1 package org.apache.turbine.util.template;
2
3
4 /*
5 * Licensed to the Apache Software Foundation (ASF) under one
6 * or more contributor license agreements. See the NOTICE file
7 * distributed with this work for additional information
8 * regarding copyright ownership. The ASF licenses this file
9 * to you under the Apache License, Version 2.0 (the
10 * "License"); you may not use this file except in compliance
11 * with the License. You may obtain a copy of the License at
12 *
13 * http://www.apache.org/licenses/LICENSE-2.0
14 *
15 * Unless required by applicable law or agreed to in writing,
16 * software distributed under the License is distributed on an
17 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
18 * KIND, either express or implied. See the License for the
19 * specific language governing permissions and limitations
20 * under the License.
21 */
22
23
24 import org.apache.commons.logging.Log;
25 import org.apache.commons.logging.LogFactory;
26 import org.apache.ecs.ConcreteElement;
27 import org.apache.turbine.modules.Screen;
28 import org.apache.turbine.modules.ScreenLoader;
29 import org.apache.turbine.services.assemblerbroker.TurbineAssemblerBroker;
30 import org.apache.turbine.util.RunData;
31
32 /**
33 * Returns output of a Screen module. An instance of this is
34 * placed in the Velocity context by the VelocityDirectLayout. This
35 * allows the screen to be executed only at rendering.
36 * Here's how it's used in a template:
37 *
38 * <p>
39 * <code>
40 * $screen_placeholder
41 * </code>
42 * <p>
43 * <code>
44 * $screen_placeholder.setScreen("Test")
45 * </code>
46 * </p>
47 *
48 * @author <a href="raphael@apache.org">Raphaƫl Luta</a>
49 * @version $Id: TemplateScreen.java 1071044 2011-02-15 20:47:31Z tv $
50 */
51 public class TemplateScreen
52 {
53 /** Logging */
54 private static Log log = LogFactory.getLog(TemplateScreen.class);
55
56 /* The RunData object. */
57 private RunData data;
58
59 /* The name of the screen template. */
60 private String screen;
61
62 private ScreenLoader screenLoader;
63
64 /**
65 * Constructor
66 *
67 * @param data A Turbine RunData object.
68 */
69 public TemplateScreen(RunData data)
70 {
71 this.data = data;
72 this.screen = data.getScreen();
73 this.screenLoader = (ScreenLoader)TurbineAssemblerBroker.getLoader(Screen.NAME);
74 }
75
76 /**
77 * Set the screen.
78 *
79 * @param screen A String with the name of the screen module
80 * @return A TemplateScreen (self).
81 */
82 public TemplateScreen setScreen(String screen)
83 {
84 this.screen = screen;
85 return this;
86 }
87
88 /**
89 * Builds the output of the navigation template.
90 *
91 * @return A String.
92 */
93 public String toString()
94 {
95 String returnValue = "";
96
97 try
98 {
99 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 }