KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > apache > jetspeed > modules > actions > portlets > VelocityPortletAction


1 /*
2  * Copyright 2000-2001,2004 The Apache Software Foundation.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16  
17 package org.apache.jetspeed.modules.actions.portlets;
18
19
20 import java.lang.reflect.Method JavaDoc;
21
22 import org.apache.jetspeed.portal.Portlet;
23 import org.apache.jetspeed.portal.portlets.VelocityPortlet;
24
25
26 // Turbine stuff
27 import org.apache.turbine.util.RunData;
28
29
30 // Velocity Stuff
31 import org.apache.velocity.context.Context;
32
33
34 /**
35  * An abstract action class to build VelocityPortlet actions.
36  *
37  * <p>Don't call it from the URL, the Portlet and the Action are automatically
38  * associated through the registry PortletName
39  * <p>
40  * <strong>NOTE:</strong>This supports the pre-MVC style of template based
41  * portlet development and is supplied for backward compatibility. It is
42  * suggested you use a combination of
43  * @see org.apache.jetspeed.portal.portlets.GenericMVCPortlet along with
44  * subclassing @see org.apache.jetspeed.portal.portlets.GenericMVCAction
45  * for future portlet development.
46  * </p>
47  *
48  * @author <a HREF="mailto:raphael@apache.org">Raphaël Luta</a>
49  * @author <a HREF="mailto:re_carrasco@bco011.sonda.cl">Roberto Carrasco</a>
50  *
51  * @version $Id: VelocityPortletAction.java,v 1.14 2004/02/23 02:56:58 jford Exp $
52  */
53 public abstract class VelocityPortletAction extends GenericMVCAction
54 {
55
56
57
58     /**
59      * Subclasses must override this method to provide default behavior
60      * for the portlet action
61      */
62     protected abstract void buildNormalContext(VelocityPortlet portlet,
63                                                 Context context,
64                                                 RunData rundata)
65         throws Exception JavaDoc;
66
67     /**
68      * STW: Backwards compatibility so the overriden method is called specifically using a cast to VelocityPortlet
69      * @see org.apache.jetspeed.portal.portlets.mvc.PortletAction#buildNormalContext(Portlet, Context, RunData)
70      */
71     protected void buildNormalContext(Portlet portlet, Context context, RunData data)
72         throws Exception JavaDoc
73     {
74         buildNormalContext((VelocityPortlet) portlet, context, data);
75     }
76
77     /**
78      * @see org.apache.jetspeed.portal.portlets.mvc.PortletAction#buildConfigureContext(Portlet, Context, RunData)
79      */
80     protected void buildConfigureContext(Portlet portlet, Context context, RunData data)
81         throws Exception JavaDoc
82     {
83         // STW: Don't try this at home, kids. It's about the worst reflection hack you
84 // can commit. However, it was the only to have VelocityPortletAction implement
85 // GenericMVCAction an still work correctly. The sypmtom we where experiencing
86 // was that we where skipping over the overriden method in the inheriting class
87 // due to the ambiguousness of the build*() method signatures (VelocityPortlet vs. Portlet)
88 // This only happens when the class subclassing VelocityPortlet defines a build*()
89 // method with the signature build*(VelocityPortlet, Context, RunData), which is 100%
90 // of the time with any previously defined Actions subclassing VelocityPortletAction.
91 // Defining build*(Portlet, Context, RunData) fixes the problem but can't expect
92 // everyone to go back and change all of there Action method signatures just to
93 // fix this. Eventually we should deprecate this class all together.
94 try
95         {
96             Method JavaDoc method =
97                 this.getClass().getDeclaredMethod(
98                     "buildConfigureContext",
99                     new Class JavaDoc[] { VelocityPortlet.class, Context.class, RunData.class });
100             method.setAccessible(true);
101             method.invoke(this, new Object JavaDoc[] { portlet, context, data });
102             method.setAccessible(false);
103
104         }
105         catch (NoSuchMethodException JavaDoc e)
106         {
107             // Subclass did not override this method
108 super.buildConfigureContext(portlet, context, data);
109         }
110         
111     }
112     
113     /**
114      * prevents possible self-referencing loop when sub-classes invoke super.buildConfigureContext().
115      * @author <a HREF="mailto:weaver@apache.org">Scott T. Weaver</a>
116      */
117     protected void buildConfigureContext(VelocityPortlet portlet, Context context, RunData data)
118         throws Exception JavaDoc
119     {
120     }
121     
122     
123     protected void buildMaximizedContext(Portlet portlet, Context context, RunData data)
124         throws Exception JavaDoc
125     {
126         // STW: Don't try this at home, kids. It's about the worst reflection hack you
127 // can commit. However, it was the only to have VelocityPortletAction implement
128 // GenericMVCAction an still work correctly. The sypmtom we where experiencing
129 // was that we where skipping over the overriden method in the inheriting class
130 // due to the ambiguousness of the build*() method signatures (VelocityPortlet vs. Portlet)
131 // This only happens when the class subclassing VelocityPortlet defines a build*()
132 // method with the signature build*(VelocityPortlet, Context, RunData), which is 100%
133 // of the time with any previously defined Actions subclassing VelocityPortletAction.
134 // Defining build*(Portlet, Context, RunData) fixes the problem but can't expect
135 // everyone to go back and change all of there Action method signatures just to
136 // fix this. Eventually we should deprecate this class all together.
137 try
138         {
139             Method JavaDoc method =
140                 this.getClass().getDeclaredMethod(
141                     "buildMaximizedContext",
142                     new Class JavaDoc[] { VelocityPortlet.class, Context.class, RunData.class });
143             method.setAccessible(true);
144             method.invoke(this, new Object JavaDoc[] { portlet, context, data });
145             method.setAccessible(false);
146         }
147         catch (NoSuchMethodException JavaDoc e)
148         {
149             // Subclass did not override this method
150 super.buildMaximizedContext(portlet, context, data);
151         }
152     }
153     
154     /**
155      * prevents possible self-referencing loop when sub-classes invoke super.buildMaximizedContext().
156      * @author <a HREF="mailto:weaver@apache.org">Scott T. Weaver</a>
157      */
158     protected void buildMaximizedContext(VelocityPortlet portlet, Context context, RunData data)
159         throws Exception JavaDoc
160     {
161     }
162     
163    
164    
165
166 }
167
Popular Tags