/*******************************************************************************
 * Copyright (c) 2005, 2009 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.equinox.metatype;

import java.io.*;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.net.URL;
import java.util.*;
import javax.xml.parsers.*;
import org.eclipse.osgi.util.NLS;
import org.osgi.framework.Bundle;
import org.osgi.service.metatype.AttributeDefinition;
import org.xml.sax.*;
import org.xml.sax.helpers.DefaultHandler;

/**
 * Meta XML Data Parser
 */
public class DataParser {
	private static final String METADATA = "MetaData"; //$NON-NLS-1$
	private static final String LOCALIZATION = "localization"; //$NON-NLS-1$
	private static final String OCD = "OCD"; //$NON-NLS-1$
	private static final String ICON = "Icon"; //$NON-NLS-1$
	private static final String AD = "AD"; //$NON-NLS-1$
	private static final String CARDINALITY = "cardinality"; //$NON-NLS-1$
	private static final String OPTION = "Option"; //$NON-NLS-1$
	private static final String LABEL = "label"; //$NON-NLS-1$
	private static final String VALUE = "value"; //$NON-NLS-1$
	private static final String MIN = "min"; //$NON-NLS-1$
	private static final String MAX = "max"; //$NON-NLS-1$
	private static final String TYPE = "type"; //$NON-NLS-1$
	private static final String SIZE = "size"; //$NON-NLS-1$
	private static final String ID = "id"; //$NON-NLS-1$
	private static final String NAME = "name"; //$NON-NLS-1$
	private static final String DESCRIPTION = "description"; //$NON-NLS-1$
	private static final String RESOURCE = "resource"; //$NON-NLS-1$
	private static final String PID = "pid"; //$NON-NLS-1$
	private static final String DEFAULT = "default"; //$NON-NLS-1$
	private static final String ADREF = "adref"; //$NON-NLS-1$
	private static final String CONTENT = "content"; //$NON-NLS-1$
	private static final String FACTORY = "factoryPid"; //$NON-NLS-1$
	private static final String BUNDLE = "bundle"; //$NON-NLS-1$
	private static final String OPTIONAL = "optional"; //$NON-NLS-1$
	private static final String OBJECT = "Object"; //$NON-NLS-1$
	private static final String OCDREF = "ocdref"; //$NON-NLS-1$
	private static final String ATTRIBUTE = "Attribute"; //$NON-NLS-1$
	private static final String DESIGNATE = "Designate"; //$NON-NLS-1$
	private static final String MERGE = "merge"; //$NON-NLS-1$
	private static final String REQUIRED = "required"; //$NON-NLS-1$

	private static final String INTEGER = "Integer"; //$NON-NLS-1$
	private static final String STRING = "String"; //$NON-NLS-1$
	private static final String FLOAT = "Float"; //$NON-NLS-1$
	private static final String DOUBLE = "Double"; //$NON-NLS-1$
	private static final String BYTE = "Byte"; //$NON-NLS-1$
	private static final String LONG = "Long"; //$NON-NLS-1$
	private static final String CHAR = "Char"; //$NON-NLS-1$
	private static final String BOOLEAN = "Boolean"; //$NON-NLS-1$
	private static final String SHORT = "Short"; //$NON-NLS-1$

	protected Bundle _dp_bundle;
	protected URL _dp_url;
	protected SAXParserFactory _dp_parserFactory;
	protected XMLReader _dp_xmlReader;

	// DesignateHanders in DataParser class
	Vector _dp_designateHandlers = new Vector(7);
	// ObjectClassDefinitions in DataParser class w/ corresponding reference keys
	Hashtable _dp_OCDs = new Hashtable(7);
	// pid to ObjectClassDefinitions in DataParser class as a Hashtable
	Hashtable _dp_pid_to_OCDs_ = new Hashtable(7);
	// Localization in DataParser class
	String _dp_localization;

	/*
	 * Constructor of class DataParser.
	 */
	public DataParser(Bundle bundle, URL url, SAXParserFactory parserFactory) {

		this._dp_bundle = bundle;
		this._dp_url = url;
		this._dp_parserFactory = parserFactory;
		parserFactory.setValidating(false);
	}

