001    // Copyright 2007, 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.ComponentResources;
018    import org.apache.tapestry5.internal.structure.Page;
019    import org.apache.tapestry5.runtime.Component;
020    import org.apache.tapestry5.runtime.RenderCommand;
021    import org.apache.tapestry5.services.Ajax;
022    import org.apache.tapestry5.services.ComponentEventResultProcessor;
023    
024    import java.io.IOException;
025    
026    /**
027     * Performs a partial page render based on a root component.
028     */
029    public class AjaxComponentInstanceEventResultProcessor implements ComponentEventResultProcessor<Component>
030    {
031        private final RequestPageCache cache;
032    
033        private final ComponentEventResultProcessor masterProcessor;
034    
035        public AjaxComponentInstanceEventResultProcessor(RequestPageCache cache,
036                                                         @Ajax ComponentEventResultProcessor masterProcessor)
037        {
038            this.cache = cache;
039            this.masterProcessor = masterProcessor;
040        }
041    
042        public void processResultValue(Component value) throws IOException
043        {
044            ComponentResources resources = value.getComponentResources();
045    
046            boolean isPage = value == resources.getPage();
047    
048            String pageName = resources.getPageName();
049    
050            if (isPage)
051            {
052                // This will ultimately send a JSON response to redirect to the page
053    
054                masterProcessor.processResultValue(pageName);
055                return;
056            }
057    
058            // Otherwise, a component within a page.
059    
060            Page page = cache.get(pageName);
061    
062            String nestedId = resources.getNestedId();
063    
064            RenderCommand command = page.getComponentElementByNestedId(nestedId);
065    
066            masterProcessor.processResultValue(command);
067        }
068    }