// 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.engine.state;
import org.apache.tapestry.web.WebRequest;
import org.apache.tapestry.web.WebSession;
/**
* Manager for the 'session' scope; state objects are stored as HttpSession attributes. The
* HttpSession is created as necessary.
*
* @author Howard M. Lewis Ship
* @since 4.0
*/
public class SessionScopeManager implements StateObjectPersistenceManager
{
private WebRequest _request;
private String _applicationId;
private String buildKey(String objectName)
{
// For Portlets, the application id is going to be somewhat redundant, since
// the Portlet API keeps portlets seperate anyway.
return "state:" + _applicationId + ":" + objectName;
}
/**
* Returns the session for the current request, creating it if necessary.
*/
private WebSession getSession()
{
return _request.getSession(true);
}
public boolean exists(String objectName)
{
WebSession session = _request.getSession(false);
if (session == null)
return false;
return session.getAttribute(buildKey(objectName)) != null;
}
public Object get(String objectName, StateObjectFactory factory)
{
String key = buildKey(objectName);
WebSession session = getSession();
Object result = session.getAttribute(key);
if (result == null)
{
result = factory.createStateObject();
session.setAttribute(key, result);
}
return result;
}
public void store(String objectName, Object stateObject)
{
String key = buildKey(objectName);
WebSession session = getSession();
session.setAttribute(key, stateObject);
}
public void setApplicationId(String applicationName)
{
_applicationId = applicationName;
}
public void setRequest(WebRequest request)
{
_request = request;
}
}