/*

  * 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 java.io.Externalizable;

 import java.io.IOException;

 import java.io.ObjectInput;

 import java.io.ObjectOutput;

 import javax.el.ELContext;

 import javax.el.MethodExpression;

 import javax.el.ValueExpression;

 import javax.faces.FacesWrapper;

 import javax.faces.context.FacesContext;

 import javax.faces.event.AbortProcessingException;

 import javax.faces.event.ValueChangeEvent;

 import javax.faces.event.ValueChangeListener;

 /**

  *

  * @author Leonardo Uribe

  */

 public class RedirectMethodExpressionValueExpressionValueChangeListener

        implements ValueChangeListener, FacesWrapper<ValueExpression>, Externalizable

 {

     private ValueExpression valueExpression;

     public RedirectMethodExpressionValueExpressionValueChangeListener()

     {

     }

     public RedirectMethodExpressionValueExpressionValueChangeListener(ValueExpression valueExpression)

     {

         this.valueExpression = valueExpression;

     }

     public void processValueChange(ValueChangeEvent event) throws AbortProcessingException

     {

         getMethodExpression().invoke(FacesContext.getCurrentInstance().getELContext(), new Object[]{event});

     }

     private MethodExpression getMethodExpression()

     {

         return getMethodExpression(FacesContext.getCurrentInstance().getELContext());

     }

     private MethodExpression getMethodExpression(ELContext context)

     {

         Object meOrVe = valueExpression.getValue(context);

         if (meOrVe instanceof MethodExpression)

         {

             return (MethodExpression) meOrVe;

         }

         else if (meOrVe instanceof ValueExpression)

         {

             while (meOrVe != null && meOrVe instanceof ValueExpression)

             {

                 meOrVe = ((ValueExpression)meOrVe).getValue(context);

             }

             return (MethodExpression) meOrVe;

         }

         else

         {

             return null;

         }

     }

     public ValueExpression getWrapped()

     {

         return valueExpression;

     }

     public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException

     {

         this.valueExpression = (ValueExpression) in.readObject();

     }

     public void writeExternal(ObjectOutput out) throws IOException

     {

         out.writeObject(this.valueExpression);

     }

 }