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


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  * PortletAction.java
18  *
19  *
20  * $Id: PortletAction.java,v 1.8.2.1 2003/02/24 18:45:42 tkuebler Exp $
21  *
22  * Created on January 29, 2003, 2:52 PM
23  */
24 package org.apache.jetspeed.modules.actions.portlets;
25
26 import org.apache.jetspeed.portal.Portlet;
27 import org.apache.jetspeed.portal.portlets.GenericMVCPortlet;
28 import org.apache.jetspeed.util.PortletSessionState;
29 import org.apache.turbine.util.RunData;
30 import org.apache.velocity.context.Context;
31
32
33
34
35 /**
36  *
37  * Abstract holder for the portlet specific methods required above and
38  * beyond the standard turbine action.
39  *
40  * Extends the PortletActionEvent, which
41  * encapsulates the event handling feature.
42  *
43  * @author tkuebler
44  * @author <a HREF="mailto:weaver@apache.org">Scott T. Weaver</a>
45  * @version $Id: PortletAction.java,v 1.8.2.1 2003/02/24 18:45:42 tkuebler Exp $
46  * @stereotype moment-interval
47  *
48  */
49
50
51 /*
52  * Note:
53  * assumes a templated portlet, maybe should break this up into two classes
54  * the portletaction would only have the build*Context methods
55  * the templatedportletaction would have the rest
56  * skipping this complexity for now since non-templated portlet actions can just
57  * extend ActionEvent and forget about the context probably
58  */
59 public abstract class PortletAction
60     extends PortletActionEvent
61   {
62
63     /** Creates a new instance of PortletAction */
64     public PortletAction()
65       {
66       }
67
68     public void doPerform(RunData data)
69                    throws Exception JavaDoc
70       {
71
72         // assumes a context for the portlet...
73 // should check for null and create one
74 doPerform(data, getContext(data));
75       }
76
77     /**
78      * You SHOULD override this method and implement it in your
79      * action.
80      *
81      * @param data Turbine information.
82      * @param context Context for web pages.
83      * @exception Exception, a generic exception.
84      */
85     public abstract void doPerform(RunData data, Context context)
86                             throws Exception JavaDoc;
87
88     /**
89      * Return the Context
90      *
91      * @param RunData data
92      * @return Context, a context for web pages.
93      */
94     protected Context getContext(RunData data)
95       {
96
97         return (Context) data.getTemplateInfo().getTemplateContext("VelocityPortletContext");
98       }
99
100     /**
101      * This method is used when you want to short circuit an Action
102      * and change the template that will be executed next. The TTL
103      * for this is a single request.
104      *
105      * @param data Turbine information.
106      * @param template The template that will be executed next.
107      */
108     public void setTemplate(RunData data, String JavaDoc template)
109       {
110         setTemplate(data, template, false);
111       }
112       
113     /**
114      * This method is used when you want to short circuit an Action
115      * and change the template that will be executed next. If
116      * the <code>persistent</code> attribute is set to <i>true</i>
117      * the template value is stored in the portlet's session state
118      * and will be used until a new value has been set, either within
119      * portlet session or within the context. Regardless of the
120      * value of <code>persistent</code>, the context will ALWAYS
121      * have the correct "template" attribute set within.
122      *
123      * @param data Turbine information.
124      * @param template The template that will be executed next.
125      * @param persistent whether or not to make the template set
126      * persistent for the extent of the portlet session
127      * @author <a HREF="mailto:weaver@apache.org">Scott T. Weaver</a>
128      */
129     public void setTemplate(RunData data, String JavaDoc template, boolean persistent)
130     {
131         Portlet portlet = getPortlet(getContext(data));
132
133         if (template != null)
134         {
135             if (persistent)
136             {
137                 PortletSessionState.setAttribute(
138                     portlet,
139                     data,
140                     GenericMVCPortlet.TEMPLATE,
141                     template);
142             }
143             else
144             {
145                 // Make sure there is no ssession residue ;)
146 resetTemplate(data);
147             }
148
149             // Always make the current template is available within the
150 // context.
151 getContext(data).put("template", template);
152         }
153
154     }
155     
156     /**
157      * Clears the PortletSessionState of the <code>template</code>
158      * attribute.
159      */
160     protected void resetTemplate(RunData data)
161     {
162         Portlet portlet = getPortlet(getContext(data));
163         PortletSessionState.clearAttribute(portlet, data, GenericMVCPortlet.PORTLET);
164     }
165       
166   
167       
168     public Portlet getPortlet(Context context)
169     {
170         return (Portlet) context.get(GenericMVCPortlet.PORTLET);
171     }
172     /**
173      * Retrieves the template for this PortletAction's Portlet.
174      * The Portlet <code>init()</code> will have already initialized
175      * the template value within the current context in this order:<br/>
176      * 1. From the PortletSessionState's "template" attribute <br />
177      * 2. From the PortletConfig's "template" parameter.<br /><br />
178      * However, the action may have overriden this value using
179      * any of the <code>setTemplate()</code> methods.
180      * @param Context context the context for this action's portlet.
181      * @return String Current view template for this action's portlet.
182      * @author <a HREF="mailto:weaver@apache.org">Scott T. Weaver</a>
183      */
184     public String JavaDoc getTemplate(Context context)
185     {
186
187         return (String JavaDoc) context.get(GenericMVCPortlet.TEMPLATE);
188     }
189
190     protected abstract void buildConfigureContext(Portlet portlet, Context context, RunData data)
191                                            throws Exception JavaDoc;
192
193     protected abstract void buildMaximizedContext(Portlet portlet, Context context, RunData data)
194                                            throws Exception JavaDoc;
195
196     protected abstract void buildNormalContext(Portlet portlet, Context context, RunData data)
197                                         throws Exception JavaDoc;
198   }
199
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