/*

  *  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.shared_impl.util;

 import java.lang.reflect.Method;

 import java.util.Iterator;

 import javax.el.ValueExpression;

 import javax.faces.component.UIComponent;

 import javax.faces.component.UIInput;

 import javax.faces.context.FacesContext;

 import org.apache.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 /**

  * @author Martin Marinschek (latest modification by $Author: grantsmith $)

  * @version $Revision: 169655 $ $Date: 2005-05-11 18:45:06 +0200 (Mi, 11 Mai 2005) $

  */

 public class RestoreStateUtils

 {

     private static Log log = LogFactory.getLog(RestoreStateUtils.class);

     /**

      * Walk the component tree, executing any component-bindings to reattach

      * components to their backing beans. 

      * <p>

      *  Note that this method effectively breaks encapsulation; instead of

      *  asking each component to update itself and its children, this

      * method just reaches into each component. That makes it impossible

      * for any component to customise its behaviour at this point.

      * <p>

      * This has been filed as an issue against the spec. Until this

      * issue is resolved, we'll add a new marker-interface for components

      * to allow them to define their interest in handling children bindings themselves.

      */

     public static void recursivelyHandleComponentReferencesAndSetValid(FacesContext facesContext,

                                                                        UIComponent parent)

     {

         recursivelyHandleComponentReferencesAndSetValid(facesContext, parent, false);

     }

     public static void recursivelyHandleComponentReferencesAndSetValid(FacesContext facesContext,

                                                                        UIComponent parent, boolean forceHandle)

     {

         Method handleBindingsMethod = getBindingMethod(parent);

         if(handleBindingsMethod!=null && !forceHandle)

         {

             try

             {

                 handleBindingsMethod.invoke(parent,new Object[]{});

             }

             catch (Throwable th)

             {

                 log.error("Exception while invoking handleBindings on component with client-id:"

                         +parent.getClientId(facesContext),th);

             }

         }

         else

         {

             for (Iterator it = parent.getFacetsAndChildren(); it.hasNext(); )

             {

                 UIComponent component = (UIComponent)it.next();

                 ValueExpression binding = component.getValueExpression("binding");    //TODO: constant

                 if (binding != null)

                 {

                     binding.setValue(facesContext.getELContext(), component);

                 }

                 //This part is not necessary on JSF 1.2

                 //if (component instanceof UIInput)

                 //{

                 //    ((UIInput)component).setValid(true);

                 //}

                 recursivelyHandleComponentReferencesAndSetValid(facesContext, component);

             }

         }

     }

     /**This is all a hack to work around a spec-bug which will be fixed in JSF2.0

      *

      * @param parent

      * @return true if this component is bindingAware (e.g. aliasBean)

      */

     private static Method getBindingMethod(UIComponent parent)

     {

         Class[] clazzes = parent.getClass().getInterfaces();

         for (int i = 0; i < clazzes.length; i++)

         {

             Class clazz = clazzes[i];

             if(clazz.getName().indexOf("BindingAware")!=-1)

             {

                 try

                 {

                     return  parent.getClass().getMethod("handleBindings",new Class[]{});

                 }

                 catch (NoSuchMethodException e)

                 {

                     // return

                 }

             }

         }

         return null;

     }

 }