// 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.dom.Element;

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

 import org.apache.tapestry5.json.JSONObject;

 import org.apache.tapestry5.runtime.RenderCommand;

 import org.apache.tapestry5.runtime.RenderQueue;

 import org.apache.tapestry5.services.PartialMarkupRenderer;

 import org.apache.tapestry5.services.PartialMarkupRendererFilter;

 /**

  * Responsible for capturing the content for a single zone and storing it into the JSON reply object.

  *

  * @see org.apache.tapestry5.ajax.MultiZoneUpdate

  * @since 5.1.0.1

  */

 public class SingleZonePartialRendererFilter implements PartialMarkupRendererFilter

 {

     private final String zoneId;

     private final RenderCommand zoneRenderCommand;

     private final PageRenderQueue queue;

     public SingleZonePartialRendererFilter(String zoneId, RenderCommand zoneRenderCommand, PageRenderQueue queue)

     {

         this.zoneId = zoneId;

         this.zoneRenderCommand = zoneRenderCommand;

         this.queue = queue;

     }

     public void renderMarkup(MarkupWriter writer, final JSONObject reply, PartialMarkupRenderer renderer)

     {

         RenderCommand forZone = new RenderCommand()

         {

             public void render(MarkupWriter writer, RenderQueue queue)

             {

                 // Create an element to contain the content for the zone. We give it a menumonic

                 // element name and attribute just to help with debugging (the element itself is discarded).

                 final Element zoneContainer = writer.element("zone-update", "zoneId", zoneId);

                 queue.push(new RenderCommand()

                 {

                     public void render(MarkupWriter writer, RenderQueue queue)

                     {

                         writer.end(); // the zoneContainer element

                         String zoneUpdateContent = zoneContainer.getChildMarkup();

                         zoneContainer.remove();

                         reply.getJSONObject("zones").put(zoneId, zoneUpdateContent);

                     }

                 });

                 // Make sure the zone's actual rendering command is processed first, then the inline

                 // RenderCommand just above.

                 queue.push(zoneRenderCommand);

             }

         };

         RenderCommand existing = queue.getRootRenderCommand();

         queue.initializeForPartialPageRender(new CombinedRenderCommand(existing, forZone));

         renderer.renderMarkup(writer, reply);

     }

 }