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 java.util.List;
  
  import org.apache.commons.lang.StringUtils;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  import org.apache.ecs.Doctype;
  
  import org.apache.turbine.Turbine;
  import org.apache.turbine.TurbineConstants;
  import org.apache.turbine.modules.ActionLoader;
  import org.apache.turbine.modules.LayoutLoader;
  import org.apache.turbine.modules.Page;
  import org.apache.turbine.modules.Screen;
  import org.apache.turbine.modules.ScreenLoader;
  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, VelocitySiteScreen.
   *
   * <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.
   *
   * <p>
   *
   * This approach allows a site with largely static content to be
   * updated and added to regularly by those with little Java
   * experience.
   *
   * <p>
   *
   * The code is an almost a complete clone of the FreeMarkerSitePage
   * written by John McNally.  I've only modified it for Template use.
   *
   * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a>
   * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
   * @version $Id: DefaultPage.java 534527 2007-05-02 16:10:59Z tv $
   */
  public class DefaultPage
      extends Page
  {
      /*** Logging */
      protected Log log = LogFactory.getLog(this.getClass());
  
      /***
      * Builds the Page.
      *
      * @param data Turbine information.
      * @exception Exception, a generic exception.
      */
     public void doBuild(RunData data)
             throws Exception
     {
         // Template pages can use this to set up the context, so it is
         // available to the Action and Screen.  It does nothing here.
         doBuildBeforeAction(data);
 
         // If an action has been defined, execute it here.  Actions
         // can re-define the template definition.
         if (data.hasAction())
         {
             ActionLoader.getInstance().exec(data, data.getAction());
         }
 
         // if a redirect was setup in data, don't do anything else
         if (StringUtils.isNotEmpty(data.getRedirectURI()))
         {
             return;
         }
 
         // Set the default doctype from the value given in
         // TurbineResources.properties.
         setDefaultDoctype(data);
 
         // Template pages can use this to set up default templates and
         // associated class modules.  It does nothing here.
         doBuildAfterAction(data);
 
         String screenName = data.getScreen();
 
         log.debug("Building " + screenName);
 
         // Ask the Screen for its Layout and then execute the Layout.
         // The Screen can override the getLayout() method to re-define
         // the Layout depending on data passed in via the
         // data.parameters object.
         ScreenLoader sl = ScreenLoader.getInstance();
         Screen aScreen = sl.getInstance(screenName);
         String layout = aScreen.getLayout(data);
 
         // If the Layout has been set to be null, attempt to execute
         // the Screen that has been defined.
         if (layout != null)
         {
             LayoutLoader.getInstance().exec(data, layout);
         }
         else
         {
             ScreenLoader.getInstance().exec(data, screenName);
         }
 
         // Do any post build actions (overridable by subclasses -
         // does nothing here).
         doPostBuild(data);
     }
 
     /***
      * Can be used by template Pages to stuff the Context into the
      * RunData so that it is available to the Action module and the
      * Screen module via getContext().  It does nothing here.
      *
      * @param data Turbine information.
      * @exception Exception, a generic exception.
      */
     protected void doBuildBeforeAction(RunData data)
             throws Exception
     {
     }
 
     /***
      * Can be overridden by template Pages to set up data needed to
      * process a template.  It does nothing here.
      *
      * @param data Turbine information.
      * @exception Exception, a generic exception.
      */
     protected void doBuildAfterAction(RunData data)
             throws Exception
     {
     }
 
     /***
      * Can be overridden to perform actions when the request is
      * fully processed. It does nothing here.
      *
      * @param data Turbine information.
      * @exception Exception, a generic exception.
      */
     protected void doPostBuild(RunData data)
             throws Exception
     {
     }
 
     /***
      * Set the default Doctype.  If Doctype is set to null, it will
      * not be added.  The default Doctype can be set in
      * TurbineResources by using the single strings: Html40Strict,
      * Html40Transitional, or Html40Frameset.  Additionally the
      * default can be supplied as two strings giving the dtd and uri.
      *
      * @param data Turbine information.
      * @exception Exception, a generic exception.
      */
     private void setDefaultDoctype(RunData data)
             throws Exception
     {
         String errMsg =
                 "default.doctype property not set properly in TurbineResources.properties!";
         List doctypeProperty =
             Turbine.getConfiguration().getList(TurbineConstants.DEFAULT_DOCUMENT_TYPE_KEY);
 
         if (doctypeProperty != null)
         {
             switch(doctypeProperty.size())
             {
             case 0:
                 {
                     // Don't add a doctype.
                     break;
                 }
             case 1:
                 {
                     String doc = (String) doctypeProperty.get(0);
                     if (doc.equalsIgnoreCase(TurbineConstants.DOCUMENT_TYPE_HTML40TRANSITIONAL))
                     {
                         data.getPage().setDoctype(new Doctype.Html40Transitional());
                     }
                     else if (doc.equalsIgnoreCase(TurbineConstants.DOCUMENT_TYPE_HTML40STRICT))
                     {
                         data.getPage().setDoctype(new Doctype.Html40Strict());
                     }
                     else if (doc.equalsIgnoreCase(TurbineConstants.DOCUMENT_TYPE_HTML40FRAMESET))
                     {
                         data.getPage().setDoctype(new Doctype.Html40Frameset());
                     }
                     else
                     {
                         throw new TurbineException(errMsg);
                     }
                     break;
                 }
             case 2:
                 {
                     data.getPage()
                         .setDoctype(new Doctype()
                                     .setIdentifier((String) doctypeProperty.get(0))
                                     .setUri((String) doctypeProperty.get(1)));
                     break;
                 }
             default:
                 {
                     throw new TurbineException(errMsg);
                 }
             }
         }
     }
 }