/* * Copyright (c) 2002-2003 by OpenSymphony * All rights reserved. */package com.opensymphony.workflow.util;import com.opensymphony.workflow.InvalidWorkflowDescriptorException;/** * Abstact base class for elements that can be validated. * * @author <a href="mailto:vorburger@users.sourceforge.net">Michael Vorburger</a> * @version $Revision: 1.2 $ */public interface Validatable {    //~ Methods ////////////////////////////////////////////////////////////////    /**     * Validate this element, and propagate validation to all contained sub-elements.     * Should throw an InvalidWorkflowDescriptorException with details in message if the element     * is invalid. Validity checks should be checks that cannot be encapsulated in the DTD.     *     * Validation has to be called explicitly on writting, a writeXML() does not validate implicitly;     * it *IS* thus possible to write invalid descriptor files.  This could be useful for e.g.     * a graphical workflow definition editor which would like to write incomplete definitions.     * Validation *IS* performed on loading a workflow definition.     *     * @see  com.opensymphony.workflow.loader.WorkflowLoader#load     * @throws InvalidWorkflowDescriptorException     */    public void validate() throws InvalidWorkflowDescriptorException;}