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 }