    001    // Copyright 2007, 2008, 2010, 2011 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.MarkupWriter;
    018    import org.apache.tapestry5.dom.Element;
    019    import org.apache.tapestry5.internal.services.ajax.AjaxFormUpdateController;
    020    import org.apache.tapestry5.json.JSONObject;
    021    import org.apache.tapestry5.runtime.RenderCommand;
    022    import org.apache.tapestry5.services.ComponentEventResultProcessor;
    023    import org.apache.tapestry5.services.PartialMarkupRenderer;
    024    import org.apache.tapestry5.services.PartialMarkupRendererFilter;
    025
    026    import java.io.IOException;
    027
    028    /**
    029     * Processor for objects that implement {@link RenderCommand} (such as
    030     * {@link org.apache.tapestry5.internal.structure.BlockImpl}), used with an Ajax component event.
    031     *
    032     * @see AjaxPartialResponseRenderer#renderPartialPageMarkup()
    033     */
    034    public class RenderCommandComponentEventResultProcessor implements ComponentEventResultProcessor<RenderCommand>,
    035            PartialMarkupRendererFilter
    036    {
    037        private final PageRenderQueue pageRenderQueue;
    038
    039        private final AjaxFormUpdateController ajaxFormUpdateController;
    040
    041        private final AjaxPartialResponseRenderer partialRenderer;
    042
    043        public RenderCommandComponentEventResultProcessor(PageRenderQueue pageRenderQueue,
    044                                                          AjaxFormUpdateController ajaxFormUpdateController, AjaxPartialResponseRenderer partialRenderer)
    045        {
    046            this.pageRenderQueue = pageRenderQueue;
    047            this.ajaxFormUpdateController = ajaxFormUpdateController;
    048            this.partialRenderer = partialRenderer;
    049        }
    050
    051        public void processResultValue(RenderCommand value) throws IOException
    052        {
    053            pageRenderQueue.addPartialMarkupRendererFilter(this);
    054            pageRenderQueue.addPartialRenderer(value);
    055
    056            // And render the content right now.
    057
    058            partialRenderer.renderPartialPageMarkup();
    059        }
    060
    061        /**
    062         * As a filter, this class does three things:
    063         * <ul>
    064         * <li>It creates an outer element to capture the partial page content that will be rendered</li>
    065         * <li>It does setup and cleanup with the {@link AjaxFormUpdateController}</li>
    066         * <li>It extracts the child markup and stuffs it into the reply's "content" property.</li>
    067         * </ul>
    068         */
    069        public void renderMarkup(MarkupWriter writer, JSONObject reply, PartialMarkupRenderer renderer)
    070        {
    071            // The partial will quite often contain multiple elements (or just a block of plain text),
    072            // so those must be enclosed in a root element.
    073
    074            Element root = writer.element("ajax-partial");
    075
    076            ajaxFormUpdateController.setupBeforePartialZoneRender(writer);
    077
    078            renderer.renderMarkup(writer, reply);
    079
    080            ajaxFormUpdateController.cleanupAfterPartialZoneRender();
    081
    082            writer.end();
    083
    084            String content = root.getChildMarkup().trim();
    085
    086            reply.put("content", content);
    087        }
    088    }