package org.apache.turbine.services.template.mapper;
   
   /*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.List;
  
  import org.apache.commons.lang.StringUtils;
  
  import org.apache.turbine.modules.Loader;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  import org.apache.turbine.services.template.TemplateService;
  
  /***
   * This mapper tries to map Template names to class names. If no direct match
   * is found, it tries matches "upwards" in the package hierarchy until either
   * a match is found or the root is hit. Then it returns the name of the
   * default class from the TemplateEngineService.
   *
   * 1. about.directions.Driving     <- direct matching the template to the class name
   * 2. about.directions.Default     <- matching the package, class name is Default
   * 3. about.Default                <- stepping up in the package hierarchy, looking for Default
   * 4. Default                      <- Class called "Default" without package
   * 5. VelocityScreen               <- The class configured by the Service (VelocityService) to
   *
   * Please note, that no actual packages are searched. This is the scope of the
   * TemplateEngine Loader which is passed at construction time.
   *
   * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
   * @version $Id: ClassMapper.java 534527 2007-05-02 16:10:59Z tv $
   */
  
  public class ClassMapper
      extends BaseMapper
      implements Mapper
  {
      /**</package-summary/html">The loader for actually trying out the package names *//package-summary.html">em>* The loader for actually trying out the package names */
      private Loader loader = null;
  
      /*** Logging */
      private static Log log = LogFactory.getLog(ClassMapper.class);
  
      /***
       * Default C'tor. If you use this C'tor, you must use
       * the bean setter to set the various properties needed for
       * this mapper before first usage.
       */
      public ClassMapper()
      {
      }
  
      /***
       * Get the Loader value.
       * @return the Loader value.
       */
      public Loader getLoader()
      {
          return loader;
      }
  
      /***
       * Set the Loader value.
       * @param loader The new Loader value.
       */
      public void setLoader(Loader loader)
      {
          this.loader = loader;
          log.debug("Loader is " + this.loader);
      }
  
      /***
       * Strip off a possible extension, replace all "," with "."
       * Look through the given package path until a match is found.
       *
       * @param template The template name.
       * @return A class name for the given template.
       */
      public String doMapping(String template)
     {
         log.debug("doMapping(" + template + ")");
 
         // Copy our elements into an array
         List components
             = new ArrayList(Arrays.asList(StringUtils.split(
                                               template,
                                               String.valueOf(TemplateService.TEMPLATE_PARTS_SEPARATOR))));
         int componentSize = components.size() - 1 ;
 
         // This method never gets an empty string passed.
         // So this is never < 0
         String className = (String) components.get(componentSize);
         components.remove(componentSize--);
 
         log.debug("className is " + className);
 
         // Strip off a possible Extension
         int dotIndex = className.lastIndexOf(TemplateService.EXTENSION_SEPARATOR);
         className = (dotIndex < 0) ? className : className.substring(0, dotIndex);
 
         // This is an optimization. If the name we're looking for is
         // already the default name for the template, don't do a "first run"
         // which looks for an exact match.
         boolean firstRun = !className.equals(TemplateService.DEFAULT_NAME);
 
         for(;;)
         {
             String pkg = StringUtils.join(components.iterator(), String.valueOf(separator));
             StringBuffer testName = new StringBuffer();
 
             log.debug("classPackage is now: " + pkg);
 
             if (!components.isEmpty())
             {
                 testName.append(pkg);
                 testName.append(separator);
             }
 
             testName.append((firstRun)
                 ? className
                 : TemplateService.DEFAULT_NAME);
 
             log.debug("Looking for " + testName);
             try
             {
                 loader.getAssembler(testName.toString());
                 log.debug("Found it, returning " + testName);
                 return testName.toString();
             }
             catch (Exception e)
             {
                 // Not found. Go on.
             }
 
             if (firstRun)
             {
                 firstRun = false;
             }
             else
             {
                 if (components.isEmpty())
                 {
                     break; // for(;;)
                 }
                 components.remove(componentSize--);
             }
         }
 
         log.debug("Returning default");
         return getDefaultName(template);
     }
 }