XmlExamples.scala

/*
* Copyright 2009-2011 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 org.json4s

import org.specs2.mutable.Specification
import org.json4s.native.Document

object NativeXmlExamples extends XmlExamples[Document]("Native") with native.JsonMethods
object JacksonXmlExamples extends XmlExamples[JValue]("Jackson") with jackson.JsonMethods

abstract class XmlExamples[T](mod: String) extends Specification with JsonMethods[T]{
  import Xml._
  import scala.xml.{Group, Text}

  (mod+" XML Examples") should {
    "Basic conversion example" in {
      val json = toJson(users1)
      compact(render(json)) must_== """{"users":{"count":"2","user":[{"disabled":"true","id":"1","name":"Harry"},{"id":"2","name":"David","nickname":"Dave"}]}}"""
    }

    "Conversion transformation example 1" in {
      val json = toJson(users1).transformField {
        case JField("id", JString(s)) => JField("id", JInt(s.toInt))
      }
      compact(render(json)) must_== """{"users":{"count":"2","user":[{"disabled":"true","id":1,"name":"Harry"},{"id":2,"name":"David","nickname":"Dave"}]}}"""
    }

    "Conversion transformation example 2" in {
      val json = toJson(users2).transformField {
        case JField("id", JString(s)) => JField("id", JInt(s.toInt))
        case JField("user", x: JObject) => JField("user", JArray(x :: Nil))
      }
      compact(render(json)) must_== """{"users":{"user":[{"id":1,"name":"Harry"}]}}"""
    }

    "Primitive array example" in {
      val xml = <chars><char>a</char><char>b</char><char>c</char></chars>
      compact(render(toJson(xml))) must_== """{"chars":{"char":["a","b","c"]}}"""
    }

    "Lotto example which flattens number arrays into encoded string arrays" in {
      def flattenArray(nums: List[JValue]) = JString(nums.map(_.values).mkString(","))

      val printer = new scala.xml.PrettyPrinter(100,2)
      val lotto: JObject = LottoExample.json
      val xml = toXml(lotto.transformField {
        case JField("winning-numbers", JArray(nums)) => JField("winning-numbers", flattenArray(nums))
        case JField("numbers", JArray(nums)) => JField("numbers", flattenArray(nums))
      })


      printer.format(xml(0)) must_== printer.format(
        <lotto>
          <id>5</id>
          <winning-numbers>2,45,34,23,7,5,3</winning-numbers>
          <winners>
            <winner-id>23</winner-id>
            <numbers>2,45,34,23,3,5</numbers>
          </winners>
          <winners>
            <winner-id>54</winner-id>
            <numbers>52,3,12,11,18,22</numbers>
          </winners>
        </lotto>)
    }

    "Band example with namespaces" in {
      val json = toJson(band)
      json mustEqual parse("""{
    "b:band":{
      "name":"The Fall",
      "genre":"rock",
      "influence":"",
      "playlists":{
        "playlist":[{
          "name":"hits",
          "song":["Hit the north","Victoria"]
        },{
          "name":"mid 80s",
          "song":["Eat your self fitter","My new house"]
        }]
      }
    }
  }""")
    }

    "Grouped text example" in {
      val json = toJson(groupedText)
      compact(render(json)) mustEqual """{"g":{"group":"foobar","url":"http://example.com/test"}}"""
    }

    "Example with multiple attributes, multiple nested elements " in  {
      val a1 = attrToObject("stats", "count", s => JInt(s.s.toInt)) _
      val a2 = attrToObject("messages", "href", identity) _
      val json = a1(a2(toJson(messageXml1)))
      (json diff parse(expected1)) mustEqual Diff(JNothing, JNothing, JNothing)
    }

    "Example with one attribute, one nested element " in {
      val a = attrToObject("stats", "count", s => JInt(s.s.toInt)) _
      compact(render(a(toJson(messageXml2)))) mustEqual expected2
      compact(render(a(toJson(messageXml3)))) mustEqual expected2

    }
  }

  val messageXml1 =
    <message expiry_date="20091126" text="text" word="ant" self="me">
      <stats count="0"></stats>
      <messages href="https://domain.com/message/ant"></messages>
    </message>

  val expected1 = """{"message":{"expiry_date":"20091126","word":"ant","text":"text","self":"me","stats":{"count":0},"messages":{"href":"https://domain.com/message/ant"}}}"""

  val messageXml2 =
    <message expiry_date="20091126">
      <stats count="0"></stats>
    </message>

  val messageXml3 = <message expiry_date="20091126"><stats count="0"></stats></message>

  val expected2 = """{"message":{"expiry_date":"20091126","stats":{"count":0}}}"""


  val band =
        <b:band>
          <name>The Fall</name>
          <genre>rock</genre>
          <influence/>
          <playlists>
            <playlist name="hits">
              <song>Hit the north</song>
              <song>Victoria</song>
            </playlist>
            <playlist name="mid 80s">
              <song>Eat your self fitter</song>
              <song>My new house</song>
            </playlist>
          </playlists>
        </b:band>


  val users1 =
        <users count="2">
          <user disabled="true">
            <id>1</id>
            <name>Harry</name>
          </user>
          <user>
            <id>2</id>
            <name nickname="Dave">David</name>
          </user>
        </users>

  val users2 =
    <users>
      <user>
        <id>1</id>
        <name>Harry</name>
      </user>
    </users>

  val url = "test"
  val groupedText =
    <g>
      <group>{ Group(List(Text("foo"), Text("bar"))) }</group>
      <url>http://example.com/{ url }</url>
    </g>

  // Examples by Jonathan Ferguson. See http://groups.google.com/group/liftweb/browse_thread/thread/f3bdfcaf1c21c615/c311a91e44f9c178?show_docid=c311a91e44f9c178
  // This example shows how to use a transformation function to correct JSON generated by
  // default conversion rules. The transformation function 'attrToObject' makes following conversion:
  // { ..., "fieldName": "", "attrName":"someValue", ...}      ->
  // { ..., "fieldName": { "attrName": f("someValue") }, ... }
  def attrToObject(fieldName: String, attrName: String, f: JString => JValue)(json: JValue) = json.transformField {
    case (n, v: JString) if n == attrName => JField(fieldName, JObject(JField(n, f(v)) :: Nil))
    case (n, JString("")) if n == fieldName => JField(n, JNothing)
  } transformField {
    case (n, x: JObject) if n == attrName => JField(fieldName, x)
  }

}