/*
 * IfNode.java
 * Copyright (C) 2004 The Free Software Foundation
 * 
 * This file is part of GNU JAXP, a library.
 *
 * GNU JAXP 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.
 * 
 * GNU JAXP 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Linking this library statically or dynamically with other modules is
 * making a combined work based on this library.  Thus, the terms and
 * conditions of the GNU General Public License cover the whole
 * combination.
 *
 * As a special exception, the copyright holders of this library give you
 * permission to link this library with independent modules to produce an
 * executable, regardless of the license terms of these independent
 * modules, and to copy and distribute the resulting executable under
 * terms of your choice, provided that you also meet, for each linked
 * independent module, the terms and conditions of the license of that
 * module.  An independent module is a module which is not derived from
 * or based on this library.  If you modify this library, you may extend
 * this exception to your version of the library, but you are not
 * obliged to do so.  If you do not wish to do so, delete this
 * exception statement from your version. 
 */

package gnu.xml.transform;

import javax.xml.namespace.QName;
import javax.xml.transform.TransformerException;
import org.w3c.dom.Node;
import gnu.xml.xpath.Expr;

/**
 * A template node representing an XSL <code>if</code> instruction.
 *
 * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a>
 */
final class IfNode
  extends TemplateNode
{

  final Expr test;

  IfNode(TemplateNode children, TemplateNode next, Expr test)
  {
    super(children, next);
    this.test = test;
  }

  TemplateNode clone(Stylesheet stylesheet)
  {
    return new IfNode((children == null) ? null :
                      children.clone(stylesheet),
                      (next == null) ? null :
                      next.clone(stylesheet),
                      test.clone(stylesheet));
  }

  void doApply(Stylesheet stylesheet, QName mode,
             Node context, int pos, int len,
             Node parent, Node nextSibling)
    throws TransformerException
  {
    Object ret = test.evaluate(context, pos, len);
    boolean success = (ret instanceof Boolean) ?
      ((Boolean) ret).booleanValue() :
      Expr._boolean(context, ret);
    if (success)
      {
        if (children != null)
          {
            children.apply(stylesheet, mode,
                           context, pos, len,
                           parent, nextSibling);
          }
      }
    if (next != null)
      {
        next.apply(stylesheet, mode,
                   context, pos, len,
                   parent, nextSibling);
      }
  }
  
  public String toString()
  {
    StringBuffer buf = new StringBuffer(getClass().getName());
    buf.append('[');
    buf.append("test=");
    buf.append(test);
    buf.append(']');
    return buf.toString();
  }
  
}
