Lift Framework example source code file (Jx.scala)

This example Lift Framework source code file (Jx.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

jscmd, jscmd, jscrvar, jsexp, jsraw, jsraw, jxbase, jxbase, nil, node, nodeseq, noop, string, string

The Lift Framework Jx.scala source code

/*
 * Copyright 2007-2011 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 http
package js

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

import JE._
import JsCmds._

trait JxYieldFunc {
  this: JxBase =>
  def yieldFunction: JsExp
}

trait JxBase {
  self: Node =>

  private val logger = Logger(classOf[JxBase])
  def appendToParent(parentName: String): JsCmd

  def label = "jx" 

  def addAttrs(varName: String, attrs: List[MetaData]): JsCmd = attrs.map {
    m =>
            m.value.map {
              case exp: JsExp =>
                JsRaw(varName + "." + m.key + " = " + exp.toJsCmd).cmd

              case cmd: JsCmd => val varName = "v" + Helpers.nextFuncName
              JsCrVar(varName, AnonFunc(cmd)) &
                      JsRaw(varName + "." + m.key + " = " + varName + "()")

              case JxAttr(cmd) =>
                JsRaw(varName + "." + m.key + " = " + cmd.toJsCmd).cmd

              case JxFuncAttr(cmd) =>
                JsRaw(varName + "." + m.key + " = " + AnonFunc(cmd).toJsCmd).cmd

              case x =>
                if (m.key == "class") {
                  // JsRaw(varName+".setAttribute('className',"+x.text.encJs+");").cmd

                  JsRaw(varName + ".className = " + x.text.encJs).cmd &
                          JsRaw(varName + ".setAttribute(" + m.key.encJs + "," + x.text.encJs + ");").cmd
                } else {
                  JsRaw(varName + ".setAttribute(" + m.key.encJs + "," + x.text.encJs + ");").cmd
                }
            }.foldLeft(Noop)(_ & _)
  }.foldLeft(Noop)(_ & _)

  private def fixText(in: String): String = (in, in.trim) match {
    case (x, y) if x == y => x
    case (x, y) if x startsWith y => y + " "
    case (x, y) if y.length == 0 => " "
    case (x, y) if x endsWith y => " " + y
    case (_, y) => " " + y + " "
  }

  def addToDocFrag(parent: String, elems: List[Node]): JsCmd = elems.map {
    case Jx(kids) => addToDocFrag(parent, kids.toList)
    case jb: JxBase => jb.appendToParent(parent)
    case Group(nodes) => addToDocFrag(parent, nodes.toList)
    case Text(txt) => JsRaw(parent + ".appendChild(document.createTextNode(" + fixText(txt).encJs + "));").cmd
    case a: Atom[_] => JsRaw(parent + ".appendChild(document.createTextNode(" + a.text.encJs + "));").cmd
    case e: scala.xml.Elem =>
      val varName = "v" + Helpers.nextFuncName
      JsCrVar(varName, JsRaw("document.createElement(" + e.label.encJs + ")")) &
              addAttrs(varName, e.attributes.toList) &
              JsRaw(parent + ".appendChild(" + varName + ")") &
              addToDocFrag(varName, e.child.toList)
    case ns: NodeSeq =>
      if (ns.length == 0) Noop
      else if (ns.length == 1) {
        logger.error("In addToDocFrag, got a " + ns + " of type " + ns.getClass.getName)
        Noop
      } else addToDocFrag(parent, ns.toList)

  }.foldLeft(Noop)(_ & _)
}


abstract class JxNodeBase extends Node with JxBase {
}

case class JxAttr(in: JsCmd) extends Node with JxBase {
  def child = Nil

  def appendToParent(parentName: String): JsCmd = {
    Noop
  }
}

case class JxFuncAttr(in: JsCmd) extends Node with JxBase {
  def child = Nil

  def appendToParent(parentName: String): JsCmd = {
    Noop
  }
}

case class JxMap(in: JsExp, what: JxYieldFunc) extends Node with JxBase {
  def child = Nil

  def appendToParent(parentName: String): JsCmd = {
    val ran = "v" + Helpers.nextFuncName
    val fr = "f" + Helpers.nextFuncName
    val cr = "c" + Helpers.nextFuncName
    JsCrVar(ran, in) &
            JsCrVar(fr, what.yieldFunction) &
            JsRaw("for (" + cr + " = 0; " + cr + " < " + ran + ".length; " + cr + "++) {" +
                    parentName + ".appendChild(" + fr + "(" + ran + "[" + cr + "]));" +
                    "}")
  }
}

case class JxCmd(in: JsCmd) extends Node with JxBase {
  def child = Nil

  def appendToParent(parentName: String) = in
}

case class JxMatch(exp: JsExp, cases: JxCase*) extends Node with JxBase {
  def child = Nil

  def appendToParent(parentName: String): JsCmd = {
    val vn = "v" + Helpers.nextFuncName
    JsCrVar(vn, exp) &
            JsRaw("if (false) {\n} " +
                    cases.map {
                      c =>
                              " else if (" + vn + " == " + c.toMatch.toJsCmd + ") {" +
                                      addToDocFrag(parentName, c.toDo.toList).toJsCmd +
                                      "\n}"
                    }.mkString("") +
                    " else {throw new Exception('Unmatched: '+" + vn + ");}")
  }
}

case class JxCase(toMatch: JsExp, toDo: NodeSeq)

case class JxIf(toTest: JsExp, ifTrue: NodeSeq) extends Node with JxBase {
  def child = Nil

  def appendToParent(parentName: String): JsCmd = {
    JsRaw("if (" + toTest.toJsCmd + ") {\n" +
            addToDocFrag(parentName, ifTrue.toList).toJsCmd +
            "}\n")
  }
}

case class JxIfElse(toTest: JsExp, ifTrue: NodeSeq, ifFalse: NodeSeq) extends Node with JxBase {
  def child = Nil

  def appendToParent(parentName: String): JsCmd = {
    JsRaw("if (" + toTest.toJsCmd + ") {\n" +
            addToDocFrag(parentName, ifTrue.toList).toJsCmd +
            "} else {\n" +
            addToDocFrag(parentName, ifFalse.toList).toJsCmd +
            "}\n")
  }
}



case class Jx(child: NodeSeq) extends Node with JxBase with JxYieldFunc {
  def appendToParent(parentName: String): JsCmd =
    addToDocFrag(parentName, child.toList)

  def yieldFunction: JsExp = toJs

  def toJs: JsExp = AnonFunc("it",
    JsCrVar("df", JsRaw("document.createDocumentFragment()")) &
            addToDocFrag("df", child.toList) &
            JsRaw("return df"))


}