Lift Framework example source code file (BundleBuilder.scala)

This example Lift Framework source code file (BundleBuilder.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Lift Framework tags/keywords

box, elem, entryinfo, enumeration, list, list, nil, nil, nodeseq, nodeseq, option, option, some, string, util

The Lift Framework BundleBuilder.scala source code

/*
 * Copyright 2010-2011 WorldWide Conferencing, LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package net.liftweb
package util

import net.liftweb.common._
import scala.xml._
import java.util.{ResourceBundle, Enumeration, Locale}

/**
 * Converts a NodeSeq of a particular format into
 * a ResourceBundle.  Basically, each of the second-level
 * nodes that contain the attribute "name" the name becomes an
 * entry in the resulting resource bundle.  It is possible
 * to localize each of the entries with the lang and country
 * attributes which will be compared against the incoming
 * Locale.  If the default attribute is true, then that entry
 * is used if no others match.  Note that language is weighted
 * more heavily than country.<br/>

 * If the node
 * is a Text or PCData node, it will be returned as a String.
 * Otherwise, it will be returned as a NodeSeq.
 */
object BundleBuilder {
  private object IsText {
    def unapply(in: NodeSeq): Option[String] = in.toList match {
      case (x: Atom[_]) :: Nil => Some(x.text)
      case _ => None
    }
  }

  final private case class EntryInfo(name: String, lang: Option[String], country: Option[String], default: Boolean)

  /**
   * Convers
   */
  def convert(nodes: NodeSeq, loc: Locale): Box[ResourceBundle] = {
    val country = Some(loc.getCountry()).filter(_.length > 0)
    val lang = Some(loc.getLanguage()).filter(_.length > 0)

    val vals: List[ResourceBundle] =
      nodes.toList.flatMap {
        case e: Elem => {
          val all: List[(EntryInfo, NodeSeq)] =
            e.child.toList.flatMap {
              case e: Elem => {
                e.attribute("name").toList.
                map(attr => EntryInfo(attr.text,
                                      e.attribute("lang").map(_.text),
                                      e.attribute("country").map(_.text),
                                      e.attribute("default").map(_.text).
                                      flatMap(Helpers.asBoolean) getOrElse false) -> (e.child: NodeSeq))
              }
              
              case _ => Nil
            }

          val map = all.foldLeft[Map[String, List[(EntryInfo, NodeSeq)]]](Map()) {
            case (map, pair @ (info, ns)) =>
              map + (info.name -> (pair :: map.getOrElse(info.name, Nil)))
          }

          def points(i: EntryInfo): Int = {
            (if (i.lang == lang) 4 else 0) +
            (if (i.country == country) 2 else 0) +
            (if (i.default) 1 else 0)
          }
          
          def choose(lst: List[(EntryInfo, NodeSeq)]): NodeSeq = 
            lst.reduceLeft{
              (a, b) => {
                val ap = points(a._1)
                val bp = points(b._1)
                if (ap > bp) {
                  a
                } else if (bp > ap) {
                  b
                } else if (a._1.default) a
                else b
              }
            }._2

          val res: Map[String, NodeSeq] = Map(map.map {
            case (name, lst) => name -> choose(lst)
          }.toSeq :_*)
          
          List(new ResourceBundle {
            def getKeys(): Enumeration[String] = {
              val it = res.keys.iterator
              new Enumeration[String] {
                def hasMoreElements() = it.hasNext
                def nextElement() = it.next
              }
            }
            
            def handleGetObject(key: String): Object = 
              res.get(key) match {
                case Some(IsText(str)) => str
                case Some(ns) => ns
                case _ => null
              }
          })
        }

        case _ => Nil
      }

    vals.headOption
  }
}