KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > apache > turbine > services > template > mapper > LayoutTemplateMapper


1 package org.apache.turbine.services.template.mapper;
2
3 /*
4  * Copyright 2001-2004 The Apache Software Foundation.
5  *
6  * Licensed under the Apache License, Version 2.0 (the "License")
7  * you may not use this file except in compliance with the License.
8  * You may obtain a copy of the License at
9  *
10  * http://www.apache.org/licenses/LICENSE-2.0
11  *
12  * Unless required by applicable law or agreed to in writing, software
13  * distributed under the License is distributed on an "AS IS" BASIS,
14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15  * See the License for the specific language governing permissions and
16  * limitations under the License.
17  */
18
19 import java.util.List JavaDoc;
20 import java.util.ArrayList JavaDoc;
21 import java.util.Arrays JavaDoc;
22
23 import org.apache.commons.lang.StringUtils;
24
25 import org.apache.commons.logging.Log;
26 import org.apache.commons.logging.LogFactory;
27
28 import org.apache.turbine.services.template.TemplateEngineService;
29 import org.apache.turbine.services.template.TemplateService;
30 import org.apache.turbine.services.template.TurbineTemplate;
31
32 /**
33  * This mapper is responsible for the lookup of templates for the Layout
34  * It tries to look in various packages for a match:
35  *
36  * 1. about,directions,Driving.vm <- exact match
37  * 2. about,directions,Default.vm <- package match, Default name
38  * 3. about,Default.vm <- stepping up in the hierarchy
39  * 4. Default.vm <- The name configured as default.layout.template
40  * in the corresponding Templating Engine
41
42  *
43  * @author <a HREF="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
44  * @version $Id: LayoutTemplateMapper.java,v 1.1.2.2 2004/05/20 03:06:48 seade Exp $
45  */
46
47 public class LayoutTemplateMapper
48     extends BaseTemplateMapper
49     implements Mapper
50 {
51     /** Logging */
52     private static Log log = LogFactory.getLog(LayoutTemplateMapper.class);
53
54     /**
55      * Default C'tor. If you use this C'tor, you must use
56      * the bean setter to set the various properties needed for
57      * this mapper before first usage.
58      */
59     public LayoutTemplateMapper()
60     {
61     }
62
63     /**
64      * Look for a given Template, then try the
65      * defaults until we hit the root.
66      *
67      * @param template The template name.
68      * @return The parsed module name.
69      */
70     public String JavaDoc doMapping(String JavaDoc template)
71     {
72         log.debug("doMapping(" + template + ")");
73         // Copy our elements into an array
74 List JavaDoc components
75             = new ArrayList JavaDoc(Arrays.asList(StringUtils.split(
76                                               template,
77                                               String.valueOf(TemplateService.TEMPLATE_PARTS_SEPARATOR))));
78         int componentSize = components.size() - 1 ;
79
80         // This method never gets an empty string passed.
81 // So this is never < 0
82 String JavaDoc templateName = (String JavaDoc) components.get(componentSize);
83         components.remove(componentSize--);
84
85         log.debug("templateName is " + templateName);
86
87         // Last element decides, which template Service to use...
88 TemplateEngineService tes = TurbineTemplate.getTemplateEngineService(templateName);
89
90         if (tes == null)
91         {
92             return null;
93         }
94
95         String JavaDoc defaultName =
96             TurbineTemplate.getDefaultLayoutTemplateName(templateName); // We're, after all, a Layout Template Mapper...
97
98         // This is an optimization. If the name we're looking for is
99 // already the default name for the template, don't do a "first run"
100 // which looks for an exact match.
101 boolean firstRun = !templateName.equals(defaultName);
102
103         for(;;)
104         {
105             String JavaDoc templatePackage = StringUtils.join(components.iterator(), String.valueOf(separator));
106
107             log.debug("templatePackage is now: " + templatePackage);
108
109             StringBuffer JavaDoc testName = new StringBuffer JavaDoc();
110
111             if (!components.isEmpty())
112             {
113                 testName.append(templatePackage);
114                 testName.append(separator);
115             }
116
117             testName.append((firstRun)
118                 ? templateName
119                 : defaultName);
120
121             // But the Templating service must look for the name with prefix
122 StringBuffer JavaDoc templatePath = new StringBuffer JavaDoc();
123             if (StringUtils.isNotEmpty(prefix))
124             {
125                 templatePath.append(prefix);
126                 templatePath.append(separator);
127             }
128             templatePath.append(testName);
129
130             log.debug("Looking for " + templatePath);
131
132             if (tes.templateExists(templatePath.toString()))
133             {
134                 log.debug("Found it, returning " + testName);
135                 return testName.toString();
136             }
137
138             if (firstRun)
139             {
140                 firstRun = false;
141             }
142             else
143             {
144                 // We're no longer on the first Run (so we
145 // already tested the "Default" template)
146 // and the package is empty (we've hit the
147 // root. So we now break the endless loop.
148 if (components.isEmpty())
149                 {
150                     break; // for(;;)
151 }
152                 // We still have components. Remove the
153 // last one and go through the loop again.
154 components.remove(componentSize--);
155             }
156         }
157
158         log.debug("Returning default");
159         return getDefaultName(template);
160     }
161 }
162
Popular Tags