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.tapestry.BaseComponent;
021    import org.apache.tapestry.event.PageBeginRenderListener;
022    import org.apache.tapestry.event.PageEvent;
023    import org.apache.tapestry.web.WebRequest;
024    import org.apache.tapestry.web.WebSession;
025    
026    /**
027     * Component of the {@link Inspector} page used to display the properties of the
028     * {@link org.apache.tapestry.IEngine} as well as a serialized view of it. Also, the
029     * {@link org.apache.tapestry.request.RequestContext} is dumped out.
030     * 
031     * @author Howard Lewis Ship
032     */
033    
034    public abstract class ShowEngine extends BaseComponent implements PageBeginRenderListener
035    {
036        // Injected
037        public abstract WebRequest getRequest();
038    
039        // Transient
040        public abstract void setSessionAttributeNames(List names);
041    
042        // Transient
043        public abstract void setSession(WebSession session);
044    
045        public void pageBeginRender(PageEvent event)
046        {
047            WebSession session = getRequest().getSession(false);
048    
049            setSession(session);
050    
051            setSessionAttributeNames(session == null ? Collections.EMPTY_LIST : session
052                    .getAttributeNames());
053        }
054    
055    }