content: /* ========================================================================
   * 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;
      }
  
  }
  