package org.apache.turbine.util.template;

 /*

  * 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.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 import org.apache.turbine.modules.Screen;

 import org.apache.turbine.modules.ScreenLoader;

 import org.apache.turbine.services.TurbineServices;

 import org.apache.turbine.services.assemblerbroker.AssemblerBrokerService;

 import org.apache.turbine.util.RunData;

 /**

  * Returns output of a Screen module.  An instance of this is

  * placed in the Velocity context by the VelocityDirectLayout.  This

  * allows the screen to be executed only at rendering.

  * Here's how it's used in a template:

  *

  * <p>

  * <code>

  * $screen_placeholder

  * </code>

  * <p>

  * <code>

  * $screen_placeholder.setScreen("Test")

  * </code>

  * </p>

  *

  * @author <a href="raphael@apache.org">Raphaël Luta</a>

  * @version $Id: TemplateScreen.java 1723699 2016-01-08 11:29:21Z tv $

  */

 public class TemplateScreen

 {

     /** Logging */

     private static Log log = LogFactory.getLog(TemplateScreen.class);

     /* The RunData object. */

     private final RunData data;

     /* The name of the screen template. */

     private String screen;

     private final ScreenLoader screenLoader;

     /**

      * Constructor

      *

      * @param data A Turbine RunData object.

      */

     public TemplateScreen(RunData data)

     {

         this.data = data;

         this.screen = data.getScreen();

         AssemblerBrokerService abs = (AssemblerBrokerService)TurbineServices.getInstance()

             .getService(AssemblerBrokerService.SERVICE_NAME);

         this.screenLoader = (ScreenLoader)abs.getLoader(Screen.class);

     }

     /**

      * Set the screen.

      *

      * @param screen A String with the name of the screen module

      * @return A TemplateScreen (self).

      */

     public TemplateScreen setScreen(String screen)

     {

         this.screen = screen;

         return this;

     }

     /**

      * Builds the output of the navigation template.

      *

      * @return A String.

      */

     @Override

     public String toString()

     {

         String returnValue = "";

         try

         {

             String results = screenLoader.eval(data, this.screen);

             if (results != null)

             {

                 returnValue = results;

             }

         }

         catch (Exception e)

         {

             log.error(e);

         }

         return returnValue;

     }

 }