..1	code	Value of extension Binding: ConstraintSeverity (required)
extension:expression	1..1	Extension	The invariant expression
extension	0..0
url	1..1	uri	"expression"
value[x]	1..1	Expression	Value of extension
extension:human	1..1	Extension	Human-readable rule
extension	0..0
url	1..1	uri	"human"
value[x]	1..1	string	Value of extension
extension:location	0..*	Extension	Relative path to elements
extension	0..0
url	1..1	uri	"location"
value[x]	1..1	string	Value of extension
url	1..1	uri	"http://hl7.org/fhir/StructureDefinition/targetConstraint"
value[x]	0..0
Documentation for this format

Name	Card.	Type	Description & Constraints
Extension	0..*	Extension	A constraint on the target resource
id	0..1	id	Unique id for inter-element referencing
Slices for extension	4..*	Extension	Additional content defined by implementations Slice: Unordered, Open by value:url
extension:key	1..1	Extension	Unique identifier
id	0..1	id	Unique id for inter-element referencing
extension	0..0
url	1..1	uri	"key"
value[x]	1..1	id	Value of extension
extension:requirements	0..1	Extension	Why the constraint is defined
id	0..1	id	Unique id for inter-element referencing
extension	0..0
url	1..1	uri	"requirements"
value[x]	1..1	markdown	Value of extension
extension:severity	1..1	Extension	error \| warning
id	0..1	id	Unique id for inter-element referencing
extension	0..0
url	1..1	uri	"severity"
value[x]	1..1	code	Value of extension Binding: ConstraintSeverity (required)
extension:expression	1..1	Extension	The invariant expression
id	0..1	id	Unique id for inter-element referencing
extension	0..0
url	1..1	uri	"expression"
value[x]	1..1	Expression	Value of extension
extension:human	1..1	Extension	Human-readable rule
id	0..1	id	Unique id for inter-element referencing
extension	0..0
url	1..1	uri	"human"
value[x]	1..1	string	Value of extension
extension:location	0..*	Extension	Relative path to elements
id	0..1	id	Unique id for inter-element referencing
extension	0..0
url	1..1	uri	"location"
value[x]	1..1	string	Value of extension
url	1..1	uri	"http://hl7.org/fhir/StructureDefinition/targetConstraint"
Documentation for this format

This structure is derived from Extension

Summary

Complex Extension: Specifies a constraint that is enforced on instantiated (or target) resources. This extension can be applied to definitional resources (such as ActivityDefinition or Measure) and indicates that the constraint should be enforced on resources that are instantiated from the definition. For example, this extension can be used to define a constraint such as numerator count must be less than or equal to denominator count.

key: id: A unique identifier for the invariant (unique in the context of the resource).
requirements: markdown: A brief description of why the constraint is necessary or appropriate.
severity: code: Whether the constraint indicates an error condition or a warning.
expression: Expression: An expression providing a formal representation of the invariant condition.
human: string: A free text expression of the rule to display to the user if the rule is violated.
location: string: Relative paths to the elements this rule is enforced against.

Maturity: 2

Differential View

This structure is derived from Extension

Name	Card.	Type	Description & Constraints
Extension	0..*	Extension	A constraint on the target resource
Slices for extension			Content/Rules for all slices
extension:key	1..1	Extension	Unique identifier
extension	0..0
url	1..1	uri	"key"
value[x]	1..1	id	Value of extension
extension:requirements	0..1	Extension	Why the constraint is defined
extension	0..0
url	1..1	uri	"requirements"
value[x]	1..1	markdown	Value of extension
extension:severity	1..1	Extension	error \| warning
extension	0..0
url	1..1	uri	"severity"
value[x]	1..1	code	Value of extension Binding: ConstraintSeverity (required)
extension:expression	1..1	Extension	The invariant expression
extension	0..0
url	1..1	uri	"expression"
value[x]	1..1	Expression	Value of extension
extension:human	1..1	Extension	Human-readable rule
extension	0..0
url	1..1	uri	"human"
value[x]	1..1	string	Value of extension
extension:location	0..*	Extension	Relative path to elements
extension	0..0
url	1..1	uri	"location"
value[x]	1..1	string	Value of extension
url	1..1	uri	"http://hl7.org/fhir/StructureDefinition/targetConstraint"
value[x]	0..0
Documentation for this format

