    001// Copyright 2006, 2009 The Apache Software Foundation
    002//
    003// Licensed under the Apache License, Version 2.0 (the "License");
    004// you may not use this file except in compliance with the License.
    005// You may obtain a copy of the License at
    006//
    007//     http://www.apache.org/licenses/LICENSE-2.0
    008//
    009// Unless required by applicable law or agreed to in writing, software
    010// distributed under the License is distributed on an "AS IS" BASIS,
    011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012// See the License for the specific language governing permissions and
    013// limitations under the License.
    014
    015package org.apache.tapestry5.ioc;
    016
    017/**
    018 * A service decorator is derived from a {@link org.apache.tapestry5.ioc.def.DecoratorDef} and is responsible for
    019 * building an interceptor around an existing implementation (called the "delegate").
    020 *
    021 * @see org.apache.tapestry5.ioc.ServiceAdvisor
    022 */
    023public interface ServiceDecorator
    024{
    025    /**
    026     * Creates a new interceptor object implementing the same service interface as the delegate object.
    027     *
    028     * @param delegate an existing object implementing the service interface.
    029     * @return a new object implementing the same service interface, or delegate or null if the decorator chooses not to
    030     *         create a new interceptor.
    031     */
    032    Object createInterceptor(Object delegate);
    033}