Snipet for reading version.txt

App.scala

package org.example.project.snippet

import scala.xml._
import net.liftweb.util.Helpers._

/* Access to the build number (e.g., supplied by Hudson/Jenkins) 
    
  Example usage:
  <lift:App.version> Project:<v:project/> Build:<v:number/> </lift:App.version> 

 Kick off SBT with:
 -Dbuild.number=$BUILD_NUMBER -Dbuild.vcs.number=master
 
 (change master to pilot on pilot builds).
 
 */

class App {

  // Wrapper Java Properties to give us Option rather than null
  class Properties(path: String) {
    import java.util.{Properties => JProps}
        
    private def propsFrom(in: java.io.InputStream): JProps = {
        val p = new JProps
        p.load(in)
        p
    }

    private val props: Option[JProps] = for { 
        stream <- Option(getClass getResourceAsStream path)    
    } yield propsFrom(stream)
    

   def apply(key: String): Option[String] = for { 
     jp <- props
     v <- Option(jp getProperty key) 
     } yield v
  }

  
  
  private lazy val props = new Properties("/version.txt")
  
  private def get(key: String): Text = Text(props(key) getOrElse "dev")

  def version(xhtml: NodeSeq) = bind("v", xhtml,
    "project" -> get("Revision"), // we map this to branch in our Hudson builds
    "number" -> get("Build") )

  /*
   The version.txt file produced by the Guardian sbt plugin:
    
      Build: 87
      Built-By: hudson
      Built-On: ip-10-224-66-18
      Date: Tue Nov 22 16:20:42 UTC 2011
      Revision: pilot
  */

}