/*
    * $Id$
    *
    * 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.struts.tiles2.preparer;
  
  import java.io.IOException;
  
  import org.apache.tiles.AttributeContext;
  import org.apache.tiles.preparer.PreparerException;
  import org.apache.tiles.preparer.ViewPreparer;
  import org.apache.tiles.request.Request;
  import org.apache.tiles.request.jakarta.servlet.ServletRequest;
  
  import jakarta.servlet.RequestDispatcher;
  import jakarta.servlet.ServletException;
  import jakarta.servlet.http.HttpServletRequest;
  import jakarta.servlet.http.HttpServletResponse;
  
  /**
   * @version $Rev$ $Date$
   */
  public class UrlPreparer implements ViewPreparer {
  
      /**
       * The URL to be used as a preparer.
       */
      private String url;
  
      /**
       * Constructor.
       *
       * @param url The URL to be used as a preparer.
       */
      public UrlPreparer(String url) {
          this.url = url;
      }
  
      /** {@inheritDoc} */
      public void execute(Request tilesContext,
              AttributeContext attributeContext) throws PreparerException {
  
          if (tilesContext instanceof ServletRequest) {
              ServletRequest servletTilesContext =
                  (ServletRequest) tilesContext;
              HttpServletRequest request = servletTilesContext.getRequest();
              HttpServletResponse response = servletTilesContext.getResponse();
              RequestDispatcher rd = request.getSession().getServletContext()
                      .getRequestDispatcher(url);
              if (rd == null) {
                  throw new PreparerException(
                      "Controller can't find url '" + url + "'.");
              }
  
              try {
                  rd.include(request, response);
              } catch (ServletException e) {
                  throw new PreparerException(
                          "The request dispatcher threw an exception", e);
              } catch (IOException e) {
                  throw new PreparerException(
                          "The request dispatcher threw an I/O exception", e);
              }
          } else {
              throw new PreparerException("Cannot dispatch url '" + url
                      + "' since this preparer has not been called under a servlet environment");
          }
      }
  
  }