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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 is a pretty simple mapper which returns template pathes for
37   * a supplied template name. If the path does not exist, it looks for
38   * a templated called "Default" in the same package.
39   * This path can be used by the TemplateEngine to access
40   * a certain resource to actually render the template.
41   *
42   * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
43   * @version $Id: ScreenDefaultTemplateMapper.java 1709648 2015-10-20 17:08:10Z tv $
44   */
45  
46  public class ScreenDefaultTemplateMapper
47      extends BaseTemplateMapper
48      implements Mapper
49  {
50      /** Logging */
51      private static Log log = LogFactory.getLog(ScreenDefaultTemplateMapper.class);
52  
53      /**
54       * Default C'tor. If you use this C'tor, you must use
55       * the bean setter to set the various properties needed for
56       * this mapper before first usage.
57       */
58      public ScreenDefaultTemplateMapper()
59      {
60      	// empty
61      }
62  
63      /**
64       * Look for a given Template, then try the
65       * default.
66       *
67       * @param template The template name.
68       * @return The parsed module name.
69       */
70      public String doMapping(String template)
71      {
72          log.debug("doMapping(" + template + ")");
73          // Copy our elements into an array
74          List<String> components
75              = new ArrayList<String>(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 templateName = 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 defaultName = "Default.vm";
96  
97          // This is an optimization. If the name we're looking for is
98          // already the default name for the template, don't do a "first run"
99          // which looks for an exact match.
100         boolean firstRun = !templateName.equals(defaultName);
101 
102         for(;;)
103         {
104             String templatePackage = StringUtils.join(components.iterator(), String.valueOf(separator));
105 
106             log.debug("templatePackage is now: " + templatePackage);
107 
108             StringBuilder testName = new StringBuilder();
109 
110             if (!components.isEmpty())
111             {
112                 testName.append(templatePackage);
113                 testName.append(separator);
114             }
115 
116             testName.append((firstRun)
117                 ? templateName
118                 : defaultName);
119 
120             // But the Templating service must look for the name with prefix
121             StringBuilder templatePath = new StringBuilder();
122             if (StringUtils.isNotEmpty(prefix))
123             {
124                 templatePath.append(prefix);
125                 templatePath.append(separator);
126             }
127             templatePath.append(testName);
128 
129             log.debug("Looking for " + templatePath);
130 
131             if (tes.templateExists(templatePath.toString()))
132             {
133                 log.debug("Found it, returning " + testName);
134                 return testName.toString();
135             }
136 
137             if (firstRun)
138             {
139                 firstRun = false;
140             }
141             else
142             {
143                 // We run this loop only two times. The
144                 // first time with the 'real' name and the
145                 // second time with "Default". The second time
146                 // we will end up here and break the for(;;) loop.
147                 break;
148             }
149         }
150 
151         log.debug("Returning default");
152         return getDefaultName(template);
153     }
154 }