/*

  * $Id: FreemarkerRenderer.java 1306435 2012-03-28 15:39:11Z nlebas $

  *

  * 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.

  */

 package org.apache.tiles.request.freemarker.render;

 import java.io.IOException;

 import javax.servlet.ServletException;

 import javax.servlet.http.HttpServletRequest;

 import javax.servlet.http.HttpServletResponse;

 import org.apache.tiles.request.Request;

 import org.apache.tiles.request.freemarker.FreemarkerRequestException;

 import org.apache.tiles.request.render.CannotRenderException;

 import org.apache.tiles.request.render.Renderer;

 import org.apache.tiles.request.servlet.ExternalWriterHttpServletResponse;

 import org.apache.tiles.request.servlet.ServletRequest;

 /**

  * FreeMarker renderer for rendering FreeMarker templates as Tiles attributes.

  * It is only usable under a Servlet environment, because it uses

  * {@link AttributeValueFreemarkerServlet} internally to forward the request.<br/>

  * To initialize it correctly, call {@link #setParameter(String, String)} for all the

  * parameters that you want to set, and then call {@link #commit()}.

  *

  * @version $Rev: 1306435 $ $Date: 2012-03-29 02:39:11 +1100 (Thu, 29 Mar 2012) $

  */

 public class FreemarkerRenderer implements Renderer {

     /**

      * The servlet that is used to forward the request to.

      */

     private AttributeValueFreemarkerServlet servlet;

     /**

      * Constructor.

      *

      * @param servlet The servlet to use.

      */

     public FreemarkerRenderer(AttributeValueFreemarkerServlet servlet) {

         this.servlet = servlet;

     }

     /** {@inheritDoc} */

     @Override

     public void render(String path, Request request) throws IOException {

         if (path == null) {

             throw new CannotRenderException("Cannot dispatch a null path");

         }

         ServletRequest servletRequest = org.apache.tiles.request.servlet.ServletUtil.getServletRequest(request);

         HttpServletRequest httpRequest = servletRequest.getRequest();

         HttpServletResponse httpResponse = servletRequest.getResponse();

         servlet.setValue(path);

         try {

             servlet.doGet(httpRequest,

                     new ExternalWriterHttpServletResponse(httpResponse,

                             request.getPrintWriter()));

         } catch (ServletException e) {

             throw new FreemarkerRequestException("Exception when rendering a FreeMarker attribute", e);

         }

     }

     /** {@inheritDoc} */

     public boolean isRenderable(String path, Request request) {

         return path != null && path.startsWith("/") && path.endsWith(".ftl");

     }

 }