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 *     http://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 *
031 */
032public class BaseConfigurationXMLReader extends ConfigurationXMLReader {
033    /** Stores the actual configuration. */
034    private Configuration config;
035
036    /**
037     * Creates a new instance of {@code BaseConfigurationXMLReader}.
038     */
039    public BaseConfigurationXMLReader() {
040    }
041
042    /**
043     * Creates a new instance of {@code BaseConfigurationXMLReader} and sets the configuration object to be parsed.
044     *
045     * @param conf the configuration to be parsed
046     */
047    public BaseConfigurationXMLReader(final Configuration conf) {
048        this();
049        setConfiguration(conf);
050    }
051
052    /**
053     * Returns the actual configuration to be processed.
054     *
055     * @return the actual configuration
056     */
057    public Configuration getConfiguration() {
058        return config;
059    }
060
061    /**
062     * Sets the configuration to be processed.
063     *
064     * @param conf the configuration
065     */
066    public void setConfiguration(final Configuration conf) {
067        config = conf;
068    }
069
070    /**
071     * Returns the configuration to be processed.
072     *
073     * @return the actual configuration
074     */
075    @Override
076    public Configuration getParsedConfiguration() {
077        return getConfiguration();
078    }
079
080    /**
081     * The main SAX event generation method. This element uses an internal {@code HierarchicalConfigurationConverter} object
082     * to iterate over all keys in the actual configuration and to generate corresponding SAX events.
083     */
084    @Override
085    protected void processKeys() {
086        fireElementStart(getRootName(), null);
087        new SAXConverter().process(getConfiguration());
088        fireElementEnd(getRootName());
089    }
090
091    /**
092     * An internally used helper class to iterate over all configuration keys ant to generate corresponding SAX events.
093     *
094     */
095    class SAXConverter extends HierarchicalConfigurationConverter {
096        /**
097         * Callback for the start of an element.
098         *
099         * @param name the element name
100         * @param value the element value
101         */
102        @Override
103        protected void elementStart(final String name, final Object value) {
104            fireElementStart(name, null);
105            if (value != null) {
106                fireCharacters(value.toString());
107            }
108        }
109
110        /**
111         * Callback for the end of an element.
112         *
113         * @param name the element name
114         */
115        @Override
116        protected void elementEnd(final String name) {
117            fireElementEnd(name);
118        }
119    }
120}