package org.trails.component;

 import org.apache.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 import org.apache.tapestry.annotations.ComponentClass;

 import org.apache.tapestry.annotations.InjectObject;

 import org.apache.tapestry.form.IPropertySelectionModel;

 import org.trails.descriptor.DescriptorService;

 import org.trails.descriptor.IClassDescriptor;

 import org.trails.persistence.PersistenceService;

 /**

  * This guy interacts with persistence service to produce a Select

  * containing all the elements of the PropertyDescriptor's type.

  *

  * @author Chris Nelson

  */

 @ComponentClass(allowBody = false, allowInformalParameters = true)

 public abstract class AssociationSelect extends AbstractPropertySelection

 {

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

         @InjectObject("spring:persistenceService")

         public abstract PersistenceService getPersistenceService();

         @InjectObject("spring:descriptorService")

         public abstract DescriptorService getDescriptorService();

         public IClassDescriptor getClassDescriptor()

         {

                 return getDescriptorService().getClassDescriptor(getPropertyDescriptor().getPropertyType());

         }

         @Override

         public IPropertySelectionModel buildSelectionModel()

         {

                 if (LOG.isDebugEnabled())

                 {

                         LOG.debug("Building propertySelectionModel for " + getClassDescriptor().getDisplayName());

                 }

                 IdentifierSelectionModel selectionModel;

                 if (getInstances() != null)

                 {

                         selectionModel = new IdentifierSelectionModel(getInstances(),

                                 getClassDescriptor().getIdentifierDescriptor().getName(),

                                 isAllowNone());

                 } else

                 {

                         selectionModel = new IdentifierSelectionModel(getPersistenceService().getAllInstances(getClassDescriptor().getType()),

                                 getClassDescriptor().getIdentifierDescriptor().getName(),

                                 isAllowNone());

                 }

                 selectionModel.setNoneLabel(getNoneLabel());

                 return selectionModel;

         }

 }