001 /* ========================================================================
002 * JCommon : a free general purpose class library for the Java(tm) platform
003 * ========================================================================
004 *
005 * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
006 *
007 * Project Info: http://www.jfree.org/jcommon/index.html
008 *
009 * This library is free software; you can redistribute it and/or modify it
010 * under the terms of the GNU Lesser General Public License as published by
011 * the Free Software Foundation; either version 2.1 of the License, or
012 * (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but
015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017 * License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this library; if not, write to the Free Software
021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
022 * USA.
023 *
024 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
025 * in the United States and other countries.]
026 *
027 * -----------------------
028 * GenericReadHandler.java
029 * -----------------------
030 * (C)opyright 2003, by Thomas Morgner and Contributors.
031 *
032 * Original Author: Thomas Morgner;
033 * Contributor(s): David Gilbert (for Object Refinery Limited);
034 *
035 * $Id: GenericReadHandler.java,v 1.5 2005/10/18 13:33:32 mungady Exp $
036 *
037 * Changes
038 * -------
039 * 23-Sep-2003 : Initial version
040 *
041 */
042
043 package org.jfree.xml.parser.coretypes;
044
045 import java.util.ArrayList;
046 import java.util.HashMap;
047
048 import org.jfree.util.Log;
049 import org.jfree.xml.parser.AbstractXmlReadHandler;
050 import org.jfree.xml.parser.RootXmlReadHandler;
051 import org.jfree.xml.parser.XmlReadHandler;
052 import org.jfree.xml.parser.XmlReaderException;
053 import org.jfree.xml.util.AttributeDefinition;
054 import org.jfree.xml.util.ConstructorDefinition;
055 import org.jfree.xml.util.GenericObjectFactory;
056 import org.jfree.xml.util.LookupDefinition;
057 import org.jfree.xml.util.ObjectDescriptionException;
058 import org.jfree.xml.util.PropertyDefinition;
059 import org.xml.sax.Attributes;
060 import org.xml.sax.SAXException;
061
062 /**
063 * A SAX handler for reading a generic object from an XML element.
064 */
065 public class GenericReadHandler extends AbstractXmlReadHandler {
066
067 /** The object under construction. */
068 private Object object;
069
070 /** The generic object factory. */
071 private GenericObjectFactory objectFactory;
072
073 /** The object reference handlers. */
074 private ArrayList objectRefHandlers;
075
076 /** The created handler. */
077 private HashMap createdHandler;
078
079 /**
080 * Creates a new handler.
081 *
082 * @param factory the generic object factory.
083 */
084 public GenericReadHandler(final GenericObjectFactory factory) {
085 this.createdHandler = new HashMap();
086 this.objectRefHandlers = new ArrayList();
087 this.objectFactory = factory;
088 }
089
090 /**
091 * Called at the start of parsing.
092 *
093 * @param attrs the attributes.
094 *
095 * @throws SAXException if there is a parsing error.
096 */
097 protected void startParsing(final Attributes attrs) throws SAXException {
098
099 try {
100 final AttributeDefinition[] attribs = this.objectFactory.getAttributeDefinitions();
101 for (int i = 0; i < attribs.length; i++) {
102 final AttributeDefinition attrDef = attribs[i];
103 final String value = attrs.getValue(attrDef.getAttributeName());
104 if (value == null) {
105 continue;
106 }
107 final Object o = attrDef.getHandler().toPropertyValue(value);
108 this.objectFactory.setProperty(attrDef.getPropertyName(), o);
109 }
110 }
111 catch (ObjectDescriptionException ode) {
112 throw new SAXException(ode);
113 }
114 }
115
116 /**
117 * Returns the child handler.
118 *
119 * @param tagName the tag name.
120 * @param atts the attributes.
121 *
122 * @return The handler.
123 *
124 * @throws SAXException if there is a parsing problem.
