    001// Copyright 2007-2014 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
    015package org.apache.tapestry5.internal.services;
    016
    017import org.apache.tapestry5.MarkupWriter;
    018import org.apache.tapestry5.dom.Element;
    019import org.apache.tapestry5.internal.services.ajax.AjaxFormUpdateController;
    020import org.apache.tapestry5.json.JSONObject;
    021import org.apache.tapestry5.runtime.RenderCommand;
    022import org.apache.tapestry5.services.ComponentEventResultProcessor;
    023import org.apache.tapestry5.services.PartialMarkupRenderer;
    024import org.apache.tapestry5.services.PartialMarkupRendererFilter;
    025
    026import 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 */
    034public 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 setup to render the content deferred.
    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}