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    
015    package org.apache.tapestry5.ioc;
016    
017    import 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     */
031    public 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    }