Scala - replace xml element with specific text

Question

so i have this XMl

<a>blah</a>

And i want to change it to

<a>someValueIDoNotKnowAtCompileTime</a>

Currently, I am looking at this SO question . However, this just changes the value to "2"

What i want is exactly the same thing, but to be able to define the value (so that it can change at runtime - i am reading the values from a file!)

I tried passing the value into the overridden methods, but that didn't work - compile errors everywhere (obviously)

How can i change static xml with dynamic values?

ADDING CODE

var splitString = someString.split("/t") //where someString is a line from a file
val action = splitString(0)
val ref = splitString(1)
xmlMap.get(action) match { //maps the  "action" string to some XML
    case Some(entry) => {
        val xmlToSend = insertRefIntoXml(ref,entry) 
        //for the different XML, i want to put the string "ref" in an appropriate place
    }
    ...

Answer 1

For example:

scala> val x = <foo>Hi</foo>
x: scala.xml.Elem = <foo>Hi</foo>

scala> x match { case <foo>{what}</foo> => <foo>{System.nanoTime}</foo> }
res1: scala.xml.Elem = <foo>213370280150006</foo>

update with linked example:

import scala.xml._
import System.{ nanoTime => now }

object Test extends App {
  val InputXml : Node =
    <root>
      <subnode> <version>1</version> </subnode>
      <contents> <version>1</version> </contents>
    </root>
  def substitution = now   // whatever you like
  def updateVersion(node: Node): Node = node match {
    case <root>{ ch @ _* }</root> => <root>{ ch.map(updateVersion )}</root>
    case <subnode>{ ch @ _* }</subnode> => <subnode>{ ch.map(updateVersion ) }</subnode>
    case <version>{ contents }</version> => <version>{ substitution }</version>
    case other @ _ => other
  }
  val res = updateVersion(InputXml)
  val pp = new PrettyPrinter(width = 2, step = 1)
  Console println (pp format res)
}