    001// Copyright 2006, 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
    015package org.apache.tapestry5.internal.services;
    016
    017import org.apache.tapestry5.MarkupWriter;
    018import org.apache.tapestry5.internal.structure.Page;
    019import org.apache.tapestry5.services.MarkupRenderer;
    020
    021public class PageMarkupRendererImpl implements PageMarkupRenderer
    022{
    023    private final PageRenderQueue pageRenderQueue;
    024
    025    private final MarkupRenderer markupRendererPipeline;
    026
    027    public PageMarkupRendererImpl(MarkupRenderer markupRendererPipeline, PageRenderQueue pageRenderQueue)
    028    {
    029        // We have to go through some awkward tricks here:
    030        // - MarkupRenderer and MarkupRendererFilter are PUBLIC
    031        // - Page, PageMarkupRenderer, PageRenderQueue are PRIVATE
    032        // - This service is the bridge between public and private
    033
    034        this.pageRenderQueue = pageRenderQueue;
    035
    036        this.markupRendererPipeline = markupRendererPipeline;
    037    }
    038
    039    public void renderPageMarkup(Page page, MarkupWriter writer)
    040    {
    041        // This is why the PRQ is scope perthread; we tell it what to render here ...
    042
    043        pageRenderQueue.initializeForCompletePage(page);
    044
    045        // ... then our statically fixed pipeline is able to (eventually) call into it.
    046
    047        markupRendererPipeline.renderMarkup(writer);
    048
    049        if (writer.getDocument().getRootElement() == null)
    050        {
    051            throw new RuntimeException(String.format("Page %s did not generate any markup when rendered. This could be because its template file could not be located, or because a render phase method in the page prevented rendering.", page.getName()));
    052        }
    053    }
    054}