	/*
	 * Main method to parse specific MetaData file.
	 */
	public Hashtable doParse() {

		try {
			SAXParser saxParser = _dp_parserFactory.newSAXParser();
			_dp_xmlReader = saxParser.getXMLReader();
			_dp_xmlReader.setContentHandler(new RootHandler());
			_dp_xmlReader.setErrorHandler(new MyErrorHandler(System.err));
			InputStream is = _dp_url.openStream();
			InputSource isource = new InputSource(is);
			Logging.log(Logging.DEBUG, "Starting to parse " + _dp_url); //$NON-NLS-1$					
			_dp_xmlReader.parse(isource);
		} catch (ParserConfigurationException pce) {
			pce.printStackTrace();
			return null;
		} catch (SAXException saxe) {
			saxe.printStackTrace();
			return null;
		} catch (IOException ioe) {
			ioe.printStackTrace();
			return null;
		}
		return _dp_pid_to_OCDs_;
	}

	/*
	 * Convert String for expected data type.
	 */
	static Object convert(String value, int type) {

		if (value == null) {
			return null;
		}

		switch (type) {
			case AttributeDefinition.STRING :
				// Both the min and max of STRING are Integers.
				return new Integer(value);
			case AttributeDefinition.LONG :
				return new Long(value);
			case AttributeDefinition.INTEGER :
				return new Integer(value);
			case AttributeDefinition.SHORT :
				return new Short(value);
			case AttributeDefinition.CHARACTER :
				return new Character(value.charAt(0));
			case AttributeDefinition.BYTE :
				return new Byte(value);
			case AttributeDefinition.DOUBLE :
				return new Double(value);
			case AttributeDefinition.FLOAT :
				return new Float(value);
			case AttributeDefinition.BIGINTEGER :
				try {
					Class bigIntClazz = Class.forName("java.math.BigInteger");//$NON-NLS-1$
					Constructor bigIntConstructor = bigIntClazz.getConstructor(new Class[] {String.class});
					return bigIntConstructor.newInstance(new Object[] {value});
				} catch (ClassNotFoundException e) {
					e.printStackTrace();
					return null;
				} catch (SecurityException e) {
					e.printStackTrace();
					return null;
				} catch (NoSuchMethodException e) {
					e.printStackTrace();
					return null;
				} catch (IllegalArgumentException e) {
					e.printStackTrace();
					return null;
				} catch (InstantiationException e) {
					e.printStackTrace();
					return null;
				} catch (IllegalAccessException e) {
					e.printStackTrace();
					return null;
				} catch (InvocationTargetException e) {
					e.printStackTrace();
					return null;
				}
			case AttributeDefinition.BIGDECIMAL :
				try {
					Class bigDecimalClazz = Class.forName("java.math.BigDecimal");//$NON-NLS-1$
					Constructor bigDecimalConstructor = bigDecimalClazz.getConstructor(new Class[] {String.class});
					return bigDecimalConstructor.newInstance(new Object[] {value});
				} catch (ClassNotFoundException e) {
					e.printStackTrace();
					return null;
				} catch (SecurityException e) {
					e.printStackTrace();
					return null;
				} catch (NoSuchMethodException e) {
					e.printStackTrace();
					return null;
				} catch (IllegalArgumentException e) {
					e.printStackTrace();
					return null;
				} catch (InstantiationException e) {
					e.printStackTrace();
					return null;
				} catch (IllegalAccessException e) {
					e.printStackTrace();
					return null;
				} catch (InvocationTargetException e) {
					e.printStackTrace();
					return null;
				}
			case AttributeDefinition.BOOLEAN :
				return new Boolean(value);
			default :
				// Unknown data type
				return null;
		}
	}

	/**
	 * Abstract of all Handlers.
	 */
	private class AbstractHandler extends DefaultHandler {

		protected ContentHandler _doc_handler;
		protected boolean _isParsedDataValid = true;

		public AbstractHandler(ContentHandler parentHandler) {

			this._doc_handler = parentHandler;
			_dp_xmlReader.setContentHandler(this);
		}

		public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {

			throw new SAXException(NLS.bind(MetaTypeMsg.UNEXPECTED_ELEMENT, qName));
		}

		public void characters(char[] buf, int start, int end) throws SAXException {

			String s = new String(buf, start, end).trim();
			if (s.length() > 0) {
				throw new SAXException(NLS.bind(MetaTypeMsg.UNEXPECTED_TEXT, s));
			}
		}

