/*

  * $Source: /usr/cvsroot/melati/melati/src/main/java/org/melati/template/freemarker/FreemarkerServletTemplateEngine.java,v $

  * $Revision: 1.3 $

  *

  * Copyright (C) 2007 Tim Pizey

  *

  * Part of Melati (http://melati.org), a framework for the rapid

  * development of clean, maintainable web applications.

  *

  * Melati is free software; Permission is granted to copy, distribute

  * and/or modify this software under the terms either:

  *

  * a) the GNU General Public License as published by the Free Software

  *    Foundation; either version 2 of the License, or (at your option)

  *    any later version,

  *

  *    or

  *

  * b) any version of the Melati Software License, as published

  *    at http://melati.org

  *

  * You should have received a copy of the GNU General Public License and

  * the Melati Software License along with this program;

  * if not, write to the Free Software Foundation, Inc.,

  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA to obtain the

  * GNU General Public License and visit http://melati.org to obtain the

  * Melati Software License.

  *

  * Feel free to contact the Developers of Melati (http://melati.org),

  * if you would like to work out a different arrangement than the options

  * outlined here.  It is our intention to allow Melati to be used by as

  * wide an audience as possible.

  *

  * This program is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  * GNU General Public License for more details.

  *

  * Contact details for copyright holder:

  *

  *     Tim Pizey <timp At paneris.org>

  */

 package org.melati.template.freemarker;

 import java.io.IOException;

 import java.util.HashMap;

 import java.util.Map;

 import javax.servlet.http.HttpServlet;

 import javax.servlet.http.HttpServletResponse;

 import org.melati.Melati;

 import org.melati.MelatiConfig;

 import org.melati.template.ServletTemplateContext;

 import org.melati.template.ServletTemplateEngine;

 import org.melati.template.TemplateEngineException;

 import org.melati.template.TemplateIOException;

 import org.melati.template.velocity.MelatiBufferedVelocityWriter;

 import org.melati.template.velocity.MelatiVelocityWriter;

 import org.melati.util.MelatiWriter;

 /**

  * @author timp

  * @since 7 Mar 2012

  *

  */

 public class FreemarkerServletTemplateEngine extends FreemarkerTemplateEngine 

         implements ServletTemplateEngine {

   /**    

    * The HTTP request object context key.    

    */    

    public static final String REQUEST = "Request";    

   /**    

    * The HTTP response object context key.    

    */    

    public static final String RESPONSE = "Response";    

    /** Mimicking the $Form behaviour of Webmacro. */

    public static final String FORM = "Form";

   /**

    * Constructor.

    */

   public FreemarkerServletTemplateEngine() {

     super();

   }

   /**

    * Construct a new Engine for use in a servlet environment. For Velocity this

    * is no different to initialisation outside of a servlets environment.

    * 

    * @param melatiConfig

    *          a {@link MelatiConfig}

    * @param servlet

    *          the servlet we are within

    * @throws TemplateEngineException

    *           if any problem occurs with the engine

    * @see org.melati.template.ServletTemplateEngine#init(org.melati.MelatiConfig, javax.servlet.http.HttpServlet)

    */

   @Override

   public void init(MelatiConfig melatiConfig, HttpServlet servlet)

           throws TemplateEngineException {

     init(melatiConfig);

   }

   /**

    * @param response

    *          the <code>HttpServletResponse</code> that this writer will be

    *          part of

    * @param buffered

    *          whether the writer should be buffered

    * @return a {@link MelatiWriter} appropriate for this engine.

    * @see org.melati.template.ServletTemplateEngine#getServletWriter(javax.servlet.http.HttpServletResponse, boolean)

    */

   @Override

   public MelatiWriter getServletWriter(HttpServletResponse response, 

           boolean buffered) {

     if (buffered) {

       try {

         return new MelatiBufferedVelocityWriter(response);

       } catch (IOException e) {

         throw new TemplateIOException(e);

       }

     } else {

       try {

         return new MelatiVelocityWriter(response);

       } catch (IOException e) {

         throw new TemplateIOException(e);

       }

     }

   }

   /**

    * Get the template context for Velocity, with servlet specific objects added.

    * 

    * @param melati

    *        the {@link Melati}

    * @return a {@link TemplateContext}

    * @see org.melati.template.ServletTemplateEngine#getServletTemplateContext(org.melati.Melati)

    */

   @Override

   public ServletTemplateContext getServletTemplateContext(Melati melati) throws TemplateEngineException {

     Map<String, Object> context = new HashMap<String, Object>();

     context.put(REQUEST, melati.getRequest());

     context.put(RESPONSE, melati.getResponse());

     return new FreemarkerServletTemplateContext(context);

   }

 }