001// Licensed under the Apache License, Version 2.0 (the "License");
002// you may not use this file except in compliance with the License.
003// You may obtain a copy of the License at
004//
005//     http://www.apache.org/licenses/LICENSE-2.0
006//
007// Unless required by applicable law or agreed to in writing, software
008// distributed under the License is distributed on an "AS IS" BASIS,
009// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
010// See the License for the specific language governing permissions and
011// limitations under the License.
012
013package org.apache.tapestry5.ioc;
014
015import org.apache.tapestry5.ioc.def.ServiceDef;
016
017/**
018 * Definition of a service advisor, which (by default) is derived from a service advisor method. Service advisor methods
019 * are static or instance methods on module classes prefixed with "advise". When a service is realized, a list of
020 * matching AdvisorDefs is generated, then ordered, and from each a {@link org.apache.tapestry5.ioc.ServiceAdvisor} is
021 * obtained and invoked.
022 *
023 * Note: service decorators (via {@link org.apache.tapestry5.ioc.def.DecoratorDef} are applied <em>around</em> the
024 * interceptor generated via service advisors, (for compatibility with Tapestry 5.0). In general, you should use service
025 * decoration or service advice, not both.
026 *
027 * @since 5.1.0.0
028 */
029public interface AdvisorDef
030{
031    /**
032     * Returns the id of the advisor, which is derived from the advisor method name.
033     */
034    String getAdvisorId();
035
036    /**
037     * Returns ordering constraints for this advisor, to order it relative to other advisors.
038     *
039     * @return zero or more constraint strings
040     */
041    String[] getConstraints();
042
043    /**
044     * Creates an object that can provide the service advice (in the default case, by invoking the advise method on the
045     * module class or instance).
046     *
047     * @param moduleSource used to obtain the module instance
048     * @param resources    used to provide injections into the advise method
049     * @return advisor
050     */
051    ServiceAdvisor createAdvisor(ModuleBuilderSource moduleSource, ServiceResources resources);
052
053    /**
054     * Used to determine which services may be advised. When advising a service, first the advisors that target the
055     * service are identified, then ordering occurs, then the {@link org.apache.tapestry5.ioc.ServiceAdvisor}s are
056     * obtained and invoked.
057     *
058     * @param serviceDef identifies a service that may be advised
059     * @return true if this advisor applies to the service
060     */
061    boolean matches(ServiceDef serviceDef);
062}