skinny-validator with multiParams

RootController.scala

package controller

import skinny._
import skinny.validator._

class RootController extends ApplicationController {

  object twoElements extends ValidationRule {
    def name = "twoElements"
    def isValid(v: Any) = v == null || {
      v.isInstanceOf[Seq[_]] &&
      v.asInstanceOf[Seq[String]].size == 2
    }
  }
  def form = MapValidator(multiParams).apply(paramKey("foo") is twoElements)

  implicit val format = Format.JSON

  def index = {
    if (form.validate) renderWithFormat(Map("result" -> "ok"))
    else renderWithFormat(form.errors)
  }

}