tapestry-ioc/src/main/java/org/apache/tapestry5/ioc/def/ServiceDef.java

// Copyright 2006, 2007 The Apache Software Foundation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package org.apache.tapestry5.ioc.def;

import org.apache.tapestry5.ioc.ObjectCreator;
import org.apache.tapestry5.ioc.ServiceBuilderResources;

import java.util.Set;

/**
 * Service definition derived, by default, from a service builder method.
 */
public interface ServiceDef
{
    /**
     * Returns an {@link ObjectCreator} that can create the core service implementation.
     *
     * @param resources used to resolve dependencies of the service, or access its configuration
     * @return an object that can (later) be used to instantiate the service itself
     */
    ObjectCreator createServiceCreator(ServiceBuilderResources resources);

    /**
     * Returns the service id, derived from the method name or the unqualified service interface name. Service ids must
     * be unique among <em>all</em> services in all modules. Service ids are used in a heavy handed way to support
     * ultimate disambiguation, but their primary purpose is to support service contribution methods.
     */
    String getServiceId();

    /**
     * Returns an optional <em>marker annotation</em>. Marker annotations are used to disambiguate services; the
     * combination of a marker annotation and a service type is expected to be unique. The annotation is placed on the
     * field or method/constructor parameter and the service is located by combining the marker with service type (the
     * parameter or field type).
     *
     * @return the annotation, or null if the service has no annotation
     */
    Set<Class> getMarkers();

    /**
     * Returns the service interface associated with this service. This is the interface exposed to the outside world,
     * as well as the one used to build proxies. In cases where the service is <em>not</em> defined in terms of an
     * interface, this will return the actual implementation class of the service. Services without a true service
     * interfaced are <strong>not proxied</strong>.
     */
    Class getServiceInterface();

    /**
     * Returns the lifecycle defined for the service. This is indicated by adding a {@link
     * org.apache.tapestry5.ioc.annotations.Scope} annotation to the service builder method for the service.
     * <p/>
     * Services that are not proxied will ignore their scope; such services are always treated as singletons.
     */
    String getServiceScope();

    /**
     * Returns true if the service should be eagerly loaded at Registry startup.
     *
     * @see org.apache.tapestry5.ioc.annotations.EagerLoad
     */
    boolean isEagerLoad();
}