		/**
		 * Called when this element and all elements nested into it have been
		 * handled.
		 */
		protected void finished() throws SAXException {
			// do nothing by default
		}

		public void endElement(String namespaceURI, String localName, String qName) throws SAXException {

			finished();
			// Let parent resume handling SAX events
			_dp_xmlReader.setContentHandler(_doc_handler);
		}
	}

	/**
	 * Handler for the root element.
	 */
	private class RootHandler extends DefaultHandler {

		public RootHandler() {
			super();
		}

		public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {

			Logging.log(Logging.TRACE, "Here is AbstractHandler:startElement():" //$NON-NLS-1$
					+ qName);
			String name = getName(localName, qName);
			if (name.equalsIgnoreCase(METADATA)) {
				new MetaDataHandler(this).init(name, attributes);
			} else {
				Logging.log(Logging.WARN, NLS.bind(MetaTypeMsg.UNEXPECTED_ELEMENT, name));
			}
		}

		public void setDocumentLocator(Locator locator) {
			// do nothing
		}
	}

	/**
	 * Handler for the MetaData element.
	 */
	private class MetaDataHandler extends AbstractHandler {

		public MetaDataHandler(ContentHandler handler) {
			super(handler);
		}

		public void init(String name, Attributes attributes) throws SAXException {

			Logging.log(Logging.TRACE, "Here is MetaDataHandler():init()"); //$NON-NLS-1$
			_dp_localization = attributes.getValue(LOCALIZATION);
			if (_dp_localization == null) {
				// Not a problem, because LOCALIZATION is an optional attribute.
			}
			// The global variable "_dp_localization" will be used within
			// OcdHandler and AttributeDefinitionHandler later.
		}

		public void startElement(String uri, String localName, String qName, Attributes atts) throws SAXException {

			Logging.log(Logging.TRACE, "Here is MetaDataHandler:startElement():" //$NON-NLS-1$
					+ qName);
			String name = getName(localName, qName);
			if (name.equalsIgnoreCase(DESIGNATE)) {
				DesignateHandler designateHandler = new DesignateHandler(this);
				designateHandler.init(name, atts);
				if (designateHandler._isParsedDataValid) {
					_dp_designateHandlers.addElement(designateHandler);
				}
			} else if (name.equalsIgnoreCase(OCD)) {
				OcdHandler ocdHandler = new OcdHandler(this);
				ocdHandler.init(name, atts, _dp_OCDs);
			} else {
				Logging.log(Logging.WARN, NLS.bind(MetaTypeMsg.UNEXPECTED_ELEMENT, name));
			}
		}

		protected void finished() throws SAXException {

			Logging.log(Logging.TRACE, "Here is MetaDataHandler():finished()"); //$NON-NLS-1$
			if (_dp_designateHandlers.size() == 0) {
				// Schema defines at least one DESIGNATE is required.
				_isParsedDataValid = false;
				Logging.log(Logging.ERROR, this, "finished()", //$NON-NLS-1$
						NLS.bind(MetaTypeMsg.MISSING_ELEMENT, DESIGNATE));
				return;
			}
			Enumeration designateHandlerKeys = _dp_designateHandlers.elements();
			while (designateHandlerKeys.hasMoreElements()) {
				DesignateHandler designateHandler = (DesignateHandler) designateHandlerKeys.nextElement();

				ObjectClassDefinitionImpl ocd = (ObjectClassDefinitionImpl) _dp_OCDs.get(designateHandler._ocdref);
				if (ocd != null) {
					if (designateHandler._factory_val == null) {
						ocd.setType(ObjectClassDefinitionImpl.PID);
						_dp_pid_to_OCDs_.put(designateHandler._pid_val, ocd);
					} else {
						ocd.setType(ObjectClassDefinitionImpl.FPID);
						_dp_pid_to_OCDs_.put(designateHandler._factory_val, ocd);
					}
				} else {
					Logging.log(Logging.ERROR, this, "finished()", //$NON-NLS-1$
							NLS.bind(MetaTypeMsg.OCD_ID_NOT_FOUND, designateHandler._ocdref));
				}
			}
		}
	}

