package org.trails.record;

 import org.apache.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 import org.apache.tapestry.record.PropertyChange;

 import org.apache.tapestry.record.PropertyChangeImpl;

 import java.util.ArrayList;

 import java.util.Collection;

 /**

  * This class is a Trails adaptation of Tapernate's ReattachPropertyPersistenceStrategy

  * Credits to James Carman.

  */

 public abstract class ReattachPropertyPersistenceStrategy extends AbstractSessionPropertyPersistenceStrategy

 {

         protected abstract Object reattach(Object entity);

         private static final Log LOG = LogFactory.getLog(ReattachPropertyPersistenceStrategy.class);

         public Collection getStoredChanges(String pageName)

         {

                 final Collection<PropertyChange> pageChanges = super.getStoredChanges(pageName);

                 Collection<PropertyChange> result = new ArrayList<PropertyChange>();

                 for (PropertyChange propertyChange : pageChanges)

                 {

                         final Object entity = propertyChange.getNewValue();

                         LOG.debug("Reattaching property " + propertyChange.getPropertyName() + " on component " + propertyChange.getComponentPath());

                         try

                         {

                                 result.add(new PropertyChangeImpl(propertyChange.getComponentPath(), propertyChange.getPropertyName(), reattach(entity)));

                         } catch (Exception e)

                         {

                                 e.printStackTrace();  //@todo throw a proper Exception

                         }

                 }

                 return result;

         }

 }