001    package org.apache.commons.digester3.plugins;
002    
003    /*
004     * Licensed to the Apache Software Foundation (ASF) under one
005     * or more contributor license agreements.  See the NOTICE file
006     * distributed with this work for additional information
007     * regarding copyright ownership.  The ASF licenses this file
008     * to you under the Apache License, Version 2.0 (the
009     * "License"); you may not use this file except in compliance
010     * with the License.  You may obtain a copy of the License at
011     *
012     *   http://www.apache.org/licenses/LICENSE-2.0
013     *
014     * Unless required by applicable law or agreed to in writing,
015     * software distributed under the License is distributed on an
016     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
017     * KIND, either express or implied.  See the License for the
018     * specific language governing permissions and limitations
019     * under the License.
020     */
021    
022    import org.apache.commons.digester3.Digester;
023    
024    /**
025     * Interface for classes which can dynamically load custom plugin rules associated with a user's plugin class.
026     * <p>
027     * Each plugin declaration has an associated RuleLoader instance, and that instance's addRules method is invoked each
028     * time the input xml specifies that an instance of that plugged-in class is to be created.
029     * <p>
030     * This is an abstract class rather than an interface in order to make it possible to enhance this class in future
031     * without breaking binary compatibility; it is possible to add methods to an abstract class, but not to an interface.
032     * 
033     * @since 1.6
034     */
035    public abstract class RuleLoader
036    {
037    
038        /**
039         * Configures the digester with custom rules for some plugged-in class.
040         * <p>
041         * This method is invoked when the start of an xml tag is encountered which maps to a PluginCreateRule. Any rules
042         * added here are removed from the digester when the end of that xml tag is encountered.
043         *
044         * @param d The gigester has to be configured
045         * @param path The path where rule has to be bound
046         * @throws PluginException if any error occurs
047         */
048        public abstract void addRules( Digester d, String path )
049            throws PluginException;
050    
051    }