/* ========================================================================
* JCommon : a free general purpose class library for the Java(tm) platform
* ========================================================================
*
* (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
*
* Project Info: http://www.jfree.org/jcommon/index.html
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library 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 Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc.
* in the United States and other countries.]
*
* -----------------------
* GenericReadHandler.java
* -----------------------
* (C)opyright 2003, by Thomas Morgner and Contributors.
*
* Original Author: Thomas Morgner;
* Contributor(s): David Gilbert (for Object Refinery Limited);
*
* $Id: GenericReadHandler.java,v 1.5 2005/10/18 13:33:32 mungady Exp $
*
* Changes
* -------
* 23-Sep-2003 : Initial version
*
*/
package org.jfree.xml.parser.coretypes;
import java.util.ArrayList;
import java.util.HashMap;
import org.jfree.util.Log;
import org.jfree.xml.parser.AbstractXmlReadHandler;
import org.jfree.xml.parser.RootXmlReadHandler;
import org.jfree.xml.parser.XmlReadHandler;
import org.jfree.xml.parser.XmlReaderException;
import org.jfree.xml.util.AttributeDefinition;
import org.jfree.xml.util.ConstructorDefinition;
import org.jfree.xml.util.GenericObjectFactory;
import org.jfree.xml.util.LookupDefinition;
import org.jfree.xml.util.ObjectDescriptionException;
import org.jfree.xml.util.PropertyDefinition;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
/**
* A SAX handler for reading a generic object from an XML element.
*/
public class GenericReadHandler extends AbstractXmlReadHandler {
/** The object under construction. */
private Object object;
/** The generic object factory. */
private GenericObjectFactory objectFactory;
/** The object reference handlers. */
private ArrayList objectRefHandlers;
/** The created handler. */
private HashMap createdHandler;
/**
* Creates a new handler.
*
* @param factory the generic object factory.
*/
public GenericReadHandler(final GenericObjectFactory factory) {
this.createdHandler = new HashMap();
this.objectRefHandlers = new ArrayList();
this.objectFactory = factory;
}
/**
* Called at the start of parsing.
*
* @param attrs the attributes.
*
* @throws SAXException if there is a parsing error.
*/
protected void startParsing(final Attributes attrs) throws SAXException {
try {
final AttributeDefinition[] attribs = this.objectFactory.getAttributeDefinitions();
for (int i = 0; i < attribs.length; i++) {
final AttributeDefinition attrDef = attribs[i];
final String value = attrs.getValue(attrDef.getAttributeName());
if (value == null) {
continue;
}
final Object o = attrDef.getHandler().toPropertyValue(value);
this.objectFactory.setProperty(attrDef.getPropertyName(), o);
}
}
catch (ObjectDescriptionException ode) {
throw new SAXException(ode);
}
}
/**
* Returns the child handler.
*
* @param tagName the tag name.
* @param atts the attributes.
*
* @return The handler.
*
* @throws SAXException if there is a parsing problem.
*/
protected XmlReadHandler getHandlerForChild(final String tagName, final Attributes atts)
throws SAXException {
try {
if (tagName.equals("objectRef")) {
// store them all and copy the properties later when the object is created
final XmlReadHandler handler = new ObjectRefHandler();
this.objectRefHandlers.add(handler);
return handler;
}
final XmlReadHandler handler = getRootHandler().createHandler
(this.objectFactory.getTypeForTagName(tagName), tagName, atts);
if (handler != null) {
this.createdHandler.put(tagName, handler);
}
// will throw exception if handler is null...
return handler;
}
catch (ObjectDescriptionException ode) {
Log.debug ("Failed to get handler for child: ", ode);
throw new SAXException(ode);
}
}
/**
* Returns the object.
*
* @return The object.
*
* @throws XmlReaderException ???
*/
public Object getObject() throws XmlReaderException {
if (this.object != null) {
return this.object;
}
final RootXmlReadHandler rootHandler = getRootHandler();
try {
for (int i = 0; i < this.objectRefHandlers.size(); i++) {
final ObjectRefHandler handler = (ObjectRefHandler) this.objectRefHandlers.get(i);
this.objectFactory.setProperty(handler.getPropertyName(), handler.getObject());
}
final ArrayList lookups = new ArrayList();
final LookupDefinition[] lookupDefs = this.objectFactory.getLookupDefinitions();
for (int i = 0; i < lookupDefs.length; i++) {
final LookupDefinition ldef = lookupDefs[i];
lookups.add(ldef.getPropertyName());
Log.debug ("lookup object: " + ldef.getPropertyName());
final Object value = rootHandler.getHelperObject(ldef.getRegistryKey());
if (value == null) {
// todo may or may not be fatal -> define it in the xml?
Log.warn ("Failed to lookup object: " + value);
}
else {
this.objectFactory.setProperty(ldef.getPropertyName(), value);
}
}
final ConstructorDefinition[] conDefs = this.objectFactory.getConstructorDefinitions();
for (int i = 0; i < conDefs.length; i++) {
final ConstructorDefinition cDef = conDefs[i];
// if this is a lookup, then ignore
if (lookups.contains(cDef.getPropertyName())) {
continue;
}
if (this.objectFactory.isPropertyDefinition(cDef.getPropertyName())) {
final PropertyDefinition pd = this.objectFactory.getPropertyDefinitionByPropertyName(
cDef.getPropertyName()
);
final XmlReadHandler handler = (XmlReadHandler) this.createdHandler.get(
pd.getElementName()
);
if (handler != null) {
this.objectFactory.setProperty(pd.getPropertyName(), handler.getObject());
}
}
// hoping that the attribute is set ..
}
this.object = this.objectFactory.createObject();
Object oldValue = null;
if (this.objectFactory.getRegisterName() != null) {
oldValue = rootHandler.getHelperObject(this.objectFactory.getRegisterName());
rootHandler.setHelperObject(this.objectFactory.getRegisterName(), this.object);
}
final PropertyDefinition[] propertyDefs = this.objectFactory.getPropertyDefinitions();
for (int i = 0; i < propertyDefs.length; i++) {
final PropertyDefinition pdef = propertyDefs[i];
final XmlReadHandler handler = (XmlReadHandler) this.createdHandler.get(
pdef.getElementName()
);
if (handler == null) {
continue;
}
this.objectFactory.setProperty(pdef.getPropertyName(), handler.getObject());
}
this.objectFactory.writeObjectProperties(this.object);
if (this.objectFactory.getRegisterName() != null) {
rootHandler.setHelperObject(this.objectFactory.getRegisterName(), oldValue);
}
}
catch (ObjectDescriptionException ode) {
Log.error ("Unable to create object.", ode);
throw new XmlReaderException("Unable to create object.", ode);
}
return this.object;
}
}