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1   package org.apache.turbine.services.template.mapper;
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 java.util.ArrayList;
25  import java.util.Arrays;
26  import java.util.List;
27  
28  import org.apache.commons.lang.StringUtils;
29  import org.apache.commons.logging.Log;
30  import org.apache.commons.logging.LogFactory;
31  import org.apache.turbine.services.template.TemplateEngineService;
32  import org.apache.turbine.services.template.TemplateService;
33  import org.apache.turbine.services.template.TurbineTemplate;
34  
35  /**
36   * This mapper is responsible for the lookup of templates for the Layout
37   * It tries to look in various packages for a match:
38   *
39   * 1. about,directions,Driving.vm      <- exact match
40   * 2. about,directions,Default.vm      <- package match, Default name
41   * 3. about,Default.vm                 <- stepping up in the hierarchy
42   * 4. Default.vm                       <- The name configured as default.layout.template
43   *                                        in the corresponding Templating Engine
44  
45   *
46   * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
47   * @version $Id: LayoutTemplateMapper.java 1709648 2015-10-20 17:08:10Z tv $
48   */
49  
50  public class LayoutTemplateMapper
51      extends BaseTemplateMapper
52      implements Mapper
53  {
54      /** Logging */
55      private static Log log = LogFactory.getLog(LayoutTemplateMapper.class);
56  
57      /**
58       * Default C'tor. If you use this C'tor, you must use
59       * the bean setter to set the various properties needed for
60       * this mapper before first usage.
61       */
62      public LayoutTemplateMapper()
63      {
64      	// empty
65      }
66  
67      /**
68       * Look for a given Template, then try the
69       * defaults until we hit the root.
70       *
71       * @param template The template name.
72       * @return The parsed module name.
73       */
74      public String doMapping(String template)
75      {
76          log.debug("doMapping(" + template + ")");
77          // Copy our elements into an array
78          List<String> components
79              = new ArrayList<String>(Arrays.asList(StringUtils.split(
80                                                template,
81                                                String.valueOf(TemplateService.TEMPLATE_PARTS_SEPARATOR))));
82          int componentSize = components.size() - 1 ;
83  
84          // This method never gets an empty string passed.
85          // So this is never < 0
86          String templateName = components.get(componentSize);
87          components.remove(componentSize--);
88  
89          log.debug("templateName is " + templateName);
90  
91          // Last element decides, which template Service to use...
92          TemplateEngineService tes = TurbineTemplate.getTemplateEngineService(templateName);
93  
94          if (tes == null)
95          {
96              return null;
97          }
98  
99          String defaultName =
100             TurbineTemplate.getDefaultLayoutTemplateName(templateName); // We're, after all, a Layout Template Mapper...
101 
102         // This is an optimization. If the name we're looking for is
103         // already the default name for the template, don't do a "first run"
104         // which looks for an exact match.
105         boolean firstRun = !templateName.equals(defaultName);
106 
107         for(;;)
108         {
109             String templatePackage = StringUtils.join(components.iterator(), String.valueOf(separator));
110 
111             log.debug("templatePackage is now: " + templatePackage);
112 
113             StringBuilder testName = new StringBuilder();
114 
115             if (!components.isEmpty())
116             {
117                 testName.append(templatePackage);
118                 testName.append(separator);
119             }
120 
121             testName.append((firstRun)
122                 ? templateName
123                 : defaultName);
124 
125             // But the Templating service must look for the name with prefix
126             StringBuilder templatePath = new StringBuilder();
127             if (StringUtils.isNotEmpty(prefix))
128             {
129                 templatePath.append(prefix);
130                 templatePath.append(separator);
131             }
132             templatePath.append(testName);
133 
134             log.debug("Looking for " + templatePath);
135 
136             if (tes.templateExists(templatePath.toString()))
137             {
138                 log.debug("Found it, returning " + testName);
139                 return testName.toString();
140             }
141 
142             if (firstRun)
143             {
144                 firstRun = false;
145             }
146             else
147             {
148                 // We're no longer on the first Run (so we
149                 // already tested the "Default" template)
150                 // and the package is empty (we've hit the
151                 // root. So we now break the endless loop.
152                 if (components.isEmpty())
153                 {
154                     break; // for(;;)
155                 }
156                 // We still have components. Remove the
157                 // last one and go through the loop again.
158                 components.remove(componentSize--);
159             }
160         }
161 
162         log.debug("Returning default");
163         return getDefaultName(template);
164     }
165 }