// Copyright 2005 The Apache Software Foundation
//
// 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.apache.tapestry.record;
import java.util.Collection;
import java.util.Iterator;
import org.apache.hivemind.ApplicationRuntimeException;
import org.apache.hivemind.ErrorLog;
import org.apache.hivemind.util.Defense;
import org.apache.hivemind.util.PropertyUtils;
import org.apache.tapestry.IComponent;
import org.apache.tapestry.IPage;
import org.apache.tapestry.IRequestCycle;
import org.apache.tapestry.engine.IPageRecorder;
import org.apache.tapestry.event.ObservedChangeEvent;
import org.apache.tapestry.spec.IPropertySpecification;
/**
* @author Howard M. Lewis Ship
* @since 4.0
*/
public class PageRecorderImpl implements IPageRecorder
{
private String _pageName;
private IRequestCycle _requestCycle;
private PropertyPersistenceStrategySource _strategySource;
private boolean _locked = false;
private ErrorLog _log;
public PageRecorderImpl(String pageName, IRequestCycle requestCycle,
PropertyPersistenceStrategySource strategySource, ErrorLog log)
{
Defense.notNull(pageName, "pageName");
Defense.notNull(requestCycle, "requestCycle");
Defense.notNull(strategySource, "strategySource");
Defense.notNull(log, "log");
_pageName = pageName;
_requestCycle = requestCycle;
_strategySource = strategySource;
_log = log;
}
public void commit()
{
_locked = true;
}
public Collection getChanges()
{
return _strategySource.getAllStoredChanges(_pageName, _requestCycle);
}
public void rollback(IPage page)
{
Collection changes = getChanges();
Iterator i = changes.iterator();
while (i.hasNext())
{
PropertyChange change = (PropertyChange) i.next();
applyChange(page, change);
}
}
private void applyChange(IPage page, PropertyChange change)
{
String idPath = change.getComponentPath();
IComponent component = (idPath == null) ? page : page.getNestedComponent(idPath);
PropertyUtils.write(component, change.getPropertyName(), change.getNewValue());
}
public void observeChange(ObservedChangeEvent event)
{
IComponent component = event.getComponent();
String propertyName = event.getPropertyName();
if (_locked)
{
_log.error(RecordMessages.recorderLocked(propertyName, component), null, null);
return;
}
PropertyPersistenceStrategy strategy = findStrategy(component, propertyName);
if (strategy != null)
strategy.store(_pageName, component.getIdPath(), propertyName, event.getNewValue());
}
// package private for testing
PropertyPersistenceStrategy findStrategy(IComponent component, String propertyName)
{
// So much for Law of Demeter!
IPropertySpecification propertySpecification = component.getSpecification()
.getPropertySpecification(propertyName);
if (propertySpecification == null)
{
_log.error(
RecordMessages.missingPropertySpecification(propertyName, component),
null,
null);
return null;
}
String name = propertySpecification.getPersistence();
// Should check for nulls, but the architecture of the framework pretty much
// ensures that we won't get here unless there is a property
// and a persistence value for the property.
try
{
return _strategySource.getStrategy(name);
}
catch (ApplicationRuntimeException ex)
{
_log.error(ex.getMessage(), propertySpecification.getLocation(), ex);
return null;
}
}
}