001// Copyright 2007, 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
015package org.apache.tapestry5.annotations;
016
017import org.apache.tapestry5.Block;
018import org.apache.tapestry5.ioc.annotations.Inject;
019import org.apache.tapestry5.ioc.annotations.UseWith;
020import static org.apache.tapestry5.ioc.annotations.AnnotationUseContext.*;
021
022import java.lang.annotation.Documented;
023import static java.lang.annotation.ElementType.FIELD;
024import java.lang.annotation.Retention;
025import static java.lang.annotation.RetentionPolicy.RUNTIME;
026import java.lang.annotation.Target;
027
028/**
029 * Optional annotation, used with {@link Inject}, which exists to provide the id of an object when it can not be
030 * determined by other means (such as from the field name). Currently, this is used when injecting a {@link Block}.
031 */
032@Target(FIELD)
033@Documented
034@Retention(RUNTIME)
035@UseWith({COMPONENT,MIXIN,PAGE,SERVICE})
036public @interface Id
037{
038    /**
039     * The id.
040     */
041    String value();
042}