001/* -*- mode: Java; c-basic-offset: 2; indent-tabs-mode: nil; coding: utf-8-unix -*-
002 *
003 * Copyright © 2023–2025 microBean™.
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
006 * the License. You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
011 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
012 * specific language governing permissions and limitations under the License.
013 */
014package org.microbean.bean;
015
016/**
017 * An interface whose implementations {@linkplain #initialize(Object, Request) initialize} contextual instances.
018 *
019 * <p>{@link Initializer}s are subordinate to {@link Producer}s, typically operating on the contextual instances they
020 * produce.</p>
021 *
022 * @param <I> the type of contextual instance
023 *
024 * @author <a href="https://about.me/lairdnelson" target="_top">Laird Nelson</a>
025 *
026 * @see #initialize(Object, Request)
027 */
028// Subordinate to Factory<I> (really to PostInitializer<I>). Normally applied to Producer<I> output.
029// Calls initializer methods and injects fields
030// Note that this deliberately extends Aggregate, providing access to dependencies.
031public interface Initializer<I> extends Aggregate {
032
033  /**
034   * Initializes the supplied contextual instance, possibly using the supplied {@link Request} to obtain supporting
035   * contextual references.
036   *
037   * <p>Typically {@link Initializer} implementations will call <dfn>initializer methods</dfn> and perform <dfn>field
038   * injection</dfn> on the supplied contextual instance.</p>
039   *
040   * @param i the contextual instance to initialize; may be {@code null}
041   *
042   * @param r a {@link Request} that can be used to acquire supporting contextual references; may be {@code null}
043   *
044   * @return the initialized instance, or a copy of it, or a stand-in for it
045   *
046   * @see Producer#produce(Request)
047   */
048  public I initialize(final I i, final Request<I> r);
049
050}