001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.juneau.commons.inject;
018
019/**
020 * Post-bind extension seam for {@link ConfigPropertiesBinder}.
021 *
022 * <p>
023 * The binder invokes {@link #validate(Object)} once on each fully-bound target. {@link #NO_OP} is the default and
024 * performs no validation; supply a custom implementation to enforce constraints on a bound object without changing
025 * {@link ConfigPropertiesBinder}'s public shape.
026 *
027 * @since 10.0.0
028 */
029@FunctionalInterface
030public interface ConfigPropertiesValidator {
031
032   /** The default: performs no validation. */
033   ConfigPropertiesValidator NO_OP = target -> { /* No-op: no validation is performed. */ };
034
035   /**
036    * Called once, after a target has been fully bound.
037    *
038    * <p>
039    * Under nesting, this is called once per bound object — innermost (most deeply nested) first, then each
040    * enclosing object in turn as the recursive bind unwinds.
041    *
042    * @param target The bound instance.
043    */
044   void validate(Object target);
045}