    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
    015    package org.apache.tapestry5.annotations;
    016
    017    import org.apache.tapestry5.Block;
    018    import org.apache.tapestry5.ioc.annotations.Inject;
    019    import org.apache.tapestry5.ioc.annotations.UseWith;
    020    import static org.apache.tapestry5.ioc.annotations.AnnotationUseContext.*;
    021
    022    import java.lang.annotation.Documented;
    023    import static java.lang.annotation.ElementType.FIELD;
    024    import java.lang.annotation.Retention;
    025    import static java.lang.annotation.RetentionPolicy.RUNTIME;
    026    import 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})
    036    public @interface Id
    037    {
    038        /**
    039         * The id.
    040         */
    041        String value();
    042    }