	/**
	 * Handler for the ObjectClassDefinition element.
	 */
	private class OcdHandler extends AbstractHandler {

		Hashtable _parent_OCDs_hashtable;
		// This ID "_refID" is only used for reference by Designate element,
		// not the PID or FPID of this OCD.
		String _refID;
		ObjectClassDefinitionImpl _ocd;
		Vector _ad_vector = new Vector(7);

		public OcdHandler(ContentHandler handler) {
			super(handler);
		}

		public void init(String name, Attributes atts, Hashtable ocds_hashtable) throws SAXException {

			Logging.log(Logging.TRACE, "Here is OcdHandler():init()"); //$NON-NLS-1$
			_parent_OCDs_hashtable = ocds_hashtable;

			String ocd_name_val = atts.getValue(NAME);
			if (ocd_name_val == null) {
				_isParsedDataValid = false;
				Logging.log(Logging.ERROR, this, "init(String, Attributes, Hashtable)", //$NON-NLS-1$
						NLS.bind(MetaTypeMsg.MISSING_ATTRIBUTE, NAME, name));
				return;
			}

			String ocd_description_val = atts.getValue(DESCRIPTION);
			if (ocd_description_val == null) {
				// Not a problem, because DESCRIPTION is an optional attribute.
			}

			_refID = atts.getValue(ID);
			if (_refID == null) {
				_isParsedDataValid = false;
				Logging.log(Logging.ERROR, this, "init(String, Attributes, Hashtable)", //$NON-NLS-1$
						NLS.bind(MetaTypeMsg.MISSING_ATTRIBUTE, ID, name));
				return;
			}

			_ocd = new ObjectClassDefinitionImpl(ocd_name_val, ocd_description_val, _refID, _dp_localization);
		}

		public void startElement(String uri, String localName, String qName, Attributes atts) throws SAXException {

			Logging.log(Logging.TRACE, "Here is OcdHandler:startElement():" //$NON-NLS-1$
					+ qName);
			if (!_isParsedDataValid)
				return;

			String name = getName(localName, qName);
			if (name.equalsIgnoreCase(AD)) {
				AttributeDefinitionHandler attributeDefHandler = new AttributeDefinitionHandler(this);
				attributeDefHandler.init(name, atts, _ad_vector);
			} else if (name.equalsIgnoreCase(ICON)) {
				IconHandler iconHandler = new IconHandler(this);
				iconHandler.init(name, atts);
				if (iconHandler._isParsedDataValid) {
					// Because XML schema allows at most one icon for
					// one OCD, if more than one icons are read from 
					// MetaData, then only the final icon will be kept.
					_ocd.setIcon(iconHandler._icon);
				}
			} else {
				Logging.log(Logging.WARN, NLS.bind(MetaTypeMsg.UNEXPECTED_ELEMENT, name));
			}
		}

		protected void finished() throws SAXException {

			Logging.log(Logging.TRACE, "Here is OcdHandler():finished()"); //$NON-NLS-1$
			if (!_isParsedDataValid)
				return;

			if (_ad_vector.size() == 0) {
				// Schema defines at least one AD is required.
				_isParsedDataValid = false;
				Logging.log(Logging.ERROR, this, "finished()", //$NON-NLS-1$
						NLS.bind(MetaTypeMsg.MISSING_ELEMENT, AD, _refID));
				return;
			}
			// OCD gets all parsed ADs.
			Enumeration adKey = _ad_vector.elements();
			while (adKey.hasMoreElements()) {
				AttributeDefinitionImpl ad = (AttributeDefinitionImpl) adKey.nextElement();
				_ocd.addAttributeDefinition(ad, ad._isRequired);
			}

			_parent_OCDs_hashtable.put(_refID, _ocd);
		}
	}

	/**
	 * Handler for the Icon element.
	 */
	private class IconHandler extends AbstractHandler {

