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.annotation.TurbineService;
027import org.apache.turbine.modules.ActionEvent;
028import org.apache.turbine.pipeline.PipelineData;
029import org.apache.turbine.services.velocity.VelocityService;
030import org.apache.velocity.context.Context;
031
032/**
033 * If you are using VelocitySite stuff, then your Action's should
034 * extend this class instead of extending the ActionEvent class.  The
035 * difference between this class and the ActionEvent class is that
036 * this class will first attempt to execute one of your doMethod's
037 * with a constructor like this:
038 *
039 * <p><code>doEvent(RunData data, Context context)</code></p>
040 *
041 * <p>It gets the context from the TemplateInfo.getTemplateContext()
042 * method. If it can't find a method like that, then it will try to
043 * execute the method without the Context in it.</p>
044 *
045 * @author <a href="mailto:jon@latchkey.com">Jon S. Stevens</a>
046 * @author <a href="mailto:jvanzyl@periapt.com">Jason van Zyl</a>
047 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
048 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
049 * @version $Id$
050 */
051public abstract class VelocityActionEvent extends ActionEvent
052{
053    /** Injected velocity service */
054    @TurbineService
055    protected VelocityService velocity;
056
057    /** Indicates whether or not this module has been initialized. */
058    protected boolean initialized = false;
059
060    /**
061     * Provides a means of initializing the module.
062     *
063     * @throws Exception a generic exception.
064     */
065    protected abstract void initialize()
066        throws Exception;
067
068    /**
069     * This overrides the default Action.doPerform() to execute the
070     * doEvent() method.  If that fails, then it will execute the
071     * doPerform() method instead.
072     *
073     * @param pipelineData A Turbine RunData object.
074     * @throws Exception a generic exception.
075     */
076    @Override
077    public void doPerform(PipelineData pipelineData)
078            throws Exception
079    {
080        if (!initialized)
081        {
082            initialize();
083        }
084
085        ParameterParser pp = pipelineData.get(Turbine.class, ParameterParser.class);
086        Context context = velocity.getContext(pipelineData);
087        executeEvents(pp, new Class<?>[]{ PipelineData.class, Context.class },
088                new Object[]{ pipelineData, context });
089    }
090}