/*
    Transit - Remote procedure calls made simple
    Copyright (c) 2012  Ulrich Hilger

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

package de.uhilger.transit;

import java.io.Writer;

import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.io.json.JsonHierarchicalStreamDriver;
import com.thoughtworks.xstream.io.json.JsonWriter;
import com.thoughtworks.xstream.io.HierarchicalStreamWriter;

/**
 * Java-Objekte in die JavaScript Object Notation (JSON) 
 * verwandeln und umgekehrt
 * 
 * Dieser Wandler erzeugt ein strukturiertes und gut lesbares JSON-Format, 
 * bei dem das Wurzelelement weggelassen wird. Im Falle einer Liste wird 
 * damit z.B. der Inhalt ohne umschliessendes 
 * <pre>{"List": [ ]}</pre>
 * erezeugt.
 * 
 * <p>Diese Klasse benoetigt die Java-Klassenbibliotheken 
 * <a href="http://xstream.codehaus.org/" target="_blank">XStream</a>  
 * und <a href="http://jettison.codehaus.org/" target="_blank">Jettison</a> 
 * im Classpath.</p>
 * 
 * @author Copyright (c) Ulrich Hilger, http://uhilger.de
 * @author Published under the terms and conditions of
 * the <a href="http://www.gnu.org/licenses/agpl-3.0" target="_blank">GNU Affero General Public License</a>
 * 
 * @version 1, September 16, 2012
 */
public class JsonFlatWandler extends AbstractWandler {
        
  /** Bezeichnerdes Formats, das dieser Wandler unterstuetzt */
  public static final String FORMAT_FLATJSON = "FLATJSON";

  protected XStream getXStream() {
    //XStream xstream = new XStream(new JettisonMappedXmlDriver());
    XStream xstream = new XStream(new JsonHierarchicalStreamDriver() {
        public HierarchicalStreamWriter createWriter(Writer writer) {
            return new JsonWriter(writer, JsonWriter.DROP_ROOT_MODE);
        }
    });    
    return xstream;
  }

	/**
	 * Das Format ermitteln, das dieser Wandler verarbeitet
	 * @return das Format, das dieser Wandler verarbeitet
	 */
	@Override
	public String getFormat() {
		return FORMAT_FLATJSON;
	}
  
}