how to apply Form validators on object - forms

Question

I have an API in Scala. When I want to create a new User, i need validators on some fields (UserName, FirstName, LastName). I can't find a solution to apply the Form on my case class User. I thought using (User.apply) this will override automatically my User class, but this isn't happening.
User.scala
case class User(
id: Int = 0,
userName: String,
firstName: String,
lastName: String
)
object User {
import play.api.libs.json._
implicit val jsonWrites = Json.writes[User]
implicit val userReads = Json.reads[User]
def tupled = (User.apply _).tupled
}
// Form validator for post requests
object UserForm {
val form: Form[User] = Form(
mapping(
"id" -> number,
"userName" -> text(minLength = 5),
"firstName" -> text(minLength = 5),
"lastName" -> nonEmptyText
)(User.apply)(User.unapply)
)
}
UsersController.scala
def create = Action(parse.json) { implicit request => {
val userFromJson = Json.fromJson[User](request.body)
userFromJson match {
case JsSuccess(user: User, path: JsPath) => {
var createdUser = Await.result(usersRepository.create(user), Duration.Inf)
Ok(Json.toJson(createdUser))
}
case error # JsError(_) => {
println(error)
InternalServerError(Json.toJson("Can not create user"))
}
}
}
}
UsersRepository.scala
def create(user: User): Future[User] = {
val insertQuery = dbUsers returning dbUsers.map(_.id) into ((x, id) => x.copy(id = id))
val query = insertQuery += user
db.run(query)
}
(UsersRepository doesn't matter so much in this problem)
So, when I read the json, I think there need to apply the form validators
val userFromJson = Json.fromJson[User](request.body)
but nothing happening. Another problem is if I send from client a null parameter, will get an error, can not read and create an User.
For example :
"firstName": "" - empty userName will pass
"firstName": null - will fail
This depends on how is configured the User class in client (Angular), with the field null or empty in constructor. I prefer to set it null, even if is a string, if is not a required field (better NULL value in database, than an empty cell)

Answer 1

Try to use this:
request.body.validate[User]
One other thing, you shouldn't use
var createdUser = Await.result(usersRepository.create(user), Duration.Inf)
So use val´s over var´s and the other thing, you don't need to force the future to resolve, use it like this:
val createdUser = usersRepository.create(user)
createdUser.map(Ok(Json.toJson(_)))
And your action should be async.

Answer 2

Find a solution, my Form need to be part of object User, and not to be another object.
object User {
import play.api.libs.json._
implicit val jsonWrites = Json.writes[User]
implicit val userReads = Json.reads[User]
val form: Form[User] = Form(
mapping(
"id" -> number,
"userName" -> text(minLength = 2),
"firstName" -> text(minLength = 4),
"lastName" -> nonEmptyText
)(User.apply)(User.unapply)
)
def tupled = (User.apply _).tupled
}
and the method in Controller became :
def create = Action(parse.json) { implicit request => {
User.form.bindFromRequest.fold(
formWithErrors => BadRequest(Json.toJson("Some form fields are not validated.")),
success => {
val userFromJson = Json.fromJson[User](request.body)
userFromJson match {
case JsSuccess(user: User, path: JsPath) => {
val createdUser = Await.result(usersRepository.create(user), Duration.Inf)
Ok(Json.toJson(createdUser))
}
case error#JsError(_) => {
println(error)
InternalServerError(Json.toJson("Can not create user"))
}
}
}
)
}
}
I know, I need to format my code ... using IntelliJ is so annoying after Visual Studio :(