001    // Copyright 2008 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.tapestry5.internal.services;
016    
017    import org.apache.tapestry5.EventConstants;
018    import org.apache.tapestry5.internal.InternalConstants;
019    import org.apache.tapestry5.internal.structure.Page;
020    import org.apache.tapestry5.services.*;
021    
022    import java.io.IOException;
023    
024    public class ImmediateActionRenderResponseFilter implements ComponentEventRequestFilter
025    {
026        private final Request request;
027    
028        private final Response response;
029    
030        private final PageResponseRenderer renderer;
031    
032        public ImmediateActionRenderResponseFilter(Request request, PageResponseRenderer renderer, Response response)
033        {
034            this.request = request;
035            this.renderer = renderer;
036            this.response = response;
037        }
038    
039        public void handle(ComponentEventRequestParameters parameters, ComponentEventRequestHandler handler)
040                throws IOException
041        {
042            handler.handle(parameters);
043    
044            // If markup or a redirect has already been generated, then we're good.
045    
046            if (response.isCommitted()) return;
047    
048            // Otherwise, we should be operating in immediate mode.  Figure out which page
049            // was selected to render.
050    
051            Page page = (Page) request.getAttribute(InternalConstants.IMMEDIATE_RESPONSE_PAGE_ATTRIBUTE);
052    
053            if (page != null)
054            {
055                // We don't have a context to provide but this still nags me as not the right thing to do.
056    
057                page.getRootElement().triggerEvent(EventConstants.ACTIVATE, new Object[0], null);
058    
059                renderer.renderPageResponse(page);
060                return;
061            }
062    
063            throw new IllegalStateException(
064                    "Sanity check - neither a stream response nor a redirect response was generated for this action request.");
065        }
066    }