		Icon _icon;

		public IconHandler(ContentHandler handler) {
			super(handler);
		}

		public void init(String name, Attributes atts) throws SAXException {

			Logging.log(Logging.TRACE, "Here is IconHandler:init()"); //$NON-NLS-1$
			String icon_resource_val = atts.getValue(RESOURCE);
			if (icon_resource_val == null) {
				_isParsedDataValid = false;
				Logging.log(Logging.ERROR, this, "init(String, Attributes)", //$NON-NLS-1$
						NLS.bind(MetaTypeMsg.MISSING_ATTRIBUTE, RESOURCE, name));
				return;
			}

			String icon_size_val = atts.getValue(SIZE);
			if (icon_size_val == null) {
				// Not a problem, because SIZE is an optional attribute.
				icon_size_val = "0"; //$NON-NLS-1$
			} else if (icon_size_val.equalsIgnoreCase("")) { //$NON-NLS-1$
				icon_size_val = "0"; //$NON-NLS-1$
			}

			_icon = new Icon(icon_resource_val, Integer.parseInt(icon_size_val), _dp_bundle);
		}
	}

	/**
	 * Handler for the Attribute element.
	 */
	private class AttributeDefinitionHandler extends AbstractHandler {

		AttributeDefinitionImpl _ad;
		int _dataType;

		Vector _parent_ADs_vector;
		Vector _optionLabel_vector = new Vector(7);
		Vector _optionValue_vector = new Vector(7);

		public AttributeDefinitionHandler(ContentHandler handler) {
			super(handler);
		}

		public void init(String name, Attributes atts, Vector ad_vector) throws SAXException {

			Logging.log(Logging.TRACE, "Here is AttributeDefinitionHandler():init()"); //$NON-NLS-1$
			_parent_ADs_vector = ad_vector;

			String ad_name_val = atts.getValue(NAME);
			if (ad_name_val == null) {
				// Not a problem, because NAME is an optional attribute.
			}

			String ad_description_val = atts.getValue(DESCRIPTION);
			if (ad_description_val == null) {
				// Not a problem, because DESCRIPTION is an optional attribute.
			}

			String ad_id_val = atts.getValue(ID);
			if (ad_id_val == null) {
				_isParsedDataValid = false;
				Logging.log(Logging.ERROR, this, "init(String, Attributes, Vector)", //$NON-NLS-1$
						NLS.bind(MetaTypeMsg.MISSING_ATTRIBUTE, ID, name));
				return;
			}

			String ad_type_val = atts.getValue(TYPE);
			if (ad_type_val.equalsIgnoreCase(STRING)) {
				_dataType = AttributeDefinition.STRING;
			} else if (ad_type_val.equalsIgnoreCase(LONG)) {
				_dataType = AttributeDefinition.LONG;
			} else if (ad_type_val.equalsIgnoreCase(DOUBLE)) {
				_dataType = AttributeDefinition.DOUBLE;
			} else if (ad_type_val.equalsIgnoreCase(FLOAT)) {
				_dataType = AttributeDefinition.FLOAT;
			} else if (ad_type_val.equalsIgnoreCase(INTEGER)) {
				_dataType = AttributeDefinition.INTEGER;
			} else if (ad_type_val.equalsIgnoreCase(BYTE)) {
				_dataType = AttributeDefinition.BYTE;
			} else if (ad_type_val.equalsIgnoreCase(CHAR)) {
				_dataType = AttributeDefinition.CHARACTER;
			} else if (ad_type_val.equalsIgnoreCase(BOOLEAN)) {
				_dataType = AttributeDefinition.BOOLEAN;
			} else if (ad_type_val.equalsIgnoreCase(SHORT)) {
				_dataType = AttributeDefinition.SHORT;
			} else {
				_isParsedDataValid = false;
				Logging.log(Logging.ERROR, this, "init(String, Attributes, Vector)", //$NON-NLS-1$
						NLS.bind(MetaTypeMsg.MISSING_ATTRIBUTE, TYPE, name));
				return;

			}

			String ad_cardinality_str = atts.getValue(CARDINALITY);
			int ad_cardinality_val = 0;
			if (ad_cardinality_str == null) {
				// Not a problem, because CARDINALITY is an optional attribute.
				// And the default value is 0.
			} else {
				ad_cardinality_val = Integer.parseInt(ad_cardinality_str);
			}

			String ad_min_val = atts.getValue(MIN);
			if (ad_min_val == null) {
				// Not a problem, because MIN is an optional attribute.
			}

