Need to validate nested json arrays in play 2.1 in scala - scala

Question

I was able to perform simple validations on simple json structures like this one:
object RestTest extends Controller {
case class Address(street: String,
number: Int)
case class Person(name: String,
age: Int,
address: Address)
implicit val address = Json.reads[Address]
implicit val rds = Json.reads[Person]
def restTest = Action(parse.json) {
request =>
request.body.validate[Person].map {
case person => Ok(Json.obj("e" -> 0, "message" -> ("The name is: " + person.name + " and he lives in " + person.address.street)))
}.recoverTotal(e => Ok("e" -> 1)
}
}
Now I have the following structure that contains arrays, but I wasn't able to validate it correctly so far. I have tried many different ways, but I keep receiving compilation errors.
case class SecondStructure(index: Int)
case class EntryStructure(field1: String,
muSecondJsonArray: List[SecondStructure])
case class MyJsonArray(allEntries: List[EntryStructure])
How can I validate this json?
Thanks

Answer 1

First of all, ensure you are using the latest Play 2.1.1 releases. There was an issue with earlier versions when validating case classes with a single field. After that, it should all work - please see below for an example:
object JsonTest {
case class SecondStructure(index: Int)
case class EntryStructure(field1: String, muSecondJsonArray: List[SecondStructure])
case class MyJsonArray(allEntries: List[EntryStructure])
// Use the macro "inception" feature to automatically build your Readers.
implicit val ssReads = Json.reads[SecondStructure]
implicit val esReads = Json.reads[EntryStructure]
implicit val arrayReads = Json.reads[MyJsonArray]
// Defining an example instance...
val testArray = MyJsonArray(
List(
EntryStructure("foo", List(SecondStructure(1), SecondStructure(2))),
EntryStructure("bar", List(SecondStructure(3), SecondStructure(4)))))
// And the equivilant JSON structure...
val testJson = Json.obj("allEntries" ->
Json.arr(
Json.obj("field1" -> "foo", "muSecondJsonArray" -> Json.arr(
Json.obj("index" -> 1), Json.obj("index" -> 2))),
Json.obj("field1" -> "bar", "muSecondJsonArray" -> Json.arr(
Json.obj("index" -> 3), Json.obj("index" -> 4)))))
testJson.validate[MyJsonArray].map {
case foo if foo == testArray => println("Okay, we're good!")
}
}