/* * Copyright (c) 2002-2003 by OpenSymphony * All rights reserved. */package com.opensymphony.workflow;import com.opensymphony.module.propertyset.PropertySet;import java.util.Map;/** * Interface that must be implemented to define a java-based validator in your workflow definition. * * @author <a href="mailto:plightbo@hotmail.com">Patrick Lightbody</a> */public interface Validator {    //~ Methods ////////////////////////////////////////////////////////////////    /**     * Validates the user input.     *     * @param transientVars Variables that will not be persisted. These include inputs     * given in the {@link Workflow#initialize} and {@link Workflow#doAction} method calls.     * There are a number of special variable names:     * <ul>     * <li><code>entry</code>: (object type: {@link com.opensymphony.workflow.spi.WorkflowEntry})     *  The workflow instance     * <li><code>context</code>:     * (object type: {@link com.opensymphony.workflow.WorkflowContext}). The workflow context.     * <li><code>actionId</code>: The Integer ID of the current action that was take (if applicable).     * <li><code>currentSteps</code>: A Collection of the current steps in the workflow instance.     * <li><code>store</code>: The {@link com.opensymphony.workflow.spi.WorkflowStore}.     * <li><code>descriptor</code>: The {@link com.opensymphony.workflow.loader.WorkflowDescriptor}.     * </ul>     * Also, any variable set as a {@link com.opensymphony.workflow.Register}), will also be     * available in the transient map. These transient variables only last through     * the method call that they were invoked in, such as {@link Workflow#initialize}     * and {@link Workflow#doAction}.     * @param args The properties for this function invocation. Properties are created     * from arg nested elements within the xml, an arg element takes in a name attribute     * which is the properties key, and the CDATA text contents of the element map to     * the property value.     * @param ps The persistent variables that are associated with the current     * instance of the workflow. Any change made to the propertyset are persisted to     * the propertyset implementation's persistent store.     * @throws InvalidInputException if the input is deemed to be invalid     */    public void validate(Map transientVars, Map args, PropertySet ps) throws InvalidInputException, WorkflowException;}