001package org.apache.turbine.services.jsp.util;
002
003
004/*
005 * Licensed to the Apache Software Foundation (ASF) under one
006 * or more contributor license agreements.  See the NOTICE file
007 * distributed with this work for additional information
008 * regarding copyright ownership.  The ASF licenses this file
009 * to you under the Apache License, Version 2.0 (the
010 * "License"); you may not use this file except in compliance
011 * with the License.  You may obtain a copy of the License at
012 *
013 *   http://www.apache.org/licenses/LICENSE-2.0
014 *
015 * Unless required by applicable law or agreed to in writing,
016 * software distributed under the License is distributed on an
017 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
018 * KIND, either express or implied.  See the License for the
019 * specific language governing permissions and limitations
020 * under the License.
021 */
022
023
024import org.apache.commons.logging.Log;
025import org.apache.commons.logging.LogFactory;
026import org.apache.turbine.modules.Screen;
027import org.apache.turbine.modules.ScreenLoader;
028import org.apache.turbine.services.assemblerbroker.TurbineAssemblerBroker;
029import org.apache.turbine.services.template.TurbineTemplate;
030import org.apache.turbine.util.RunData;
031
032/**
033 * Returns output of a Screen module. An instance of this is placed in the
034 * request by the JspLayout. This allows template authors to
035 * place the screen template within the layout.<br>
036 * Here's how it's used in a JSP template:<br>
037 * <code>
038 * <%useBean id="screen_placeholder" class="JspScreenPlaceholder" scope="request"/%>
039 * ...
040 * <%= screen_placeholder %>
041 *</code>
042 *
043 * @author <a href="john.mcnally@clearink.com">John D. McNally</a>
044 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
045 * @version $Id: JspScreenPlaceholder.java 1199089 2011-11-08 03:14:28Z tv $
046 */
047public class JspScreenPlaceholder
048{
049    /** Logging */
050    private static Log log = LogFactory.getLog(JspNavigation.class);
051
052    /* The RunData object */
053    private final RunData data;
054
055    private final ScreenLoader screenLoader;
056
057    /**
058     * Constructor
059     *
060     * @param data A Rundata Object
061     */
062    public JspScreenPlaceholder(RunData data)
063    {
064        this.data = data;
065        this.screenLoader = (ScreenLoader)TurbineAssemblerBroker.getLoader(Screen.class);
066    }
067
068    /**
069     * builds the output of the navigation template
070     */
071    public void exec()
072    {
073        String template = null;
074        String module = null;
075        try
076        {
077            template = data.getTemplateInfo().getScreenTemplate();
078            module = TurbineTemplate.getScreenName(template);
079            screenLoader.exec(data, module);
080        }
081        catch (Exception e)
082        {
083            String message = "Error processing navigation template:" +
084                    template + " using module: " + module;
085            log.error(message, e);
086            try
087            {
088                data.getResponse().getWriter().print("Error processing navigation template: "
089                        + template + " using module: " + module);
090            }
091            catch (java.io.IOException ioe)
092            {
093                // ignore
094            }
095        }
096    }
097}