Value types

A value type is a named schema you can reuse across properties. Use one when values such as addresses or coordinates should have the same shape wherever they appear.

Define a value type

Export defineValueType() from ontology/. An address can describe the same fields on customers, invoices, and other types:

// ontology/address.ts
import { defineValueType } from "@sixb/core/ontology"

export const Address = defineValueType({
  id: "Address",
  name: "Address",
  schema: {
    type: "object",
    properties: {
      street: { schema: "string", required: true },
      city: { schema: "string", required: true },
      postcode: { schema: "string" },
    },
  },
})

id, name, and schema are required. Add a description when it helps explain the value. The schema can use any of the property schema forms.

Use it in a property

Pass the imported definition to valueTypeRef(). This preserves the schema's TypeScript types and lets Sixb validate each value against it:

// ontology/customer.ts
import { defineObjectType, prop, valueTypeRef } from "@sixb/core/ontology"
import { Address } from "./address"

export const Customer = defineObjectType({
  id: "Customer",
  name: "Customer",
  properties: [
    prop("id", "string", { required: true, primary: true }),
    prop("name", "string", { required: true }),
    prop("billingAddress", valueTypeRef(Address), { required: true }),
    prop("shippingAddress", valueTypeRef(Address)),
  ],
})

The property's required and nullable options control whether the whole address may be omitted or null. The address schema controls the fields inside it.

A value type reuses a shape, not a shared record. Billing and shipping addresses hold independent values. If several objects should refer to one address with its own identity, define an object type and connect it with links.