001package org.apache.turbine.util.velocity;
002
003
004/*
005 * Licensed to the Apache Software Foundation (ASF) under one
006 * or more contributor license agreements.  See the NOTICE file
007 * distributed with this work for additional information
008 * regarding copyright ownership.  The ASF licenses this file
009 * to you under the Apache License, Version 2.0 (the
010 * "License"); you may not use this file except in compliance
011 * with the License.  You may obtain a copy of the License at
012 *
013 *   http://www.apache.org/licenses/LICENSE-2.0
014 *
015 * Unless required by applicable law or agreed to in writing,
016 * software distributed under the License is distributed on an
017 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
018 * KIND, either express or implied.  See the License for the
019 * specific language governing permissions and limitations
020 * under the License.
021 */
022
023
024import org.apache.fulcrum.parser.ParameterParser;
025import org.apache.turbine.Turbine;
026import org.apache.turbine.modules.ActionEvent;
027import org.apache.turbine.pipeline.PipelineData;
028import org.apache.turbine.services.velocity.TurbineVelocity;
029import org.apache.velocity.context.Context;
030
031/**
032 * If you are using VelocitySite stuff, then your Action's should
033 * extend this class instead of extending the ActionEvent class.  The
034 * difference between this class and the ActionEvent class is that
035 * this class will first attempt to execute one of your doMethod's
036 * with a constructor like this:
037 *
038 * <p><code>doEvent(RunData data, Context context)</code></p>
039 *
040 * <p>It gets the context from the TemplateInfo.getTemplateContext()
041 * method. If it can't find a method like that, then it will try to
042 * execute the method without the Context in it.</p>
043 *
044 * @author <a href="mailto:jon@latchkey.com">Jon S. Stevens</a>
045 * @author <a href="mailto:jvanzyl@periapt.com">Jason van Zyl</a>
046 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
047 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
048 * @version $Id: VelocityActionEvent.java 1706425 2015-10-02 14:47:51Z tv $
049 */
050public abstract class VelocityActionEvent extends ActionEvent
051{
052    /** Indicates whether or not this module has been initialized. */
053    protected boolean initialized = false;
054
055    /**
056     * Provides a means of initializing the module.
057     *
058     * @throws Exception a generic exception.
059     */
060    protected abstract void initialize()
061        throws Exception;
062
063    /**
064     * This overrides the default Action.doPerform() to execute the
065     * doEvent() method.  If that fails, then it will execute the
066     * doPerform() method instead.
067     *
068     * @param pipelineData A Turbine RunData object.
069     * @exception Exception a generic exception.
070     */
071    @Override
072    public void doPerform(PipelineData pipelineData)
073            throws Exception
074    {
075        if (!initialized)
076        {
077            initialize();
078        }
079
080        ParameterParser pp = pipelineData.get(Turbine.class, ParameterParser.class);
081        Context context = TurbineVelocity.getContext(pipelineData);
082        executeEvents(pp, new Class<?>[]{ PipelineData.class, Context.class },
083                new Object[]{ pipelineData, context });
084    }
085}