001    // Copyright 2007, 2008, 2010 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. If the component is actually a page,
028     * it will send an JSON reponse to rediret to the page.
029     */
030    @SuppressWarnings("all")
031    public class AjaxComponentInstanceEventResultProcessor implements ComponentEventResultProcessor<Component>
032    {
033        private final RequestPageCache cache;
034    
035        private final ComponentEventResultProcessor masterProcessor;
036    
037        public AjaxComponentInstanceEventResultProcessor(RequestPageCache cache, @Ajax
038        ComponentEventResultProcessor masterProcessor)
039        {
040            this.cache = cache;
041            this.masterProcessor = masterProcessor;
042        }
043    
044        public void processResultValue(Component value) throws IOException
045        {
046            ComponentResources resources = value.getComponentResources();
047    
048            boolean isPage = value == resources.getPage();
049    
050            String pageName = resources.getPageName();
051    
052            if (isPage)
053            {
054                // This will ultimately send a JSON response to redirect to the page
055    
056                masterProcessor.processResultValue(pageName);
057                return;
058            }
059    
060            // Otherwise, a component within a page. Components are transformed to implement RenderCommand, but if we just
061            // pass the component itself to the master processor, we'll get in a loop, so we instead
062            // pass the ComponentPageElement (which implements RenderCommand as well).
063    
064            Page page = cache.get(pageName);
065    
066            String nestedId = resources.getNestedId();
067    
068            RenderCommand command = page.getComponentElementByNestedId(nestedId);
069    
070            masterProcessor.processResultValue(command);
071        }
072    }