Play JSON Refined

A tiny library providing Json formats for refined types.

Context

Refined types come in handy to limit the valid values accepted in a function. However as values are often not available at compile time you need to validate them as soon as they enter your application.

In case of JSON inputs we need a format to convert from JSON to a refined type. (e.g. We want to read a non empty list or a positive integer directly from JSON).

Setup

In order to use play-json-refined you need to add the following lines to your build.sbt:

resolvers += Resolver.bintrayRepo("beyondthelines", "maven")

libraryDependencies += "beyondthelines" %% "play-json-refined" % "0.0.2"

## Dependencies

Play JSON Refined has only 2 dependencies: Play-json and Refined.

Usage

In order to use Play JSON with refined types you need to import the following:

import eu.timepit.refined.api.Refined
import eu.timepit.refined.auto._
import play.api.libs.json._ 
import play.json.refined._

Importing play.json.refined._ adds implicit definitions to derive Json formats for refined types.

Example

Let's take a basic example to illustrate the usage:

// import the refined that you need
// here we use numeric and collection
import eu.timepit.refined.collection._
import eu.timepit.refined.numeric._

type PosInt = Int Refined Positive
type NonEmptyString = String Refined NonEmpty

final case class Data(
  i: PosInt,
  s: NonEmptyString
)

implicit val dataFormat: OFormat[Data] =
  Json.format[Data]

val data = Data(1, "a")
// convert to JSON
val json = Json.toJson(data)
// convert from JSON
val parsed = json.as[Data]