如何在表单中显示字段错误内联？

Question

我定义了一个案例类和一个表单对象来处理表单提交。

case class NewUser(
  userName: String,
  password: String,
  email: String  
)

val form = Form(
  mapping(
    "userName" -> nonEmptyText.verifying("The username already exists", User.userNameExists(_) == false),
    "password" -> tuple(
    "main" -> nonEmptyText,
    "confirm" -> nonEmptyText
  ).verifying(
    "Password does not match confirmed password", password => password._1 == password._2
  ).transform[String](
    password => password._1,
    password => ("", "")
  ),
  "email" -> email.verifying("This email belongs to an existing account. Please try another one", emailExists(_) == false))
  (NewUser.apply)(NewUser.unapply)
)

在模板中，代码为：

@helper.inputText(newUserForm("userName"), 'class -> "form-control", 'required -> "true")
@helper.inputPassword(newUserForm("password.main"), 'class -> "form-control", 'required -> "true")
@helper.inputPassword(newUserForm("password.confirm"), 'class -> "form-control", 'required -> "true")
@helper.inputText(newUserForm("email"), 'class -> "form-control")

如果用户键入现有的userName，则错误将以内联方式显示。但是，如果用户键入的confirm password与password不同，则错误不会显示在任何位置。

如何显示错误内联？任何人都可以帮忙吗？谢谢。