Packages

class flatten extends Annotation with StaticAnnotation

Changes the serialization format used by GenCodecs automatically derived for sealed hierarchies. The format is changed from "nested" to "flat".

@flatten sealed trait Value
case class Numeric(int: Int) extends Value
case class Textual(string: String) extends Value
object Value {
  implicit val codec: GenCodec[Value] = GenCodec.materialize[Value]
}

Without flatten annotation, the "nested" format is used, e.g. when Numeric(42) would be encoded to JSON as:

{"Numeric": {"int": 42}}

but when flatten annotation is applied on sealed trait/class, then it changes to:

{"_case": "Numeric", "int": 42}

The "_case" field name can be customized with annotation parameter

Linear Supertypes
StaticAnnotation, Annotation, AnyRef, Any
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Instance Constructors

  1. new flatten()
  2. new flatten(caseFieldName: String)

Value Members

  1. val caseFieldName: String