001// Copyright 2008, 2011 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.services;
016
017import org.apache.tapestry5.ioc.AnnotationAccess;
018import org.apache.tapestry5.ioc.MethodAdvice;
019
020/**
021 * A decorator used to create an interceptor that delegates each method's invocation to an
022 * {@link org.apache.tapestry5.ioc.MethodAdvice} for advice. Advice can inspect or change method parameters, inspect or
023 * change
024 * the method's return value, and inspect and change thrown exceptions (checked and unchecked).
025 */
026public interface AspectDecorator
027{
028    /**
029     * Intercepts method invocations on the delegate and passes them through the provided aspect. Note that the advice
030     * <em>must</em> be thread-safe.
031     * 
032     * @param serviceInterface
033     *            defines the interface of the interceptor and delegate
034     * @param delegate
035     *            the object on which methods will be invoked
036     * @param advice
037     *            intercepts the method invocations on the delegate
038     * @param description
039     *            used as the toString() of the returned interceptor, unless toString() is part of the
040     *            service interface
041     * @return the interceptor, wrapping the delegate with all the advice
042     */
043    <T> T build(Class<T> serviceInterface, T delegate, MethodAdvice advice, String description);
044
045    /**
046     * Creates a builder that can be used to create the interceptor. This is used when only some of the methods need to
047     * be advised, or when different methods need to receive different advice, or when multiple advice is to be
048     * applied.
049     * 
050     * @param serviceInterface
051     *            defines the interface of the interceptor and the delegate
052     * @param delegate
053     *            the object on which methods will be invokes
054     * @param description
055     *            used as the toString() of the interceptor unless toString() is part of the service
056     *            interface
057     * @return a builder that can be used to generate the final interceptor
058     */
059    <T> AspectInterceptorBuilder<T> createBuilder(Class<T> serviceInterface, T delegate, String description);
060
061    /**
062     * Creates a builder that can be used to create the interceptor. This is used when only some of the methods need to
063     * be advised, or when different methods need to receive different advice, or when multiple advice is to be
064     * applied.
065     * 
066     * @param serviceInterface
067     *            defines the interface of the interceptor and the delegate
068     * @param delegate
069     *            the object on which methods will be invokes
070     * @param annotationAccess
071     *            provides access to combined annotations of the underlying service
072     *            and service interface
073     * @param description
074     *            used as the toString() of the interceptor unless toString() is part of the service
075     *            interface
076     * @return a builder that can be used to generate the final interceptor
077     */
078    <T> AspectInterceptorBuilder<T> createBuilder(Class<T> serviceInterface, T delegate,
079            AnnotationAccess annotationAccess, String description);
080}