/*

  * 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.myfaces.view.facelets.el;

 import javax.el.ValueExpression;

 import javax.el.VariableMapper;

 /**

  * Composite VariableMapper that attempts to load the ValueExpression from the first VariableMapper, then the second if

  * <code>null</code>.

  * 

  * @see javax.el.VariableMapper

  * @see javax.el.ValueExpression

  * 

  * @author Jacob Hookom

  * @version $Id$

  */

 public final class CompositeVariableMapper extends VariableMapper

 {

     private final VariableMapper var0;

     private final VariableMapper var1;

     public CompositeVariableMapper(VariableMapper var0, VariableMapper var1)

     {

         this.var0 = var0;

         this.var1 = var1;

     }

     /**

      * @see javax.el.VariableMapper#resolveVariable(java.lang.String)

      */

     public ValueExpression resolveVariable(String name)

     {

         ValueExpression ve = this.var0.resolveVariable(name);

         if (ve == null)

         {

             return this.var1.resolveVariable(name);

         }

         return ve;

     }

     /**

      * @see javax.el.VariableMapper#setVariable(java.lang.String, javax.el.ValueExpression)

      */

     public ValueExpression setVariable(String name, ValueExpression expression)

     {

         return this.var0.setVariable(name, expression);

     }

 }