/*

  * 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.page;

 import java.util.List;

 import org.apache.tapestry.IExternalPage;

 import org.apache.tapestry.IRequestCycle;

 import org.apache.tapestry.event.PageBeginRenderListener;

 import org.trails.TrailsRuntimeException;

 import org.trails.callback.ListCallback;

 import org.trails.component.TrailsTableColumn;

 import org.trails.component.Utils;

 import org.trails.descriptor.IClassDescriptor;

 /**

  * List all the instances of a type

  * 

  * @author Chris Nelson

  */

 public abstract class ListPage extends TrailsPage implements IExternalPage, PageBeginRenderListener

 {

         /**

          * (non-Javadoc)

          * 

          * @see org.apache.tapestry.IExternalPage#activateExternalPage(java.lang.Object[],org.apache.tapestry.IRequestCycle)

          */

         public void activateExternalPage(Object[] args, IRequestCycle cycle)

         {

                 Class instanceClass = (Class) args[0];

                 setType(instanceClass);

                 reloadInstances();

         }

         public abstract List getInstances();

         public abstract void setInstances(List Instances);

         public abstract TrailsTableColumn getColumn();

         public abstract void setColumn(TrailsTableColumn column);

         public abstract Class getType();

         public abstract void setType(Class type);

         public IClassDescriptor getClassDescriptor()

         {

                 return getDescriptorService().getClassDescriptor(getType());

         }

         public void pushCallback()

         {

                 getCallbackStack().push(new ListCallback(getPageName(), getType()));

         }

         private void loadInstances(Class clazz)

         {

                 setInstances(getPersistenceService().getAllInstances(clazz));

         }

         public void reloadInstances()

         {

                 loadInstances(getType());

         }

 }