001    //  Copyright 2008 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    
018    /**
019     * Defines constants for built-in scopes (used with the {@link org.apache.tapestry5.ioc.annotations.Scope} annotation.
020     */
021    public class ScopeConstants
022    {
023        /**
024         * The default scope is a singleton within the {@link org.apache.tapestry5.ioc.Registry}. A single instance will be
025         * created on demand.  The lifespan of the instance lasts until the registry is {@linkplain Registry#shutdown() shut
026         * down}. <p/>Some implementations will want to know when the Registry is shutdown; they should register for
027         * notifications via the {@link org.apache.tapestry5.ioc.services.RegistryShutdownHub} service.
028         */
029        public static final String DEFAULT = "singleton";
030    
031        /**
032         * An alternate scope provided with Tapestry; a per-thread instance is created on demand, behind a shared proxy.
033         * Method invocations on the shared proxy are forwarded to the per-thread instance. Each per-thread instance lasts
034         * until the {@linkplain Registry#cleanupThread() thread is cleaned up} (at the end of a request for a web
035         * application). <p>Some implementations will want to be notified before being discarded and should register with
036         * the {@link org.apache.tapestry5.ioc.services.PerthreadManager} to receive notifications.
037         *
038         * @see org.apache.tapestry5.ioc.internal.services.PerThreadServiceLifecycle
039         */
040        public static final String PERTHREAD = "perthread";
041    }