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 */
017
018package org.apache.logging.log4j.core.lookup;
019
020public interface LookupResult {
021
022    /** Value of the lookup result. Never null. */
023    String value();
024
025    /**
026     * True if the {@link #value()} should be re-evaluated for other lookups.
027     * This is used by {@link PropertiesLookup} to allow properties to be evaluated against other properties,
028     * because the configuration properties are completely trusted and designed with lookups in mind. It is
029     * unsafe to return true in most cases because it may allow unintended lookups to evaluate other lookups.
030     */
031    default boolean isLookupEvaluationAllowedInValue() {
032        return false;
033    }
034
035}