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
27 import org.apache.ecs.ConcreteElement;
28
29 import org.apache.turbine.modules.NavigationLoader;
30
31 import org.apache.turbine.services.template.TurbineTemplate;
32
33 import org.apache.turbine.util.RunData;
34
35 /**
36 * Returns output of a Navigation module. An instance of this is
37 * placed in the WebMacro context by the WebMacroSiteLayout. This
38 * allows template authors to set the navigation template they'd like
39 * to place in their templates. Here's how it's used in a
40 * template:
41 *
42 * <p><code>
43 * $navigation.setTemplate("admin_navigation.wm")
44 * </code>
45 *
46 * @author <a href="mbryson@mont.mindspring.com">Dave Bryson</a>
47 * @version $Id: TemplateNavigation.java 615328 2008-01-25 20:25:05Z tv $
48 */
49 public class TemplateNavigation
50 {
51 /** Logging */
52 private static Log log = LogFactory.getLog(TemplateNavigation.class);
53
54 /* The RunData object. */
55 private RunData data;
56
57 /* The name of the navigation template. */
58 private String template = null;
59
60 /**
61 * Constructor
62 *
63 * @param data A Turbine RunData object.
64 */
65 public TemplateNavigation(RunData data)
66 {
67 this.data = data;
68 }
69
70 /**
71 * Set the template.
72 *
73 * @param template A String with the name of the navigation
74 * template.
75 * @return A TemplateNavigation (self).
76 */
77 public TemplateNavigation setTemplate(String template)
78 {
79 log.debug("setTemplate(" + template + ")");
80 this.template = template;
81 return this;
82 }
83
84 /**
85 * Builds the output of the navigation template.
86 *
87 * @return A String.
88 */
89 public String toString()
90 {
91 String module = null;
92 String returnValue = null;
93
94 try
95 {
96 if (template == null)
97 {
98 returnValue = "Navigation Template is null (Might be unset)";
99 throw new Exception(returnValue);
100 }
101
102 data.getTemplateInfo().setNavigationTemplate(template);
103 module = TurbineTemplate.getNavigationName(template);
104
105 if (module == null)
106 {
107 returnValue = "Template Service returned null for Navigation Template " + template;
108 throw new Exception(returnValue);
109 }
110
111 ConcreteElement results =
112 NavigationLoader.getInstance().eval(data, module);
113 returnValue = results.toString();
114 }
115 catch (Exception e)
116 {
117 if (returnValue == null)
118 {
119 returnValue = "Error processing navigation template: "
120 + template + ", using module: " + module;
121 }
122 log.error(returnValue, e);
123 }
124
125 return returnValue;
126 }
127 }