DSTU2

This page is part of the FHIR Specification (v1.0.2: DSTU 2). 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: R5 R4B R4 R3 R2

6.17.8 Resource StructureDefinition - Detailed Descriptions

Detailed Descriptions for the elements in the StructureDefinition resource.

StructureDefinition
Definition

A definition of a FHIR structure. This resource is used to describe the underlying resources, data types defined in FHIR, and also for describing extensions, and constraints on resources and data types.

Control1..1
Alternate NamesTemplate; Profile
InvariantsDefined on this element
sdf-1: Element paths must be unique unless the structure is a constraint (xpath: exists(f:constrainedType) or (count(f:snapshot/f:element) = count(distinct-values(f:snapshot/f:element/f:path/@value))))
sdf-10: If the structure is not abstract, or there's a constrained type, then there SHALL be a base (xpath: (f:abstract/@value=true()) or not(exists(f:constrainedType)) or exists(f:base))
sdf-11: If there's a constrained type, its content must match the path name in the first element of a snapshot (xpath: not(exists(f:constrainedType)) or not(exists(f:snapshot)) or (f:constrainedType/@value = f:snapshot/f:element[1]/f:path/@value))
sdf-12: element.base cannot appear if there is no base on the structure definition (xpath: f:base or not(exists(f:snapshot/f:element/f:base) or exists(f:differential/f:element/f:base)))
sdf-13: element.base must appear if there is a base on the structure definition (xpath: not(f:constrainedType) or not(f:snapshot/f:element[not(f:base)]))
sdf-4: A structure must have a base unless abstract = true (xpath: (f:abstract/@value =true()) or exists(f:base))
sdf-5: If the structure defines an extension then the structure must have context information (xpath: not(f:constrainedType/@value = 'extension') or (exists(f:context) and exists(f:contextType)))
sdf-6: A structure must have either a differential, or a snapshot (or both) (xpath: exists(f:snapshot) or exists(f:differential))
sdf-7: If the structure describes a base Resource or Type, the URL has to start with "http://hl7.org/fhir/StructureDefinition/" and the tail must match the id (xpath: exists(f:constrainedType) or f:url/@value=concat('http://hl7.org/fhir/StructureDefinition/', f:id/@value))
sdf-8: In any snapshot or differential, all the elements except the first have to have a path that starts with the path of the first + "." (xpath: string-join(for $elementName in f:*[self::f:snapshot or self::f:differential]/f:element[position()>1]/f:path/@value return if (starts-with($elementName, concat($elementName/ancestor::f:element/parent::f:*/f:element[1]/f:path/@value, '.'))) then '' else $elementName,'')='')
sdf-9: In any snapshot or differential, no label, code or requirements on the an element without a "." in the path (e.g. the first element) (xpath: not(exists(f:snapshot/f:element[not(contains(f:path/@value, '.')) and (f:label or f:code or f:requirements)])) and not(exists(f:differential/f:element[not(contains(f:path/@value, '.')) and (f:label or f:code or f:requirements)])))
StructureDefinition.url
Definition

An absolute URL that is used to identify this structure definition when it is referenced in a specification, model, design or an instance. This SHALL be a URL, SHOULD be globally unique, and SHOULD be an address at which this structure definition is (or will be) published.

Control1..1
Typeuri
Requirements

So you can say, in a StructureDefinition, what the full extension URLs should be. This is required to allow hosting StructureDefinitions on multiple different servers, and to allow for the editorial process.

Alternate Namesurl; authoritative-url; destination; identity
Summarytrue
gForge Tasks3265
StructureDefinition.identifier
Definition

Formal identifier that is used to identify this StructureDefinition when it is represented in other formats, or referenced in a specification, model, design or an instance (should be globally unique OID, UUID, or URI), (if it's not possible to use the literal URI).

NoteThis is a business identifer, not a resource identifier (see discussion)
Control0..*
TypeIdentifier
Summarytrue
StructureDefinition.version
Definition

The identifier that is used to identify this version of the StructureDefinition when it is referenced in a specification, model, design or instance. This is an arbitrary value managed by the StructureDefinition author manually.

NoteThis is a business versionId, not a resource identifier (see discussion)
Control0..1
Typestring
Requirements

There may be multiple resource versions of the StructureDefinition that have this same identifier. The resource version id will change for technical reasons, whereas the stated version number needs to be under the author's control.

Summarytrue
StructureDefinition.name
Definition

A free text natural language name identifying the StructureDefinition.

Control1..1
Typestring
Summarytrue
Comments

Not expected to be globally unique.

StructureDefinition.display
Definition

Defined so that applications can use this name when displaying the value of the extension to the user.

Control0..1
Typestring
Summarytrue
Comments

Applications don't have to use this name, but can always fall back to it. In the absence of a value for this element, use the name.

StructureDefinition.status
Definition

The status of the StructureDefinition.

Control1..1
BindingConformanceResourceStatus: The lifecycle status of a Value Set or Concept Map. (Required)
Typecode
Is Modifiertrue
Requirements

Allows filtering of StructureDefinitions that are appropriate for use vs. not.

