Modifier

zio.blocks.schema.Modifier

See theModifier companion object

sealed trait Modifier extends StaticAnnotation

A Modifier is metadata on a schema, or on one of its fields or cases, that codecs and other derivations read: it renames a field in JSON, accepts an old name, leaves a field out, or carries format-specific configuration. Modifiers are plain data with schemas of their own, so they can be serialized together with a schema.

Every modifier is also an annotation. Schema.derived reads Modifier.Term annotations on fields and cases, and Modifier.Reflect annotations on the type. To leave the type unannotated, add them with Schema#modifier for the type, or with DerivationBuilder#modifier or Deriver#withModifier for one derivation.

Which modifiers a codec reads depends on its format: the JSON codec reads all the built-in ones except id and config, while the Avro and MessagePack codecs, for example, ignore transient, rename and alias.

case class Book(
 @Modifier.rename("name") title: String,
 @Modifier.alias("published") year: Int,
 @Modifier.transient() notes: String = ""
)
object Book {
 implicit val schema: Schema[Book] = Schema.derived
}

val json = Book("Zionomicon", 2021, "signed copy").toJsonString
// {"name":"Zionomicon","year":2021}
val book = """{"name":"Zionomicon","published":2021}""".fromJson[Book]
// Right(Book(Zionomicon,2021,))

Attributes

See also: Modifier
Companion: object
Source: Modifier.scala
Graph
Supertypes: trait StaticAnnotation

class Annotation

class Object

trait Matchable

class Any
Known subtypes: trait Reflect

class caseNaming

class config

class discriminator

class fieldNaming

class noExtraFields

trait Term

class alias

class encodeTransient

class id

class rename

class transient
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