package org.apache.turbine.modules.pages;

 /*

  * 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 org.apache.turbine.annotation.TurbineService;

 import org.apache.turbine.pipeline.PipelineData;

 import org.apache.turbine.services.template.TemplateService;

 import org.apache.turbine.util.RunData;

 import org.apache.turbine.util.TurbineException;

 /**

  * When building sites using templates, Screens need only be defined

  * for templates which require dynamic (database or object) data.

  *

  * <p>

  *

  * This page can be used on sites where the number of Screens can be

  * much less than the number of templates.  The templates can be

  * grouped in directories with common layouts.  Screen modules are

  * then expected to be placed in packages corresponding with the

  * templates' directories and follow a specific naming scheme.

  *

  * <p>

  *

  * The template parameter is parsed and and a Screen whose package

  * matches the templates path and shares the same name minus any

  * extension and beginning with a capital letter is searched for.  If

  * not found, a Screen in a package matching the template's path with

  * name Default is searched for.  If still not found, a Screen with

  * name Default is looked for in packages corresponding to parent

  * directories in the template's path until a match is found.

  *

  * <p>

  *

  * For example if data.getParameters().getString("template") returns

  * /about_us/directions/driving.wm, the search follows

  * about_us.directions.Driving, about_us.directions.Default,

  * about_us.Default, Default, WebMacroSiteScreen (i.e. the default

  * screen set in TurbineResources).

  *

  * <p>

  *

  * Only one Layout module is used, since it is expected that any

  * dynamic content will be placed in navigations and screens.  The

  * layout template to be used is found in a similar way to the Screen.

  * For example the following paths will be searched in the layouts

  * subdirectory: /about_us/directions/driving.wm,

  * /about_us/directions/default.wm, /about_us/default.wm, /default.wm,

  * where wm is the value of the template.default.extension property.

  *

  * <p>

  *

  * This approach allows a site with largely static content to be

  * updated and added to regularly by those with little Java

  * experience.

  *

  * @author <a href="mailto:john.mcnally@clearink.com">John D. McNally</a>

  * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a>

  * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>

  * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>

  * @version $Id: TemplatePage.java 1854797 2019-03-04 20:41:39Z tv $

  */

 public class TemplatePage

     extends DefaultPage

 {

     /** Injected service instance */

     @TurbineService

     private TemplateService templateService;

     /**

      * Works with TemplateService to set up default templates and

      * corresponding class modules.

      *

      * @param pipelineData Turbine information.

      * @throws Exception a generic exception.

      */

     @Override

     protected void doBuildAfterAction(PipelineData pipelineData)

         throws Exception

     {

         RunData data = pipelineData.getRunData();

         // The Template Service at this point must fetch the Screen class

         // to match a given template. If the Screen class has already been

         // set by an action, skip this, because the user has the already

         // specified the Screen class he wants to use.

         if (!data.hasScreen())

         {

             // This is effectively getting the "template" parameter

             // from the parameter parser in rundata. This is coming

             // from the request for a template.

             String template = data.getTemplateInfo().getScreenTemplate();

             // Get the layout template and the correct Screen.

             String layoutTemplate =

                     templateService.getLayoutTemplateName(template);

             data.getTemplateInfo().setLayoutTemplate(layoutTemplate);

             String screen = templateService.getScreenName(template);

             if (screen == null)

             {

                 String errMsg = "Couldn't map Template "

                     + template + " to any Screen class!";

                 log.error(errMsg);

                 throw new TurbineException(errMsg);

             }

             data.setScreen(screen);

         }

     }

 }