PageHistoryValve xref

This project has retired. For details please refer to its Attic page.

1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    * 
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   * 
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.jetspeed.container;
18  
19  import org.apache.commons.logging.Log;
20  import org.apache.commons.logging.LogFactory;
21  import org.apache.jetspeed.om.page.Page;
22  import org.apache.jetspeed.pipeline.PipelineException;
23  import org.apache.jetspeed.pipeline.valve.AbstractValve;
24  import org.apache.jetspeed.pipeline.valve.ValveContext;
25  import org.apache.jetspeed.request.RequestContext;
26  
27  
28  /***
29   * <p>
30   * Valve basically mantains the page navigation history by maintaining a previous page id in the session.
31   * Required by JS2-806
32   * </p>
33   * 
34   * @author <a href="mailto:kmoh.raj@gmail.com">Mohan Kannapareddy</a>
35   * @version $Id$
36   */
37  public class PageHistoryValve extends AbstractValve
38  {
39      protected final Log log = LogFactory.getLog(getClass());
40      
41      // SessionFullExtendedNavigationalState object needs this.
42      public static final String REQUEST_CLEAR_PORTLETS_MODE_AND_WINDOWSTATE_KEY = "clearPortletsModeAndWindowState";
43      
44      private final String SESSION_PREVIOUS_PAGEID_KEY = "PreviousPageId";
45      private boolean valveDisabled = false;
46      
47      /* (non-Javadoc)
48       * @see org.apache.jetspeed.pipeline.valve.AbstractValve#invoke(org.apache.jetspeed.request.RequestContext, org.apache.jetspeed.pipeline.valve.ValveContext)
49       */
50      public void invoke(RequestContext request, ValveContext context) throws PipelineException
51      {
52          if (valveDisabled)
53          {
54              if (log.isDebugEnabled())
55              {
56                  log.debug(toString() + " is DISABLED");
57              }
58          }
59          else
60          {   //OK, the valve is enabled check and see if are a inter-page nav.
61              try
62              {
63                  // create a session if not already created, necessary for Tomcat 5
64                  request.getRequest().getSession(true);
65                  
66                  Page page = request.getPage();
67                  String curPageId = page.getId();
68                  
69                  String prevPageId = (String) request.getSessionAttribute(SESSION_PREVIOUS_PAGEID_KEY);
70                  if (prevPageId == null)
71                  {
72                      //First time, lets set it
73                      request.setSessionAttribute(SESSION_PREVIOUS_PAGEID_KEY, curPageId);
74                      if (log.isDebugEnabled())
75                      {
76                          log.debug("No previous page Id found in session, setting it for the first time");
77                      }
78                  }
79                  else
80                  {
81                      
82                      if (prevPageId.equalsIgnoreCase(curPageId))
83                      {
84                          if (log.isDebugEnabled())
85                          {
86                              log.debug("Previous page id is same as current page id, not clearing page state");
87                          }
88                      }
89                      else
90                      {
91                          if (log.isDebugEnabled())
92                          {
93                              log.debug("Page Change encountered Current Page:" + curPageId + " Prev Page:" + prevPageId);
94                          }
95                          // Make sure we set the prevPageId in session
96                          request.setSessionAttribute(SESSION_PREVIOUS_PAGEID_KEY, curPageId);
97                          // inform NavigationalState object we want to clear all Modes
98                          request.setAttribute(REQUEST_CLEAR_PORTLETS_MODE_AND_WINDOWSTATE_KEY, Boolean.TRUE);
99                      }
100                 }
101             }
102             catch (Exception e)
103             {
104                 throw new PipelineException(e);
105             }
106         }
107         // Pass control to the next Valve in the Pipeline
108         context.invokeNext(request);
109 
110     }
111 
112     public String toString()
113     {
114         return "PageHistoryValve";
115     }
116 
117     public void setValveDisabled(boolean valveDisabled)
118     {
119         this.valveDisabled = valveDisabled;
120     }
121 
122     public boolean isValveDisabled()
123     {
124         return valveDisabled;
125     }
126 
127 }