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    1   package org.apache.turbine.modules.layouts;
    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.io.StringReader;
    25
    26  import org.apache.commons.logging.Log;
    27  import org.apache.commons.logging.LogFactory;
    28  import org.apache.ecs.ConcreteElement;
    29  import org.apache.fulcrum.xslt.XSLTServiceFacade;
    30  import org.apache.turbine.TurbineConstants;
    31  import org.apache.turbine.modules.Layout;
    32  import org.apache.turbine.modules.Screen;
    33  import org.apache.turbine.modules.ScreenLoader;
    34  import org.apache.turbine.pipeline.PipelineData;
    35  import org.apache.turbine.services.assemblerbroker.TurbineAssemblerBroker;
    36  import org.apache.turbine.services.velocity.TurbineVelocity;
    37  import org.apache.turbine.util.RunData;
    38  import org.apache.turbine.util.template.TemplateNavigation;
    39  import org.apache.velocity.context.Context;
    40
    41  /**
    42   * This Layout module allows Velocity XML templates to be used as layouts.
    43   * <br><br>
    44   * Once the (XML) screen and navigation templates have been inserted into
    45   * the layout template the result is transformed with a XSL stylesheet.
    46   * The stylesheet (with the same name than the screen template) is loaded
    47   * and executed by the XSLT service, so it is important that you correctly
    48   * set up your XSLT service.  If the named stylsheet does not exist the
    49   * default.xsl stylesheet is executed.  If default.xsl does not exist
    50   * the XML is merely echoed.
    51   * <br><br>
    52   * Since dynamic content is supposed to be primarily located in
    53   * screens and navigations there should be relatively few reasons to
    54   * subclass this Layout.
    55   *
    56   * @author <a href="mailto:leon@opticode.co.za">Leon Messerschmidt</a>
    57   * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
    58   * @version $Id: VelocityXslLayout.java 1066558 2011-02-02 18:12:40Z ludwig $
    59   */
    60  public class VelocityXslLayout extends Layout
    61  {
    62      /** Logging */
    63      private static Log log = LogFactory.getLog(VelocityXslLayout.class);
    64
    65      /** The prefix for lookup up layout pages */
    66      private String prefix = Layout.PREFIX + "/";
    67
    68      private ScreenLoader screenLoader;
    69
    70      /**
    71       * Default constructor
    72       */
    73      public VelocityXslLayout()
    74      {
    75          super();
    76
    77          this.screenLoader = (ScreenLoader)TurbineAssemblerBroker.getLoader(Screen.NAME);
    78      }
    79
    80      /**
    81       * Build the layout.  Also sets the ContentType and Locale headers
    82       * of the HttpServletResponse object.
    83       * @deprecated Use PipelineData version instead.
    84       * @param data Turbine information.
    85       * @exception Exception a generic exception.
    86       */
    87      @Deprecated
    88      @Override
    89      public void doBuild(RunData data)
    90          throws Exception
    91      {
    92          // Get the context needed by Velocity.
    93          Context context = TurbineVelocity.getContext(data);
    94
    95          data.getResponse().setContentType("text/html");
    96
    97          String screenName = data.getScreen();
    98
    99          log.debug("Loading Screen " + screenName);
    100
    101         // First, generate the screen and put it in the context so
    102         // we can grab it the layout template.
    103         ConcreteElement results =
    104             screenLoader.eval(data, screenName);
    105
    106         String returnValue = (results == null) ? "" : results.toString();
    107
    108         // variable for the screen in the layout template
    109         context.put(TurbineConstants.SCREEN_PLACEHOLDER, returnValue);
    110
    111         // variable to reference the navigation screen in the layout template
    112         context.put(TurbineConstants.NAVIGATION_PLACEHOLDER,
    113                     new TemplateNavigation(data));
    114
    115         // Grab the layout template set in the VelocityPage.
    116         // If null, then use the default layout template
    117         // (done by the TemplateInfo object)
    118         String templateName = data.getTemplateInfo().getLayoutTemplate();
    119
    120         log.debug("Now trying to render layout " + templateName);
    121
    122         // Now, generate the layout template.
    123         String temp = TurbineVelocity.handleRequest(context,
    124                 prefix + templateName);
    125
    126         // Finally we do a transformation and send the result
    127         // back to the browser
    128         XSLTServiceFacade.transform(
    129             data.getTemplateInfo().getScreenTemplate(),
    130                 new StringReader(temp), data.getResponse().getWriter());
    131     }
    132
    133     /**
    134      * Build the layout.  Also sets the ContentType and Locale headers
    135      * of the HttpServletResponse object.
    136      *
    137      * @param data Turbine information.
    138      * @exception Exception a generic exception.
    139      */
    140     @Override
    141     public void doBuild(PipelineData pipelineData)
    142         throws Exception
    143     {
    144         RunData data = getRunData(pipelineData);
    145         // Get the context needed by Velocity.
    146         Context context = TurbineVelocity.getContext(pipelineData);
    147
    148         data.getResponse().setContentType("text/html");
    149
    150         String screenName = data.getScreen();
    151
    152         log.debug("Loading Screen " + screenName);
    153
    154         // First, generate the screen and put it in the context so
    155         // we can grab it the layout template.
    156         ConcreteElement results =
    157             screenLoader.eval(pipelineData, screenName);
    158
    159         String returnValue = (results == null) ? "" : results.toString();
    160
    161         // variable for the screen in the layout template
    162         context.put(TurbineConstants.SCREEN_PLACEHOLDER, returnValue);
    163
    164         // variable to reference the navigation screen in the layout template
    165         context.put(TurbineConstants.NAVIGATION_PLACEHOLDER,
    166                     new TemplateNavigation(data));
    167
    168         // Grab the layout template set in the VelocityPage.
    169         // If null, then use the default layout template
    170         // (done by the TemplateInfo object)
    171         String templateName = data.getTemplateInfo().getLayoutTemplate();
    172
    173         log.debug("Now trying to render layout " + templateName);
    174
    175         // Now, generate the layout template.
    176         String temp = TurbineVelocity.handleRequest(context,
    177                 prefix + templateName);
    178
    179         // Finally we do a transformation and send the result
    180         // back to the browser
    181         XSLTServiceFacade.transform(
    182             data.getTemplateInfo().getScreenTemplate(),
    183                 new StringReader(temp), data.getResponse().getWriter());
    184     }
    185 }