/*

  * $Id: DispatchRenderer.java 1375743 2012-08-21 20:05:58Z 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.render;

 import java.io.IOException;

 import org.apache.tiles.request.Request;

 import org.apache.tiles.request.DispatchRequest;

 import org.apache.tiles.request.RequestWrapper;

 /**

  * Renders an attribute that contains a reference to a template.

  *

  * @version $Rev: 1375743 $ $Date: 2012-08-22 06:05:58 +1000 (Wed, 22 Aug 2012) $

  */

 public class DispatchRenderer implements Renderer {

     /** {@inheritDoc} */

     @Override

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

         if (path == null) {

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

         }

         DispatchRequest dispatchRequest = getDispatchRequest(request);

         if (dispatchRequest == null) {

             throw new CannotRenderException("Cannot dispatch outside of a web environment");

         }

         dispatchRequest.dispatch(path);

     }

     /** {@inheritDoc} */

     public boolean isRenderable(String path, Request request) {

         return path != null && getDispatchRequest(request) != null && path.startsWith("/");

     }

     private DispatchRequest getDispatchRequest(Request request) {

         Request result = request;

         while (!(result instanceof DispatchRequest) && result instanceof RequestWrapper) {

             result = ((RequestWrapper) result).getWrappedRequest();

         }

         if (!(result instanceof DispatchRequest)) {

             result = null;

         }

         return (DispatchRequest) result;

     }

 }