// Copyright 2009 The Apache Software Foundation

 //

 // Licensed under the Apache License, Version 2.0 (the "License");

 // you may not use this file except in compliance with the License.

 // You may obtain a copy of the License at

 //

 //     http://www.apache.org/licenses/LICENSE-2.0

 //

 // Unless required by applicable law or agreed to in writing, software

 // distributed under the License is distributed on an "AS IS" BASIS,

 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 // See the License for the specific language governing permissions and

 // limitations under the License.

 package org.apache.tapestry5.services.ajax;

 import org.apache.tapestry5.MarkupWriter;

 import org.apache.tapestry5.ajax.MultiZoneUpdate;

 import org.apache.tapestry5.internal.services.PageRenderQueue;

 import org.apache.tapestry5.ioc.internal.util.InternalUtils;

 import org.apache.tapestry5.ioc.services.TypeCoercer;

 import org.apache.tapestry5.runtime.RenderCommand;

 import org.apache.tapestry5.runtime.RenderQueue;

 import org.apache.tapestry5.services.ComponentEventResultProcessor;

 import java.io.IOException;

 import java.util.Map;

 /**

  * Handler for {@link org.apache.tapestry5.ajax.MultiZoneUpdate} responses from a component event handler method. Works

  * by adding {@link org.apache.tapestry5.services.ajax.SingleZonePartialRendererFilter}s for each zone to the

  * {@linkplain org.apache.tapestry5.internal.services.PageRenderQueue#addPartialMarkupRendererFilter(org.apache.tapestry5.services.PartialMarkupRendererFilter)

  * filter stack}.  Each zone writes its content as a string in the zones object of the reply, keyed on its id.

  * JavaScript and CSS are collected for all zones rendered in the request (not for each individua zone).  The final

  * repsonse will have some combination of "script", "scripts", "stylesheets", "content" (which is expected to be blank)

  * and "zones".

  *

  * @since 5.1.0.1

  */

 public class MultiZoneUpdateEventResultProcessor implements ComponentEventResultProcessor<MultiZoneUpdate>

 {

     private final PageRenderQueue queue;

     private final TypeCoercer typeCoercer;

     public MultiZoneUpdateEventResultProcessor(PageRenderQueue queue, TypeCoercer typeCoercer)

     {

         this.queue = queue;

         this.typeCoercer = typeCoercer;

     }

     public void processResultValue(final MultiZoneUpdate value) throws IOException

     {

         // There has to be at least a single command in the queue to force a render.

         queue.initializeForPartialPageRender(new RenderCommand()

         {

             public void render(MarkupWriter writer, RenderQueue queue)

             {

             }

         });

         queue.addPartialMarkupRendererFilter(new SetupZonesFilter());

         Map<String, Object> map = value.getZoneToRenderMap();

         for (String zoneId : map.keySet())

         {

             Object provided = map.get(zoneId);

             RenderCommand zoneRenderCommand = toRenderer(zoneId, provided);

             queue.addPartialMarkupRendererFilter(new SingleZonePartialRendererFilter(zoneId, zoneRenderCommand, queue));

         }

     }

     private RenderCommand toRenderer(String zoneId, Object provided)

     {

         try

         {

             return typeCoercer.coerce(provided, RenderCommand.class);

         }

         catch (Exception ex)

         {

             throw new IllegalArgumentException(String.format("Failure converting renderer for zone '%s': %s",

                                                              zoneId,

                                                              InternalUtils.toMessage(ex)), ex);

         }

     }

 }