| // Copyright 2007 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.tapestry5.internal.services; |
| |
| import org.apache.tapestry5.services.Request; |
| import org.apache.tapestry5.services.Session; |
| |
| /** |
| * The "flash" strategy stores data inside the {@link Session session}, just like {@link |
| * SessionPersistentFieldStrategy}, but also removes the values from the session on first use. In this way, a short-term |
| * value (such as an error message) will "survive" from an action request to a render request and then disappear. |
| */ |
| public class FlashPersistentFieldStrategy extends AbstractSessionPersistentFieldStrategy |
| { |
| /** |
| * Prefix used to identify keys stored in the session. |
| */ |
| static final String PREFIX = "flash:"; |
| |
| public FlashPersistentFieldStrategy(Request request) |
| { |
| super(PREFIX, request); |
| } |
| |
| @Override |
| protected void didReadChange(Session session, String attributeName) |
| { |
| // For flash persistence, after reading a value, get rid of it. |
| session.setAttribute(attributeName, null); |
| } |
| |
| } |