001/* $Id: VariableExpander.java 992060 2010-09-02 19:09:47Z simonetripodi $
002 *
003 * Licensed to the Apache Software Foundation (ASF) under one or more
004 * contributor license agreements.  See the NOTICE file distributed with
005 * this work for additional information regarding copyright ownership.
006 * The ASF licenses this file to You under the Apache License, Version 2.0
007 * (the "License"); you may not use this file except in compliance with
008 * the License.  You may obtain a copy of the License at
009 *
010 *      http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018
019
020package org.apache.commons.digester.substitution;
021
022/**
023 * <p>An Interface describing a class capable of expanding strings which
024 * may contain variable references. The exact syntax of the "reference",
025 * and the mechanism for determining the corresponding value to be used
026 * is up to the concrete implementation.</p>
027 *
028 * @since 1.6
029 */
030public interface VariableExpander {
031    /**
032     * Return the input string with any variables replaced by their
033     * corresponding value. If there are no variables in the string,
034     * then the input parameter is returned unaltered.
035     */
036    public String expand(String param);
037}
038