/*
    * $Id: FreemarkerRequestUtil.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;
  
  import org.apache.tiles.request.ApplicationContext;
  import org.apache.tiles.request.servlet.ServletUtil;
  
  import freemarker.core.Environment;
  import freemarker.ext.servlet.FreemarkerServlet;
  import freemarker.ext.servlet.HttpRequestHashModel;
  import freemarker.ext.servlet.ServletContextHashModel;
  import freemarker.template.TemplateModelException;
  
  /**
   * Utilities to work with Freemarker requests.
   *
   * @version $Rev: 1306435 $ $Date: 2012-03-29 02:39:11 +1100 (Thu, 29 Mar 2012) $
   */
  public final class FreemarkerRequestUtil {
  
      /**
       * Constructor.
       */
      private FreemarkerRequestUtil() {
      }
  
      /**
       * Returns the HTTP request hash model.
       *
       * @param env The current FreeMarker environment.
       * @return The request hash model.
       */
      public static HttpRequestHashModel getRequestHashModel(Environment env) {
          try {
              return (HttpRequestHashModel) env.getDataModel().get(
                      FreemarkerServlet.KEY_REQUEST);
          } catch (TemplateModelException e) {
              throw new NotAvailableFreemarkerServletException(
                      "Exception got when obtaining the request hash model", e);
          }
      }
  
      /**
       * Returns the servlet context hash model.
       *
       * @param env The current FreeMarker environment.
       * @return The servlet context hash model.
       */
      public static ServletContextHashModel getServletContextHashModel(
              Environment env) {
          try {
              return (ServletContextHashModel) env.getDataModel().get(
                      FreemarkerServlet.KEY_APPLICATION);
          } catch (TemplateModelException e) {
              throw new NotAvailableFreemarkerServletException(
                      "Exception got when obtaining the application hash model",
                      e);
          }
      }
  
      /**
       * Returns the application context. It must be
       * first saved creating an {@link ApplicationContext} and using
       * {@link org.apache.tiles.request.ApplicationAccess#register(ApplicationContext)}.
       *
       * @param env The Freemarker environment.
       * @return The
       */
      public static ApplicationContext getApplicationContext(
              Environment env) {
          return ServletUtil
                  .getApplicationContext(getServletContextHashModel(env)
                          .getServlet().getServletContext());
      }
  
  }