I separate business transaction from UI logic.
When create or update business model will occur notice or error,
and then do something for UI by the business transaction

for example:
business:
def MyBusinessTransaction(v: String) : Option[MyModel] = {
val myModel = MyModel.create.title(v)
myModel.validate match {
case Nil => {myModel.save();Some(myModel)}
case xs => {S.error(xs);None}
}
}


Snippet
def doSomething(): JsCmd = MyBusinessTransaction(v) match {
case Some(v) => //do something for UI, such as replace the old value
case None => //notice what's wrong. I could code fadeOutErrors(5 seconds, 1 second) if want, but should I code every where?
}

I think it's better could configure this at one place but not code every where.

Thanks