    001// Copyright 2009, 2010 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.json.JSONObject;
    019import org.apache.tapestry5.services.PartialMarkupRenderer;
    020
    021/**
    022 * Terminator for the {@link org.apache.tapestry5.services.PartialMarkupRenderer} pipeline, which ultimately invokes
    023 * {@link org.apache.tapestry5.internal.services.PageRenderQueue#renderPartial(org.apache.tapestry5.MarkupWriter, org.apache.tapestry5.json.JSONObject)}
    024 * .
    025 *
    026 * @since 5.1.0.0
    027 */
    028public class PartialMarkupRendererTerminator implements PartialMarkupRenderer
    029{
    030    private final PageRenderQueue renderQueue;
    031
    032    public PartialMarkupRendererTerminator(PageRenderQueue renderQueue)
    033    {
    034        this.renderQueue = renderQueue;
    035    }
    036
    037    public void renderMarkup(MarkupWriter writer, JSONObject reply)
    038    {
    039        // Ensure that whatever renders will do so inside a root element.
    040        // Omitting this causes NPEs when rendering individual zones
    041        // of a MultiZoneUpdate
    042
    043        writer.element("partial-render-root-element");
    044
    045        renderQueue.renderPartial(writer, reply);
    046
    047        writer.end();
    048    }
    049}