Resources: the building blocks

Everything exchangeable is a resource. Which ones exist?

Everything exchangeable in FHIR is a resource. So which resources exist? One index page lists them all, grouped in layers.

The index is grouped in layers

The resource index groups resources into layers; here are four of them. Foundation holds conformance, terminology, security and documents. Base covers individuals, entities, workflow and management, and includes the patient and practitioner resources. Clinical covers summary, diagnostics, medications, care provision, and requests and responses, and includes observation and condition. And financial covers support, billing, payment and general.

• Financial · Support, billing, payment, general. · scale
• Clinical · Summary, diagnostics, medications, care. · pill
• Base · Individuals, entities, workflow, management. · people
• Foundation · Conformance, terminology, security, documents. · layers

Every resource has a logical id

Each resource has an id element, called the logical id. It is assigned by the server responsible for storing the resource. It is unique among resources of the same type on that server. And once the server has assigned it, the id is never changed.

• Assigned · By the server · The server that stores the resource. · gear
• Unique · Within a resource type · On that server. · key
• Stable · Never changed · Once assigned, it stays. · lock

Each element has a datatype

Look inside the patient resource. Each element has a name and a datatype. Identifier is an identifier. Name is a human name. Telecom is a contact point. Gender is a code. Birth date is a date. And address is an address. The next lesson explains these datatypes.

• identifier · Identifier · tag · navy
• name · HumanName · person · navy
• telecom · ContactPoint · share · amber
• gender · code · people · slate
• birthDate · date · calendar · slate
• address · Address · pin · slate

Check yourself

Pause and think. What happens to a resource's logical id once the server has assigned it? The answer: it is never changed.

• It is never changed
• It changes on every update
• It is chosen again by each client
• It is reused for another resource type

Keep these in mind

The resource index groups resources in layers. Each resource has a logical id from its server. A logical id is unique for its type and never changes. And each element has a datatype.

• The resource index groups resources in layers
• Each resource has a logical id from its server
• A logical id is unique per type and never changes
• Each element has a datatype