/*

  * Created on Feb 28, 2005

  *

  * Copyright 2004 Chris Nelson

  * 

  * Licensed under the Apache License, Version 2.0 (the "License"); 

  * you may not use this file except in compliance with the License. 

  * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 

  * Unless required by applicable law or agreed to in writing, 

  * software distributed under the License is distributed on an "AS IS" BASIS, 

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 

  * See the License for the specific language governing permissions and limitations under the License.

  */

 package org.trails.callback;

 import java.util.HashMap;

 import ognl.Ognl;

 import ognl.OgnlException;

 import org.trails.TrailsRuntimeException;

 import org.trails.descriptor.CollectionDescriptor;

 import org.trails.persistence.PersistenceService;

 /**

  * This guy is responsible for returning from an add or remove on a

  * collection.

  */

 public class CollectionCallback extends EditCallback

 {

         private CollectionDescriptor collectionDescriptor;

         private boolean childRelationship;

         /**

          * @param pageName

          * @param model

          */

         public CollectionCallback(String pageName, Object model, CollectionDescriptor collectionDescriptor)

         {

                 super(pageName, model);

                 this.collectionDescriptor = collectionDescriptor;

         }

         public void save(PersistenceService persistenceService, Object newObject)

         {

                 executeOgnlExpression(collectionDescriptor.findAddExpression(), newObject);

                 persistenceService.save(getModel());

         }

         public void remove(PersistenceService persistenceService, Object object)

         {

                 executeOgnlExpression(collectionDescriptor.findRemoveExpression(), object);

                 persistenceService.save(getModel());

         }

         /**

          * @param previousModel

          */

         private void executeOgnlExpression(String ognlExpression, Object newObject)

         {

                 HashMap context = new HashMap();

                 context.put("member", newObject);

                 try

                 {

                         Ognl.getValue(ognlExpression + "(#member)", context, model);

                 } catch (OgnlException e)

                 {

                         throw new TrailsRuntimeException(e, model.getClass());

                 }

         }

         public boolean isChildRelationship()

         {

                 return childRelationship;

         }

         public void setChildRelationship(boolean child)

         {

                 this.childRelationship = child;

         }

 }