Summarytrue
StructureDefinition.experimental
Definition

This StructureDefinition was authored for testing purposes (or education/evaluation/marketing), and is not intended to be used for genuine usage.

Control0..1
Typeboolean
Requirements

Allows filtering of StructureDefinitions that are appropriate for use vs. not.

Summarytrue
StructureDefinition.publisher
Definition

The name of the individual or organization that published the structure definition.

Control0..1
Typestring
Requirements

Helps establish the "authority/credibility" of the structure definition. May also allow for contact.

Summarytrue
Comments

Usually an organization, but may be an individual. This item SHOULD be populated unless the information is available from context.

StructureDefinition.contact
Definition

Contacts to assist a user in finding and communicating with the publisher.

Control0..*
Summarytrue
Comments

May be a web site, an email address, a telephone number (tel:), etc.

StructureDefinition.contact.name
Definition

The name of an individual to contact regarding the structure definition.

Control0..1
Typestring
Summarytrue
Comments

If there is no named individual, the telecom is for the organization as a whole.

StructureDefinition.contact.telecom
Definition

Contact details for individual (if a name was provided) or the publisher.

Control0..*
TypeContactPoint
Summarytrue
StructureDefinition.date
Definition

The date this version of the structure definition was published. The date must change when the business version changes, if it does, and it must change if the status code changes. In addition, it should change when the substantive content of the structure definition changes.

Control0..1
TypedateTime
Summarytrue
Comments

Additional specific dates may be added as extensions.

StructureDefinition.description
Definition

A free text natural language description of the StructureDefinition and its use.

Control0..1
Typestring
Summarytrue
Comments

This field can be used for things such as why the StructureDefinition was written, comments about misuse, instructions for clinical use and interpretation, literature references, examples from the paper world, etc. It is not a rendering of the StructureDefinition as conveyed in StructureDefinition.text. This item SHOULD be populated unless the information is available from context.

StructureDefinition.useContext
Definition

The content was developed with a focus and intent of supporting the contexts that are listed. These terms may be used to assist with indexing and searching of structure definitions.

Control0..*
BindingContext of Use ValueSet: Indicates the countries, regions, disciplines and other aspects of use within which this artifact is targeted for use. (Extensible)
TypeCodeableConcept
Requirements

Assist in searching for appropriate content.

Summarytrue
StructureDefinition.requirements
Definition

Explains why this structure definition is needed and why it's been constrained as it has.

Control0..1
Typestring
Comments

This element does not describe the usage of the structure definition (that's done in comments), rather it's for traceability of why the element is either needed or why the constraints exist as they do. This may be used to point to source materials or specifications that drove the structure of this data element.

StructureDefinition.copyright
Definition

A copyright statement relating to the structure definition and/or its contents. Copyright statements are generally legal restrictions on the use and publishing of the details of the constraints and mappings.

Control0..1
Typestring
Alternate NamesLicense; Restrictions
StructureDefinition.code
Definition

A set of terms from external terminologies that may be used to assist with indexing and searching of templates.

Control0..*
BindingStructure Definition Codes: Codes for the meaning of the defined structure (SNOMED CT and LOINC codes, as an example). (Example)
TypeCoding
Requirements

Assist in searching for appropriate StructureDefinitions.

Summarytrue
StructureDefinition.fhirVersion
Definition

The version of the FHIR specification on which this StructureDefinition is based - this is the formal version of the specification, without the revision number, e.g. [publication].[major].[minor], which is 1.0.2 for this version.

Control0..1
Typeid
Summarytrue
Comments

A StructureDefinition does not need to specify the target it applies to,as StructureDefinitions will often be valid across multiple versions of FHIR. FHIR tooling can determine whether a StructureDefinition is consistent with a particular StructureDefinition if desired.

StructureDefinition.mapping
Definition

An external specification that the content is mapped to.

Control0..*
InvariantsDefined on this element
sdf-2: Must have at a name or a uri (or both) (xpath: exists(f:uri) or exists(f:name))
StructureDefinition.mapping.identity
Definition

An Internal id that is used to identify this mapping set when specific mappings are made.

Control1..1
Typeid
Comments

The specification is described once, with general comments, and then specific mappings are made that reference this declaration.

StructureDefinition.mapping.uri
Definition

An absolute URI that identifies the specification that this mapping is expressed to.

Control0..1
Typeuri
Comments

A formal identity for the specification being mapped to helps with identifying maps consistently.

InvariantsAffect this element
sdf-2: Must have at a name or a uri (or both) (xpath: exists(f:uri) or exists(f:name))
StructureDefinition.mapping.name
Definition

A name for the specification that is being mapped to.

Control0..1
Typestring
InvariantsAffect this element
sdf-2: Must have at a name or a uri (or both) (xpath: exists(f:uri) or exists(f:name))
StructureDefinition.mapping.comments
Definition

Comments about this mapping, including version notes, issues, scope limitations, and other important notes for usage.

