001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *     https://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package org.apache.commons.configuration2;
019
020/**
021 * <p>
022 * A specialized SAX2 XML parser that processes configuration objects.
023 * </p>
024 *
025 * <p>
026 * This class mimics to be a SAX compliant XML parser. It is able to iterate over the keys in a configuration object and
027 * to generate corresponding SAX events. By registering a {@code ContentHandler} at an instance it is possible to
028 * perform XML processing on a configuration object.
029 * </p>
030 */
031public class BaseConfigurationXMLReader extends ConfigurationXMLReader {
032
033    /**
034     * An internally used helper class to iterate over all configuration keys ant to generate corresponding SAX events.
035     */
036    final class SAXConverter extends HierarchicalConfigurationConverter {
037
038        /**
039         * Callback for the end of an element.
040         *
041         * @param name the element name
042         */
043        @Override
044        protected void elementEnd(final String name) {
045            fireElementEnd(name);
046        }
047
048        /**
049         * Callback for the start of an element.
050         *
051         * @param name the element name
052         * @param value the element value
053         */
054        @Override
055        protected void elementStart(final String name, final Object value) {
056            fireElementStart(name, null);
057            if (value != null) {
058                fireCharacters(value.toString());
059            }
060        }
061    }
062
063    /** Stores the actual configuration. */
064    private Configuration config;
065
066    /**
067     * Creates a new instance of {@code BaseConfigurationXMLReader}.
068     */
069    public BaseConfigurationXMLReader() {
070    }
071
072    /**
073     * Creates a new instance of {@code BaseConfigurationXMLReader} and sets the configuration object to be parsed.
074     *
075     * @param conf the configuration to be parsed
076     */
077    public BaseConfigurationXMLReader(final Configuration conf) {
078        this();
079        setConfiguration(conf);
080    }
081
082    /**
083     * Gets the actual configuration to be processed.
084     *
085     * @return the actual configuration
086     */
087    public Configuration getConfiguration() {
088        return config;
089    }
090
091    /**
092     * Gets the configuration to be processed.
093     *
094     * @return the actual configuration
095     */
096    @Override
097    public Configuration getParsedConfiguration() {
098        return getConfiguration();
099    }
100
101    /**
102     * The main SAX event generation method. This element uses an internal {@code HierarchicalConfigurationConverter} object
103     * to iterate over all keys in the actual configuration and to generate corresponding SAX events.
104     */
105    @Override
106    protected void processKeys() {
107        fireElementStart(getRootName(), null);
108        new SAXConverter().process(getConfiguration());
109        fireElementEnd(getRootName());
110    }
111
112    /**
113     * Sets the configuration to be processed.
114     *
115     * @param conf the configuration
116     */
117    public void setConfiguration(final Configuration conf) {
118        config = conf;
119    }
120}