/*

  * $Id: VelocityUtil.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.velocity.autotag;

 import java.util.Map;

 import org.apache.velocity.context.InternalContextAdapter;

 import org.apache.velocity.runtime.parser.node.ASTMap;

 import org.apache.velocity.runtime.parser.node.Node;

 /**

  * Utilities for Velocity usage in Tiles.

  *

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

  */

 public final class VelocityUtil {

     /**

      * Private constructor to avoid instantiation.

      */

     private VelocityUtil() {

     }

     /**

      * Extracts the parameters from the directives, by getting the child at

      * position 0 supposing it is a map.

      *

      * @param context The Velocity context.

      * @param node The node to use.

      * @return The extracted parameters.

      */

     @SuppressWarnings("unchecked")

     public static Map<String, Object> getParameters(InternalContextAdapter context,

             Node node) {

         ASTMap astMap = (ASTMap) node.jjtGetChild(0);

         Map<String, Object> params = (Map<String, Object>) astMap

                 .value(context);

         return params;

     }

     /**

      * Returns the "value" parameter if it is not null, otherwise returns

      * "defaultValue".

      *

      * @param value The value to return, if it is not null.

      * @param defaultValue The value to return, if <code>value</code> is null.

      * @return The value, defaulted if necessary.

      */

     public static Object getObject(Object value, Object defaultValue) {

         if (value == null) {

             value = defaultValue;

         }

         return value;

     }

 }