			String ad_max_val = atts.getValue(MAX);
			if (ad_max_val == null) {
				// Not a problem, because MAX is an optional attribute.
			}

			String ad_defaults_str = atts.getValue(DEFAULT);
			if (ad_defaults_str == null) {
				// Not a problem, because DEFAULT is an optional attribute.
				if (ad_cardinality_val == 0) {
					// But when it is not assigned, CARDINALITY cannot be '0'.
					_isParsedDataValid = false;
					Logging.log(Logging.ERROR, this, "init(String, Attributes, Vector)", //$NON-NLS-1$
							MetaTypeMsg.NULL_DEFAULTS);
					return;
				}
			}

			String ad_required_val = atts.getValue(REQUIRED);
			if (ad_required_val == null) {
				// Not a problem, because REQUIRED is an optional attribute.
				// And the default value is 'true'.
				ad_required_val = Boolean.TRUE.toString();
			}

			_ad = new AttributeDefinitionImpl(ad_id_val, ad_name_val, ad_description_val, _dataType, ad_cardinality_val, convert(ad_min_val, _dataType), convert(ad_max_val, _dataType), Boolean.valueOf(ad_required_val).booleanValue(), _dp_localization);

			if (ad_cardinality_val == 0) {
				// Attribute DEFAULT has one and only one occurance.
				_ad.setDefaultValue(new String[] {ad_defaults_str}, false);
			} else {
				// Attribute DEFAULT is a comma delimited list.
				_ad.setDefaultValue(ad_defaults_str, false);
			}
		}

		public void startElement(String uri, String localName, String qName, Attributes atts) throws SAXException {

			Logging.log(Logging.TRACE, "Here is AttributeDefinitionHandler:startElement():" //$NON-NLS-1$
					+ qName);
			if (!_isParsedDataValid)
				return;

			String name = getName(localName, qName);
			if (name.equalsIgnoreCase(OPTION)) {
				OptionHandler optionHandler = new OptionHandler(this);
				optionHandler.init(name, atts);
				if (optionHandler._isParsedDataValid) {
					// Only add valid Option
					_optionLabel_vector.addElement(optionHandler._label_val);
					_optionValue_vector.addElement(optionHandler._value_val);
				}
			} else {
				Logging.log(Logging.WARN, NLS.bind(MetaTypeMsg.UNEXPECTED_ELEMENT, name));
			}
		}

		protected void finished() throws SAXException {

			Logging.log(Logging.TRACE, "Here is AttributeDefinitionHandler():finished()"); //$NON-NLS-1$
			if (!_isParsedDataValid)
				return;

			_ad.setOption(_optionLabel_vector, _optionValue_vector, true);
			_parent_ADs_vector.addElement(_ad);
		}
	}

	/**
	 * Handler for the Option element.
	 */
	private class OptionHandler extends AbstractHandler {

		String _label_val;
		String _value_val;

		public OptionHandler(ContentHandler handler) {
			super(handler);
		}

		public void init(String name, Attributes atts) throws SAXException {

			Logging.log(Logging.TRACE, "Here is OptionHandler:init()"); //$NON-NLS-1$
			_label_val = atts.getValue(LABEL);
			if (_label_val == null) {
				_isParsedDataValid = false;
				Logging.log(Logging.ERROR, this, "init(String, Attributes)", //$NON-NLS-1$
						NLS.bind(MetaTypeMsg.MISSING_ATTRIBUTE, LABEL, name));
				return;
			}

			_value_val = atts.getValue(VALUE);
			if (_value_val == null) {
				_isParsedDataValid = false;
				Logging.log(Logging.ERROR, this, "init(String, Attributes)", //$NON-NLS-1$
						NLS.bind(MetaTypeMsg.MISSING_ATTRIBUTE, VALUE, name));
				return;
			}
		}
	}

