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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.configuration2.convert;
/**
*
* Definition of an interface used by {@link ListDelimiterHandler} to perform
* additional transformations on behalf of a configuration when a property value
* is escaped.
*
*
* Some {@code Configuration} implementations require a special encoding of
* their property values before they get written on disk. In some
* constellations, e.g. when a property with multiple values is to be forced on
* a single line, this encoding has to be done together with the escaping of
* list delimiter characters - which is in the responsibility of
* {@link ListDelimiterHandler}.
*
*
* In order to allow a proper collaboration between the parties involved, this
* interface was introduced. A configuration object provides an implementation
* of {@code ValueTransformer} and passes it to the {@code ListDelimiterHandler}
* when escaping of properties is needed. The delimiter handler can then call
* back to perform the additional encoding as its pleasure.
*
*
* @version $Id: ValueTransformer.java 1624601 2014-09-12 18:04:36Z oheger $
* @since 2.0
*/
public interface ValueTransformer
{
/**
* Performs an arbitrary encoding of the passed in value object. This method
* is called by a {@link ListDelimiterHandler} implementation before or
* after list delimiters have been escaped.
*
* @param value the property value to be transformed
* @return the transformed property value
*/
Object transformValue(Object value);
}