    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}