	//	/**
	//	 * Handler for the Simple Value element.
	//	 */
	//	private class SimpleValueHandler extends AbstractHandler {
	//
	//		StringBuffer	_buffer	= new StringBuffer();
	//		Vector			_parent_value_vector;
	//		String			_elementName;
	//
	//		public SimpleValueHandler(ContentHandler handler) {
	//			super(handler);
	//		}
	//
	//		public void init(String name, Attributes atts, Vector value_vector)
	//				throws SAXException {
	//
	//			Logging.log(Logging.TRACE,
	//					"Here is SimpleValueHandler():init()"); //$NON-NLS-1$
	//			_elementName = name;
	//			_parent_value_vector = value_vector;
	//		}
	//
	//		protected void finished() throws SAXException {
	//
	//			Logging.log(Logging.TRACE,
	//					"Here is SimpleValueHandler():finished()"); //$NON-NLS-1$
	//			if (_parent_value_vector != null) {
	//				_parent_value_vector.addElement(_buffer.toString());
	//			}
	//		}
	//
	//		public void characters(char buf[], int offset, int len)
	//				throws SAXException {
	//
	//			Logging.log(Logging.TRACE,
	//					"Here is SimpleValueHandler(" //$NON-NLS-1$
	//					+ _elementName
	//					+ "):characters():[" //$NON-NLS-1$
	//					+ new String(buf, offset, len)
	//					+ "]"); //$NON-NLS-1$
	//			_buffer.append(new String(buf, offset, len));
	//		}
	//	}

	/**
	 * Handler for the Designate element.
	 */
	class DesignateHandler extends AbstractHandler {

		String _pid_val = null;
		String _factory_val = null;
		String _bundle_val = null; // Only used by RFC94
		boolean _optional_val = false; // Only used by RFC94
		boolean _merge_val = false; // Only used by RFC94

		// Referenced OCD ID
		String _ocdref;

		public DesignateHandler(ContentHandler handler) {
			super(handler);
		}

		public void init(String name, Attributes atts) throws SAXException {

			Logging.log(Logging.TRACE, "Here is DesignateHandler():init()"); //$NON-NLS-1$
			_pid_val = atts.getValue(PID);
			if (_pid_val == null) {
				_isParsedDataValid = false;
				Logging.log(Logging.ERROR, this, "init(String, Attributes)", //$NON-NLS-1$
						NLS.bind(MetaTypeMsg.MISSING_ATTRIBUTE, PID, name));
				return;
			}
			_factory_val = atts.getValue(FACTORY);

			_bundle_val = atts.getValue(BUNDLE);
			if (_bundle_val == null) {
				// Not a problem because BUNDLE is an optional attribute.
			}

			String optional_str = atts.getValue(OPTIONAL);
			if (optional_str == null) {
				// Not a problem, because OPTIONAL is an optional attribute.
				// The default value is "false".
				_optional_val = false;
			} else {
				_optional_val = Boolean.valueOf(optional_str).booleanValue();
			}

			String merge_str = atts.getValue(MERGE);
			if (merge_str == null) {
				// Not a problem, because MERGE is an optional attribute.
				// The default value is "false".
				_merge_val = false;
			} else {
				_merge_val = Boolean.valueOf(merge_str).booleanValue();
			}
		}

		public void startElement(String uri, String localName, String qName, Attributes atts) throws SAXException {

			Logging.log(Logging.TRACE, "Here is DesignateHandler:startElement():" //$NON-NLS-1$
					+ qName);
			if (!_isParsedDataValid)
				return;

			String name = getName(localName, qName);
			if (name.equalsIgnoreCase(OBJECT)) {
				ObjectHandler objectHandler = new ObjectHandler(this);
				objectHandler.init(name, atts);
				if (objectHandler._isParsedDataValid) {
					_ocdref = objectHandler._ocdref;
				}
			} else {
				Logging.log(Logging.WARN, NLS.bind(MetaTypeMsg.UNEXPECTED_ELEMENT, name));
			}
		}

		protected void finished() throws SAXException {

			Logging.log(Logging.TRACE, "Here is DesignateHandler():finished()"); //$NON-NLS-1$
			if (!_isParsedDataValid)
				return;

			if (_ocdref == null) {
				_isParsedDataValid = false;
				// Schema defines at least one OBJECT is required.
				Logging.log(Logging.ERROR, this, "finished()", //$NON-NLS-1$
						NLS.bind(MetaTypeMsg.MISSING_ELEMENT, OBJECT, _pid_val));
				return;

			}
		}
	}

	/**
	 * Handler for the Object element.
	 */
	private class ObjectHandler extends AbstractHandler {

