    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.annotations;
    014
    015import org.apache.tapestry5.ioc.ServiceBinder;
    016import org.apache.tapestry5.ioc.ServiceLifecycle;
    017import org.apache.tapestry5.ioc.services.ServiceLifecycleSource;
    018
    019import java.lang.annotation.Documented;
    020import java.lang.annotation.Retention;
    021import java.lang.annotation.Target;
    022
    023import static java.lang.annotation.ElementType.METHOD;
    024import static java.lang.annotation.ElementType.TYPE;
    025import static java.lang.annotation.RetentionPolicy.RUNTIME;
    026
    027/**
    028 * An optional annotation that may be placed on a service building method of a module, or on the implementation class
    029 * (when using service binding). The annotation overrides the default scope for services (the default being a global
    030 * singleton that is instantiated on demand) for an alternate lifecycle. Alternate lifecycles are typically used to bind
    031 * a service implementation to a single thread or request. Modules may define new scopes. Each scope should have a
    032 * corresponding {@link ServiceLifecycle} implementation. The linkage from scope name to service lifecycle occurs via a
    033 * contribution to the {@link ServiceLifecycleSource} service configuration.
    034 *
    035 * The annotation may also be placed directly on a service implementation class, when using service binding (via
    036 * the {@link ServiceBinder}).
    037 *
    038 * @see org.apache.tapestry5.ioc.ScopeConstants
    039 */
    040@Target(
    041        {TYPE, METHOD})
    042@Retention(RUNTIME)
    043@Documented
    044@UseWith({AnnotationUseContext.SERVICE, AnnotationUseContext.MODULE})
    045public @interface Scope
    046{
    047    /**
    048     * An identifier used to look up a non-default {@link ServiceLifecycle}.
    049     */
    050    String value();
    051}