TemplateModel.java

/*
 * FreeMarker: a tool that allows Java programs to generate HTML
 * output using templates.
 * Copyright (C) 1998-2004 Benjamin Geer
 * Email: beroul@users.sourceforge.net
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA  02111-1307, USA.
 */

package freemarker.template;

/**
 * <p>
 * A template's data model must be a tree of objects, each of which implements a
 * subinterface of <code>TemplateModel</code>. The root of the tree must
 * implement {@link TemplateWriteableHashModel}.
 * 
 * <p>
 * The detail messages of any {@link TemplateModelException}s thrown will be
 * included as HTML comments in the output.
 * </p>
 * 
 * @version $Id: TemplateModel.java 1123 2005-10-04 10:48:25Z run2000 $
 */
public interface TemplateModel {
	/**
	 * Is the object empty?
	 * 
	 * @return <code>true</code> if this object is empty, otherwise
	 *         <code>false</code>
	 */
	public boolean isEmpty() throws TemplateModelException;
}