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1   package org.apache.turbine.util.velocity;
2   
3   
4   /*
5    * Licensed to the Apache Software Foundation (ASF) under one
6    * or more contributor license agreements.  See the NOTICE file
7    * distributed with this work for additional information
8    * regarding copyright ownership.  The ASF licenses this file
9    * to you under the Apache License, Version 2.0 (the
10   * "License"); you may not use this file except in compliance
11   * with the License.  You may obtain a copy of the License at
12   *
13   *   http://www.apache.org/licenses/LICENSE-2.0
14   *
15   * Unless required by applicable law or agreed to in writing,
16   * software distributed under the License is distributed on an
17   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
18   * KIND, either express or implied.  See the License for the
19   * specific language governing permissions and limitations
20   * under the License.
21   */
22  
23  
24  import org.apache.fulcrum.parser.ParameterParser;
25  import org.apache.turbine.Turbine;
26  import org.apache.turbine.modules.ActionEvent;
27  import org.apache.turbine.pipeline.PipelineData;
28  import org.apache.turbine.services.velocity.TurbineVelocity;
29  import org.apache.velocity.context.Context;
30  
31  /**
32   * If you are using VelocitySite stuff, then your Action's should
33   * extend this class instead of extending the ActionEvent class.  The
34   * difference between this class and the ActionEvent class is that
35   * this class will first attempt to execute one of your doMethod's
36   * with a constructor like this:
37   *
38   * <p><code>doEvent(RunData data, Context context)</code></p>
39   *
40   * <p>It gets the context from the TemplateInfo.getTemplateContext()
41   * method. If it can't find a method like that, then it will try to
42   * execute the method without the Context in it.</p>
43   *
44   * @author <a href="mailto:jon@latchkey.com">Jon S. Stevens</a>
45   * @author <a href="mailto:jvanzyl@periapt.com">Jason van Zyl</a>
46   * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
47   * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
48   * @version $Id: VelocityActionEvent.java 1706425 2015-10-02 14:47:51Z tv $
49   */
50  public abstract class VelocityActionEvent extends ActionEvent
51  {
52      /** Indicates whether or not this module has been initialized. */
53      protected boolean initialized = false;
54  
55      /**
56       * Provides a means of initializing the module.
57       *
58       * @throws Exception a generic exception.
59       */
60      protected abstract void initialize()
61          throws Exception;
62  
63      /**
64       * This overrides the default Action.doPerform() to execute the
65       * doEvent() method.  If that fails, then it will execute the
66       * doPerform() method instead.
67       *
68       * @param pipelineData A Turbine RunData object.
69       * @exception Exception a generic exception.
70       */
71      @Override
72      public void doPerform(PipelineData pipelineData)
73              throws Exception
74      {
75          if (!initialized)
76          {
77              initialize();
78          }
79  
80          ParameterParser pp = pipelineData.get(Turbine.class, ParameterParser.class);
81          Context context = TurbineVelocity.getContext(pipelineData);
82          executeEvents(pp, new Class<?>[]{ PipelineData.class, Context.class },
83                  new Object[]{ pipelineData, context });
84      }
85  }