/*
 * 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>Service interface implemented by extensions. An extension 
 * is a service provider declared in <tt>META-INF/services</tt>.</p>
 * 
 * <p>Service providers may have 
 * {@linkplain javax.enterprise.event.Observes observer methods}, 
 * which may observe any event, including any 
 * {@linkplain javax.enterprise.inject.spi container lifecycle event}, 
 * and obtain an injected 
 * {@link javax.enterprise.inject.spi.BeanManager}.<p>
 * 
 * <p>The container instantiates a single instance of each 
 * extension at the beginning of the application initialization 
 * process and maintains a reference to it until the application 
 * shuts down. The container delivers event notifications to this 
 * instance by calling its observer methods.</p>
 *  
 * <p>Service providers are made available for injection as beans
 * with the qualifier {@link javax.enterprise.inject.Default &#064;Default}.</p>
 * 
 * @author Gavin King
 * @author Pete Muir
 *
 */
public interface Extension {}