/*
 * JBoss, Home of Professional Open Source
 * Copyright 2008, Red Hat Middleware LLC, and individual contributors
 * by the @authors tag. See the copyright.txt in the distribution for a
 * full listing of individual contributors.
 *
 * 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 javax.enterprise.inject.spi;

/**
 * <p>
 * The container fires an event of this type for every Java EE component class supporting 
 * injection that may be instantiated by the container at runtime, including every
 * managed bean declared using {@code javax.annotation.ManagedBean}, EJB session 
 * or message-driven bean, enabled bean, enabled interceptor or enabled decorator.
 * </p>
 * <p>
 * Any observer of this event is permitted to wrap and/or replace the
 * {@link javax.enterprise.inject.spi.InjectionTarget}. The container must use
 * the final value of this property, after all observers have been called,
 * whenever it performs injection upon the managed bean, session bean or other
 * Java EE component class supporting injection.
 * </p>
 * <p>
 * For example, this observer decorates the {@code InjectionTarget} for all
 * servlets.
 * </p>
 * 
 * <pre>
 * public &lt;T extends Servlet&gt; void decorateServlet(@Observes ProcessInjectionTarget&lt;T&gt; pit)
 * {
 *    pit.setInjectionTarget(decorate(pit.getInjectionTarget()));
 * }
 * </pre>
 * <p>
 * If any observer method of a {@code ProcessInjectionTarget} event throws an exception,
 * the exception is treated as a definition error by the container.
 * </p>
 * 
 * @see InjectionTarget
 * @author David Allen
 * @param <X> The managed bean class, session bean class or Java EE component
 *           class supporting injection
 */
public interface ProcessInjectionTarget<X>
{
   /**
    * Returns the {@link javax.enterprise.inject.spi.AnnotatedType} representing
    * the managed bean class, session bean class or other Java EE component
    * class supporting injection.
    * 
    * @return the {@link javax.enterprise.inject.spi.AnnotatedType} of the bean
    *         with an injection target
    */
   public AnnotatedType<X> getAnnotatedType();

   /**
    * Returns the {@link javax.enterprise.inject.spi.InjectionTarget} object
    * that will be used by the container to perform injection.
    * 
    * @return the {@link javax.enterprise.inject.spi.InjectionTarget} object
    *         which performs the injection
    */
   public InjectionTarget<X> getInjectionTarget();

   /**
    * Replaces the {@link javax.enterprise.inject.spi.InjectionTarget} which
    * performs injection for this target.
    * 
    * @param injectionTarget The new
    *           {@link javax.enterprise.inject.spi.InjectionTarget} to use
    */
   public void setInjectionTarget(InjectionTarget<X> injectionTarget);

   /**
    * Registers a definition error with the container, causing the container to
    * abort deployment after bean discovery is complete.
    * 
    * @param t A {@link java.lang.Throwable} representing the definition error
    */
   public void addDefinitionError(Throwable t);
}
