Custom toForm generation for MappedField

I can't figure out how to properly override toForm (or is it _toForm?) in MappedField.

Specifically I'd like my

object pro开发者_Python百科videsInternship  extends MappedBoolean(this) {
    override def displayName = "Provides Internship"
    override def asHtml = Text(if (is) "Yes" else "No")
    override def dbNotNull_? = true
}

to be rendered (through the toForm call) as

<input type="radio" name=... value=... /> Yes
<input type="radio" name=... value=... /> No

I've Googled, read the ScalaDocs and the source code for MappedField to no avail.

Any hints or pointers to tutorial-like documentation are welcome!

---

I have not done this for MappedXXX but for fields in a LiftScreen to make them readonly, not sure if the same thing works for you.

val input4 = new Field {
    type ValueType = String
    override def name = "Not Editable"
    override def default = "Cannot change"
    lazy val manifest = buildIt[ValueType]
    override def toForm: Box[NodeSeq] =
    SHtml.text(is, set _, "readonly" -> "readonly")
}