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    1   package org.apache.turbine.modules.pages;
    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 org.apache.turbine.annotation.TurbineService;
    25  import org.apache.turbine.pipeline.PipelineData;
    26  import org.apache.turbine.services.template.TemplateService;
    27  import org.apache.turbine.util.RunData;
    28  import org.apache.turbine.util.TurbineException;
    29
    30  /**
    31   * When building sites using templates, Screens need only be defined
    32   * for templates which require dynamic (database or object) data.
    33   *
    34   * <p>
    35   *
    36   * This page can be used on sites where the number of Screens can be
    37   * much less than the number of templates.  The templates can be
    38   * grouped in directories with common layouts.  Screen modules are
    39   * then expected to be placed in packages corresponding with the
    40   * templates' directories and follow a specific naming scheme.
    41   *
    42   * <p>
    43   *
    44   * The template parameter is parsed and and a Screen whose package
    45   * matches the templates path and shares the same name minus any
    46   * extension and beginning with a capital letter is searched for.  If
    47   * not found, a Screen in a package matching the template's path with
    48   * name Default is searched for.  If still not found, a Screen with
    49   * name Default is looked for in packages corresponding to parent
    50   * directories in the template's path until a match is found.
    51   *
    52   * <p>
    53   *
    54   * For example if data.getParameters().getString("template") returns
    55   * /about_us/directions/driving.wm, the search follows
    56   * about_us.directions.Driving, about_us.directions.Default,
    57   * about_us.Default, Default, WebMacroSiteScreen (i.e. the default
    58   * screen set in TurbineResources).
    59   *
    60   * <p>
    61   *
    62   * Only one Layout module is used, since it is expected that any
    63   * dynamic content will be placed in navigations and screens.  The
    64   * layout template to be used is found in a similar way to the Screen.
    65   * For example the following paths will be searched in the layouts
    66   * subdirectory: /about_us/directions/driving.wm,
    67   * /about_us/directions/default.wm, /about_us/default.wm, /default.wm,
    68   * where wm is the value of the template.default.extension property.
    69   *
    70   * <p>
    71   *
    72   * This approach allows a site with largely static content to be
    73   * updated and added to regularly by those with little Java
    74   * experience.
    75   *
    76   * @author <a href="mailto:john.mcnally@clearink.com">John D. McNally</a>
    77   * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a>
    78   * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
    79   * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
    80   * @version $Id: TemplatePage.java 1773378 2016-12-09 13:19:59Z tv $
    81   */
    82  public class TemplatePage
    83      extends DefaultPage
    84  {
    85      /** Injected service instance */
    86      @TurbineService
    87      private TemplateService templateService;
    88
    89      /**
    90       * Works with TemplateService to set up default templates and
    91       * corresponding class modules.
    92       *
    93       * @param pipelineData Turbine information.
    94       * @throws Exception a generic exception.
    95       */
    96      @Override
    97      protected void doBuildAfterAction(PipelineData pipelineData)
    98          throws Exception
    99      {
    100         RunData data = getRunData(pipelineData);
    101         // The Template Service at this point must fetch the Screen class
    102         // to match a given template. If the Screen class has already been
    103         // set by an action, skip this, because the user has the already
    104         // specified the Screen class he wants to use.
    105         if (!data.hasScreen())
    106         {
    107             // This is effectively getting the "template" parameter
    108             // from the parameter parser in rundata. This is coming
    109             // from the request for a template.
    110             String template = data.getTemplateInfo().getScreenTemplate();
    111
    112             // Get the layout template and the correct Screen.
    113             String layoutTemplate =
    114                     templateService.getLayoutTemplateName(template);
    115             data.getTemplateInfo().setLayoutTemplate(layoutTemplate);
    116
    117             String screen = templateService.getScreenName(template);
    118
    119             if (screen == null)
    120             {
    121                 String errMsg = "Couldn't map Template "
    122                     + template + " to any Screen class!";
    123                 log.error(errMsg);
    124                 throw new TurbineException(errMsg);
    125             }
    126             data.setScreen(screen);
    127         }
    128     }
    129 }