125 */
126 protected XmlReadHandler getHandlerForChild(final String tagName, final Attributes atts)
127 throws SAXException {
128 try {
129 if (tagName.equals("objectRef")) {
130 // store them all and copy the properties later when the object is created
131 final XmlReadHandler handler = new ObjectRefHandler();
132 this.objectRefHandlers.add(handler);
133 return handler;
134 }
135 final XmlReadHandler handler = getRootHandler().createHandler
136 (this.objectFactory.getTypeForTagName(tagName), tagName, atts);
137 if (handler != null) {
138 this.createdHandler.put(tagName, handler);
139 }
140 // will throw exception if handler is null...
141 return handler;
142 }
143 catch (ObjectDescriptionException ode) {
144 Log.debug ("Failed to get handler for child: ", ode);
145 throw new SAXException(ode);
146 }
147 }
148
149 /**
150 * Returns the object.
151 *
152 * @return The object.
153 *
154 * @throws XmlReaderException ???
155 */
156 public Object getObject() throws XmlReaderException {
157
158 if (this.object != null) {
159 return this.object;
160 }
161 final RootXmlReadHandler rootHandler = getRootHandler();
162 try {
163 for (int i = 0; i < this.objectRefHandlers.size(); i++) {
164 final ObjectRefHandler handler = (ObjectRefHandler) this.objectRefHandlers.get(i);
165 this.objectFactory.setProperty(handler.getPropertyName(), handler.getObject());
166 }
167
168 final ArrayList lookups = new ArrayList();
169 final LookupDefinition[] lookupDefs = this.objectFactory.getLookupDefinitions();
170 for (int i = 0; i < lookupDefs.length; i++) {
171 final LookupDefinition ldef = lookupDefs[i];
172 lookups.add(ldef.getPropertyName());
173 Log.debug ("lookup object: " + ldef.getPropertyName());
174
175 final Object value = rootHandler.getHelperObject(ldef.getRegistryKey());
176 if (value == null) {
177 // todo may or may not be fatal -> define it in the xml?
178 Log.warn ("Failed to lookup object: " + value);
179 }
180 else {
181 this.objectFactory.setProperty(ldef.getPropertyName(), value);
182 }
183 }
184
185 final ConstructorDefinition[] conDefs = this.objectFactory.getConstructorDefinitions();
186 for (int i = 0; i < conDefs.length; i++) {
187 final ConstructorDefinition cDef = conDefs[i];
188 // if this is a lookup, then ignore
189 if (lookups.contains(cDef.getPropertyName())) {
190 continue;
191 }
192 if (this.objectFactory.isPropertyDefinition(cDef.getPropertyName())) {
193 final PropertyDefinition pd = this.objectFactory.getPropertyDefinitionByPropertyName(
194 cDef.getPropertyName()
195 );
196 final XmlReadHandler handler = (XmlReadHandler) this.createdHandler.get(
197 pd.getElementName()
198 );
199 if (handler != null) {
200 this.objectFactory.setProperty(pd.getPropertyName(), handler.getObject());
201 }
202 }
203 // hoping that the attribute is set ..
204 }
205
206 this.object = this.objectFactory.createObject();
207 Object oldValue = null;
208 if (this.objectFactory.getRegisterName() != null) {
209 oldValue = rootHandler.getHelperObject(this.objectFactory.getRegisterName());
210 rootHandler.setHelperObject(this.objectFactory.getRegisterName(), this.object);
211 }
212
213 final PropertyDefinition[] propertyDefs = this.objectFactory.getPropertyDefinitions();
214 for (int i = 0; i < propertyDefs.length; i++) {
215 final PropertyDefinition pdef = propertyDefs[i];
216 final XmlReadHandler handler = (XmlReadHandler) this.createdHandler.get(
217 pdef.getElementName()
218 );
219 if (handler == null) {
220 continue;
221 }
222 this.objectFactory.setProperty(pdef.getPropertyName(), handler.getObject());
223 }
224
225 this.objectFactory.writeObjectProperties(this.object);
226
227 if (this.objectFactory.getRegisterName() != null) {
228 rootHandler.setHelperObject(this.objectFactory.getRegisterName(), oldValue);
229 }
230 }
231 catch (ObjectDescriptionException ode) {
232 Log.error ("Unable to create object.", ode);
233 throw new XmlReaderException("Unable to create object.", ode);
234 }
235 return this.object;
236 }
237
238 }