Schema

The schema defines elements and specifies constraint rules, which are applied on top of base schemas.

Syntax

Properties applicable only to schema

All properties are required

URL property

url : string

Resource type property

type : string

Name property

name : string

Derivation property

derivation : specialization or constraint

Optional properties

Base type property

base : string

Properties shared with elements

Requires and exclusions properties

excluded (array of strings)
required (array of strings)

Nested elements property

elements (object)

Constraints property

constraints

Extensions property

extensions

Base

The base property defines the base profile from which schema will inherit all elements and constraints

Example

You can create resource with base profile of US Core Patient:

url: http://example.com/patient
base: http://hl7.org/fhir/us/core/StructureDefinition/us-core-patient|6.0.0
type: Patient
name: ExamplePatient

Valid Patient resource:

resourceType: Patient
meta:
  profile:
  - http://example.com/patient
identifier:
- system: exampleSystem
  value: exampleValue
gender: male
name:
- given:
  - Example name

Invalid Patient resource with wrong `gender` type:

resourceType: Patient
meta:
  profile:
  - http://example.com/patient
identifier:
- system: exampleSystem
  value: exampleValue
gender: true # wrong type
name:
- given:
  - Example name

Derivation

The derivation property defines the type of described object of FHIR Schema: specialization for custom resources and constraint for profiles (see details: TypeDerivationRule)

Examples

The custom resource with specialization:

url: http://example.com/Foo
base: http://hl7.org/fhir/StructureDefinition/Resource
name: Foo
type: Foo
derivation: specialization

The profile with constraint:

url: http://example.com/Foo-Bar-profile
base: Foo
name: Bar
type: Foo
derivation: constraint

URL

The url is used to reference the profile in base property in other profiles.

Example

After creating profile with following url:

base: http://hl7.org/fhir/StructureDefinition/Patient
url: http://example.com/Patient/patient
elements:
  new-element:
    type: string

You can reference it, for example, in base property from another profile:

base: http://example.com/Patient/patient|1.0.0

Or you can reference it with meta.profile in resource, if you want to validate resource against not default profile:

Valid Patient resource

meta:
  profile: http://example.com/Patient/patient|1.0.0
new-element: "Example"

Invalid Patient resource with wrong elements type

meta:
  profile: http://example.com/Patient/patient|1.0.0
new-element: true

Resource type

The type property defines which resource type being constrained. The type must match with type property of base profile.

Example:

base: http://hl7.org/fhir/StructureDefinition/Patient
type: Patient

Name

Property name is machine readable name of profile. It is can be used as alias.

Example

After creating profile

name: ExamplePatient

You can reference it with name in other profiles


elements:
  a:
    refers: [ExamplePatient]

FHIRSchema