Snapshot View

Name	Card.	Type	Description & Constraints
Extension	0..*	Extension	A constraint on the target resource
id	0..1	id	Unique id for inter-element referencing
Slices for extension	4..*	Extension	Additional content defined by implementations Slice: Unordered, Open by value:url
extension:key	1..1	Extension	Unique identifier
id	0..1	id	Unique id for inter-element referencing
extension	0..0
url	1..1	uri	"key"
value[x]	1..1	id	Value of extension
extension:requirements	0..1	Extension	Why the constraint is defined
id	0..1	id	Unique id for inter-element referencing
extension	0..0
url	1..1	uri	"requirements"
value[x]	1..1	markdown	Value of extension
extension:severity	1..1	Extension	error \| warning
id	0..1	id	Unique id for inter-element referencing
extension	0..0
url	1..1	uri	"severity"
value[x]	1..1	code	Value of extension Binding: ConstraintSeverity (required)
extension:expression	1..1	Extension	The invariant expression
id	0..1	id	Unique id for inter-element referencing
extension	0..0
url	1..1	uri	"expression"
value[x]	1..1	Expression	Value of extension
extension:human	1..1	Extension	Human-readable rule
id	0..1	id	Unique id for inter-element referencing
extension	0..0
url	1..1	uri	"human"
value[x]	1..1	string	Value of extension
extension:location	0..*	Extension	Relative path to elements
id	0..1	id	Unique id for inter-element referencing
extension	0..0
url	1..1	uri	"location"
value[x]	1..1	string	Value of extension
url	1..1	uri	"http://hl7.org/fhir/StructureDefinition/targetConstraint"
Documentation for this format

Other representations of profile: CSV, Excel, Schematron

Terminology Bindings

Path	Conformance	ValueSet	URI
Extension.extension:severity.value[x]	required	ConstraintSeverity `http://hl7.org/fhir/ValueSet/constraint-severity` from the FHIR Standard

Constraints

Id	Grade	Path(s)	Details	Requirements
ele-1	error	ALL elements	All FHIR elements must have a @value or children : hasValue() or (children().count() > id.count())
ext-1	error	ALL extensions	Must have either extensions or value[x], not both : extension.exists() != value.exists()

Notes:

When reporting the results of this custom validation rule via an OperationOutcome (issue), the following property mappings should be considered:

Issue property	Constraint property	Comments
severity	severity
code	‘Invariant’	Fixed code value from issue-type CodeSystem
details.coding.system	`Questionnaire.url`	Canonical URL of Questionnaire that contains this constraint
details.coding.code	`key`
details.coding.display	`human`	This is the human readable error message
details.text	`human`	This value can also be displayed to a user (instead of the coding.display above) and is often useful to also prefix the {}human{} value with the display text from the item(s)
diagnostics	`expression`	The validation fhirpath expression (helps diagnose issues with validation rules)
expression	evaluate `location`	The location expression should be evaluated on the QuestionnaireResponse (or item) to provide the location(s) of the error to permit a User Interface to show the error associated with the specific field(s) that caused the error/warning

The location component is a FHIRPath expression that should be executed on the target resource (or item that the constraint is associated with) to locate the path of the property(s) that should be flagged to the user when the constraint is violated.

When the location property is missing, it is assumed that the path of the answer being validated should be reported in the issue, and the path to the item in the target resource being validated should be used in the issue.expression field

e.g. A Questionnaire that has a group (g1) with 2 items (acc-date and review-date).

A validation rule will be added on the g1 item:

"url":"http://example.org/Questionnaire/abc",
...
"linkId":"q1",
"text": "Question 1",
{ 
    "key": "seq-dt", 
    "severity": "error", 
    "expression" : "item.where(linkId='acc-date').answer.first().trace('acc-date') < %resource.authored.trace('authored')", 
    "human": "The accident date must be before the completion date of the form", 
    "location": "item.where(linkId='acc-date').answer.first()" 
}

Example issue created from the above invariant example

{
  "severity": "error",
  "code": "Invariant",
  "details": {
    "coding": [{
      "system": "http://example.org/Questionnaire/abc", 
      "code" : "seq-dt", 
      "display": "The accident date must be before the review date"
    }],
    "text":"Question 1: The accident date must be before the completion date"
  },
  "diagnostics": "item.where(linkId='acc-date').answer.first().trace('acc-date') <  %resource.authored.trace('authored') acc-date: 2024-03-17; authored: 2024-02-01",
  "expression": ["QuestionnaireResponse.item[0].item[1].answer[0].value[0]"]
}

Search Parameters for this Extension

(none found)

IG © 2022+ HL7 International / FHIR Infrastructure. Package hl7.fhir.uv.extensions#5.2.0-ballot based on FHIR 5.0.0. Generated 2024-08-28
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