1 package org.apache.turbine.modules.actions;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import org.apache.turbine.modules.screens.TemplateScreen;
23 import org.apache.turbine.pipeline.PipelineData;
24 import org.apache.turbine.util.velocity.VelocityActionEvent;
25 import org.apache.velocity.context.Context;
26
27 /**
28 * This class provides a convenience methods for Velocity Actions to use. Since
29 * this class is abstract, it should only be extended and not used directly.
30 *
31 * @author <a href="mailto:jon@latchkey.com">Jon S. Stevens</a>
32 * @author <a href="mailto:jvanzyl@periapt.com">Jason van Zyl</a>
33 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
34 * @version $Id$
35 */
36 public abstract class VelocityAction extends VelocityActionEvent
37 {
38 /**
39 * Initialize the module.
40 *
41 * @throws Exception a generic exception.
42 */
43 @Override
44 public void initialize() throws Exception
45 {
46 initialized = true;
47 }
48
49 /**
50 * You SHOULD override this method and implement it in your action.
51 *
52 * @param pipelineData Turbine information.
53 * @param context Context for web pages.
54 * @throws Exception a generic exception.
55 */
56 public abstract void doPerform(PipelineData pipelineData, Context context)
57 throws Exception;
58
59 /**
60 * Sets up the context and then calls super.perform(); thus, subclasses
61 * don't have to worry about getting a context themselves! If a subclass
62 * throws an exception then depending on whether
63 * action.event.bubbleexception is true, then it bubbles it farther up, or
64 * traps it there.
65 *
66 * @param pipelineData Turbine information.
67 * @throws Exception a generic exception.
68 */
69 @Override
70 public void perform(PipelineData pipelineData) throws Exception
71 {
72 try
73 {
74 super.perform(pipelineData);
75 }
76 catch (Exception e)
77 {
78 if (bubbleUpException)
79 {
80 throw e;
81 }
82 }
83 }
84
85 /**
86 * This method is used when you want to short circuit an Action and change
87 * the template that will be executed next.
88 *
89 * @param pipelineData Turbine information.
90 * @param template The template that will be executed next.
91 */
92 public void setTemplate(PipelineData pipelineData, String template)
93 {
94 TemplateScreen.setTemplate(pipelineData, template);
95 }
96 }