XMLMapId.java

/*
 * (c) Copyright 2010-2011 AgileBirds
 *
 * This file is part of OpenFlexo.
 *
 * OpenFlexo is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * OpenFlexo is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with OpenFlexo. If not, see <http://www.gnu.org/licenses/>.
 *
 */

package org.openflexo.xmlcode;

import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Vector;

import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class XMLMapId {

	private Vector _mapEntryList;
	private String _description;

	public XMLMapId(Node mapIdNode, XMLMapping anXMLMapping) throws InvalidModelException {

		super();

		Node tempAttribute;
		NamedNodeMap attributes;

		NodeList propertiesNodeList;
		Node tempNode;

		if (!mapIdNode.getNodeName().equals(XMLMapping.mapIdLabel)) {
			throw new InvalidModelException("Invalid tag '" + mapIdNode.getNodeName() + "' found in model file");
		}

		attributes = mapIdNode.getAttributes();
		for (int i = 0; i < attributes.getLength(); i++) {
			tempAttribute = attributes.item(i);
			/*if (tempAttribute.getNodeName().equals(XMLMapping.nameLabel)) {
			    nameIsSpecified = true;
			    name = tempAttribute.getNodeValue();
			} else {
			    throw new InvalidModelException("Invalid attribute '" + tempAttribute.getNodeName() + "' found in model file for tag 'entity'");
			}*/
		}

		_mapEntryList = new Vector();

		propertiesNodeList = mapIdNode.getChildNodes();
		for (int i = 0; i < propertiesNodeList.getLength(); i++) {
			tempNode = propertiesNodeList.item(i);
			if (tempNode.getNodeType() == Node.ELEMENT_NODE) {
				if (tempNode.getNodeName().equals(XMLMapping.descriptionLabel)) {
					if (tempNode.getChildNodes().getLength() == 1 && tempNode.getFirstChild().getNodeType() == Node.TEXT_NODE) {
						setDescription(tempNode.getFirstChild().getNodeValue());
						// System.out.println("Description = "+getDescription());
					}
				} else if (tempNode.getNodeName().equals(XMLMapping.mapLabel)) {
					MapEntry newMapEntry = new MapEntry(tempNode);
					_mapEntryList.add(newMapEntry);
					// System.out.println("Register map entry "+newMapEntry.getEntityClass()+" and "+newMapEntry.getKeyValueProperty().getName());
				} else {
					throw new InvalidModelException("Invalid tag '" + tempNode.getNodeName() + "' found in model file for tag 'entity'");
				}
			} else if (tempNode.getNodeType() == Node.TEXT_NODE) {
				// Non significative text will be simply ignored
				if (tempNode.getNodeValue().trim().length() > 0) {
					throw new InvalidModelException("Invalid text found in model file");
				}
			} else if (tempNode.getNodeType() == Node.ATTRIBUTE_NODE) {
				// Simply ignore it
			} else if (tempNode.getNodeType() == Node.COMMENT_NODE) {
				// Simply ignore it
			} else {
				throw new InvalidModelException("Invalid xml tag found as child of 'mapId' tag in model file");
			}
		}

		if (_mapEntryList.size() == 0) {
			throw new InvalidModelException("No identifier mapping defined");
		}

	}

	public String getDescription() {
		return _description;
	}

	public void setDescription(String description) {
		_description = description;
	}

	public class MapEntry {
		private Class entityClass;
		private SingleKeyValueProperty keyValueProperty;
		private String entityClassName;
		private String identifierAccessorName;

		public MapEntry(Node mapEntryNode) throws InvalidModelException {

			super();

			Node tempAttribute;
			NamedNodeMap attributes;

			if (!mapEntryNode.getNodeName().equals(XMLMapping.mapLabel)) {
				throw new InvalidModelException("Invalid tag '" + mapEntryNode.getNodeName() + "' found in model file");
			}

			attributes = mapEntryNode.getAttributes();
			for (int i = 0; i < attributes.getLength(); i++) {
				tempAttribute = attributes.item(i);
				if (tempAttribute.getNodeName().equals(XMLMapping.entityClassLabel)) {
					entityClassName = tempAttribute.getNodeValue();
				} else if (tempAttribute.getNodeName().equals(XMLMapping.identifierAccessorLabel)) {
					identifierAccessorName = tempAttribute.getNodeValue();
				} else {
					throw new InvalidModelException("Invalid attribute '" + tempAttribute.getNodeName()
							+ "' found in model file for tag 'entity'");
				}
			}

			try {
				entityClass = Class.forName(entityClassName);
			} catch (ClassNotFoundException e) {
				throw new InvalidModelException("Class " + entityClassName + " not found.");
			}

			keyValueProperty = new SingleKeyValueProperty(entityClass, identifierAccessorName, false);

		}

		public Class getEntityClass() {
			return entityClass;
		}

		public SingleKeyValueProperty getKeyValueProperty() {
			return keyValueProperty;
		}

	}

	private Hashtable mapEntriesForClass = new Hashtable();

	private MapEntry mapEntryForClass(Class aClass) throws NoMapIdEntryException {
		MapEntry returned = (MapEntry) mapEntriesForClass.get(aClass);
		if (returned == null) {
			for (Enumeration en = _mapEntryList.elements(); en.hasMoreElements();) {
				MapEntry next = (MapEntry) en.nextElement();
				if (next.getEntityClass().isAssignableFrom(aClass)) {
					// May match
					if (returned == null || returned.getEntityClass().isAssignableFrom(next.getEntityClass())) {
						returned = next;
					}
				}
			}
			if (returned == null) {
				throw new NoMapIdEntryException("Could not find identifier map entry for " + aClass);
			}
			// System.out.println("MapEntry for "+aClass+" is "+returned);
			mapEntriesForClass.put(aClass, returned);
		}
		return returned;
	}

	public String getIdentifierAsStringForObject(XMLSerializable object) throws NoMapIdEntryException {
		SingleKeyValueProperty kvProperty = mapEntryForClass(object.getClass()).getKeyValueProperty();
		return KeyValueDecoder.valueForKey(object, kvProperty, StringEncoder.getDefaultInstance());
	}

	public String getIdentifierAsStringForObject(XMLSerializable object, StringEncoder stringEncoder) throws NoMapIdEntryException {
		SingleKeyValueProperty kvProperty = mapEntryForClass(object.getClass()).getKeyValueProperty();
		return KeyValueDecoder.valueForKey(object, kvProperty, stringEncoder);
	}

	public static class NoMapIdEntryException extends Exception {

		public NoMapIdEntryException(String message) {
			super(message);
		}
	}
}