enumeratum.values.Forms.scala Maven / Gradle / Ivy

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package enumeratum.values

import play.api.data.format.Formatter
import play.api.data.{FormError, Mapping, Forms => PlayForms}

/**
  * Created by Lloyd on 4/13/16.
  *
  * Copyright 2016
  */
object Forms {

  /**
    * Returns a [[ValueEnum]] mapping for Play form fields
    */
  def enum[ValueType,
           EntryType <: ValueEnumEntry[ValueType],
           EnumType <: ValueEnum[ValueType, EntryType]](baseFormatter: Formatter[ValueType])(
      enum: EnumType
  ): Mapping[EntryType] = {
    PlayForms.of(formatter(baseFormatter)(enum))
  }

  private[this] def formatter[ValueType,
                              EntryType <: ValueEnumEntry[ValueType],
                              EnumType <: ValueEnum[ValueType, EntryType]](
      baseFormatter: Formatter[ValueType]
  )(enum: EnumType) = {
    new Formatter[EntryType] {
      def bind(key: String, data: Map[String, String]): Either[Seq[FormError], EntryType] =
        baseFormatter.bind(key, data).right.flatMap { s =>
          val maybeBound = enum.withValueOpt(s)
          maybeBound match {
            case Some(obj) => Right(obj)
            case None      => Left(Seq(FormError(key, "error.enum", Nil)))
          }
        }

      def unbind(key: String, value: EntryType): Map[String, String] =
        baseFormatter.unbind(key, value.value)
    }
  }

  /**
    * Taken from Play 2.4.x implementation
    */
  private[values] val charFormatter: Formatter[Char] = new Formatter[Char] {
    def bind(key: String, data: Map[String, String]) =
      data
        .get(key)
        .filter(s => s.length == 1 && s != " ")
        .map(s => Right(s.charAt(0)))
        .getOrElse(
          Left(Seq(FormError(key, "error.required", Nil)))
        )
    def unbind(key: String, value: Char) = Map(key -> value.toString)
  }
}