001    // Copyright 2004, 2005 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    //     http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry.contrib.inspector;
016    
017    import java.util.Collections;
018    import java.util.List;
019    
020    import org.apache.commons.fileupload.RequestContext;
021    import org.apache.tapestry.BaseComponent;
022    import org.apache.tapestry.event.PageBeginRenderListener;
023    import org.apache.tapestry.event.PageEvent;
024    import org.apache.tapestry.web.WebRequest;
025    import org.apache.tapestry.web.WebSession;
026    
027    /**
028     * Component of the {@link Inspector} page used to display the properties of the
029     * {@link org.apache.tapestry.IEngine} as well as a serialized view of it. Also, the
030     * {@link RequestContext} is dumped out.
031     * 
032     * @author Howard Lewis Ship
033     */
034    
035    public abstract class ShowEngine extends BaseComponent implements PageBeginRenderListener
036    {
037        // Injected
038        public abstract WebRequest getRequest();
039    
040        // Transient
041        public abstract void setSessionAttributeNames(List names);
042    
043        // Transient
044        public abstract void setSession(WebSession session);
045    
046        public void pageBeginRender(PageEvent event)
047        {
048            WebSession session = getRequest().getSession(false);
049    
050            setSession(session);
051    
052            setSessionAttributeNames(session == null ? Collections.EMPTY_LIST : session
053                    .getAttributeNames());
054        }
055    
056    }