Maps a GraphQL enum type to a Java enum class through a jOOQ converter. Pairs with the schema’s database-bound enum columns: jOOQ’s converter materialises rows as the Java enum, the GraphQL layer presents the same shape, and Graphitron generates the GraphQL ↔ Java translation. This is the type-level alternative to per-value @field mapping (which targets a column literal per ENUM_VALUE).

SDL signature

directive @enum(enumReference: ExternalCodeReference!) on ENUM

Parameters

Name Type Default Description

enumReference

ExternalCodeReference!

(required)

Points at the Java enum class (or a jOOQ converter for it). The directive uses className: (and optionally method:); other ExternalCodeReference slots are structurally inert. argMapping: is rejected at parse time.

Canonical example

A GraphQL enum mapped to a Java enum class via a jOOQ converter:

enum Mood @enum(enumReference: {className: "no.sikt.graphitron.codereferences.dummyreferences.MoodEnum"}) {
    HAPPY
    SAD
}

Each member of the GraphQL Mood enum is paired with the same-named constant on MoodEnum at code-generation time. At read time the converter produces a MoodEnum instance from the column’s stored representation; at write time the Java constant is converted back. Mismatches between the GraphQL enum members and the Java enum’s constants surface as a build-time validation error.

className: must be a fully-qualified class name; the carrying artifact must be on the rewrite Maven plugin’s classpath (<dependencies> of the <plugin> block).

Constraints

  • The argument is required; graphql-java rejects a no-arg @enum at parse time. Mirrors @service, @tableMethod, and @externalField, which all take ExternalCodeReference!.

  • argMapping: on the enumReference is structurally inert and is rejected at parse time with "argMapping is not supported on @enum`". `@enum does not consume GraphQL-argument-bound parameters.

  • Each GraphQL enum member must correspond to a Java constant of the same name on the referenced class. Missing or extra constants fail the build.

  • @enum is mutually exclusive with per-value @field: declare @enum on the type for converter-based mapping, or @field(name: …​) on each ENUM_VALUE for column-literal mapping. Don’t mix the two on the same enum.

  • Applies only to GraphQL enum types. The directive on any other site is rejected.

See also

  • @field on ENUM_VALUE is the alternative axis: a per-member literal binding (@field(name: "DB_VALUE")) without a converter.

  • ExternalCodeReference is the shared shape across @service, @tableMethod, @externalField, and @enum. Only className/method carry meaning here.

  • How-to: Wiring external Java code covers the rewrite plugin’s classpath setup and the FQCN requirement.

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