/*
 * Copyright 2002-2012 the original author or authors.
 *
 * Licensed 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.springframework.beans.factory.xml;

import org.w3c.dom.Node;

import org.springframework.beans.factory.config.BeanDefinitionHolder;

Interface used by the DefaultBeanDefinitionDocumentReader to handle custom, nested (directly under a <bean>) tags. 
Decoration may also occur based on custom attributes applied to the <bean> tag. Implementations are free to turn the metadata in the custom tag into as many BeanDefinitions as required and to transform the BeanDefinition of the enclosing <bean> tag, potentially even returning a completely different BeanDefinition to replace the original. 
BeanDefinitionDecorators should be aware that they may be part of a chain. In particular, a BeanDefinitionDecorator should be aware that a previous BeanDefinitionDecorator may have replaced the original BeanDefinition with a ProxyFactoryBean definition allowing for custom interceptors to be added. 
BeanDefinitionDecorators that wish to add an interceptor to the enclosing bean should extend AbstractInterceptorDrivenBeanDefinitionDecorator which handles the chaining ensuring that only one proxy is created and that it contains all interceptors from the chain. 
The parser locates a BeanDefinitionDecorator from the NamespaceHandler for the namespace in which the custom tag resides. 
Author:
Rob Harrop
See Also:
NamespaceHandler
BeanDefinitionParser
Since:
2.0/**
 * Interface used by the {@link DefaultBeanDefinitionDocumentReader}
 * to handle custom, nested (directly under a {@code <bean>}) tags.
 *
 * <p>Decoration may also occur based on custom attributes applied to the
 * {@code <bean>} tag. Implementations are free to turn the metadata in the
 * custom tag into as many
 * {@link org.springframework.beans.factory.config.BeanDefinition BeanDefinitions} as
 * required and to transform the
 * {@link org.springframework.beans.factory.config.BeanDefinition} of the enclosing
 * {@code <bean>} tag, potentially even returning a completely different
 * {@link org.springframework.beans.factory.config.BeanDefinition} to replace the
 * original.
 *
 * <p>{@link BeanDefinitionDecorator BeanDefinitionDecorators} should be aware that
 * they may be part of a chain. In particular, a {@link BeanDefinitionDecorator} should
 * be aware that a previous {@link BeanDefinitionDecorator} may have replaced the
 * original {@link org.springframework.beans.factory.config.BeanDefinition} with a
 * {@link org.springframework.aop.framework.ProxyFactoryBean} definition allowing for
 * custom {@link org.aopalliance.intercept.MethodInterceptor interceptors} to be added.
 *
 * <p>{@link BeanDefinitionDecorator BeanDefinitionDecorators} that wish to add an
 * interceptor to the enclosing bean should extend
 * {@link org.springframework.aop.config.AbstractInterceptorDrivenBeanDefinitionDecorator}
 * which handles the chaining ensuring that only one proxy is created and that it
 * contains all interceptors from the chain.
 *
 * <p>The parser locates a {@link BeanDefinitionDecorator} from the
 * {@link NamespaceHandler} for the namespace in which the custom tag resides.
 *
 * @author Rob Harrop
 * @since 2.0
 * @see NamespaceHandler
 * @see BeanDefinitionParser
 */
public interface BeanDefinitionDecorator {

	
Parse the specified Node (either an element or an attribute) and decorate the supplied BeanDefinition, returning the decorated definition. 
Implementations may choose to return a completely new definition, which will replace the original definition in the resulting BeanFactory. 
The supplied ParserContext can be used to register any additional beans needed to support the main definition. /**
	 * Parse the specified {@link Node} (either an element or an attribute) and decorate
	 * the supplied {@link org.springframework.beans.factory.config.BeanDefinition},
	 * returning the decorated definition.
	 * <p>Implementations may choose to return a completely new definition, which will
	 * replace the original definition in the resulting
	 * {@link org.springframework.beans.factory.BeanFactory}.
	 * <p>The supplied {@link ParserContext} can be used to register any additional
	 * beans needed to support the main definition.
	 */
	BeanDefinitionHolder decorate(Node node, BeanDefinitionHolder definition, ParserContext parserContext);

}