/**

  * Alt2XML

  * Copyright © 2014 František Kučera (frantovo.cz)

  *

  * This program is free software: you can redistribute it and/or modify

  * it under the terms of the GNU General Public License as published by

  * the Free Software Foundation, version 3 of the License.

  *

  * 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 General Public License for more details.

  *

  * You should have received a copy of the GNU General Public License

  * along with this program. If not, see <http://www.gnu.org/licenses/>.

  */

 package cz.frantovo.alt2xml.out;

 import java.io.IOException;

 import java.util.logging.Level;

 import java.util.logging.Logger;

 import javax.xml.parsers.SAXParser;

 import org.xml.sax.InputSource;

 import org.xml.sax.SAXException;

 import org.xml.sax.SAXNotRecognizedException;

 import org.xml.sax.SAXNotSupportedException;

 import org.xml.sax.ext.LexicalHandler;

 import org.xml.sax.helpers.DefaultHandler;

 /**

  * Recommended base class for Actions based on handlers.

  *

  * @author Ing. František Kučera (frantovo.cz)

  */

 public abstract class AbstractHandlerAction extends AbstractAction {

 	private static final Logger log = Logger.getLogger(AbstractHandlerAction.class.getName());

 	public static final String LEXICAL_HANDLER_PROPERTY = "http://xml.org/sax/properties/lexical-handler";

 	public AbstractHandlerAction(ActionContext actionContext) {

 		super(actionContext);

 	}

 	public abstract DefaultHandler getDefaultHandler();

 	/**

 	 * For e.g. comment nodes.

 	 *

 	 * @return may return null if this output module does not support lexical events

 	 */

 	public LexicalHandler getLexicalHandler() {

 		return null;

 	}

 	@Override

 	public void run(SAXParser parser, InputSource source) throws OutputActionException {

 		DefaultHandler defaultHandler = getDefaultHandler();

 		LexicalHandler lexicalHandler = getLexicalHandler();

 		if (lexicalHandler == null) {

 			log.log(Level.FINE, "No LexicalHandler provided → no comment nodes etc. on output.");

 		} else {

 			try {

 				parser.setProperty(LEXICAL_HANDLER_PROPERTY, lexicalHandler);

 			} catch (SAXNotRecognizedException | SAXNotSupportedException e) {

 				log.log(Level.WARNING, "LexicalHandler registration exception:", e);

 				log.log(Level.WARNING,

 						"Tried to register the handler {0} as a LexicalHandler but LexicalHandlers are not supported by the parser {1}",

 						new Object[]{lexicalHandler, parser});

 			}

 		}

 		try {

 			parser.parse(source, defaultHandler);

 		} catch (IOException | SAXException e) {

 			throw new OutputActionException("Error while parsing document: " + source, e);

 		}

 	}

 }