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scalaspray-jsoncompanion-object

Which among importing companion object or extending trait is better

I have a JSON protocol written in spray

trait MyJsonProtocol {
   //some logic
}

object MyJsonProtocol extends MyJsonProtocol {

}

Now which is better ?? Importing this companion object or extending the trait ?

Solution

  • If you are creating some JsonFormat instances for spray, then you can just create an object directly and import that. This means that you only have a single instance of your implicit vals and objects.

    object MyJsonProtocol extends DefaultJsonProtocol {
  implicit object MyTypeJsonFormat extends RootJsonFormat[MyType] {
    def write(v: MyType): JsValue = ...
    def read(value: JsValue): MyType = ...
  }

  implicit val myClassFormat = jsonFormat5(MyClass)
}

class OtherClass {
  import MyJsonProtocol._

  ...
}