001// Copyright 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
017import org.apache.tapestry5.ioc.def.ServiceDef;
018
019/**
020 * Definition of a service advisor, which (by default) is derived from a service advisor method. Service advisor methods
021 * are static or instance methods on module classes prefixed with "advise". When a service is realized, a list of
022 * matching AdvisorDefs is generated, then ordered, and from each a {@link org.apache.tapestry5.ioc.ServiceAdvisor} is
023 * obtained and invoked.
024 * <p/>
025 * Note: service decorators (via {@link org.apache.tapestry5.ioc.def.DecoratorDef} are applied <em>around</em> the
026 * interceptor generated via service advisors, (for compatibility with Tapestry 5.0). In general, you should use service
027 * decoration or service advice, not both.
028 *
029 * @since 5.1.0.0
030 */
031public interface AdvisorDef
032{
033    /**
034     * Returns the id of the advisor, which is derived from the advisor method name.
035     */
036    String getAdvisorId();
037
038    /**
039     * Returns ordering constraints for this advisor, to order it relative to other advisors.
040     *
041     * @return zero or more constraint strings
042     */
043    String[] getConstraints();
044
045    /**
046     * Creates an object that can provide the service advice (in the default case, by invoking the advise method on the
047     * module class or instance).
048     *
049     * @param moduleSource used to obtain the module instance
050     * @param resources    used to provide injections into the advise method
051     * @return advisor
052     */
053    ServiceAdvisor createAdvisor(ModuleBuilderSource moduleSource, ServiceResources resources);
054
055    /**
056     * Used to determine which services may be advised. When advising a service, first the advisors that target the
057     * service are identified, then ordering occurs, then the {@link org.apache.tapestry5.ioc.ServiceAdvisor}s are
058     * obtained and invoked.
059     *
060     * @param serviceDef identifies a service that may be advised
061     * @return true if this advisor applies to the service
062     */
063    boolean matches(ServiceDef serviceDef);
064}