/*

  * 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.tag;

 import java.lang.reflect.InvocationTargetException;

 import java.lang.reflect.Method;

 import javax.el.MethodExpression;

 import javax.faces.view.facelets.FaceletContext;

 import javax.faces.view.facelets.MetaRule;

 import javax.faces.view.facelets.Metadata;

 import javax.faces.view.facelets.MetadataTarget;

 import javax.faces.view.facelets.TagAttribute;

 import javax.faces.view.facelets.TagAttributeException;

 /**

  * Optional Rule for binding Method[Binding|Expression] properties

  * 

  * @author Mike Kienenberger

  * @author Jacob Hookom

  */

 public final class MethodRule extends MetaRule

 {

     private final String methodName;

     private final Class<?> returnTypeClass;

     private final Class<?>[] params;

     public MethodRule(String methodName, Class<?> returnTypeClass, Class<?>[] params)

     {

         this.methodName = methodName;

         this.returnTypeClass = returnTypeClass;

         this.params = params;

     }

     public Metadata applyRule(String name, TagAttribute attribute, MetadataTarget meta)

     {

         if (false == name.equals(this.methodName))

         {

             return null;

         }

         if (MethodExpression.class.equals(meta.getPropertyType(name)))

         {

             Method method = meta.getWriteMethod(name);

             if (method != null)

             {

                 return new MethodExpressionMetadata(method, attribute, this.returnTypeClass, this.params);

             }

         }

         return null;

     }

     private class MethodExpressionMetadata extends Metadata

     {

         private final Method _method;

         private final TagAttribute _attribute;

         private Class<?>[] _paramList;

         private Class<?> _returnType;

         public MethodExpressionMetadata(Method method, TagAttribute attribute, Class<?> returnType, 

                                         Class<?>[] paramList)

         {

             _method = method;

             _attribute = attribute;

             _paramList = paramList;

             _returnType = returnType;

         }

         public void applyMetadata(FaceletContext ctx, Object instance)

         {

             MethodExpression expr = _attribute.getMethodExpression(ctx, _returnType, _paramList);

             try

             {

                 _method.invoke(instance, new Object[] { expr });

             }

             catch (InvocationTargetException e)

             {

                 throw new TagAttributeException(_attribute, e.getCause());

             }

             catch (Exception e)

             {

                 throw new TagAttributeException(_attribute, e);

             }

         }

     }

 }