GossipProcessor.java

/*
 * 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; either version 2 of the License, or (at your option) any later
 * version. You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

package org.aitools.programd.processor.aiml;

import java.io.FileWriter;
import java.io.IOException;

import org.aitools.programd.Core;
import org.aitools.programd.parser.TemplateParser;
import org.aitools.programd.processor.ProcessorException;
import org.aitools.util.resource.Filesystem;
import org.aitools.util.runtime.DeveloperError;
import org.aitools.util.runtime.UserError;
import org.jdom.Element;

/**
 * Handles a <code><a href="http://aitools.org/aiml/TR/2001/WD-aiml/#section-gossip">gossip</a></code> element.
 * 
 * @author Jon Baer
 * @author Thomas Ringate, Pedro Colla
 */
public class GossipProcessor extends AIMLProcessor {

  /** The label (as required by the registration scheme). */
  public static final String label = "gossip";

  private static FileWriter gossipFile;

  /**
   * Creates a new GossipProcessor using the given Core.
   * 
   * @param core the Core object to use
   */
  public GossipProcessor(Core core) {
    super(core);
  }

  /**
   * @see AIMLProcessor#process(Element, TemplateParser)
   */
  @SuppressWarnings("unchecked")
  @Override
  public String process(Element element, TemplateParser parser) throws ProcessorException {
    // Get the gossip.
    String response = parser.evaluate(element.getContent());

    // Initialize the FileWriter if necessary.
    if (gossipFile == null) {
      try {
        gossipFile = new FileWriter(Filesystem.checkOrCreate(parser.getCore().getSettings().getGossipURL().getPath(),
            "gossip file"));
      }
      catch (IOException e) {
        throw new UserError(e);
      }
    }

    // Put the gossip in the log.
    try {
      gossipFile.append(String.format("<li>%s</li>%n", response));
      gossipFile.flush();
    }
    catch (IOException e) {
      throw new DeveloperError("Error trying to write gossip.", e);
    }
    return "";
  }
}