001    // Copyright 2004, 2005 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    //     http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry.contrib.table.model;
016    
017    /**
018     * An interface for converting an object to its primary key and back. 
019     * Typically used to determine how to store a given object as a hidden 
020     * value when rendering a form.
021     * 
022     * @author mb
023     * @since 3.0
024     */
025    public interface IPrimaryKeyConvertor
026    {
027        /**
028         * Gets the serializable primary key of the given value.
029         * 
030         * @param objValue the value for which a primary key needs to be extracted
031         * @return the serializable primary key of the value
032         */
033        Object getPrimaryKey(Object objValue);
034        
035        /**
036         * Gets the value corresponding the given primary key .
037         *  
038         * @param objPrimaryKey the primary key for which a value needs to be generated
039         * @return the generated value corresponding to the given primary key
040         */
041        Object getValue(Object objPrimaryKey); 
042    }