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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      &lt;- exact match
    40   * 2. about,directions,Default.vm      &lt;- package match, Default name
    41   * 3. about,Default.vm                 &lt;- stepping up in the hierarchy
    42   * 4. Default.vm                       &lt;- 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 1071091 2011-02-15 22:06:55Z 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             StringBuffer testName = new StringBuffer();
    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             StringBuffer templatePath = new StringBuffer();
    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 }