Control0..1
Typestring
StructureDefinition.kind
Definition

Defines the kind of structure that this definition is describing.

Control1..1
BindingStructureDefinitionKind: Defines the type of structure that a definition is describing. (Required)
Typecode
Summarytrue
StructureDefinition.constrainedType
Definition

The type of type that is being constrained - a data type, an extension, a resource, including abstract ones. If this field is present, it indicates that the structure definition is a constraint. If it is not present, then the structure definition is the definition of a base structure.

Control0..1
BindingFHIRDefinedType: Any defined Resource or Data Type name
Typecode
Summarytrue
Comments

if a constrained type is present, then there SHALL be a base resource as well. Note that the constrained type could be determined by chasing through the base references until the base definition is reached, or by looking at the path of the first element in the snapshot - if present - but providing the constrainedType directly makes for simpler tooling and indexing.

InvariantsAffect this element
sdf-10: If the structure is not abstract, or there's a constrained type, then there SHALL be a base (xpath: (f:abstract/@value=true()) or not(exists(f:constrainedType)) or exists(f:base))
sdf-11: If there's a constrained type, its content must match the path name in the first element of a snapshot (xpath: not(exists(f:constrainedType)) or not(exists(f:snapshot)) or (f:constrainedType/@value = f:snapshot/f:element[1]/f:path/@value))
StructureDefinition.abstract
Definition

Whether structure this definition describes is abstract or not - that is, whether an actual exchanged item can ever be of this type.

Control1..1
Typeboolean
Summarytrue
Comments

Abstract Resources cannot be instantiated - a concrete sub-type must be used. Abstract datatypes and extensions cannot be used in an instance. Flagging a constraint structure as abstract conveys design intent but makes no difference to how the structure definition is handled. Note that inline declared elements that are given the type "Element" in the profile, but have children described, are anonymous concrete types that specialise Element. Abstract is not relevant for logical models.

StructureDefinition.contextType
Definition

If this is an extension, Identifies the context within FHIR resources where the extension can be used.

Control0..1
BindingExtensionContext: How an extension context is interpreted. (Required)
Typecode
Summarytrue
InvariantsAffect this element
sdf-5: If the structure defines an extension then the structure must have context information (xpath: not(f:constrainedType/@value = 'extension') or (exists(f:context) and exists(f:contextType)))
StructureDefinition.context
Definition

Identifies the types of resource or data type elements to which the extension can be applied.

Control0..*
Typestring
Summarytrue
Comments

If the context is an element that can have multiple types, then use (e.g.) value[x] if the extension works on all choice types, or otherwise an enumeration of explicitly named elements if not. Note that a context of "string" doesn't mean that the extension can be used with one of the string patterns such as "id" etc.

InvariantsAffect this element
sdf-5: If the structure defines an extension then the structure must have context information (xpath: not(f:constrainedType/@value = 'extension') or (exists(f:context) and exists(f:contextType)))
StructureDefinition.base
Definition

An absolute URI that is the base structure from which this set of constraints is derived.

Control0..1
Typeuri
Summarytrue
Comments

If differential constraints are specified in this structure, they are applied to the base in a "differential" fashion. If there is no base, then the differential constraints cannot be provided (snapshot only). Differential structures are useful for the editing perspective, and snapshot structures are suitable for operational use. The FHIR Project provides a number of tools/services to populate snapshots from differential constraints. Logical Models have a base of "Element" or another logical model.

InvariantsAffect this element
sdf-4: A structure must have a base unless abstract = true (xpath: (f:abstract/@value =true()) or exists(f:base))
sdf-10: If the structure is not abstract, or there's a constrained type, then there SHALL be a base (xpath: (f:abstract/@value=true()) or not(exists(f:constrainedType)) or exists(f:base))
StructureDefinition.snapshot
Definition

A snapshot view is expressed in a stand alone form that can be used and interpreted without considering the base StructureDefinition.

Control0..1
InvariantsDefined on this element
sdf-3: Each element definition in a snapshot must have a formal definition and cardinalities (xpath: count(f:element) = count(f:element[exists(f:definition) and exists(f:min) and exists(f:max)]))
Affect this element
sdf-6: A structure must have either a differential, or a snapshot (or both) (xpath: exists(f:snapshot) or exists(f:differential))
StructureDefinition.snapshot.element
Definition

Captures constraints on each element within the resource.

Control1..*
TypeElementDefinition
InvariantsAffect this element
sdf-3: Each element definition in a snapshot must have a formal definition and cardinalities (xpath: count(f:element) = count(f:element[exists(f:definition) and exists(f:min) and exists(f:max)]))
StructureDefinition.differential
Definition

A differential view is expressed relative to the base StructureDefinition - a statement of differences that it applies.

Control0..1
InvariantsAffect this element
sdf-6: A structure must have either a differential, or a snapshot (or both) (xpath: exists(f:snapshot) or exists(f:differential))
StructureDefinition.differential.element
Definition

Captures constraints on each element within the resource.

Control1..*
TypeElementDefinition