    001// Copyright 2008, 2009, 2022 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 java.lang.annotation.Documented;
    018import static java.lang.annotation.ElementType.FIELD;
    019import java.lang.annotation.Retention;
    020import static java.lang.annotation.RetentionPolicy.RUNTIME;
    021import java.lang.annotation.Target;
    022
    023import static org.apache.tapestry5.ioc.annotations.AnnotationUseContext.*;
    024import org.apache.tapestry5.ioc.annotations.UseWith;
    025
    026/**
    027 * Allows components defined in the template to be injected as read-only properties.
    028 */
    029@Target(FIELD)
    030@Documented
    031@Retention(RUNTIME)
    032@UseWith({COMPONENT,PAGE})
    033public @interface InjectComponent
    034{
    035    /**
    036     * The name of the component to inject. Defaults to the name of the annotated field.
    037     */
    038    String value() default "";
    039
    040    /**
    041     * If true, allows the component to be missing without throwing an exception.
    042     * @since 5.8.2
    043     */
    044    boolean optional() default false;
    045}