/*

  * 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 javax.faces.validator;

 import javax.el.ELContext;

 import javax.el.ValueExpression;

 import javax.el.ValueReference;

 import javax.faces.el.CompositeComponentExpressionHolder;

 /**

  * Utility class that isolates UEL calls, to prevent ClassNotFoundException

  * when bean validation is used without it. It is a similar hack to the one

  * used in portlet case.

  * 

  * @since 2.0

  */

 final class _BeanValidatorUELUtils

 {

     /**

      * Get the ValueReference from the ValueExpression.

      *

      * @param valueExpression

      * @param elCtx

      * @return A ValueReferenceWrapper with the necessary information about the ValueReference.

      */

     public static _ValueReferenceWrapper getUELValueReferenceWrapper(ValueExpression valueExpression,

                                                                      final ELContext elCtx)

     {

         ValueReference valueReference = valueExpression.getValueReference(elCtx);

         while (valueReference != null 

                 && valueReference.getBase() instanceof CompositeComponentExpressionHolder)

         {

             valueExpression = ((CompositeComponentExpressionHolder) valueReference.getBase())

                                   .getExpression((String) valueReference.getProperty());

             if(valueExpression == null)

             {

                 break;

             }

             valueReference = valueExpression.getValueReference(elCtx);

         }

         if (valueReference != null)

         {

             return new _ValueReferenceWrapper(valueReference.getBase(), valueReference.getProperty());

         }

         return null;

     }

 }