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.commons.configuration2.io;
018
019/**
020 * <p>
021 * Definition of an interface to be implemented by {@link FileBased} objects which need access to the current
022 * {@link FileLocator}.
023 * </p>
024 * <p>
025 * When loading or saving a {@code FileBased} object using {@code FileHandler} the handler eventually invokes the
026 * {@code read()} or {@code write()} methods passing in a reader or writer. For some implementations this may not be
027 * sufficient because they need information about the current location. For instance, a concrete {@code FileBased}
028 * implementation may have to resolve other data sources based on relative file names which have to be interpreted in
029 * the context of the current file location.
030 * </p>
031 * <p>
032 * To deal with such scenarios, affected implementations can choose to implement this interface. They are then passed
033 * the current location to the file being accessed before their {@code read()} or {@code write()} method is called.
034 * </p>
035 *
036 * @since 2.0
037 */
038public interface FileLocatorAware {
039    /**
040     * Passes the current {@code FileLocator} to this object. Note that this {@code FileLocator} object is only temporarily
041     * valid for the following invocation of {@code read()} or {@code write(}. Depending on the state of the
042     * {@code FileHandler} and which of its methods was called, the object may not be fully initialized. For instance, if
043     * the {@code FileHandler}'s {@code load(InputStream)} method was called, no file information is available, and all
044     * methods of the {@code FileLocator} will return <b>null</b>.
045     *
046     * @param locator the current {@code FileLocator}
047     */
048    void initFileLocator(FileLocator locator);
049}