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