/*
 * TimeZoneTransform.java May 2007
 *
 * Copyright (C) 2007, Niall Gallagher <niallg@users.sf.net>
 *
 * 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.simpleframework.xml.transform;

import java.util.TimeZone;

/**
 * The <code>TimeZoneTransform</code> is used to transform time zone
 * values to and from string representations, which will be inserted
 * in the generated XML document as the value place holder. The
 * value must be readable and writable in the same format. Fields
 * and methods annotated with the XML attribute annotation will use
 * this to persist and retrieve the value to and from the XML source.
 * <pre>
 * 
 *    &#64;Attribute
 *    private TimeZone zone;
 *    
 * </pre>
 * As well as the XML attribute values using transforms, fields and
 * methods annotated with the XML element annotation will use this.
 * Aside from the obvious difference, the element annotation has an
 * advantage over the attribute annotation in that it can maintain
 * any references using the <code>CycleStrategy</code> object. 
 * 
 * @author Niall Gallagher
 */
class TimeZoneTransform implements Transform<TimeZone> {
   
   /**
    * This method is used to convert the string value given to an
    * appropriate representation. This is used when an object is
    * being deserialized from the XML document and the value for
    * the string representation is required.
    * 
    * @param zone the string representation of the time zone 
    * 
    * @return this returns an appropriate instanced to be used
    */
   public TimeZone read(String zone) {
      return TimeZone.getTimeZone(zone);
   }
   
   /**
    * This method is used to convert the provided value into an XML
    * usable format. This is used in the serialization process when
    * there is a need to convert a field value in to a string so 
    * that that value can be written as a valid XML entity.
    * 
    * @param zone this is the value to be converted to a string
    * 
    * @return this is the string representation of the given value
    */
   public String write(TimeZone zone) {
      return zone.getID();
   }
}