/*
    * $Id: AbstractDefaultToStringRenderable.java 791161 2009-07-04 18:53:36Z apetrelli $
    *
    * 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.velocity.template;
  
  import java.io.IOException;
  import java.io.StringWriter;
  import java.util.Map;
  
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.apache.tiles.velocity.TilesVelocityException;
  import org.apache.velocity.context.Context;
  import org.apache.velocity.exception.MethodInvocationException;
  import org.apache.velocity.exception.ParseErrorException;
  import org.apache.velocity.exception.ResourceNotFoundException;
  import org.apache.velocity.runtime.Renderable;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Renderable that provides a default implementation of {@link Renderable#toString()}
   * and allows access to parameters and context objects.
   *
   * @version $Rev: 791161 $ $Date: 2009-07-05 04:53:36 +1000 (Sun, 05 Jul 2009) $
   * @since 2.2.0
   */
  public abstract class AbstractDefaultToStringRenderable implements Renderable {
  
  
      /**
       * The Velocity context.
       *
       * @since 2.2.0
       */
      protected final Context velocityContext;
  
      /**
       * The parameters used in the current tool call.
       *
       * @since 2.2.0
       */
      protected final Map<String, Object> params;
  
      /**
       * The HTTP response.
       *
       * @since 2.2.0
       */
      protected final HttpServletResponse response;
  
      /**
       * The HTTP request.
       *
       * @since 2.2.0
       */
      protected final HttpServletRequest request;
  
      /**
       * The logging object.
       */
      private final Logger log = LoggerFactory.getLogger(getClass());
  
      /**
       * Constructor.
       *
       * @param velocityContext The Velocity context.
       * @param params The parameters used in the current tool call.
       * @param response The HTTP response.
       * @param request The HTTP request.
       * @since 2.2.0
       */
      public AbstractDefaultToStringRenderable(Context velocityContext,
              Map<String, Object> params, HttpServletResponse response,
              HttpServletRequest request) {
          this.velocityContext = velocityContext;
          this.params = params;
          this.response = response;
          this.request = request;
      }
 
     /** {@inheritDoc} */
     @Override
     public String toString() {
         StringWriter writer = new StringWriter();
         try {
             render(null, writer);
         } catch (MethodInvocationException e) {
             throw new TilesVelocityException("Cannot invoke method when rendering", e);
         } catch (ParseErrorException e) {
             throw new TilesVelocityException("Cannot parse when rendering", e);
         } catch (ResourceNotFoundException e) {
             throw new TilesVelocityException("Cannot find resource when rendering", e);
         } catch (IOException e) {
             throw new TilesVelocityException("I/O exception when rendering", e);
         } finally {
             try {
                 writer.close();
             } catch (IOException e) {
                 log.error("Error when closing a StringWriter, the impossible happened!", e);
             }
         }
         return writer.toString();
     }
 }