    001    /* $Id: RuleLoader.java 471661 2006-11-06 08:09:25Z skitching $
    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    package org.apache.commons.digester.plugins;
    020
    021    import org.apache.commons.digester.Digester;
    022
    023    /**
    024     * Interface for classes which can dynamically load custom
    025     * plugin rules associated with a user's plugin class.
    026     * <p>
    027     * Each plugin declaration has an associated RuleLoader instance, and that
    028     * instance's addRules method is invoked each time the input xml specifies
    029     * that an instance of that plugged-in class is to be created.
    030     * <p>
    031     * This is an abstract class rather than an interface in order to make
    032     * it possible to enhance this class in future without breaking binary
    033     * compatibility; it is possible to add methods to an abstract class, but
    034     * not to an interface.
    035     *
    036     * @since 1.6
    037     */
    038
    039    public abstract class RuleLoader {
    040
    041        /**
    042         * Configures the digester with custom rules for some plugged-in
    043         * class.
    044         * <p>
    045         * This method is invoked when the start of an xml tag is encountered
    046         * which maps to a PluginCreateRule. Any rules added here are removed
    047         * from the digester when the end of that xml tag is encountered.
    048         */
    049        public abstract void addRules(Digester d, String path) throws PluginException;
    050    }