001 package org.apache.turbine.util.template;
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
024 import org.apache.commons.logging.Log;
025 import org.apache.commons.logging.LogFactory;
026 import org.apache.ecs.ConcreteElement;
027 import org.apache.turbine.modules.Screen;
028 import org.apache.turbine.modules.ScreenLoader;
029 import org.apache.turbine.services.assemblerbroker.TurbineAssemblerBroker;
030 import org.apache.turbine.util.RunData;
031
032 /**
033 * Returns output of a Screen module. An instance of this is
034 * placed in the Velocity context by the VelocityDirectLayout. This
035 * allows the screen to be executed only at rendering.
036 * Here's how it's used in a template:
037 *
038 * <p>
039 * <code>
040 * $screen_placeholder
041 * </code>
042 * <p>
043 * <code>
044 * $screen_placeholder.setScreen("Test")
045 * </code>
046 * </p>
047 *
048 * @author <a href="raphael@apache.org">Raphaƫl Luta</a>
049 * @version $Id: TemplateScreen.java 1071044 2011-02-15 20:47:31Z tv $
050 */
051 public class TemplateScreen
052 {
053 /** Logging */
054 private static Log log = LogFactory.getLog(TemplateScreen.class);
055
056 /* The RunData object. */
057 private RunData data;
058
059 /* The name of the screen template. */
060 private String screen;
061
062 private ScreenLoader screenLoader;
063
064 /**
065 * Constructor
066 *
067 * @param data A Turbine RunData object.
068 */
069 public TemplateScreen(RunData data)
070 {
071 this.data = data;
072 this.screen = data.getScreen();
073 this.screenLoader = (ScreenLoader)TurbineAssemblerBroker.getLoader(Screen.NAME);
074 }
075
076 /**
077 * Set the screen.
078 *
079 * @param screen A String with the name of the screen module
080 * @return A TemplateScreen (self).
081 */
082 public TemplateScreen setScreen(String screen)
083 {
084 this.screen = screen;
085 return this;
086 }
087
088 /**
089 * Builds the output of the navigation template.
090 *
091 * @return A String.
092 */
093 public String toString()
094 {
095 String returnValue = "";
096
097 try
098 {
099 ConcreteElement results = screenLoader.eval(data, this.screen);
100
101 if (results != null)
102 {
103 returnValue = results.toString();
104 }
105 }
106 catch (Exception e)
107 {
108 log.error(e);
109 }
110
111 return returnValue;
112 }
113 }