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1   /*
2    * $Source$
3    * $Revision$
4    *
5    * Copyright (C) 2007 Tim Pizey
6    *
7    * Part of Melati (http://melati.org), a framework for the rapid
8    * development of clean, maintainable web applications.
9    *
10   * Melati is free software; Permission is granted to copy, distribute
11   * and/or modify this software under the terms either:
12   *
13   * a) the GNU General Public License as published by the Free Software
14   *    Foundation; either version 2 of the License, or (at your option)
15   *    any later version,
16   *
17   *    or
18   *
19   * b) any version of the Melati Software License, as published
20   *    at http://melati.org
21   *
22   * You should have received a copy of the GNU General Public License and
23   * the Melati Software License along with this program;
24   * if not, write to the Free Software Foundation, Inc.,
25   * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA to obtain the
26   * GNU General Public License and visit http://melati.org to obtain the
27   * Melati Software License.
28   *
29   * Feel free to contact the Developers of Melati (http://melati.org),
30   * if you would like to work out a different arrangement than the options
31   * outlined here.  It is our intention to allow Melati to be used by as
32   * wide an audience as possible.
33   *
34   * This program is distributed in the hope that it will be useful,
35   * but WITHOUT ANY WARRANTY; without even the implied warranty of
36   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
37   * GNU General Public License for more details.
38   *
39   * Contact details for copyright holder:
40   *
41   *     Tim Pizey <timp At paneris.org>
42   */
43  package org.melati.template.freemarker;
44  
45  import java.io.IOException;
46  import java.util.HashMap;
47  import java.util.Map;
48  
49  import javax.servlet.http.HttpServlet;
50  import javax.servlet.http.HttpServletResponse;
51  
52  import org.melati.Melati;
53  import org.melati.MelatiConfig;
54  import org.melati.template.ServletTemplateContext;
55  import org.melati.template.ServletTemplateEngine;
56  import org.melati.template.TemplateEngineException;
57  import org.melati.template.TemplateIOException;
58  import org.melati.template.velocity.MelatiBufferedVelocityWriter;
59  import org.melati.template.velocity.MelatiVelocityWriter;
60  import org.melati.util.MelatiWriter;
61  
62  /**
63   * @author timp
64   * @since 7 Mar 2012
65   *
66   */
67  public class FreemarkerServletTemplateEngine extends FreemarkerTemplateEngine 
68          implements ServletTemplateEngine {
69    /**    
70     * The HTTP request object context key.    
71     */    
72     public static final String REQUEST = "Request";    
73       
74    /**    
75     * The HTTP response object context key.    
76     */    
77     public static final String RESPONSE = "Response";    
78       
79     /** Mimicking the $Form behaviour of Webmacro. */
80     public static final String FORM = "Form";
81  
82    /**
83     * Constructor.
84     */
85    public FreemarkerServletTemplateEngine() {
86      super();
87    }
88  
89    /**
90     * Construct a new Engine for use in a servlet environment. For Velocity this
91     * is no different to initialisation outside of a servlets environment.
92     * 
93     * @param melatiConfig
94     *          a {@link MelatiConfig}
95     * @param servlet
96     *          the servlet we are within
97     * @throws TemplateEngineException
98     *           if any problem occurs with the engine
99     * @see org.melati.template.ServletTemplateEngine#init(org.melati.MelatiConfig, javax.servlet.http.HttpServlet)
100    */
101   @Override
102   public void init(MelatiConfig melatiConfig, HttpServlet servlet)
103           throws TemplateEngineException {
104     init(melatiConfig);
105   }
106 
107   /**
108    * @param response
109    *          the <code>HttpServletResponse</code> that this writer will be
110    *          part of
111    * @param buffered
112    *          whether the writer should be buffered
113    * @return a {@link MelatiWriter} appropriate for this engine.
114    * @see org.melati.template.ServletTemplateEngine#getServletWriter(javax.servlet.http.HttpServletResponse, boolean)
115    */
116   @Override
117   public MelatiWriter getServletWriter(HttpServletResponse response, 
118           boolean buffered) {
119     if (buffered) {
120       try {
121         return new MelatiBufferedVelocityWriter(response);
122       } catch (IOException e) {
123         throw new TemplateIOException(e);
124       }
125     } else {
126       try {
127         return new MelatiVelocityWriter(response);
128       } catch (IOException e) {
129         throw new TemplateIOException(e);
130       }
131     }
132   }
133 
134   /**
135    * Get the template context for Velocity, with servlet specific objects added.
136    * 
137    * @param melati
138    *        the {@link Melati}
139    * @return a {@link ServletTemplateContext}
140    * @see org.melati.template.ServletTemplateEngine#getServletTemplateContext(org.melati.Melati)
141    */
142   @Override
143   public ServletTemplateContext getServletTemplateContext(Melati melati) throws TemplateEngineException {
144     Map<String, Object> context = new HashMap<String, Object>();
145     
146     context.put(REQUEST, melati.getRequest());
147     context.put(RESPONSE, melati.getResponse());
148     return new FreemarkerServletTemplateContext(context);
149   }
150 
151 }