1 /*
2 * $Id: FreemarkerRenderer.java 1306435 2012-03-28 15:39:11Z nlebas $
3 *
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 package org.apache.tiles.request.freemarker.render;
23
24 import java.io.IOException;
25
26 import javax.servlet.ServletException;
27 import javax.servlet.http.HttpServletRequest;
28 import javax.servlet.http.HttpServletResponse;
29
30 import org.apache.tiles.request.Request;
31 import org.apache.tiles.request.freemarker.FreemarkerRequestException;
32 import org.apache.tiles.request.render.CannotRenderException;
33 import org.apache.tiles.request.render.Renderer;
34 import org.apache.tiles.request.servlet.ExternalWriterHttpServletResponse;
35 import org.apache.tiles.request.servlet.ServletRequest;
36
37 /**
38 * FreeMarker renderer for rendering FreeMarker templates as Tiles attributes.
39 * It is only usable under a Servlet environment, because it uses
40 * {@link AttributeValueFreemarkerServlet} internally to forward the request.<br/>
41 * To initialize it correctly, call {@link #setParameter(String, String)} for all the
42 * parameters that you want to set, and then call {@link #commit()}.
43 *
44 * @version $Rev: 1306435 $ $Date: 2012-03-29 02:39:11 +1100 (Thu, 29 Mar 2012) $
45 */
46 public class FreemarkerRenderer implements Renderer {
47
48 /**
49 * The servlet that is used to forward the request to.
50 */
51 private AttributeValueFreemarkerServlet servlet;
52
53 /**
54 * Constructor.
55 *
56 * @param servlet The servlet to use.
57 */
58 public FreemarkerRenderer(AttributeValueFreemarkerServlet servlet) {
59 this.servlet = servlet;
60 }
61
62 /** {@inheritDoc} */
63 @Override
64 public void render(String path, Request request) throws IOException {
65 if (path == null) {
66 throw new CannotRenderException("Cannot dispatch a null path");
67 }
68 ServletRequest servletRequest = org.apache.tiles.request.servlet.ServletUtil.getServletRequest(request);
69 HttpServletRequest httpRequest = servletRequest.getRequest();
70 HttpServletResponse httpResponse = servletRequest.getResponse();
71 servlet.setValue(path);
72 try {
73 servlet.doGet(httpRequest,
74 new ExternalWriterHttpServletResponse(httpResponse,
75 request.getPrintWriter()));
76 } catch (ServletException e) {
77 throw new FreemarkerRequestException("Exception when rendering a FreeMarker attribute", e);
78 }
79 }
80
81 /** {@inheritDoc} */
82 public boolean isRenderable(String path, Request request) {
83 return path != null && path.startsWith("/") && path.endsWith(".ftl");
84 }
85 }