		String _ocdref;

		public ObjectHandler(ContentHandler handler) {
			super(handler);
		}

		public void init(String name, Attributes atts) throws SAXException {

			Logging.log(Logging.TRACE, "Here is ObjectHandler():init()"); //$NON-NLS-1$
			_ocdref = atts.getValue(OCDREF);
			if (_ocdref == null) {
				_isParsedDataValid = false;
				Logging.log(Logging.ERROR, this, "init(String, Attributes)", //$NON-NLS-1$
						NLS.bind(MetaTypeMsg.MISSING_ATTRIBUTE, OCDREF, name));
				return;
			}
		}

		public void startElement(String uri, String localName, String qName, Attributes atts) throws SAXException {

			Logging.log(Logging.TRACE, "Here is ObjectHandler:startElement():" //$NON-NLS-1$
					+ qName);
			if (!_isParsedDataValid)
				return;

			String name = getName(localName, qName);
			if (name.equalsIgnoreCase(ATTRIBUTE)) {
				AttributeHandler attributeHandler = new AttributeHandler(this);
				attributeHandler.init(name, atts);
				// The ATTRIBUTE element is only used by RFC94, do nothing for it here.
			} else {
				Logging.log(Logging.WARN, NLS.bind(MetaTypeMsg.UNEXPECTED_ELEMENT, name));
			}
		}
	}

	/**
	 * Handler for the Attribute element.
	 * 
	 * This Handler is only used by RFC94.
	 */
	private class AttributeHandler extends AbstractHandler {

		String _adref_val;
		String _content_val;

		public AttributeHandler(ContentHandler handler) {
			super(handler);
		}

		public void init(String name, Attributes atts) throws SAXException {

			Logging.log(Logging.TRACE, "Here is AttributeHandler():init()"); //$NON-NLS-1$
			_adref_val = atts.getValue(ADREF);
			if (_adref_val == null) {
				_isParsedDataValid = false;
				Logging.log(Logging.ERROR, this, "init(String, Attributes)", //$NON-NLS-1$
						NLS.bind(MetaTypeMsg.MISSING_ATTRIBUTE, ADREF, name));
				return;
			}

			_content_val = atts.getValue(CONTENT);
			if (_content_val == null) {
				_isParsedDataValid = false;
				Logging.log(Logging.ERROR, this, "init(String, Attributes)", //$NON-NLS-1$
						NLS.bind(MetaTypeMsg.MISSING_ATTRIBUTE, CONTENT, name));
				return;
			}
		}
	}

	/**
	 * Error Handler to report errors and warnings
	 */
	private static class MyErrorHandler implements ErrorHandler {

		/** Error handler output goes here */
		private PrintStream _out;

		MyErrorHandler(PrintStream out) {
			this._out = out;
		}

		/**
		 * Returns a string describing parse exception details
		 */
		private String getParseExceptionInfo(SAXParseException spe) {
			String systemId = spe.getSystemId();
			if (systemId == null) {
				systemId = "null"; //$NON-NLS-1$
			}
			String info = "URI=" + systemId + //$NON-NLS-1$
					" Line=" + spe.getLineNumber() + //$NON-NLS-1$
					": " + spe.getMessage(); //$NON-NLS-1$

			return info;
		}

		// The following methods are standard SAX ErrorHandler methods.
		// See SAX documentation for more info.

		public void warning(SAXParseException spe) throws SAXException {
			_out.println("Warning: " + getParseExceptionInfo(spe)); //$NON-NLS-1$
		}

		public void error(SAXParseException spe) throws SAXException {
			String message = "Error: " + getParseExceptionInfo(spe); //$NON-NLS-1$
			throw new SAXException(message);
		}

		public void fatalError(SAXParseException spe) throws SAXException {
			String message = "Fatal Error: " + getParseExceptionInfo(spe); //$NON-NLS-1$
			throw new SAXException(message);
		}
	}

	public static String getName(String localName, String qName) {
		if (localName != null && localName.length() > 0) {
			return localName;
		}

		int nameSpaceIndex = qName.indexOf(":"); //$NON-NLS-1$
		return nameSpaceIndex == -1 ? qName : qName.substring(nameSpaceIndex + 1);
	}
}