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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *   http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing,
13   * software distributed under the License is distributed on an
14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   * KIND, either express or implied.  See the License for the
16   * specific language governing permissions and limitations
17   * under the License.
18   */
19  package org.apache.myfaces.shared.util;
20  
21  import java.lang.reflect.Method;
22  import java.util.Iterator;
23  import java.util.logging.Level;
24  import java.util.logging.Logger;
25  
26  import javax.el.ValueExpression;
27  import javax.faces.component.UIComponent;
28  import javax.faces.context.FacesContext;
29  
30  /**
31   * @author Martin Marinschek (latest modification by $Author: bommel $)
32   * @version $Revision: 1187701 $ $Date: 2011-10-22 07:21:54 -0500 (Sat, 22 Oct 2011) $
33   */
34  public class RestoreStateUtils
35  {
36      //private static Log log = LogFactory.getLog(RestoreStateUtils.class);
37      private static Logger log = Logger.getLogger(RestoreStateUtils.class.getName());
38  
39      /**
40       * Walk the component tree, executing any component-bindings to reattach
41       * components to their backing beans. 
42       * <p>
43       *  Note that this method effectively breaks encapsulation; instead of
44       *  asking each component to update itself and its children, this
45       * method just reaches into each component. That makes it impossible
46       * for any component to customise its behaviour at this point.
47       * <p>
48       * This has been filed as an issue against the spec. Until this
49       * issue is resolved, we'll add a new marker-interface for components
50       * to allow them to define their interest in handling children bindings themselves.
51       */
52      public static void recursivelyHandleComponentReferencesAndSetValid(FacesContext facesContext,
53                                                                         UIComponent parent)
54      {
55          recursivelyHandleComponentReferencesAndSetValid(facesContext, parent, false);
56      }
57  
58      public static void recursivelyHandleComponentReferencesAndSetValid(FacesContext facesContext,
59                                                                         UIComponent parent, boolean forceHandle)
60      {
61          Method handleBindingsMethod = getBindingMethod(parent);
62  
63          if(handleBindingsMethod!=null && !forceHandle)
64          {
65              try
66              {
67                  handleBindingsMethod.invoke(parent,new Object[]{});
68              }
69              catch (Throwable th)
70              {
71                  log.log(Level.SEVERE, "Exception while invoking handleBindings on component with client-id:"
72                          +parent.getClientId(facesContext),th);
73              }
74          }
75          else
76          {
77              for (Iterator it = parent.getFacetsAndChildren(); it.hasNext(); )
78              {
79                  UIComponent component = (UIComponent)it.next();
80  
81                  ValueExpression binding = component.getValueExpression("binding");    //TODO: constant
82                  if (binding != null)
83                  {
84                      binding.setValue(facesContext.getELContext(), component);
85                  }
86  
87                  //This part is not necessary on JSF 1.2
88                  //if (component instanceof UIInput)
89                  //{
90                  //    ((UIInput)component).setValid(true);
91                  //}
92  
93                  recursivelyHandleComponentReferencesAndSetValid(facesContext, component);
94              }
95          }
96      }
97  
98      /**This is all a hack to work around a spec-bug which will be fixed in JSF2.0
99       *
100      * @param parent
101      * @return true if this component is bindingAware (e.g. aliasBean)
102      */
103     private static Method getBindingMethod(UIComponent parent)
104     {
105         Class[] clazzes = parent.getClass().getInterfaces();
106 
107         for (int i = 0; i < clazzes.length; i++)
108         {
109             Class clazz = clazzes[i];
110 
111             if(clazz.getName().indexOf("BindingAware")!=-1)
112             {
113                 try
114                 {
115                     return  parent.getClass().getMethod("handleBindings",new Class[]{});
116                 }
117                 catch (NoSuchMethodException e)
118                 {
119                     // return
120                 }
121             }
122         }
123 
124         return null;
125     }
126 }