1

I am following the following example https://github.com/leon/play-salat/tree/master/sample . In my data model I have lists and I tried to adopt the model to that.

I get the following compilation errors:

[error] /home/malte/workspace/bdt/app/models/Ballot.scala:26: No Json deserializer found        for type List[models.Position]. Try to implement an implicit Writes or Format for this type.
[error]         "positions" -> b.positions,
[error]                          ^
[error] /home/malte/workspace/bdt/app/models/Ballot.scala:33: No Json deserializer found for type List[models.Position]. Try to implement an implicit Reads or Format for this type.
[error]       (__ \ 'values).read[List[Position]]).map { l => l.getOrElse(Nil) } ~

For the type "Position" I have implicit reads and writes, but how to make it for List[Position] ? My implicit write and read:

implicit val ballotJsonWrite = new Writes[Ballot] {
  def writes(b: Ballot): JsValue = {
    Json.obj(
      "positions" -> b.positions,
      "title" -> b.title)
  }
}

implicit val ballotJsonRead = (
(__ \ 'positions).readNullable(
  (__ \ 'values).read[List[Position]]).map { l => l.getOrElse(Nil) } ~
  (__ \ 'title).read[String])(Ballot.apply _)

For the read I followed Create implicit json read for List collection which might be missing from input json , but I get the above mentioned error.

Community
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Malte Buchholz
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1 Answers1

0

actually now I found out that in the latest versions of salat. Json is automatically used to move between models and json objects. I removed the whole part and no it runs smoothly.

https://github.com/novus/salat/wiki/JSON

Malte Buchholz
  • 11
  • 2