Extends · closed
| anyOf The alternative schemas; a value must match at least one. When every arm is a literal, editors show a dropdown. | of | |
| description What the union is for, when it is written inline; a published schema is described by its page. | optional | |
| params Type parameters that make this schema generic, each with its default schema. | ⟨ * : ⟩ | optional |
| name Legacy: a name some published schemas still carry. New schemas are named by their page. | optional |
anyOf: the union keyword. It holds a list of schemas, and a value is valid if it matches any of them. It is the one composite construct in the schema language. A union whose arms are all literals is a fixed set of choices ({anyOf: ["draft", "published"]}), which the editors show as a dropdown.
This document describes the schema/anyof type, one variant of the meta-schema. Its formal schema is attached as the schemaDefinition in this document's metadata, so the app can show it and create values of this type. Typed documents explains how that works.
A union lists alternative schemas under anyOf. A value is valid if it matches any of them. When every arm is a literal, the union is a fixed set of choices, such as {"anyOf": ["draft", "published", "archived"]}. The editors offer that union as a dropdown.
An empty union, {"anyOf": []}, accepts no values. The library names this schema none. It differs from the literal schema null, which accepts the single value null.
See also
Discriminated union: how the meta-schema tells its variants apart.
Literal schema: the arms of a fixed set of choices.
Variant: the members of the meta-schema union.
The schema language: the full vocabulary.