Validate scala forms, when form contains inner case classes - forms

Question

Help with Scala forms validation,
Here is the case class for the form data:
case class Data(
firstName: String,
lastName: String,
email: String,
confirm_email: String,
password: String,
confirm_password: String)
}
And the Scala Form:
val form = Form(
mapping(
"firstName" -> nonEmptyText,
"lastName" -> nonEmptyText,
"email" -> email,
"confirm_email" -> email,
"password" -> nonEmptyText(minLength = 8),
"confirm_password" -> nonEmptyText(minLength = 8))(Data.apply)(Data.unapply))
Now the problem is we need to validate the "email" and "confirm" email, but the problem is we need to create tuples or mapping. And so what is the best way to handle these kinds of form validation situations. It can be easily done by only using tuples and not mapping it to any case class.
But what can be done if we are requried to use mapping and case classes in forms.

Answer 1

First things first, I'd get rid of the confirm_email and confirm_password fields since they're redundant in the Data model. After this operation, it'll look like this:
case class Data(
firstName: String,
lastName: String,
email: String,
password: String)
Next, your form mapping needs to be updated:
val form = Form[Data](
mapping(
"firstName" -> nonEmptyText,
"lastName" -> nonEmptyText,
"email" -> tuple(
"email1" -> email,
"email2" -> email
).verifying(Messages("form.error.emailNotEquals"), email => email._1 == email._2),
"password" -> tuple(
"pass1" -> nonEmptyText(minLength = 8),
"pass2" -> nonEmptyText(minLength = 8)
).verifying(Messages("form.error.passwordNotEquals"), password => password._1 == password._2)
)((firstName, lastName, email, password) => Data(firstName, lastName, email._1, password._1))
((form: Data) => Some((form.firstName, form.lastName, (form.email, form.email), ("", ""))))
)
Two changes are required:
Nested mapping with validation both for email and password fields.
Custom apply and unapply method implementation in order to map the form with six fields into the models case class with four fields.
Notice that the custom unapply method doesn't set values for password fields since it's a desired behaviour in virtually all cases.
Finally, your view must be altered to refer new form tuple mapping correctly. For instance, fields for email should look as follows:
#helper.inputText(dataForm("email.email1"))
#helper.inputText(dataForm("email.email2"))
Fields which don't use new tuple mappings stay unchanged.